{"collection":"philosophy-ethics","full_text_available":true,"graph_url":"https://unchartedknowledge.5gfusion.net/v2/api/page/gutenberg_24667/graph","html_url":"https://unchartedknowledge.5gfusion.net/v2/page/gutenberg_24667","id":"gutenberg_24667","license":"Public Domain (US)","rights_basis":"gutenberg_metadata_copyright_false","source":"gutenberg","source_url":"https://www.gutenberg.org/ebooks/24667","summary":null,"tags":["Category: Philosophy & Ethics","Category: Science - Physics","Ether (Space)","Force and energy","Gravitation","Matter"],"text":"E-text prepared by Barbara Tozier, Ronnie Sahlberg, Bill Tozier, and the\nProject Gutenberg Online Distributed Proofreading Team\n(https://www.pgdp.net)\n\n\n\nNote: Project Gutenberg also has an HTML version of this\n      file which includes the original illustrations.\n      See 24667-h.htm or 24667-h.zip:\n      (https://www.gutenberg.org/dirs/2/4/6/6/24667/24667-h/24667-h.htm)\n      or\n      (https://www.gutenberg.org/dirs/2/4/6/6/24667/24667-h.zip)\n\n\nTranscriber's note:\n\n      Numbers preceded by a carat character are superscripts\n      (example: 3^2 = 9).\n\n      Numbers preceded by an underscore are subscripts\n      (example: CO_2)\n\n      Text enclosed by underscores is italicized.\n\n      A detailed transcriber's note is at the end of the text.\n\n\n\n\n\nAETHER AND GRAVITATION\n\nby\n\nWILLIAM GEORGE HOOPER, F.S.S.\n\n\n\n\n\n\n\n[Illustration]\n\n\nLondon\nChapman and Hall, Ltd.\n1903\n\n\n\n\nINTRODUCTORY NOTES\n\n\nThe author in this work endeavours to solve the greatest scientific\nproblem that has puzzled scientists for the past two hundred years. The\nquestion has arisen over and over again, since the discovery of\nuniversal gravitation by Sir Isaac Newton, as to what is the physical\ncause of the attraction of gravitation.\n\n\"Action at a distance\" has long ceased to be recognized as a possible\nphenomenon, although up to the present, the medium and method of\ngravitational attraction have not yet been discovered.\n\nIt is, however, generally accepted by scientists, that the only possible\nmedium which can give rise to the phenomena incidental to, and\nassociated with the Law of Gravitation, must be the universal aether,\nwhich forms the common medium of all phenomena associated with light,\nheat, electricity and magnetism.\n\nIt is impossible, however, to reconcile gravitational phenomena with the\npresent conception of the universal aether medium, and a new theory is\ntherefore demanded, before the long-sought-for explanation will be\nforthcoming.\n\nProfessor Glazebrook definitely states the necessity for a new theory in\nhis work on J. C. Maxwell, page 221, where he writes: \"We are waiting\nfor some one to give us a theory of the aether, which shall include the\nfacts of electricity and magnetism, luminous radiation, and it may be\ngravitation.\"\n\nA new theory of the aether is also demanded in view of the recent\nexperimental results of Professor Lebedew, and Nichols and Hull of\nAmerica. It is logically impossible to reconcile a frictionless aether,\nwith their results relative to the pressure of light waves.\n\nIn the following pages of this work the author has endeavoured to\nperfect a theory, which will bring aetherial physics more into harmony\nwith modern observation and experiments; and by so doing, believes that\nhe has found the key that will unlock the problem not only of the cause\nof universal gravitation, but also other problems of physical science.\nThe author has taken Newton's Rules of Philosophy as his guide in the\nmaking of the new theory, as he believes that if any man knew anything\nof the rules of Philosophy, that man was Sir Isaac Newton. The first\nchapter therefore deals with the generally recognized rules which govern\nphilosophical reasoning, the same being three in number; the fundamental\nrule being, that in making any hypothesis, the results of experience as\nobtained by observation and experiments must not be violated.\n\nIn applying the rules to the present theory of the aether, he found that\nthe theory as at present recognized violated two of the most important\nrules of Philosophy, because, while aether is supposed to be matter, yet\nit failed to fulfil the primary property of all matter, that is, it is\nnot subject to the Law of Gravitation. If aether is matter, then, to be\nstrictly logical and philosophical, it must possess the properties of\nmatter as revealed by observation and experiment.\n\nThose properties are given in Chapter III., where it is shown that they\nare atomicity, heaviness or weight, elasticity, density, inertia, and\ncompressibility. To be strictly logical and philosophical, the author\nwas compelled to postulate similar properties for the aether, or else\nhis hypotheses would contravert the results of all experience.\n\nThe application of these properties to the aether will be found in\nChapter IV., where the author has postulated atomicity, heaviness or\nweight, density, elasticity, inertia, and compressibility for the\naether, and so brought the theory of the aether into perfect harmony\nwith all observation and experiments relative to ordinary matter. It\nwill be shown that Clerk Maxwell also definitely affirms the atomicity\nof the aether, while Tyndall and Huyghens also use the term \"_particles\nof aether_\" over and over again.\n\nMoreover, in view of the most recent researches in electricity made by\nSir William Crookes and Professor J. J. Thomson, we are compelled to\naccept an atomic basis for electricity, and as Dr. Lodge, in his _Modern\nViews of Electricity_, states that \"Aether is made up of positive and\nnegative electricity,\" then, unless we postulate atomicity for the\naether, we have to suppose that it is possible for a non-atomic body\n(aether) to be made up of atoms or corpuscles, which conclusion is\nabsurd, and therefore must be rejected as illogical and unphilosophical.\n\nAfter postulating atomicity for the aether, we are then able to apply\nthe Newtonian Law of Gravitation to it, which distinctly affirms that\n\"every particle of matter attracts every other particle,\" and so we\narrive at Thomas Young's fourth hypothesis given in the Philosophical\nTransactions of 1802, where he asserts that \"All material bodies have an\nattraction for the aetherial medium, by means of which it is\naccumulated within their substance, and for a small distance around them\nin a state of greater density.\" He adds the significant remark that this\nhypothesis is opposed to that of Newton's. With an atomic and\ngravitative aether it is shown in Chapter IV. how the elasticity,\ndensity, and inertia of the medium are brought into harmony with all\nobservation and experiments.\n\nIn the succeeding chapters the new theory is applied to the phenomena of\nheat, light, electricity, and magnetism, and the principles enunciated\ntherein are then applied to solar and stellar phenomena.\n\nOne of the greatest stumbling-blocks to the discovery of the physical\ncause of gravitation, apart from the unphilosophical theory of the\naether medium, lies in the fact that apparently the Law of Gravitation\nonly recognizes a force of one kind. Dr. Lodge refers to this phase of\nthe subject on page 39 of his _Modern Views of Matter_ just published.\nIt is here where scientists have failed to solve the problem of\nuniversal gravitation, as there are _two_ forces at work in the solar\nsystem and not one; that is, if we are to accept the results of\nup-to-date experiments in relation to radiant light and heat as\nperformed by Professor Lebedew, and Nichols and Hull of America. Their\nexperiments conclusively prove that light waves exert a pressure upon\nall bodies on which they fall, and by no reasoning can this pressure be\nresolved into an attractive force.\n\nHerschel in his _Lectures on Scientific Subjects_ definitely refers to\nthe existence of a repulsive force in the solar system, and asserts that\nit offers the most interesting prospect of any future discovery.\n\nThe author has therefore attacked the problem of the cause of\ngravitation, by trying to solve the problem of the cause of the\n_repulsive_ force which has been experimentally demonstrated to exist by\nProfessor Lebedew and others.\n\nIn his efforts to ascertain the physical cause of the Centrifugal Force,\nhe has been assisted by an unknown and original essay written by an\nunknown writer over twenty years ago. That unknown writer was the\nauthor's father, who wrote an essay on the _Complementary Law of\nGravitation_, and if it had not been for that essay, the present work\nwould never have been attempted.\n\nThe main object of the author in Chapters VI., VII., and VIII., is to\nprove beyond the possibility of contradiction, from the phenomena of\nheat, light, and electricity, the existence of _two_ forces in the solar\nsystem; and by so doing, to bring our philosophy of the aether medium,\nand all gravitational phenomena, into harmony with all observation and\nexperiments, which at present is not the case. In seeking to do this he\nfound that the new theory of the aether harmonized with views given, by\nFaraday and Clerk Maxwell in relation to electric and magnetic\nphenomena, and by the new theory Maxwell's hypothesis of \"Physical Lines\nof Force\" receives a definite and physical basis. In Chapter X. the\nauthor endeavours to show what the Electro-Kinetic energy is, which term\nis used by Clerk Maxwell, the term being brought for the first time into\nharmony with our experience. The Electro-Magnetic Theory of Light also\nreceives fresh light from the new theory of an atomic and gravitating\naether.\n\nIn the succeeding chapters the theory is applied to Newton's Laws of\nMotion and Kepler's Laws, and is found to harmonize with all the results\ngiven by these laws. Such a result is a distinct advance on the\napplication of a frictionless aether to solar and stellar phenomena, as\nit is impossible for Kepler's Laws to be reconciled in any way with our\npresent theory of the aether.\n\nIn the concluding chapter on the unity of the universe, certain views\nare suggested as to the ultimate constitution of all matter, upon an\naetherial basis, which hypothesis practically resolves itself into an\nelectric basis for all matter. It is suggested that aether and\nelectricity are one and the same medium, both being a form of matter,\nand both possessing exactly the same properties, viz. atomicity, weight,\ndensity, elasticity, inertia, and compressibility. This view of matter\nharmonizes with the most \"Modern Views of Matter\" as suggested by Sir\nOliver Lodge in his Romanes Lecture 1903.\n\nThe author has accepted Newton's way of spelling \"_aether_\" as given in\nhis work on _Optics_, and has given \"_aetherial_\" the same suffix as\n\"material,\" in order to differentiate the word from \"ethereal,\" which is\ntoo metaphysical a term for a material medium.\n\n    _Nottingham_,\n        _Sept._ 1903.\n\n\n\n\nCONTENTS\n\n\n                             CHAPTER I\n\n                     PHILOSOPHY OF GRAVITATION\n\n                                                                  PAGE\nART.   1. GRAVITATION                                                1\n \"     2. CAUSE OF GRAVITATION                                       1\n \"     3. NEWTON'S RULES OF PHILOSOPHY                               3\n \"     4. FIRST RULE OF PHILOSOPHY                                   3\n \"     5. SECOND RULE OF PHILOSOPHY                                  4\n \"     6. THIRD RULE OF PHILOSOPHY                                   7\n \"     7. APPLICATION OF RULES TO GRAVITATION                        9\n \"     8. ANALYSIS OF LAW OF GRAVITATION                             9\n \"     9. PRIMITIVE IMPULSE                                         10\n \"    10. CENTRIPETAL FORCE                                         12\n \"    11. CENTRIFUGAL FORCE                                         13\n \"    12. NEWTON'S LAWS OF MOTION                                   15\n \"    13. FORCE                                                     16\n \"    14. FIRST LAW OF MOTION                                       16\n \"    15. SECOND LAW OF MOTION                                      19\n \"    16. THIRD LAW OF MOTION                                       20\n \"    17. SUMMARY OF CHAPTER                                        22\n\n\n                             CHAPTER II\n\n                PHILOSOPHY OF GRAVITATION--(_continued_)\n\nART.  18. GRAVITATION ATTRACTION                                    24\n \"    19. UNIVERSALITY OF GRAVITATION                               24\n \"    20. DIRECTION OF THE FORCES                                   26\n \"    21. PROPORTION OF THE FORCES                                  26\n \"    22. LAW OF INVERSE SQUARES                                    27\n \"    23. TERRESTRIAL GRAVITY                                       29\n \"    24. CENTRIFUGAL FORCE                                         30\n \"    25. KEPLER'S LAWS                                             32\n \"    26. FIRST LAW OF KEPLER                                       33\n \"    27. SECOND LAW OF KEPLER                                      36\n \"    28. THIRD LAW OF KEPLER                                       37\n\n\n                             CHAPTER III\n\n                                MATTER\n\nART.  29. WHAT IS MATTER?                                           40\n \"    30. CONSERVATION OF MATTER                                    42\n \"    31. MATTER IS ATOMIC                                          42\n \"    32. WHAT IS AN ATOM?                                          43\n \"    33. THE ATOMIC THEORY                                         44\n \"    34. KINDS OF ATOMS                                            44\n \"    35. ELEMENTS OF MATTER                                        47\n \"    36. THREE KINDS OF MATTER                                     47\n \"    37. MATTER IS GRAVITATIVE                                     50\n \"    38. MATTER POSSESSES DENSITY                                  51\n \"    39. MATTER POSSESSES ELASTICITY                               51\n \"    40. MATTER POSSESSES INERTIA                                  52\n\n\n                             CHAPTER IV\n\n                               AETHER\n\nART.  42. AETHER IS MATTER                                          54\n \"    43. AETHER IS UNIVERSAL                                       58\n \"    44. AETHER IS ATOMIC                                          59\n \"    45. AETHER IS GRAVITATIVE                                     64\n \"    46. AETHER POSSESSES DENSITY                                  71\n \"    47. AETHER POSSESSES ELASTICITY                               74\n \"    48. AETHER POSSESSES INERTIA                                  76\n \"    49. AETHER IS IMPRESSIBLE                                     78\n \"    50. AETHER AND ITS MOTIONS                                    80\n\n\n                             CHAPTER V\n\n                              ENERGY\n\nART.  51. ENERGY                                                    83\n \"    52. CONSERVATION OF ENERGY                                    84\n \"    53. TRANSFORMATION OF ENERGY                                  86\n \"    54. POTENTIAL ENERGY                                          87\n \"    55. KINETIC ENERGY                                            89\n \"    56. ENERGY AND MOTION                                         91\n \"    57. CONSERVATION OF MOTION                                    92\n \"    58. TRANSFORMATION OF MOTION                                  93\n \"    59. MOTION AND WORK                                           95\n\n\n                             CHAPTER VI\n\n                       HEAT, A MODE OF MOTION\n\nART.  60. HEAT, A MODE OF MOTION                                    98\n \"    61. HEAT AND MATTER                                          100\n \"    62. RADIATION AND ABSORPTION                                 104\n \"    63. HEAT IS A REPULSIVE MOTION                               107\n \"    64. RADIANT HEAT                                             109\n \"    65. DIRECTION OF A RAY OF HEAT                               111\n \"    66. LAW OF INVERSE SQUARES                                   112\n \"    67. FIRST LAW OF THERMODYNAMICS                              114\n \"    68. SECOND LAW OF THERMODYNAMICS                             116\n \"    69. IDENTITY OF HEAT AND LIGHT                               119\n\n\n                            CHAPTER VII\n\n                      LIGHT, A MODE OF MOTION\n\nART.  70. LIGHT, A MODE OF MOTION                                  122\n \"    71. TRANSVERSE VIBRATION OF LIGHT                            130\n \"    72. REFLECTION AND REFRACTION                                135\n \"    73. THE SOLAR SPECTRUM                                       139\n \"    74. DIRECTION OF A RAY OF LIGHT                              144\n \"    75. INTENSITY OF LIGHT                                       145\n \"    76. VELOCITY OF LIGHT                                        148\n \"    77. DYNAMICAL VALUE OF LIGHT                                 150\n \"    78. ELECTRO-MAGNETIC THEORY OF LIGHT                         155\n\n\n                            CHAPTER VIII\n\n                       AETHER AND ELECTRICITY\n\nART.  79. ELECTRICITY, A MODE OF MOTION                            162\n \"    80. ELECTRIC FIELD                                           166\n \"    81. ELECTRIC INDUCTION                                       174\n \"    82. ELECTRIC ENERGY                                          179\n \"    83. ELECTRIC RADIATION                                       182\n \"    84. LAW OF INVERSE SQUARES                                   184\n \"    85. SECOND LAW OF ELECTRICITY                                186\n\n\n                             CHAPTER IX\n\n                        AETHER AND MAGNETISM\n\nART.  86. ELECTRO-MAGNETISM                                        192\n \"    87. THE EARTH A MAGNET                                       195\n \"    88. THE SUN AN ELECTRO-MAGNET                                199\n \"    89. FARADAY'S LINES OF FORCE                                 203\n \"    90. TERRESTRIAL MAGNETISM                                    206\n \"    91. SOLAR MAGNETS                                            211\n \"    92. CAUSE OF ROTATION OF THE EARTH ON ITS AXIS               219\n \"    93. VORTEX MOTION                                            221\n \"    94. RELATIVE MOTION OF AETHER AND MATTER                     224\n \"    95. VIBRATIONS IN THE ELECTRO-MAGNETIC THEORY OF LIGHT       228\n\n\n                             CHAPTER X\n\n                  AETHER AND NEWTON'S LAWS OF MOTION\n\nART.  96. AETHER AND CENTRIFUGAL FORCE                             232\n \"    97. AETHER AND CENTRIPETAL FORCE                             236\n \"    98. AETHER AND NEWTON'S FIRST LAW OF MOTION                  239\n \"    99. AETHER AND NEWTON'S SECOND LAW OF MOTION                 244\n \"   100. AETHER AND NEWTON'S THIRD LAW OF MOTION                  251\n \"   101. WHY PLANETS REVOLVE FROM WEST TO EAST                    253\n\n\n                             CHAPTER XI\n\n                      AETHER AND KEPLER'S LAWS\n\nART. 102. AETHER AND KEPLER'S FIRST LAW                            256\n \"   103. AETHER AND KEPLER'S SECOND LAW                           260\n \"   104. AETHER AND KEPLER'S THIRD LAW                            263\n \"   105. ORBITAL MOTION OF PLANETS                                266\n \"   106. ECCENTRICITY OF THE MOON'S ORBIT                         268\n \"   107. THE SUN AND KEPLER'S FIRST LAW                           270\n \"   108. THE SUN AND KEPLER'S SECOND LAW                          274\n \"   109. AETHER AND THE PLANE OF THE ECLIPTIC                     277\n \"   110. AETHER AND THE CENTRIPETAL FORCE                         282\n\n\n                             CHAPTER XII\n\n                          AETHER AND COMETS\n\nART. 111. WHAT IS A COMET?                                         291\n \"   112. ORBITS OF COMETS                                         293\n \"   113. KINDS OF COMETS                                          296\n \"   114. PARTS OF A COMET                                         298\n \"   115. CENTRIFUGAL FORCE AND COMETS                             300\n \"   116. FORMATION OF TAILS                                       303\n\n\n                            CHAPTER XIII\n\n                       AETHER AND STARRY WORLD\n\nART. 117. STARRY WORLD                                             306\n \"   118. STARS AND KEPLER'S LAWS                                  309\n \"   119. AETHER AND NEBULAE                                       313\n \"   120. WHAT IS A NEBULA?                                        314\n \"   121. AETHER AND NEBULAR HYPOTHESIS                            317\n \"   122. KINDS OF NEBULAE                                         319\n\n\n                             CHAPTER XIV\n\n                       AETHER AND THE UNIVERSE\n\nART. 123. THE UNIVERSE                                             323\n \"   124. UNITY OF THE UNIVERSE                                    326\n \"   125. CONSTITUTION OF MATTER                                   334\n \"   126. QUOD ERAT FACIENDUM                                      337\n \"   127. GOD AND THE UNIVERS                                      342\n\nAPPENDIX                                                           349\nINDEX                                                              351\n\n\n\n\n                        AETHER AND GRAVITATION\n\n\n\n\n                               CHAPTER I\n\n                       PHILOSOPHY OF GRAVITATION\n\n\nART. 1. _Gravitation._--In the realm of Science, there exists a Force or\nLaw that pervades and influences all Nature, and from the power of\nwhich, nothing, not even an atom, is free.\n\nIt holds together the component parts of each and every individual\nworld, and in the world's revolving prevents both its inhabitants and\nits vegetation from being whirled off its surface into space. It exists\nin each and every central sun, and circles round each sun its associated\nsystem of planets. It rolls each satellite around its primary planet,\nand regulates the comet's mysterious flight into the depths of space,\nwhile the pendulation of even the remotest star is accomplished by this\nsame force. Our own rocking world obeys the same mysterious power, that\nseems to grasp the entire material creation as with the grasp of the\nInfinite.\n\nIt exists in, and influences every atom, whose combinations compose and\nconstitute the entire material creation, or each and every orb that\nbespangle the blue infinity.\n\nAs is readily seen, it weaves as it were around each and all, a\nmysterious network or chain, that binds star to star, and world to\nworld, blending all into one entire, vast and complete unity. It decides\nall their orbits and distances, regulates and controls all their\nmotions, from the most simple even to the more complex and intricate,\nultimately producing that wondrous and beauteous order, unity and\nharmony that everywhere pervade and blend all the universe into one\ngrand and harmonious whole.\n\nThat Law I need hardly say is the Law of Gravitation.\n\n\nART. 2. _Cause of Gravitation._--Now the question arises, and indeed has\narisen a thousand times since the discovery of this law by Sir Isaac\nNewton over two hundred years ago, as to what is the physical cause, the\ntrue explanation of this universal attraction.\n\nMacLaurin in his work on the philosophical discoveries of Sir Isaac\nNewton says: \"In all cases when bodies seem to act upon each other at a\ndistance, and tend towards one another without any apparent cause\nimpelling them, this force has been commonly called Attraction, and this\nterm is frequently used by Sir Isaac Newton. But he gives repeated\ncaution that he pretends not by the use of this term to define the\nnature of the power, or the manner in which it acts. Nor does he ever\naffirm or insinuate that a body can act upon another body at a distance,\nbut by the intervention of other bodies.\"\n\nThe results of modern discovery show that action at a distance, without\nthe intervention of any medium, as for example the sun attracting the\nearth, is not the universal condition which governs all so-called\nforces.\n\nIt is now recognized that light and heat are both forms of energy, and\ntherefore forces, using the term in the same sense that it is applied to\nGravitation.\n\nBoth light and heat are transmitted through space with finite velocity\nthrough the intervention of a medium, the universal Aether. It is\ntherefore only reasonable to suppose, that if one or more particular\nkinds of energy, or forces, require a medium for their transmission, why\nnot another force, as for example Gravitation?\n\nGravitation is an universal force which operates throughout the length\nand breadth of the entire universe, and if there be a medium which is to\nGravitation, what the Aether is to light and heat, the question at once\nconfronts us, as to what are the characteristics, properties, and\nqualities of that universal medium, which is to form the physical basis\nof this universal attraction?\n\nNewton himself suggested that Gravitation was due to an aetherial subtle\nmedium, which filled all space.\n\nIn his well-known letter to Bentley, Newton writes as follows: \"That\nGravity should be innate, inherent, and essential to matter, so that one\nbody can act upon another body at a distance through a vacuum, without\nthe mediation of anything else, by and through which their action and\nforce may be conveyed from one to another, is to me so great an\nabsurdity, that I believe no man who has any philosophical nature or\ncompetent faculty of thinking can ever fall into it.\"\n\nWe also know from his Queries in his book on _Optics_, that he sought\nfor the explanation of Gravitation in the properties of a subtle,\naetherial medium diffused over the universe.\n\nMacLaurin on this point says: \"It appears from his letters to Boyle,\nthat this was his opinion early, and if he did not publish his opinion\nsooner, it proceeded from hence only, that he found he was not able from\nexperiment and observation to give a satisfactory account of this\nmedium, and the manner of its operations in producing the chief\nphenomena of Nature.\"\n\nTherefore, if we accept Newton's suggestion, and endeavour to trace the\nphysical cause of Gravitation in the qualities, properties, and motions\nof this subtle aetherial medium to which he refers, we shall be simply\nworking on the lines laid down by Sir Isaac Newton himself.\n\nI wish therefore to premise, that the future pages of this work will\ndeal with the hypothesis of this aetherial medium, by which will be\naccounted for, and that on a satisfactory and physical basis, the\nuniversal Law of Gravitation.\n\n\nART. 3. _Rules of Philosophy._--In order that we may rightly understand\nthe making of any hypothesis, I purpose giving some rules laid down by\nsuch philosophers as Newton and Herschel, so that we may be guided by\nright principles in the development of this new hypothesis as to the\ncause of Gravitation.\n\nThe rules that govern the making of any hypotheses, so far as I can\ndiscern, may be summed up under the three following heads--\n\n    (1) Simplicity of conception.\n\n    (2) Agreement with experience, observation, and experiment.\n\n    (3) Satisfactorily accounting for, and explaining all phenomena\n        sought to be explained.\n\n\nART. 4. _1st Rule. Simplicity of Conception._--From this rule we learn\nthat the hypothesis must be simple in conception, and simple in its\nfundamental principles, and further, that the same characteristic of\nsimplicity must mark each step of its development.\n\nThis rule of simplicity is distinctly laid down by Sir Isaac Newton in\nhis _Principia_, Book 3, under the heading \"Regulae Philosophandi.\"\n\nIn that work he writes: \"Natura simplex est, et rerum causis superfluis\nnon luxuriat.\"--\"Nature is simple, and does not abound in superfluous\ncauses of things.\"\n\nHe further states that: \"Not more of the natural causes of things ought\nto be admitted, than those which are true and suffice to explain\nphenomena. In the nature of Philosophy nothing is done in vain, and by\nmeans of many things, it is done in vain when it can be done by fewer.\nFor Nature is simple, and does not abound in superfluous causes.\"\n\nWhile again in Rule 3, he adds: \"Natura simplex est et sibi semper\nconsona.\"--\"Nature is simple, and always agrees with itself.\"\n\nWhewell also considers simplicity as a fundamental principle of all true\nhypotheses. On this point he writes: \"All the hypotheses should tend to\nsimplicity and harmony. The new suppositions resolve themselves into the\nold ones, or at least only require some easy modification of the\nhypothesis first assumed. In false theories the contrary is the case.\"\n\nThus, it is the very essence of philosophy to build upon a foundation of\nsimplicity, combined with the results of experience, observation, and\nexperiment. For example, if we desired to form a hypothesis as to the\ncause of day and night, two hypotheses might be assigned as to the\ncause.\n\nFirst, that the earth revolves on its axis once a day, and so presents\neach part successively to the light and heat of the sun; and second,\nthat the sun revolves round the earth once every 24 hours. But such an\nassumption as the latter would involve the revolution of the sun through\nan immense orbit at an enormous velocity, in order for the journey to be\naccomplished in the time. So that it is much simpler to conceive of the\nearth revolving on its axis once every 24 hours, than it is for the sun\nto perform this journey in the same period. Hence the rule of simplicity\nis in favour of day and night being caused by the revolving of the earth\non its axis. The same rule might be illustrated in many ways; but,\nhowever illustrated, the principle, according to Newton, always holds\ngood that all effects are produced by the simplest causes, and if there\nare apparently two causes to the same phenomenon, then the simpler cause\nis the true and correct one. So that in the making and development of\nany hypotheses of the physical cause of Gravitation, this rule of\nsimplicity must always be recognized; and, in conjunction with the other\nrules, we must seek to make our hypotheses, so as to be able to account\nand explain all phenomena sought to be explained.\n\n\nART. 5. _2nd Rule. Experience._--Newton fully recognized the necessity\nof experience in Philosophy. He saw the absolute necessity of appealing\nto experience, observation, and experiment, both as a basis for\nphilosophical reasoning, and further, for the data which were necessary\nto verify particular applications of the hypotheses suggested.\n\nIn his Rules of Philosophy, referring to experience as a guide, he says:\n\"Hoc est fundamentum philosophiae.\"--\"This is the basis of philosophy.\"\n\nHerschel, writing on the same subject in his _Natural Philosophy_,\nwrites thus with regard to experience: \"We have pointed out that the\ngreat, and indeed the only ultimate source of our knowledge of nature,\nand its laws, is experience. By which I mean, not the experience of one\nman only, or of one generation, but the accumulated experience of all\nmankind in all ages registered in books or recorded in tradition. But\nexperience may be acquired in two ways, either first by noticing facts\nas they occur without any attempt to influence the frequency of their\noccurrence, or to vary the circumstances under which they occur. This is\nobservation. Second, by putting in action causes and agents over which\nwe have no control, and purposely varying their combination, and then\nnoticing what effects take place. This is experiment. To these two\nsources we must look as the fountains of all natural science.\"\n\nHerschel further writes: \"Experience once recognized as the fountain of\nall our knowledge of nature, it follows, that in our study of nature and\nits laws, we ought at once to make up our minds to dismiss, as idle\nprejudices, or at least suspend as premature, all preconceived notion of\nwhat might, or ought to be the order of nature in any proposed case, and\ncontent ourselves as a plain matter of fact with what is. _To experience\nwe refer as the only ground for all physical enquiry._ But before\nexperience itself can be used to advantage, there is one preliminary\nstep to make which depends wholly upon ourselves.\"\n\n\"It is the _absolute dismissal_ and clearing the mind _of all\nprejudices_ from whatever source arising, and the determination to stand\nor fall by the result of direct appeal to facts in the first instance,\nand to strict logical deduction from them afterwards.\"\n\nFrom extracts like these, from such men as Newton and Herschel, it can\nat once be seen that experience, and experience alone, should be the\nchief fountain from whence we draw all our data to form the bases of any\nhypothesis or theory. If the hypothesis formed is contradicted by the\nresult of any present or future observation or experiment, then such\nhypothesis will either become untenable, or must be so modified as to\ntake in the new fact furnished by that observation and experiment.\n\nIt is a _sine qua non_ of all true philosophy, that philosophy should\nalways agree with experience. To the extent that our Philosophy of\nNature fails to agree with our experience, or with the results of\nobservation and experiment, then to that extent it ceases to be\nphilosophy. It may be a hypothesis or even a theory, but certainly it is\nnot true Philosophy.\n\nNow, in the elaboration and development of the theory as to the physical\ncause of Gravitation, I can premise that nothing will be postulated or\nsupposed, unless such supposition can be directly verified by our own\nobservation and experiments.\n\nAny theory or hypotheses that are contradicted by our own experience in\nits widest form, will find no place in the development of this work.\nFurther, any present accepted theory in relation to any natural\nphenomena, which is controverted by experiment, or observation, will be\nrejected as untenable in the scheme of Natural Philosophy to be\nsubmitted to the reader.\n\nWhatever else the theory suggested may, or may not be, one thing it\ncertainly shall be, and that is, that it shall be strictly based upon\nthe Philosophical Rules as given by some of the greatest philosophers\nthe world has ever seen. I do not premise that the hypotheses advanced\nwill be strictly correct in every detail.\n\nThat would be to assume that my experience of all natural phenomena was\nperfect. To the extent that our experience is limited, to that extent\nour hypotheses will be limited and faulty. It would need an Infinite\nmind to form a perfect theory of the philosophy of the universe, because\nonly an Infinite mind possesses infinite experience. A finite mind can,\nhowever, form true philosophical conceptions of natural phenomena, if\nthat mind will only follow the guidance of his own experience, and be\nwilling to accept the teaching that always arises from the results of\nthat experience. In order to do this, however, it must be observed, as\nHerschel points out, that all old prejudices must be put away, and the\nquestion or problem to be considered must be viewed with an open mind.\nLet me illustrate what I mean. Suppose, for example, that for two\nhundred years, chalk had always been thought to be a mineral, and then,\nowing to the development of the microscope, and to the increased\nmagnifying powers of the lenses, it was conclusively demonstrated that\nchalk is made up of the shells and remains of certain organisms that\nlived in the sea ages ago. Would it be philosophical to throw over the\nresults of the microscopical research, and, simply because for two\nhundred years chalk had been thought to be a mineral, to argue, and\nstill retain the idea that chalk was a mineral?\n\nSuch a result would be entirely opposed to all the teaching and\nprinciples of philosophy. In a similar way, suppose in the development\nof the physical cause of Gravitation, a certain conception of the\nuniversal Aether has to be put forth in order to account for\nGravitation, and that that conception is opposed to some of the theories\nwhich have been held relative to the Aether medium for the past two\nhundred years; but that the conception so advanced is supported by the\nexperiments and observation of some of the ablest scientists of the\npresent century, would it be philosophical to reject the newer\nconception which harmonized with all experiment and observation, and\nstill retain the old conception of the aetherial medium; or, to accept\nthe newer conception of that medium, and to reject some of the ideas\nincluded in the old conception? From a purely philosophic standpoint,\nthere can only be one reply, which would be in favour of the newer\nconception, by which our philosophy would be brought into harmony with\nour experience.\n\nThis I premise will be done in this work, and the result will be, that\nfor the first time, our philosophy of the aetherial medium will agree\nwith our experience; and, as the natural result, several outstanding\nproblems will be explained on a physical basis, which at the present\ntime cannot be satisfactorily explained except from the mathematical\nstandpoint.\n\n\nART. 6. _3rd Rule. Satisfactory explanation of the Phenomena sought to\nbe Explained._--The third rule which governs the making of any\nhypothesis is, that the hypothesis formed in accordance with the first\nand second rules shall satisfactorily account for all the phenomena\nsought to be explained.\n\nNewton writes on this point as follows: \"No more causes of natural\nthings are to be admitted, than such as are true, and sufficient to\nexplain the phenomena.\" While again in his fourth rule he states: \"In\nexperimental philosophy, propositions collected by induction from\nphenomena are to be regarded as accurately true, or very nearly true,\nnotwithstanding any contrary hypothesis, till other phenomena occur by\nwhich they are made more accurate, or are rendered subject to\nexceptions.\" _Principia_, Book 3. Herschel in his _Natural Philosophy_\npoints out, that one of the chief requirements of any assumed hypothesis\nis, that it shall be sufficient to account for the phenomena to be\nexplained, and that it shall be suggested by analogy.\n\nNow the object of this work is to give a physical explanation of the\ncause and working of Gravitation, and to show how, by the properties,\nqualities and motions of the universal Aether, Universal Gravitation may\nbe accounted for on a physical basis. So that every phenomenon,\nassociated with, or included in the Law of Gravitation, should receive a\nsatisfactory physical explanation by the proposed theory.\n\nThus the physical cause of the centripetal and centrifugal forces should\nreceive for the first time a physical explanation.\n\nNewton's Laws of Motion, in so far as they conform to his own Rules of\nPhilosophy, should also receive a physical explanation.\n\nKepler's Laws, which govern the motion of planets in their orbits,\nshould also receive a similar physical explanation. Indeed, all\nphenomena which the Law of Gravitation explains from a mathematical\nstandpoint, ought to receive a physical explanation by the proposed new\nconception of the Aether medium.\n\nIn addition to the outstanding physical cause of Gravitation, there are\nother physical problems that yet remain to be solved; as, for example,\nthere is the question as to what is the relative motion of Aether to\nmoving matter. Does the Aether move with matter through space as\nsuggested by Michelson's and Morley's experiment of America, or does it\nflow freely through all matter, as it is usually thought to do? I\npremise I will give a satisfactory solution of this problem in due\ncourse.\n\nAgain, in relation to the Phenomena of Light, there is still outstanding\nthe problem of the physical explanation as to the transverse vibration\nof light. This problem will also be dealt with from the standpoint of\nour new conception of the Aether. Whether it will be as satisfactorily\nsolved, as the physical cause of Gravitation, remains to be seen.\n\nFurther, there is also the important question yet unsolved, as to what\nMatter is. Lord Kelvin and Dr. Larmor have recently given to the world\ncertain conceptions as to the origin of Matter, and I shall endeavour to\nshow that such conceptions receive confirmation and support by the\nproposed new conception of the Aether.\n\nAnother problem that will be attacked and solved, will be the cause of\nthe Permanent Magnetism of the earth, with an answer to some of the\nquestions propounded by Professor Schuster at the British Association of\n1892 relative to the magnetism of solar bodies.\n\nThere is certainly some physical explanation as to the cause of the\nearth being a magnet, yet up to the present no satisfactory physical\ntheory has been given. I premise that the new conception of the Aether,\nto be submitted in the after pages, will satisfactorily account, and\nthat on a philosophical basis, for this phenomenon.\n\nLastly, one of the most interesting discoveries of the present day will\nreceive an added confirmation and explanation in the conception of the\nAether medium to be advanced. I refer to the system of Wireless\nTelegraphy that has been so successfully developed by Signor Marconi,\nand I premise that new light will be thrown on that discovery by the\nsuggested theory of the Aether.\n\nNow, if all these problems can be partially or wholly solved by the same\ntheory that is advanced to explain the physical cause of Gravitation, it\nneeds no further comment to show that that theory is considerably\nstrengthened and more firmly established.\n\nFor it is a rule in Philosophy, that the more problems any suggested\ntheory can solve, the greater are the claims of that theory for\nacceptance by scientists generally. For, if two rival theories can solve\nthree and ten physical problems respectively, then, in giving a decision\nas to which is the better theory, the balance of opinion would be\noverwhelming in favour of that theory which could solve the ten\nproblems. So that, if in addition to the satisfactory explanation of the\nphysical cause of Gravitation, some, if not all of the other problems\ncan be solved, as I premise they can, by the same conception of the\nUniversal Aether, then it follows our third rule of Philosophy will be\nmore than fulfilled, and the theory so advanced will be placed upon such\na strong foundation, that it can only be overthrown by proving that it\ncontradicts the results of some undiscovered phenomena.\n\n\nART. 7. _Application of Rules to Gravitation._--Let us therefore apply\nNewton's own Rules of Philosophy to the Law of Gravitation, and\nendeavour to find out if the law, as at present understood, fully\nsatisfies his own Rules of Philosophy. No one can reasonably object to\nsubjecting the Law of Gravitation to the test of those principles which\nhe lays down as the fundamental Rules of Philosophy.\n\nIf it comes through the ordeal with complete success, that is, if it is\nessentially simple in its conception and development, and if all its\ndetails are fully in accord with experience, as revealed by observation\nand experiment, then there will be no need to alter any of its\nhypotheses or axioms. If, on the other hand, it violates any of the\nrules as laid down by Newton, then, to that extent, an alteration will\nbe necessary, in order that the Law of Gravitation may be brought into\nconformity with his own rules, and our Philosophy made to agree with our\nexperience and observation.\n\n\nART. 8. _Analysis of Law of Gravitation._--In order to accomplish this,\nlet us ask ourselves, \"What are the component parts of this Law of\nGravitation?\" The Law is not a simple law, but a compound one. It is\ncompounded primarily of three parts.\n\n    1st. A Primitive Impulse.\n\n    2nd. A Centripetal Force.\n\n    3rd. A Centrifugal Force.\n\nTo these must be added the three Laws of Motion; although they are not\ndirectly part of the Law of Gravitation, yet they are essential to its\neffectiveness and completion. Without any one of these, the Law of\nGravitation would fail to account for all the phenomena that it does\naccount for.\n\nIf there were no Primitive Impulse, then the planets and meteors, sun\nand stars would for ever remain at rest, and the Laws of Motion would\nremain inoperative. If there were no Centripetal Force, then the\nCentrifugal Force would hurl the planets and comets, asteroids or minor\nplanets away into the depths of space, never to return to their central\nsun.\n\nIf there were no Centrifugal Force, then the Centripetal Force would\ndraw all bodies, _i. e._ all planets, etc., to their central sun, and,\ninstead of the planets continually revolving round the sun, there would\nbe but one immense solitary mass in the centre of the solar system.\n\nIf there were no Laws of Motion, with their necessary corollary the\nParallelogram of Forces, the Primitive Impulse would cease to act, and\nthe Law of Gravitation would again fail in its attempt to account for\nthose phenomena it does account for.\n\nThus, as it may easily be seen, Gravitation is a compound Law, depending\nupon at least four hypotheses, and therefore is not essentially a simple\nForce, or Law.\n\nIf, therefore, in giving a physical explanation of the cause of\nGravitation, we can reduce all these four elements of the Law into one\nsingle physical cause, _i. e._ the Universal Aether, and show how they\nmay all be explained and accounted for by the properties, qualities and\nmotions of that physical medium, then such a result will be strictly in\nharmony with the first Rule of Philosophy, as laid down by Newton and\nothers.\n\nWe will, therefore, proceed to consider some of these parts of the Law\nof Gravitation in detail.\n\n\nART. 9. _Primitive Impulse._--This may be explained as follows. At the\ncreating and launching of each world, Newton supposed that there was\ngiven to each world an impulse or tendency to fly off from the\ncontrolling centre into space. On this matter MacLaurin writes as\nfollows: \"If we had engines of sufficient force, bodies might be\nprojected from them, so as not only to be carried a vast distance away\nwithout falling to the earth, but so as to move round the whole earth\nwithout touching it; and, after returning to the first place, commence a\nnew revolution with the same force they first received from the engine;\nand after the second revolution, a third, and thus revolve as a moon or\nsatellite round the earth for ever. If this can be effected near the\nearth's surface, it may be done higher in the air, or even as high as\nthe moon. By increasing the force or power, a body proportionately\nlarger may be thus projected, and by a power sufficiently great, a heavy\nbody, not inferior to the moon, might be put in motion, which might\nrevolve for ever round the earth. Thus Sir Isaac Newton saw that the\ncurvilineal motion of the moon in her orbit, and of a projectile at the\nsurface of the earth, were phenomena of the same kind, and might be\nexplained from the same principle extended from the earth so as to reach\nthe moon, and that the moon was only a greater projectile that received\nits motion in the beginning of things from the Almighty Author of the\nUniverse.\"\n\nNow what I desire to know is, \"What is the nature, the mode of\noperation, and, above all, the physical cause of this Primitive\nImpulse?\" Is it in its nature and mode of operation a simple Force, or\nCause? Does it fulfil the condition of Newton's First Rule of\nPhilosophy? Permit me to suggest several lines of thought which may be\nmade the basis of its analysis.\n\nAstronomers tell us that there are in existence millions of stars, and\nsuns, flooding immensity and space with their light and heat.\n\nNow the question I wish to ask regarding Primitive Impulse in relation\nto all these stars is this: \"Was the Primitive Impulse imparted to each\nsun, and star, and planet, separately and distinctly?\" If so, then there\nmust have been just as many Primitive Impulses as there are stars and\nsuns and planets, and there would be according to a certain astronomer's\nestimate at least 800,000,000 Primitive Impulses, which assumption is\naltogether opposed to, and violates the First Rule of Philosophy.\n\nIf, on the other hand, it is affirmed that they all received their\nmotion at one and the same time, then I ask: \"What was the physical\ncause and method adopted to communicate the impulse to each one at the\nsame time?\" If the reply is given, that it was by Universal Gravitation,\nI have two objections to make to such a reply: first, that Gravitation\nis altogether inoperative without the Primitive Impulse, otherwise why\nwas it conceived? and secondly, what is the physical cause of\nGravitation?\n\nAgain, scientists inform us that there is every reason for believing,\nthat stars and suns are still being formed in the universe, and that\nthere are certain distinctive phenomena which go to prove that\nstatement. Now, if that be true, and I believe it to be true, I wish to\nask if the Primitive Impulse as suggested by Newton, is applicable to\nthe stars and suns already in process of formation in the various\nnebulae? and, if so, at what point in the star's history or development\nis that Impulse applied?\n\nPersonally, I cannot conceive of the Great Creator of all things being\nso lacking in inventive genius, if I may reverently use that term, as to\nnecessitate a separate Impulse being given to every separate star, or\nsun, as each one is created or formed during the progress and\ndevelopment of the universe of worlds.\n\nI would much rather believe that which I hold to be the correct\nexplanation, viz. that He has given to a certain fundamental and\nprimordial medium, certain qualities and properties, by, and through\nwhich are originated and perpetuated, all the motions of the heavenly\nbodies already existent in the universe, or that are ever likely to be\nexistent throughout all time.\n\nThe question of separate Primitive Impulses for separate bodies becomes\nmore and more incongruous and inadmissible, as we consider it in its\napplication to such small bodies as meteors and planetoids. Is it not\ncontrary to our fundamental principles of Philosophy, that a separate\nImpulse should be necessary for all small bodies that exist in their\nmyriads throughout the solar system, not to speak of the universe of\nwhich that system forms a part? Such a conception as Primitive Impulse,\nto each separate world, is altogether opposed to one's idea of that\nsimplicity and beauty which govern the universe at large, and violates\nthe first rule of our philosophical reasoning, and for this reason must\nbe rejected from the System of Philosophy to be propounded in this work.\n\n\nART. 10. _Centripetal Force._--Let us now look at the Centripetal Force,\nand ask ourselves what is meant by such a force, and what is its mode of\naction and working. Centripetal Force, strictly, may be defined as that\nforce which is always exerted towards the centre of the attracting body.\n\nTaking the earth as an example, Newton points out, that though the\ngravity of bodies arises from their gravitation towards several parts of\nthe earth; yet, because this power acts always towards the centre of\ngravity of the earth, it is therefore called the Centripetal Force.\n\nThis force, then, is that part of the Law of Gravitation which\ncorresponds to the Attraction of Gravitation, and is always exerted in\nthat straight line from the body attracted, to the centre of the\nattracting body, which joins the centres of gravity of the two bodies\nconcerned.\n\nThe combination and effect of the various forces included in the Law of\nGravitation are illustrated by the familiar illustration of the ball\nwhirled round the hand by a piece of string, or the bucket filled with\nwater, whirled round in the same way. Let us take the former. A piece of\nstring with a ball attached to one of the ends is held firmly by the\nhand. An impulse or motion is imparted to the ball by the hand, that\nmotion being continued by the movement from the hand. The first impulse\ngiven to the ball by the hand represents the Primitive Impulse. The\ntension on the string which holds the ball to its controlling centre\nrepresents the Centripetal Force, while the opposite force on the\nstring, which takes up the Primitive Impulse and continues it, is\nrepresented by the Centrifugal Force.\n\nThe conception of the Centripetal Force is therefore simple, and\nentirely in accordance with our experience as gathered from observation\nand experiments. Both in the spheres of electricity, and magnetism, we\nfind a similar force acting, which tends towards the centre of the\nattracting body, and therefore the Centripetal Force satisfies the first\ntwo Rules of our Philosophy.\n\nFurther, it adequately accounts for certain distinctive phenomena which\noccur through the Law of Gravitation, as, for example, the falling of\nbodies to the earth, and therefore is entirely in harmony with all the\nrequirements of those principles enunciated by Newton for the successful\nexplanation of any phenomena. I need hardly point out, therefore, this\nbeing so, any physical cause suggested as the explanation of Gravitation\nmust deal with the Centripetal Force, and be able to give a physical\nexplanation of the mode and manner in which the Centripetal Force\noperates.\n\nThe Attraction of Gravitation or the Centripetal Force, however, being,\nas its name implies, simply a drawing or pulling power to a centre, that\nis, a force that is ever and ever only drawing matter to matter, or body\nto body, it could not of, and by itself, accomplish those necessary\nstellar and planetary motions by which are produced that universal\norder, unity and harmony which characterize the universe. It is\nessentially in its operations and influences, a one-sided force, ever\ntending and influencing towards self, and therefore by itself would only\nbe a detriment and an evil; and, unless it were accompanied by some\ncompanion or complementary and counter force, with which it acts in\nunion and concert, and which exactly counteracts its pulling power and\ninfluence, it would soon draw star to star, and world to world, crashing\nand heaping them together in ruinous and dire confusion. So that,\ninstead of the infinitude of worlds which now exist, which flash and\nsparkle in the heavens, and in their intricate, elaborate, and mazy\nmotions move through the vast infinity like stately armies on the march,\nthere would only be one agglomeration of matter, a silent and solitary\nmass existing in the vast abyss of space.\n\nTherefore, as soon as Sir Isaac Newton had discovered and demonstrated\nthe existence of the power of Attraction, as represented by the\nCentripetal Force, and its association with the universe at large, there\nwas seen at once the necessity of another Force, of an opposite\ncharacter, which would form the companion and complementary force to\nAttraction; a repulsive, repellent force, one tending or repelling from\na centre, so as to counterbalance the influence of the Centripetal Force\nwhich ever tends towards the centre.\n\nTo fill up the blank, there was conceived to exist what is called a\nCentrifugal Force, that is, literally, a Force acting, and ever acting\nfrom a centre, and with that Force we will now deal.\n\n\nART. 11. _Centrifugal Force._--In applying our Rules of Philosophy to\nthis Force, if by Centrifugal Force is simply meant that Force which is\nthe exact opposite of the Centripetal Force, that is, a Force which acts\nfrom a centre, instead of to a centre, then such a Force is strictly in\nharmony with, and satisfies all the conditions of the two first Rules of\nPhilosophy.\n\nNot only is such a conception simple, but it is also in accordance with\nexperience and observation. Professor Hicks in his address to the\nBritish Association in 1895 said: \"What is called Centrifugal Force is\nan apparent bodily Force directed outwards from the centre of curvature\nof the body's path, and having an intensity equal to the distance from\nthe centre multiplied by the square of the absolute angular velocity.\"\n\nIn the sphere of magnetism and electricity, the operation of two equal\nand opposite forces prevails. The attractive force of electricity, which\nis exerted to the centre, is always accompanied by the generation and\ndevelopment of a repulsive force, it being one of the fundamental rules\nof electricity that equal and opposite quantities of electricity are\nalways generated at one and the same time. So that if the Centrifugal\nForce is viewed as being simply the exact opposite of the Centripetal\nForce, it fully satisfies the test when the first two rules laid down by\nNewton are applied to it.\n\nIf, on the other hand, Centrifugal Force implies and embodies the idea\nof continuance of the Primitive Impulse, as I believe it is supposed to\ndo, then to that extent it is not conformable to the principles of our\nPhilosophy, as embodied in the rules given by Newton.\n\nSimply because, while it supposes a source or origin of its activity at\nthe first, it goes on to suppose a continuance of that activity, without\nrecognizing a continuing source or cause. It only recognizes and\nsupposes the one original impulse given at the beginning, to account for\nthe cause of the continually existing, and exerted power of the\nCentrifugal Force. I do not for a moment suggest, that the Divine\nCreator of all things, and the Ordainer and Upholder of all powers,\nforces and laws could not, had He chosen to give such a force, have\ngiven it and for ever operating. With that aspect of the question I have\nnothing to do, and of it nothing to say. I am dealing, and only wish to\ndeal, with scientific facts, and scientific teaching from the purely\nphilosophical standpoint.\n\nSuch an idea of a continuing effect, without a continuing cause, is\naltogether opposed to experience and observation, and is a violation of\nthe second Rule of Philosophy.\n\nLook where we will, or at what we will, and not only effects and causes\nare seen on every side, and in every thing, linked together inseparably,\nbut wherever, and in whatever phenomena there is found a continuance of\neffect or effects, there is always and without exception found also a\ncontinuing source or cause.\n\nWherever Nature, therefore, gives us a continuous effect of any kind or\nsort, she always gives us a continuing cause, that can be both proved\nand demonstrated to exist. Nowhere in Nature, amid all her powers,\nprinciples and laws, is there to be found an effect without a cause, and\nin all continuing effects, a continuing and perpetuating cause also, and\nthat effect exists just as long as the cause exists.\n\nIf the effect is perpetual, then the source and cause is perpetual also,\nboth in its existence and energy. Hence if the Centrifugal Force\nembodies the idea of continuance of the Primitive Impulse, without\nshowing how that Primitive Impulse is continued, then such an idea is an\nanomaly in the universe, is altogether opposed to the teaching of Nature\nand science, and violates the most fundamental principles of our\nPhilosophy.\n\nThe philosophic explanation, therefore, of the Centrifugal Force, is\nthat Force which flows from a centre, and _which is the exact opposite\nand counterpart of the Centripetal Force_. Further, as the Centripetal\nForce is an attractive Force ever attracting to a centre, so the\nCentrifugal Force, being its exact opposite, is a repulsive Force, which\nfulfils all the laws and conditions which govern the Centripetal Force,\nas it is in every phase and aspect the exact opposite, being indeed its\ncomplement and counterpart.\n\nAny physical explanation of the Law of Gravitation, therefore, must also\ngive a satisfactory physical explanation of this Force, and show its\nmode of operation and working. This I premise I will do without the\nfaintest shadow of doubt or failure; that is, if we are to accept the\nevidence of some of the most delicate experiments of modern times\nrelative to aetherial physics.\n\n\nART. 12. _Laws of Motion._--One of the most important factors in the\nsuccessful application of the Attraction of Gravitation to the universe\nat large, are the Laws of Motion enunciated by Sir Isaac Newton. These\nare three in number, and are as follows--\n\n1st. Every body continues in its state of rest, or of uniform motion in\na straight line, except in so far as it may be compelled by impressed\nForces to change that state.\n\n2nd. Change of motion is proportionate to the impressed Force, and takes\nplace in the direction of the straight line in which the Force acts.\n\n3rd. To every action there is always an equal and contrary reaction.\n\n_Corollary._--To these must be added the first Corollary of the three\nlaws which is commonly known as the Parallelogram of Forces, which is as\nfollows: \"That when a body is acted upon by two Forces at the same time,\nit will describe a diagonal, by the motion resulting from their\ncomposition, in the same time that it would describe the sides of the\nparallelogram.\"\n\nNow let us apply Newton's Rules of Philosophy to these laws, and see if\nthey fulfil the conditions laid down therein.\n\nIn the first place, there being three laws necessary to cover all the\nmotions involved, there is not that simplicity of conception which is a\nprimary factor in the making of any hypothesis. Then it will be observed\nthat even after postulating the three laws, Newton was unable to account\nfor the elliptic orbits of the planets, until he had added a Corollary\nknown as the Parallelogram of Forces.\n\n\nART. 13. _Force._--The question has arisen also, as to the meaning of\nthe term Force which Newton uses. What is a Force, its cause and mode of\noperation? The idea of Force is conveyed to us by our \"muscular sense,\"\nwhich gives us the idea of pressure, as for example when we push or pull\na body along the ground.\n\nWe must not, however, limit our idea of Force to that narrow circle. It\nhas now been fully established that Sound and Heat, Light, Magnetism,\nand Electricity are Forces, and therefore capable of doing work, as will\nbe shown later on. Newton's use of the term Force is therefore somewhat\nvague; he does not definitely say what the Force is which causes the\nchange of position, of the body, or of the rate of motion of that body.\nThat it is something to do with Gravitation is obvious, but its exact\nnature or character is not revealed.\n\nSince Newton's time we have made an advance in the definition of Force,\nand have come to consider Force as a kind of energy; the application of\nForce being the application of energy. Such terms as Mechanical Force,\nChemical Force, Vital Force, are therefore out of date, and in their\nplace the more definite ideas of energy are substituted. Instead,\ntherefore, of getting such terms as Transformation of Forces, we now get\nTransformations of Energy. In the chapter on Energy, I hope to show that\neven that is not a satisfactory solution of the definition of a Force.\nIf we are to make our Philosophy agree with our experience, then Force\nis due to motion, and motion alone.\n\nSo that Centrifugal Force will imply a motion from the centre;\nCentripetal Force a motion whose effect is ever towards the centre of\ngravity of any body.\n\n\nART. 14. _First Law of Motion._--This may naturally be divided into two\nparts for the purpose of applying the Rules of Philosophy.\n\n(I) Every body continues in a state of rest, except in so far as it is\ncompelled by impressed Forces to change that state. To what extent is\nthis statement conformable to our experience and observation? If I place\na body, as for example a weight, on a table, will it remain in that\nstate until it is moved by some other Force? I think that it will so\nremain, and to that extent the law conforms to experiment.\n\nWider observation, and all experience, also prove the conformity of this\npart of the First Law of Motion to the second Rule of Philosophy, as all\nexperience testifies to the fact that a body remains at rest, until some\nother power or force moves it from the position of rest. The application\nof this position of rest to any of the planets is, however, very\ndifficult to conceive. MacLaurin, in relation to this fact, states:\n\"This perseverance of a body in a state of rest can only take place in\nabsolute space, and can then only be intelligible by admitting it.\" In\ndealing with the physical cause of Gravitation, I hope to be able to\nshow that it can not only be admitted as a mathematical proposition, but\nthat it can be made intelligible from the physical standpoint.\n\nThe second part of the First Law of Motion may be stated as follows:\n\"Every body continues in a state of uniform motion in a straight line,\nexcept in so far as it is compelled by impressed forces to change that\nstate.\"\n\nNow what is the testimony of observation and experiment in regard to\nthis part of the First Law of Motion? Let us test the question by the\nresults of our experience. If a ball is sent rolling along the ground,\nits motion is gradually reduced until it comes to rest. If the ground is\nvery rough indeed, as for example a ploughed field, then its speed will\nbe very soon reduced, and the ball quickly comes to a standstill. If,\nhowever, the ground is smooth and level, like a well-kept cricket-field,\nthen the motion of the ball will be reduced more slowly, and it will\ntravel further before being brought to rest; while, if the ball is\nthrown along a very smooth surface of ice, it will travel a much longer\ndistance before it is finally brought to rest.\n\nThus we learn, that the more we can get rid of all resistances to the\nmotion of any body, the greater distance will the body travel, and the\nless diminution there is in the uniform motion of the body. So that, if\nit were possible to obtain a medium which offered no resistance at all\nto a moving body, then it would be a legitimate inference to infer that\na body in such a medium, when once set in motion, would move with\nuniform motion for ever. Under such conditions, therefore, this part of\nNewton's First Law of Motion is physically conceivable. The crux of the\nwhole matter, therefore, lies in the problem as to whether there is, or\nthere is not, in existence, such a thing as a frictionless medium. We\nwill therefore consider the problem of the existence of a frictionless\nmedium from the philosophical standpoint.\n\nProfessor Lodge, in _Modern Views of Electricity_, p. 331, writes: \"Now,\nif there is one thing with which the human race has been more conversant\nthan another, and concerning which more experience has been\nunconsciously accumulated than about almost anything else that can be\nmentioned, it is the action of one body upon another; the exertion of\nForce by one body on another, the transfer of motion and energy from one\nbody to another, any kind of effect, no matter what, which can be\nproduced in one body by means of another, whether the bodies be animate\nor inanimate.\"\n\n\"Now I wish to appeal to this mass of experience, and to ask, Is not the\ndirect action of one body on another across empty space, and with no\nmeans of communication whatever, is not this absolutely unthinkable? We\nmust not answer the question offhand, but must give it due\nconsideration, and we shall find, I think, that wherever one body acts\non another body by obvious contact, we are satisfied and have a feeling\nthat the phenomena is simple and intelligible, and that, whenever one\nbody apparently acts on another body at a distance, we are irresistibly\nimpelled to look for the connecting medium.\"\n\nAgain, on p. 333 of the same work, he adds: \"Remember then, that\nwhenever we see a thing being moved, we must look for the rope. It may\nbe visible, or it may be invisible, but unless there is either a push or\na pull, there can be no action.\"\n\nNow, in relation to celestial phenomena, we are confronted with the fact\nof bodies acting on one another, and yet apparently they do not act upon\none another by or through a medium, and to that extent according to the\nabove extracts, such phenomena are opposed to universal experience.\nAgain, we find planets and satellites moving through space with more or\nless uniform speed, and yet apparently there is no physical medium that\nacts upon them with either a push or a pull, as the present conception\nof the Aether is that of a frictionless medium, so that experience in\nits widest form seems altogether opposed to the existence of a\nfrictionless medium.\n\nAgain, Tait in his _Natural Philosophy_ says: \"The greater masses,\nplanets and comets moving in a less resisting medium, show less\nindications of resistance. Indeed it cannot be said that observations\nupon any one of these bodies, with the exception of Encke's Comet, has\ndemonstrated resistance. The greater masses, planets and comets moving\nin a less resisting medium, show less indications. No motion in Nature\ncan take place without meeting resistance due to some if not all of\nthese influences. _The analogies of Nature and the ascertained facts of\nphysical science forbid us to doubt that every one of them, every star,\nand every body of every kind has its relative motion impeded by the air,\ngas, vapour, medium, or whatever we choose to call the substance\noccupying the space around it_, just as the motion of a rifle-bullet is\nimpeded by the resistance of the air.\"\n\nWhat is the testimony of our own personal observation and experiments to\nsuch an impossible entity as a frictionless medium? Can any of the\nreaders tell me of any medium, be it solid, liquid, or gaseous, that\nthey have ever heard of, or read of, or experimented with, that\npossesses the quality of being frictionless? The answer is unanimously\nin the negative. But a frictionless medium was absolutely imperative to\nthe success of the Newtonian aspect of the Law of Gravitation. If the\nAether had not been frictionless, then the First Law of Motion would\nhave been violated, and a body, as for example a planet set in motion,\nwould not then have moved with uniform motion, but would have been\nbrought to a standstill by the resistance of the Aether. Accepting\ntherefore experience as a guide, as we are bound to do if we wish to be\nstrictly philosophical, as Newton pointed out, then we are compelled to\ncome to the conclusion that there is no such thing in the entire\nuniverse as a frictionless medium. Such a hypothesis is contrary to all\nlaws and rules of Philosophy, and to continue to advocate its claims is\nto remain where we are in relation to the cause of Gravitation, and in\ncomplete ignorance of the beauty and harmony of the wonderful physical\nmechanism that underlies the whole of the universe. Of course, if\nexperience and observation are no guide to Philosophy, then we will let\nimagination run riot, and postulate the most extravagant explanations\nfor the varied phenomena of the heavens. With experience of no account,\nwe will affirm that the moon is made of green cheese, that the earth is\nflat, that the sun revolves round the moon, and a host of other absurd\nhypotheses that require no correction by experience and observation. But\nthere, a truce to such absurd imaginations. Experience is a guide to\nPhilosophy, its claims are recognized by the greatest Philosopher the\nworld has ever known, and therefore as either experience or a\nfrictionless medium has to go, we will part with the frictionless\nmedium, and endeavour to make a hypothesis of the Aether that is in\ngreater harmony with our Rules of Philosophy.\n\n\nART. 15. _Second Law of Motion._--The application of Newton's Rules of\nPhilosophy to the Second Law of Motion is attended with greater success\nthan was the case with his First Law. \"Change of motion,\" he states, \"is\nproportionate to the impressed Force, and takes place in the direction\nof the straight line in which the Force acts.\"\n\nNewton adds this explanation to his Second Law: \"If a Force generates\nany motion, a double Force will generate double motion, and a triple\nForce triple motion, whether they are applied simultaneously or\ngradually and successively. And this motion, if the body were already\nmoving, is either added to the previous motion, if it is in the same\ndirection, or subtracted from it if directly opposed to it, or is\ncompounded with the previous motion if the two are inclined at an\nangle.\"\n\nAccording to that, a force which presses or pushes with a four-pound\npressure per square inch, if doubled, would press with a force of eight\npounds per square inch, which fact agrees with experience. If the force\nis applied gradually, then the change of motion would be gradual; if\napplied suddenly, then the resultant motion would be sudden and violent.\n\nThe impressed force, therefore, always produces a definite and\ncorresponding effect on any moving body, however that force may be\noriginated, and however it may be applied. The effect so produced is\nalways a change of motion, or, in present scientific terms, a change of\nmomentum in the moving body. If the impressed force is halved, by an\nalteration in the mass of the body which exerts the impressed force,\nthen the resultant momentum produced is halved also. If the impressed\nforce is doubled, through any alteration in the velocity of the body\nwhich exerts the force, then the momentum produced in the moving body\nwill be doubled also. So that the impressed force is equal to the change\nof momentum in the moving body upon which it is impressed.\n\nWhen similar forces are impressed upon exactly similar bodies, the\nvelocities produced are exactly the same; but, if similar forces act on\ndissimilar bodies, then the velocities produced in the different bodies\nare not the same; yet the total motion produced on all bodies, according\nto the Second Law of Motion, must always be proportionate to the\nimpressed force. So that when we compare the effect of similar forces on\ndifferent bodies, we find that there are two factors involved, viz., the\nmass and velocity of the moving body. The product of these two\nquantities is termed the momentum of the body.\n\nWhen we apply the Second Law of Motion to the theory of aetherial\ndynamics, as suggested in this work, we shall seek to show that Newton's\nSecond Law of Motion holds good in its application to the new theory.\nWith the present conception of a frictionless Aether, however, it is\nphilosophically impossible for the Aether to exert force on any body\nthat may exist in it. Because, to the extent that it is frictionless, to\nthat extent it ceases to possess mass. If it does possess mass, then it\ncannot be frictionless. Such an assumption violates all the Rules of\nPhilosophy.\n\nYet the Aether is supposed, in some unknown manner, to possess inertia,\nwhich property is also dependent on mass. If the Aether really possesses\ninertia, then it must possess mass, and possessing mass it ceases to be\na frictionless medium. So that if it possesses mass, then it can exert\nforce the same as any other body, and Newton's Second Law of Motion is\napplicable to it.\n\n\nART. 16. _Third Law of Motion._--Newton's Third Law of Motion reads as\nfollows--\n\n\"Action and re-action are equal and opposite, or, to every action there\nis always an equal and contrary re-action.\" This law is also conformable\nto experience; for, by experiment, it has been proved to hold good for\nelectric and magnetic action. As MacLaurin points out, the Third Law of\nMotion may be extended to all sorts of powers that take place in Nature,\nand belongs to attraction and repulsion of all kinds, and must not be\nconsidered as being arbitrarily introduced by Newton.\n\nThe mutual action between any two bodies has, therefore, a double\naction. Thus a piece of stretched string must be conceived as pulling at\nboth ends; the pull at the one end being exactly equal and opposite to\nthe pull on the other end.\n\nA magnet will attract a piece of iron with a certain force, but it is\nequally true that the iron attracts the magnet with an exactly equal and\nopposite force. We might even extend the application of this Third Law\nto a falling stone in its relation to the earth. Thus, if a stone is\ndropped from a high altitude to the surface of the earth, although the\nmotion seems to be all in one direction, yet if the Third Law holds\ngood, then the earth is attracted by the stone in exactly an equal, but\nopposite direction, to that in which the earth attracts the stone.\n\nAs, however, the mass of the earth is very great compared with that of\nthe stone, it follows that the velocity of the stone compared with the\nvelocity of the earth, must be very much greater, in order that the\nforces shall be equal.\n\nThe application of this Third Rule of Motion to planetary and celestial\nphenomena is therefore philosophical, in that its conception agrees with\nexperience and observation.\n\nThus, while it is true that the sun attracts each of the planets in his\nsystem, it is equally true that the planets, in their turn, attract the\nsun with an exactly equal and opposite force. But the velocity of motion\ninduced by the earth's attractive power upon the sun, would be less than\nthe velocity of motion induced by the sun's attractive power upon the\nearth, although the two forces would be equal and opposite, simply\nbecause force, being a compound quantity, is dependent upon the mass of\na body as well as upon its velocity.\n\nNot only, however, is it true that the sun and all the planets jointly\nattract each other, but it is equally true that the planets attract each\nother also, with an exactly equal and opposite effect. Indeed, as\nGravitation is universal, it has to be conceived that there are no two\nbodies existing, but what the Third Law of Motion equally applies to\nthose two bodies; so that equality of action and re-action is as\nuniversal as the Law of Gravitation itself.\n\nIn coming to a conclusion with reference to Philosophy and the Laws of\nMotion, I wish to say that I am strongly of the opinion that the day has\ncome, or will soon come, when they will pass away and give place to a\nmore direct and simple method of working of the great Law of\nGravitation. I look upon the Laws of Motion as part of the scaffolding\nwhich has been used to build up the Law of Gravitation. That Law has now\nbeen erected, and stands firm and secure in its position in the\nuniverse. Whatever changes may take place in its scaffolding, the Law\nitself will stand out with greater beauty and clearness, if we could but\nsee the perfected structure, apart from the props and helps which have\nassisted in its successful erection and completion. As Dr. Larmor said,\nin his address to the British Association, 1900: \"There has even\nappeared a disposition to consider that the Newtonian principles, which\nhave formed the basis of physical phenomena for nearly two centuries,\nmust be replaced in these deeper subjects by a method of more direct\ndescription of the cause of the phenomena. The question has arisen, as\nto how far the new methods of aetherial physics are to be considered as\nan independent departure; or how far they form the natural development\nof existing dynamical science.\"\n\nI hope, therefore, to be able in this work to do something towards\nclearing the completed Law from some of the outside props, which have\nlong hidden the simplicity, beauty and harmony of the physical working\nof Gravitation from the eyes of those who feign would see its wonderful\nmechanism.\n\nIn the elaboration and development, therefore, of the physical cause of\nGravitation, it will be necessary to conceive a medium, whose properties\nand motions shall be able to account for all the movements of the\nplanets, comets, suns and stars that the Laws of Motion now account for.\nInstead, however, of there being several Laws purely and simply\nmathematical in their application, there will be one physical medium,\nwhich will by its properties and motions account for--and that in a\nsatisfactory manner--all the motions of the heavenly bodies. That such a\nmedium is required in the scientific world is proved by the statement\nmade by Professor Glazebrook, in his work on J. C. Maxwell, page 221,\nwhere he says: \"We are still waiting for some one to give us a theory of\nthe Aether, which shall include the facts of electricity and magnetism,\nluminous radiation, and it may be Gravitation.\"\n\n\nART. 17. _Summary of the Chapter._--In summing up the contents of this\nchapter, we find therefrom, that there is a Universal Law in existence\nthat is known as the Law of Gravitation. The physical cause of this Law,\nhowever, is unknown; Newton suggesting that it was due to the properties\nof an aetherial medium that pervaded the universe.\n\nTo form a right conception of this medium, and to develop the hypotheses\nof the same on strictly philosophical lines, it is essential for us to\nknow the rules which govern the making of any hypothesis.\n\nThose rules, according to Newton, and other philosophers, are chiefly\nthree in number, and form the very essence of any philosophical\nreasoning. Any departure from those rules will entail partial or entire\nfailure in the success of the undertaking.\n\nThe application of Newton's rules to parts of the great Law of\nGravitation show that some of those parts are not fully in harmony with\nthe rules which Newton laid down in his _Principia_.\n\nAny physical theory that may be hereafter suggested as the physical\nbasis for the Law of Gravitation, must itself not only account for the\nvarious forces already referred to, but must itself fulfil the Rules of\nPhilosophy laid down by Newton. That is to say, the conception of the\nphysical medium must be simple in character, its properties and motions\nmust agree with all our experience, as given by observation, and\nexperiments; and the properties and motions postulated for it must\nsatisfactorily account for, and explain all the phenomena that are\npresented to us by the Universal Law of Gravitation.\n\nIf all this be done, then from the standpoint of strict philosophical\nreasoning, the physical medium so suggested, and the theory so made,\nwill be incapable of being overthrown or disproved.\n\n\n\n\n                              CHAPTER II\n\n                       PHILOSOPHY OF GRAVITATION\n\n\nART. 18. _Gravitation Attraction._--The Law of Gravitation being a\ncompound law, and not a simple law (Art. 8), it is necessary that the\nprinciples which govern universal attraction should now be considered.\n\nThe law which governs Gravitation Attraction may be defined as follows:\nEvery particle of matter in the universe attracts every other particle\nwith a force whose direction is that of a line joining the centre of\ntheir masses, whose magnitude is directly as the product of their\nmasses, and inversely as the square of the distance between them.\n\nThis may be divided into four parts.\n\n    (1) The Universality of Gravitation.\n    (2) The Direction of the Forces involved.\n    (3) The Proportion of these Forces.\n    (4) The Law of Inverse Squares.\n\nThe theory of the Aether, therefore, which will be perfected in this\nwork, must not only satisfactorily account for the Attraction of\nGravitation on a strictly philosophical basis, but the laws, governing\nthe pressures or tensions of that physical medium, must harmonize with\neach of the parts of the complex Law of Gravitation into which it has\nbeen resolved.\n\n\nART. 19. _Universality of the Attractive Force._--The principle upon\nwhich Universal Attraction rests is found in the words: \"Every particle\nof matter in the universe attracts every other particle.\" It must,\nhowever, be admitted that this statement has never actually been proved.\nThe smallest body that Newton used to prove his Law of Attraction was\nour satellite the moon.\n\nCavendish, however, in 1798, by a series of experiments, conclusively\ndemonstrated that the force of Gravitation existed in small bodies. He\ntook two small leaden balls of a certain weight, and fixed them at the\nends of a rod about six feet long, the rod being suspended by a piece of\nwire in the air. Large leaden balls were then brought near the small\nones, and great care was taken to see if there were any twist in the\nwire by which they were suspended. It was found that the wire had become\ntwisted on the approach of the large leaden balls, and thus he was able\nto prove that every particle of the attracted and attracting body are\nmutually concerned in the Attraction of Gravitation. There is abundant\nevidence of the application of this force in relation to our earth, as\nwe shall see later on.\n\nThe universality of the Attraction of Gravitation is a fact that has\nbeen proved in a thousand ways, and a thousand times. All stars and\nsuns, and all planets, satellites and comets and nebulae are subject to\nthis universal law. Astronomy teaches us that its power extends across\nthe vast abysses of space, and that stars situated at distances that\ncannot possibly be measured, are subject to this world-wide law. Some of\nthe greatest discoveries in astronomical science were due to the\noperations of this wonderful law, the gravitating influences of certain\nplanets indicating their existence, although their discovery had not yet\nbeen made.\n\nThe discovery of Neptune through the mathematical calculations of Le\nVerrier and Mr. Adams in 1846 was the crowning proof of the Law of\nGravitation. Mr. Adams in England had noticed that the planet Uranus was\nbeing pulled out of the course by some unknown power, and so set to work\nto calculate the position of the body which thus influenced the motion\nof Uranus in its orbit. He located the position of the supposed\ninfluencing body strictly by mathematical calculations, and then took\nhis results to the Astronomer Royal. Delay, however, occurred in the\nsearch for the supposed new planet, and nothing was done further in the\nmatter for many months. Meanwhile Le Verrier in France, unknown to Mr.\nAdams, had been making similar calculations with reference to the\nperturbations of Uranus, and had arrived at similar results.\n\nThese results were sent to the Berlin astronomers, and the heavens were\nsearched for the supposed new planet. After a time, the planet was\ndiscovered in that part of the heavens indicated by Le Verrier, and for\na time his name stood out as the sole discoverer. Gradually, however,\nthe claims of Adams were admitted and recognized, and to-day his claims\nto participate in the honour of the wonderful achievement are generally\nadmitted. Thus the discovery of Neptune gave to the Law of Gravitation a\nstability and proof that perhaps it had never received before.\n\nFurther evidence of the existence of the universality of the attractive\nforce, is to be found in a certain system of stars known as binary\nstars, which revolve around each other, while they gravitate around a\ncommon centre. Recent researches in astronomy only seek more and more to\nconfirm the universality and effectiveness of this grand law, that seems\nto hold the entire universe in its sway.\n\nAny medium, therefore, which is postulated as the physical cause of\nGravitation, must itself be as universal as Gravitation, in order for it\nto be able to fulfil this condition of universality. We shall find, as\nwe proceed, that the only possible medium which can fulfil this\ncondition, is the universal Aether, whose qualities and properties are\nalready partly known and partly understood.\n\n\nART. 20. _Direction of the Forces._--The attraction of Gravitation is\nalways directed along the straight line which joins the centres of\nmasses of the attracting and attracted bodies. Thus, if the earth and\nmoon are taken as examples, an imaginary straight line drawn from the\ncentre of the earth's mass to the centre of the mass of the moon would\nbe the direction in which the gravitative force would be exerted. Now a\nline which joins the central body to its satellite we shall see when we\ncome to deal with Kepler's Laws is known as the Radius Vector. Thus the\npath of the attraction between the two bodies is along the Radius\nVector. It is a singular coincidence that the path of a ray of light\nfrom the sun also coincides with the Radius Vector, as it is one of the\nlaws of light that the path of a ray always follows a straight line.\n\nIt must not, however, be assumed, that while the attractive power is\nbeing exerted along any one straight line joining the centres of two\nbodies, therefore the attractive power is not operative in relation to\nany other part of the space, around the body. If our earth, for example,\nhad four moons instead of one, and they were each in different positions\nin relation to the earth, then the law as to the direction of the forces\nwould still hold good. We have examples of this in the case of Jupiter\nwith his five moons, and Saturn with his eight moons. So that the\nattractive force of Gravitation is again like light, it operates on all\nsides equally at one and the same time. A lamp in the middle of a room\nsends its light waves on every side at one and the same time, so that\nwhile each ray has for its path a straight line, yet those rays are\nemitted equally on every side. In like manner, though the direction of\nthe forces between two attracting bodies is that of a straight line, yet\nthe law of universal attraction is equally exerted on every side of the\nplanet at one and the same time.\n\nIn the theory of the Aether, therefore, to be developed in this work, it\nwill have to be demonstrated that the direction of the forces, which are\noriginated and transmitted by that physical medium, must philosophically\nfulfil the conditions which govern the direction of the forces, as\nobserved in gravitational phenomena.\n\n\nART. 21. _Proportion of the Forces._--Newton proved that the attraction\nis proportional to the product of the masses of the bodies concerned.\n\nHence it is that the sun, which is the centre of the solar system, is\ncapable of attracting the most remote planets, because the mass of the\nsun is greater than the mass of all the planets put together. Or take\nanother illustration. Suppose that the sun and the earth are at equal\ndistances from Saturn. Now the sun's mass is about 300,000 times that of\nour earth. Therefore if the earth draws Saturn through a certain\ndistance in one second, the sun would draw Saturn through a distance\nwhich is 300,000 greater than the earth in the same period.\n\nThe governing principle, therefore, which decides the proportion of the\nattractive forces between two bodies is mass, and not simply density or\nvolume. The mass of a body is a property which remains the same, as long\nas the inertia of the body remains constant. Mass is really a measure of\nthe inertia of a body, or that property of a body by which it continues\nin its state of motion or of rest.\n\nMass is therefore a compound quantity, being equal to volume multiplied\nby density, so that if the volume of any body is halved, the density is\ndoubled. Thus, the proportion of the attractive force between any two\nbodies ever remains the same, so long as the masses of the two bodies\nremain the same. Through all the changes of volume and density of any\nbody, its attractive force remains constant, as long as the mass remains\nconstant; for the simple reason, that as the volume of a body is\nincreased, the density is proportionately decreased; or, as the volume\nis decreased, the density is increased.\n\nFor example, the volume of the sun as compared with the volume of the\nearth, is about 1,300,000 times greater, but the proportion of the\nattractive forces between the two bodies, is about 324,000 to 1. This\ndifference is accounted for by the fact, that the density of the sun is\nabout one quarter the mean density of the earth, hence their masses are\nin the proportion of 324,000 to 1. Thus the proportion of the attractive\nforces between any two bodies is dependent upon their masses, and not\nsimply upon their volume or density.\n\n\nART. 22. _Law of Inverse Squares._--The Law of Inverse Squares which is\napplicable to Gravitation is equally true of Sound, Light, Heat and\nElectricity, the Law being that Gravitation acts inversely as the square\nof distance. That is to say, if the distance of any body from the sun,\nfor example, be doubled, then the force of Gravitation is diminished to\none quarter of the intensity which would be exerted on the body in the\nfirst position.\n\nThus the further a body is from its controlling centre, the weaker the\nAttraction of Gravitation upon it becomes. Taking therefore Mercury and\nthe earth as examples, we find that their mean distances are\nrespectively 35,000,000 miles and 92,000,000, which is a proportion of\nabout 1 to 2-1/2. So that the intensity of the sun's attraction on the\nearth is about four-twenty-fifths of what it is on Mercury, that being\nthe inverse square of the relative distances of the two bodies.\n\nNow the intensity of Light and Heat received by the earth is regulated\nby the same law of inverse squares, so that the earth would receive\nabout four-twenty-fifths the intensity of light and heat which Mercury\nreceives when they are both at their mean distances.\n\nThis law of inverse squares is applicable to every body which acts as a\ngravitating source throughout the whole of the universe, whether that\nbody be small or large, and whether it be in the form of meteor,\nsatellite, planet, sun or star.\n\nEach satellite, planet or sun exerts an attractive influence upon every\nbody that exists, that attractive influence being regulated by the\nmasses of the respective bodies, and decreasing inversely as the square\nof the distance from the body viewed as the centre of attraction. So\nthat, the further the attracted body is from the attracting body, the\nless is the intensity of the mutual attracting forces, though that\nintensity does not vary simply as the distance, but rather as the square\nof the distance, and that in its inverse ratio. Thus if we take two\nmasses of any kind or sort, and place them at various distances as\nrepresented by the numbers 1, 2, 3, 4, 5, 6, the intensity of the\nattracting forces between the same masses at the relative distances will\nbe represented by the numbers 1, 1/4, 1/9, 1/16, 1/25, 1/36, which are\nthe inverse squares of the respective numbers representing their\ndistances. As we shall see, the same law holds good in relation to heat,\nlight and electricity, and indeed to all forms of energy which radiate\nout from a centre equally in all directions.\n\nThere is no need to apply Newton's Rules of Philosophy to this\nAttraction of Gravitation, as it has been demonstrated to exist, times\nwithout number. Moreover its laws are exactly the same as those\ngoverning the phenomena of sound, light, heat, and electricity, so that\napart from being proved by actual experiments in relation to the gravity\nof the earth, we have a wider experience of the application of the same\nruling principles of the law in other departments of science.\n\nThe Law of Universal Attraction, which is strictly the Centripetal Force\nof the compound Law of Gravitation, fully satisfies the three governing\nrules of Newton's Philosophy. Not only is it simple in its conception,\nbut it is borne out by experience, and adequately accounts for the\ndistinctive phenomena which it seeks to explain. By it, astronomical\nobservations can be taken with a precision and certainty that defy error\nor failure. The motion of a planet in its orbit can be so perfectly\ncalculated, that its position in space in relation to other planets can\nbe foretold years in advance. The theory of the Aether, therefore, which\nis to be perfected in this work, must philosophically show that the\npressures or tensions of that medium, which are postulated as the cause\nof Gravitation Attraction, must themselves fulfil the laws of inverse\nsquares, which govern light, heat, electricity and the Attraction of\nGravitation. I premise that this will be done in the theory of the\nAether to be submitted to the reader in the after pages of this work.\n\n\nART. 23. _Terrestrial Gravity._--Before passing from this phase of the\nsubject, I should like briefly to look at the question of the Attraction\nof Gravitation from the standpoint of our own earth, as by so doing we\nshall notice some facts regarding the same, hitherto unnoticed, in the\npreceding articles.\n\nTerrestrial Gravity is but a phase of Universal Gravitation. One of the\nmost familiar facts and phenomena of everyday life is, that when a body,\nsuch as a stone or stick or bullet, is thrown or projected into the air,\nit always falls to the earth again. This is due to the attraction of the\nearth and the stone for each other. It has been proved experimentally\nthat if a stone and a weight are let fall from a height of 16 feet, they\nwould reach the earth in one second of time. Again, a feather, or cork,\nor even a piece of iron would take exactly the same time falling through\nthe same space, provided that the feather or cork could be screened from\nthe resistance of the air.\n\nThe distance, however, through which a body falls in one second varies\nat different parts of the earth's surface, being least at the equator,\nand greatest at the North and South Poles. This is accounted for by the\nfact that the polar diameter is only 7899 miles, while the equatorial\ndiameter is 7925 miles, thus the distance from the centre of the earth\nto either pole is about 3950 miles, or 13 miles less than the equatorial\nradius of the earth. Now the force of gravity decreases upwards from the\nearth's surface inversely as the square of the distance from the earth's\ncentre of gravity, but decreases downwards simply as the distance from\nthe centre decreases. Thus if a ball were taken down 2000 miles, that is\nhalf the distance to the centre, it would only weigh half-a-pound, while\nif it were taken to the centre of the earth, it would have no weight at\nall; while a pound weight at the equator would not weigh one pound at\nthe poles, because it would be nearer the centre of the earth by 13\nmiles.\n\nThus a pound weight is not always a pound weight. It varies as we carry\nit to different parts of the earth's surface, depending upon its\nrelation to the centre of the earth for its exact weight. The point\nwhich I wish to make perfectly clear, as it will be necessary for future\nreference, is, that there is no such thing as weight apart from the\ngravity of the earth; or, if we apply the principle to the solar system,\nthere is no gravitating force in that system apart from the gravitating\nforce of the central body, the sun, or the planets and other bodies\nwhich form the solar system.\n\nLet us look at this matter from another standpoint, in order to prove\nthis truth and make the same perfectly clear. If a pound weight were put\nin a spring-balance, then at the surface of the earth it would weigh one\npound. Now, we will suppose that we have taken the weight to a height of\n4000 miles above the surface of the earth, that is exactly double the\ndistance from the centre of the earth, the radius of the earth being\napproximately 4000 miles. According to the law of inverse squares, the\nforce of Gravitation decreases inversely as the square of the distance.\nThe distance having been doubled, the proportion of the forces at the\ntwo places, _i. e._ the earth's surface and 4000 miles above it, are as\n1 to 1/4.\n\nThus at a distance of 4000 miles the weight which weighed one pound at\nthe earth's surface, now only weighs a quarter of a pound. At a distance\nof 8000 miles, the distance would be trebled, therefore the force of\nGravitation is one-ninth, and the weight would weigh one-ninth of a\npound. If we could take the pound weight to the moon, the attractive\nforce of the earth would be reduced to 1-3600, as the moon is 240,000\nmiles distant, that is sixty times the earth's radius. The square of 60\nis 3600, and if we invert that we get 1-3600, so that the weight which\nweighs a pound at the earth's surface, would only weigh 1-3600 part of a\npound at the distance of the moon. This again proves, that apart from\nthe Attraction of Gravitation, there is no such thing as weight, and\nthat the weight so called of any body, such as a planet or satellite,\nincreases or decreases as its distance increases or decreases from its\ncentral attracting body.\n\n\nART. 24. _Centrifugal Force._--I have already shown in Art. 10 that\nthe Centripetal Force and Universal Attraction are one and the same; as\nthe Centripetal Force always acts towards the centre, and must therefore\nbe in its operation and influence a gravitating or attractive power.\n\nI have also pointed out in the same article, the necessity of another\nforce, which is to be the complement, and the counter part of\nGravitation Attraction. That complement and counter force was conceived\nby Newton, and called by him the Centrifugal Force. The very nature of\nthe Centripetal Force demands and necessitates a force which in its mode\nof operation is exactly the opposite of the Centripetal Force. Unless\nthere were such a force, a repellent and repulsive force, then instead\nof there being that harmonious working of the universe that now exists,\nthere must inevitably be a gradual drawing together of all planets and\nsatellites, of all stars and suns, into one vast, solitary, and ruinous\nbody.\n\nThere are also other phenomena which demand a Centrifugal Force in the\nuniverse. It is a well-known fact, that there exist between the orbits\nof Jupiter and Mars, what are called planetoids, about 500 in number,\nwhich are supposed to be the remnants of a broken or shattered world. As\nmay be expected from such an accumulation, they present the most\nextraordinary diversities and eccentricities in the orbits that can\npossibly be conceived. They are of all shapes and sizes, and besides\ntheir orbits round the sun, have orbits among themselves. They are so\nclustered together that their orbits intersect each other at numerous\npoints, and when in conjunction are said to suffer great perturbations,\nbeing pulled great distances this way and that by each other's\nattractive influence. It is further stated that their orbits so\nintersect each other, that if they were imagined to be material rings,\nthey would be inseparable, and the whole could be suspended by taking\nany one of them up at random. Here, then, is presented to us a kind or\norder of celestial phenomena for whose well-being and effectual working\nthe Centripetal Force or the Attraction of Gravitation cannot possibly\naccount. In their case another force is demanded which shall be the\nexact complement and counterpart of the Centripetal Force. There needs\ntherefore a force, not an imagined one, simply conceived to fill a want,\nbut a real Force, as real and as plainly to be understood as the\nCentripetal Force. A force existing in each world just like the\nAttraction of Gravitation, only the reverse of Gravitation, a repellent,\nrepulsive Force, acting in the reverse mode, and way, to universal\nattraction. This Force must be governed by the same rules and laws that\ngovern the Centripetal Force, if it is to work in harmony with the same.\nIt must be universal in its character, having a proportion of forces\nequal to the product of the masses of the two bodies which are\nconcerned, and its path must coincide with the path of gravitational\nattraction, that is, in the straight line which joins the centres of\ngravity of the two bodies. Further, and what is perhaps the most\nimportant of all, it must act as a repelling or repulsive force which\nshall be in the same proportion in regard to distance, as the law\ngoverning Centripetal Force, that is, inversely as the square of the\ndistance.\n\nAgain, and briefly, there are also in existence small bodies called\nmeteors, which are said to exist by myriads, which float in space, and\ncircle round the sun. They are of all shapes and sizes, from one ounce\nto a ton or even tons, thousands of them coming into contact with our\nearth's atmosphere every year, especially in August and November. All of\nthese small bodies have orbits among themselves, and gravitate round one\nanother, as they revolve round the sun. Now if the orbits of the\nplanetoids be such an entangled mass, what must be the orbits of these\nmeteors? What an indescribable, unimaginable mass of labyrinthian\nmotions must exist among these myriads of little bodies! How they must\nintersect, cross and intermingle each other's orbits! What attraction\nand counter-attraction they must exert upon each other! Let me ask any\nman to sit down and try to imagine how the present recognized\nCentripetal and Centrifugal Forces can account for the effectual working\nof these meteors. As illustrating the necessity of a real and physical\nCentrifugal Force which is to be the exact counterpart of the\nCentripetal Force, I would call the attention of the reader to\nHerschel's view of this matter. In dealing with the phenomena of comets'\ntails he writes:[1] \"Beyond a doubt, the widest and most interesting\nprospect of future discovery, which this study holds out to us, is, that\ndistinction between gravitating and levitating matter, that positive and\nirrefutable demonstration in nature of a repulsive force, co-extensive\nwith, but enormously more powerful than the attractive force we call\ngravity which the phenomena of their tails afford.\" I premise that this\nprophecy of Herschel's will be fully demonstrated and proved in the\nsucceeding pages of this work. For, in the theory of the Aether that is\nto be afterwards perfected, it will be philosophically proved that the\nphysical medium so conceived will satisfactorily account for a force or\nmotion from the centre of all bodies; which motions fulfil all the\nconditions required by that Centrifugal Force, which is the complement\nand counterpart of the Attraction of Gravitation. At the present time,\nwith the conception of a frictionless Aether, it is impossible to\nharmonize the existence of such a force or motion with our theory of the\nAether. Yet Professor Lebedew of Moscow, and Nichols and Hull of\nAmerica, have incontrovertibly demonstrated by actual experiments the\nexistence of such a force. Therefore it follows, that if our present\ntheory of the Aether fails to agree with experimental evidence, such a\ntheory must be reconstructed in order that our philosophy may be made to\nagree with our experiments and our experience.\n\n[Footnote 1: _Lectures on Scientific Subjects._]\n\n\nART. 25. _Kepler's Laws._--A long time before Newton had discovered the\nLaw of Gravitation, Kepler had found out that the motions of the planets\nwere governed by certain laws, and these came to be known as Kepler's\nLaws.\n\nThese laws which were given to the world by Kepler, simply represented\nfacts or phenomena which had been discovered by observation, as Kepler\nwas unable to account for them, or to give any mathematical basis for\nthe same.\n\nOn the discovery, however, of Universal Gravitation, Newton saw at once\nthat these laws were simply the outcome of the application of the Law of\nGravitation to the planets, and that they could be accounted for on a\nmathematical basis by the Law of Gravitation, as they seemed to flow\nnaturally from that law.\n\nKepler's Laws are three in number and may be thus stated--\n\n_1st Law._ Each planet revolves round the sun in an elliptic orbit, with\nthe sun occupying one of the Foci.\n\n_2nd Law._ In the revolution of a planet round the sun, the Radius Vector\ndescribes equal areas in equal times.\n\n_3rd Law._ The squares of the periodic times of planets are proportional\nto the cubes of their mean distances.\n\nNow the question arises, whether it is possible to form a theory of the\nAether which shall satisfactorily and philosophically account for all\nthe phenomena associated with Kepler's Laws in their relation to the\nmotions of planets, satellites, or other solar bodies? On the present\nconception of the Aether such a result is an absolute impossibility.\nWith the theory of the Aether, however, to be submitted to the reader in\nthis work, the result is possible and attainable. If, therefore, such a\nresult is philosophically proved, as I submit will be done, then we\nshall have greater evidence still that the theory so propounded is a\nmore perfect theory than the one at present recognized by scientists\ngenerally.\n\n\nART. 26. _Kepler's First Law._--Each planet revolves round the sun in an\nelliptic orbit, the sun occupying one of the Foci.\n\nThe ancients thought that the paths of the planets around the sun were\ncircular in form, because they held that circular motion was perfect. A\nsystem of circular orbits for the paths of the planets round the sun\nwould be very simple in its conception, and would be full of beauty and\nharmony. But exact calculations reveal to us that the path of a planet\nis not exactly that of a circle, as the distance of a planet from the\nsun in various parts of its orbit is sometimes greater, and sometimes\nless, than its mean distance.\n\nThe planet Venus has the nearest approach to a circular orbit, as there\nare only 500,000 miles between the mean, and greatest and least\ndistances, but both Mercury and Mars show great differences between\ntheir greatest and least distances from the sun.\n\nIf, therefore, the orbits of a planet are not exactly circular, what is\ntheir exact shape? Kepler solved this problem, and proved that the exact\npath of a planet round its central body the sun was that of an ellipse,\nor an elongated circle. Thus he gave to the world the first of his\nfamous laws which stated that each planet revolves round the sun in an\norbit which has an elliptic form, the sun occupying one of the Foci.\n\nNot only is the orbit of a planet round the sun elliptic in form, but\nthe path of the moon round the earth, or the path of any satellite, as\nfor example a satellite of Mars or Jupiter or Saturn, is also that of an\nellipse, the planet round which it revolves occupying one of the Foci.\n\nIt has also been found that certain comets have orbits which cannot be\ndistinguished from that of an elongated ellipse, the sun occupying one\nof the Foci.\n\nNow let us apply the Law of Gravitation to Kepler's First Law, and note\ncarefully its application.\n\n[Illustration: Fig: 1.]\n\nLet _A_, _B_, _C_, _D_ be an ellipse representing the orbit of the earth,\nand let _S_ represent the sun situated at one of the Foci.\n\nWe will suppose that the earth is projected into space at the point _A_,\nthen according to the First Law of Motion, it would proceed in a\nstraight line in the direction of _A_ _E_, if there were no other force\nacting upon the earth. But it is acted upon by the attraction of the\nsun, that is the Centripetal Force which is exerted along the straight\nline _S_ _A_ (Art. 20), which continues to act upon it according to the\nprinciple already explained in Arts. 21 and 22.\n\nNow, according to the Second Law of Motion and the Parallelogram of\nForces, instead of the earth going off at a tangent in the direction of\n_A_ _E_, it will take a mean path in the direction of _A_ _B_, its path\nbeing curved instead of being a straight line.\n\nIf the sun were stationary in space, then the mean distance, that is,\nthe length of the imaginary straight line joining the sun _S_ _A_ to the\nearth, would remain unaltered. The Radius Vector _S_ _A_, or the\nstraight line referred to, would then be perpendicular to the tangent,\nand the velocity of the earth round the sun would be uniform, its path\nbeing that of a circle.\n\nThe Radius Vector _S_ _A_, however, is not always perpendicular to the\ntangent _F_ _E_, and therefore the velocity of the earth is not always\nuniform in its motion in its orbit, as sometimes it travels at a lesser\nor greater speed than its average speed, which is about 18 miles per\nsecond.\n\nIt has to be remembered that the sun itself is in motion, having a\nvelocity through space of about 4-1/2 miles per second, so that, while\nthe earth is travelling from _A_ to _B_ the sun is also travelling in\nthe direction of _S_ _B_. Thus the orbital velocity of the earth, and the\norbital velocity of the sun, together with the Centripetal Force or\nuniversal Gravitation Attraction, are all acting in the same direction\nwhen the earth is travelling from _A_ to _B_, that is, in the direction\nof the orbit situated at _B_. This point of the orbit is known as the\nperihelion, and at that point the velocity of the earth is at its\ngreatest, because the earth is then nearest the sun.\n\nAccording to Newton, the planet when at _B_ would still have a tendency\nto fly off into space owing to its Centrifugal Force, but it is held in\ncheck by the Centripetal Force, so that instead of it flying off into\nspace, it is whirled round and starts off on its journey away from the\nsun in the direction of _B_, _C_. The sun, however, is still continuing\nits journey in the direction of _S_, _H_, so that not only is the\nincreased orbital velocity of the earth, which it obtained at its\nperihelion, urging the earth away from the sun, but the sun itself in\nits advance through space is leaving the earth behind it. The combined\neffect of the two motions, the advancing motion of the sun, and the\nreceding motion of the earth, due to its increased orbital velocity,\ndrives the earth towards the aphelion, where its distance from the sun\nis greatest, and its orbital velocity is the least.\n\nBy the time the planet has arrived at point _C_, its motion through\nspace has gradually decreased, and the Centripetal Force begins to\nre-assert itself, with the result that the earth is slowly made to\nproceed towards the point _D_ of the ellipse, at which point its motion\nis the slowest in orbital velocity, only travelling about 16 miles per\nsecond, while the distance of the earth from the sun is the greatest and\nhas increased from 91,000,000 miles at the perihelion to 94,500,000.\nThis point of the orbit is known as its aphelion.\n\nAfter rounding this point, the orbital velocity of the earth begins to\nincrease again, owing to the diminishing distance of the earth from the\nsun, which according to the law of inverse squares (Art. 22) gives an\nadded intensity to the Centripetal Force.\n\nThus by the combination of the Laws of Motion and the Law of Gravitation\ndiscovered by Newton, he was able to satisfactorily account for and\nexplain on a mathematical basis, the reason why the earth and all the\nother planets move round the sun in elliptic orbits, according to\nKepler's First Law.\n\nIn the development of the physical cause of gravitation, therefore, the\nsame physical medium, which accounts for that law, must also give a\nsatisfactory explanation of the first of Kepler's Laws.\n\n\nART. 27. _Kepler's Second Law._--This law states that the Radius Vector\ndescribes equal areas in equal times. The Radius Vector is the imaginary\nstraight line joining the centres of the sun and the earth or planet.\nWhile the First Law shows us the kind of path which a planet takes in\nrevolving round the sun, the Second Law describes how the velocity of\nthe planet varies in different parts of its orbit.\n\nIf the earth's orbit were a circle, it can be readily seen that equal\nareas would be traversed in equal times, as the distance from the sun\nwould always be the same, so that the Radius Vector being of uniform\nlength, the rate of motion would be uniform, and consequently equal\nareas would be traversed in equal times. Take as an illustration the\nearth, which describes its revolution round the sun in 365-1/4 days. Now\nif the orbit of the earth were circular, then equal parts of the earth's\norbit would be traversed by the Radius Vector in equal times. So that\nwith a perfectly circular orbit, one half of the orbit would be\ntraversed by the Radius Vector in half a year, one quarter in one\nquarter of a year, one-eighth in one-eighth of a year, and so on; the\narea covered by the Radius Vector being always exactly proportionate to\nthe time.\n\nFrom Kepler's First Law, however, we know that the planet's distance\ndoes vary from the sun, and therefore the Radius Vector is sometimes\nlonger and sometimes shorter than when the earth is at its mean\ndistance; the Radius Vector being shortest at the perihelion of the\norbit, and longest at the aphelion. We learn from Kepler's Second Law\nthat when the Radius Vector is shortest, that is, when the planet is\nnearest the sun, it acquires its greatest orbital velocity; and when the\nRadius Vector is longest, that is, when the planet is farthest from the\nsun, the orbital velocity of a planet is the slowest.\n\nLet _A_, _B_, _D_, _C_ represent the elliptic orbit of a planet, with\n_S_ sun at one of the Foci, and let the triangles _A_, _S_, _B_ and _D_,\n_S_, _C_ be triangles of equal area. Then, according to Kepler's Second\nLaw, the time taken for the Radius Vector to traverse the area _A_, _S_,\n_B_ is equal to the time that the Radius Vector takes to traverse the\narea _D_, _S_, _C_. So that the planet would take an equal time in going\nfrom _A_ to _B_ of its orbit, as it would take in going from _D_ to _C_.\nThus the nearer the planet is to the sun, the greater is its orbital\nvelocity, and the farther it is away from the sun the slower is its\nvelocity, the velocity being regulated by the distance. The manner in\nwhich the difference of velocity is accounted for by the Law of\nGravitation has already been explained in the preceding article. Thus\nNewton proved that Kepler's Second Law was capable of being\nmathematically explained, and accounted for, by the universal Law of\nGravitation.\n\n[Illustration: Fig: 2.]\n\nIf, therefore, a physical cause can be given for Newton's Law of\nGravitation, then such physical cause must also be able to account for,\nand that on a strictly philosophical basis, the second of Kepler's Laws\nas well as the first.\n\n\nART. 28. _Kepler's Third Law._--The Third Law of Kepler gives the\nrelation between the periodic time of a planet, and its distance from\nthe sun. The periodic time of any planet is the time which it takes to\ngo once round the sun. Thus the periodic time of the earth is 365-1/4\ndays. The periodic time of Venus is 224.7 days, while that of Mars is\n686.9 days.\n\nKepler had found out that different planets had different periodic\ntimes; he also found out that the greater the mean distance of the\nplanet, the greater was the time which the planet took to perform its\njourney round the sun, and so he set to work to find out the\nrelationship of the periodic time to the planet's mean distance.\n\nAfter many trials and many failures he arrived at the right conclusion,\nand at last discovered the true law which is known as Kepler's Third\nLaw, which states that for each and every planet, the squares of their\nperiodic times are proportional to the cubes of their mean distances.\n\nFor purposes of illustration let us take the earth and the planet Venus\nand compare these two. The periodic time of the earth is 365 days,\nomitting the quarter day. The periodic time of Venus is 224 days\napproximately. Now, according to Kepler's Third Law, the square of 365\nis to the square of 224, as the cube of the earth's mean distance is to\nthe cube of Venus's mean distance, which are 92.7 millions of miles and\n67 millions of miles respectively. The problem may be thus stated--\n\nAs 365^2: 224^2:: 92.7^3: 67^3:\n\nThis worked out gives--\n\n133,225: 50,176: 796,597.982: cube of Venus's mean distance.\n\nSo that by Kepler's Third Law, if we have the periodic time of any two\nplanets, and the mean distance of either, we can find out the mean\ndistance of the other by simple proportion.\n\nIn making astronomical calculations, the distances of the planets are\ngenerally obtained by means of Kepler's Third Law, as the periodic time\nof the planet is a calculation that may be made by astronomers with\ngreat certainty, and when once the periodic times are found, and the\nmean distance of a planet, as our earth for example, is known, the mean\ndistances of all the other planets in the solar system may soon be\nobtained.\n\nIn like manner this Third Law of Kepler's is equally applicable to the\nsatellites of any planet. For example, when the periodic time of both of\nMars' satellites, Phobos and Deimos, are known, being about 8 hours and\n30 hours respectively, and the distance of either is known, as Phobos\nwith a mean distance of 5800 miles, then the mean distance of Deimos can\neasily be calculated by this law, and is found to be 14,500 miles.\n\nAs discovered by Kepler, the Third Law was simply the result of\nobservation. He was unable to give any mathematical basis for its\nexistence. The Laws as they were given to the world by Kepler were\nsimply three great truths which had been discovered by observation. It\nrested with Newton to show how these laws could be accounted for on a\nmathematical basis, and to show how they all sprang from one and the\nsame source, namely the universal Law of Gravitation. In his\n_Principia_, he proved that all Kepler's Laws were fully expounded and\nexplained by his great discovery of Universal Gravitation.\n\nNow what Newton has done for Kepler's Laws from the mathematical\nstandpoint, we propose to do from the physical standpoint. In the\ndevelopment of the physical agency or cause of Gravitation, therefore,\namong the phenomena and laws, which have to be satisfactorily accounted\nfor on a physical basis, are these three Laws of Kepler's just referred\nto.\n\nSo that in addition to the satisfactory explanation of a physical cause\nfor the Laws of Motion, and the Centripetal and Centrifugal Forces, the\nhypothesis of a physical cause of Gravitation must fully and\nsatisfactorily account for the Laws of Kepler, whose mathematical\nexplanation was given by Newton.\n\nFurther, and what is as equally important, the explanation so given must\nbe strictly in harmony with the Rules of Philosophy as laid down in Art.\n3. That is, the explanation must be simple in character, must not be\ncontrary to experience or observation, and must satisfactorily account\nfor the laws which the hypothesis of the physical cause of Gravitation\nseeks to explain. This I premise we will do as we pass from stage to\nstage in the development of the theory.\n\nI can safely premise that it will be simple in character and conception,\nthat it will be entirely in harmony with all experience and observation,\nand that the physical cause so advanced will give as physical a basis to\nKepler's Laws as Newton's mathematical calculations gave them a\nmathematical basis.\n\nIn summing up, I need hardly point out, that if all that I have premised\nin this and the preceding chapter is accomplished in the after chapters\nof this book, then for the first time since the discovery of Universal\nGravitation by Sir Isaac Newton, his great discovery will have received\nthe long-expected and long-desired physical explanation, that\nexplanation and cause being founded on his own Rules of Philosophy given\nin his immortal _Principia_, and for the first time our Philosophy will\nbe brought strictly into harmony with our universal experience.\n\n\n\n\n                              CHAPTER III\n\n                                MATTER\n\n\nART. 29. _What is Matter?_--The law of Universal Attraction states that\n\"Every particle of matter attracts every other particle,\" etc., and the\nquestion at once arises as to what is meant by the term Matter, what are\nits properties and its constitution? Tait, in his _Natural Philosophy_,\ngives the following as the definition: \"Matter is that which can be\nperceived by the senses, or is that which can be acted upon by, or can\nexert force.\"\n\nIt has already been pointed out in Art. 13 that force is due to motion,\nand that wherever we get motion of any kind or sort, there we get\nenergy, or what used to be termed force. The consideration of this phase\nof the question will be more fully dealt with in the chapter on Energy\nand Motion. Suffice to say, that all experience teaches us that force is\nthe outcome of motion.\n\nAccepting this definition therefore of force, Tait's definition of\nmatter will read thus, if brought up to date: \"Matter is that which can\nbe perceived by the senses, or is that which can be acted upon by\nmotion, or which can exert motion.\"\n\nThe common idea that matter can only be that which can be seen or\nactually felt, is not large enough for a definition of Matter. There are\nnumbers of things in Nature which cannot either be seen or felt, yet\nwhich are included in the term Matter. Let us take one or two examples.\nEvery one admits that nitrogen and oxygen are matter, yet I venture to\nsay that no one has actually seen or felt either of these gases. Both of\nthese gases are colourless and invisible, and are both tasteless. You\nmay open your mouth and inspire both gases, and yet if they are pure,\nyou cannot taste either of them. They are only matter, in the sense that\nthey appeal to our sense of force through the motion which they may\nacquire.\n\nOr again, take air, which is a mechanical mixture of several gases. Can\nyou see air? If it be free from vapour and smoke, air is invisible, and\non a clear day you may look for miles across the sea, or from the top of\na mountain, and yet not have your sight impeded in any way by the\natmosphere. Neither can it be felt by the sense of touch. Open and shut\nyour hand, and see if you can feel the air while you do so. In similar\nways it may be demonstrated that the air is tasteless. So that it is not\nnecessary for us to see, or feel, or taste, or even smell that which we\nterm Matter, in order for it to be included in that term. So long as\nthat which we term Matter is able to accept motion in any manner from\nany body that is either moving, or in a state of vibration, and not only\naccepts, but also transmits the vibratory, or the kinetic motion so\ncalled of the moving body, then that which accepts the motion is\nlegitimately termed Matter.\n\nIt becomes perfectly clear, therefore, why air, aether, oxygen, and\nhydrogen are termed Matter. Because they can be all acted upon by\nmotion, and after being so acted upon, they can exert motion upon some\nother body. Heat is a form of motion, and when heat acts upon the air,\nthe latter is set in motion, and we have what are commonly known as\nwinds. It is unnecessary for me to prove that the motion of winds can be\ntransmitted to other matter, as we have numerous examples from our\nobservation and experience, in the case of windmills driven by the\nmotive power of the winds, and also balloons urged along by the same\ncause; apart from the devastating effect produced in towns and country\nby a hurricane or storm.\n\nThe point which I wish to emphasize is, that Matter, strictly defined,\nis that which can be acted upon by motion, such as heat or electricity,\nboth being forms of motion, and which can exert the motion so derived\nupon some other body.\n\nWherever, therefore, in the universe we find any body, whether it be\nsolid, liquid or gaseous, or any medium which can be acted upon by\nmotion, and after being so acted upon, can exert motion, that body or\nmedium may legitimately be included in the term Matter, although it may\nbe absolutely invisible to the eyes, or insensible to the sense of\ntouch, or taste, or smell. In the same work,[2] Tait states that in the\nphysical universe there are but two classes of things, \"Matter and\nEnergy,\" and then goes on to give examples of both. He adds that a\nstone, piece of brass, water, air, _aether_, are particles of matter,\nwhile springs, water-power, wind, waves, heat and electric currents are\nexamples of energy associated with Matter.\n\nNow I may add here, that within these two statements is to be found the\ngerm of the physical cause of Gravitation, together with the\nsatisfactory explanation of all phenomena that the universe reveals to\nus, either by observation or by experiments. I purpose therefore, before\ngiving any detailed accounts of that medium which is to form the\nphysical basis for the cause of Gravitation, to look at the term Matter\nin all its aspects, in order that we may get a right conception of the\nuniverse, and of the part that Matter plays in the same.\n\n[Footnote 2: Tait, _Natural Philosophy_.]\n\n\nART. 30. _Conservation of Matter._--The Theory of the Indestructibility\nof Matter was first introduced by Lavoisier in 1789. This theory may be\nthus summed up; that Matter which fills the universe is unchangeable in\nquantity, so that the total quantity ever remains the same. Changes may\ntake place in regard to the state of the Matter, but the sum-total of\nMatter throughout all the changes remains unaltered. Thus when we burn\ncoal, it is changed into carbonic acid by combination with the oxygen of\nthe atmosphere; when sugar is put into water, it simply passes from the\nsolid to the liquid condition. If a piece of iron or steel is allowed to\nrust, the surface of the iron has entered into combination with the\noxygen and water of the atmosphere, and formed a new substance. So that\na body may change from solid to liquid, as for example from ice to\nwater, or from liquid to a gaseous condition, as from water to steam,\nand probably from a gaseous condition to an aetherial condition as we\nshall see later on, but the sum-total of Matter throughout all these\nchanges ever remains the same. Thus, throughout all the physical and\nchemical changes that Matter may undergo in the universe, there is no\nactual loss in weight or quantity. Throughout the whole realm of Nature\nwe do not find a single instance of the production of absolutely new\nMatter. We may, and can produce new combinations of the forms of Matter.\nThe substance so formed by chemical combination may be different from\nanything that has ever been seen or produced before, but the elements of\nwhich it is formed must have existed in some other form before its\nproduction.\n\nThis principle is the great underlying principle of all chemical\ninvestigation and research, and may be proved at any time by means of\nthe scales or balance in the laboratory. Lavoisier first made the\nexperiment with the scales and proved this truth by actual\ndemonstration.\n\n\nART. 31. _Matter is Atomic._--The hypothesis that Matter is made up of\ninfinitely small particles which are termed atoms, was first proposed by\nthe Grecian philosophers. This hypothesis has gradually taken definite\nshape, but it remained for Dalton to first put the hypothesis into a\nconnected form, and that form is now known as Dalton's Atomic Theory.\n\nAccording to this theory, an atom of hydrogen was the lightest atom\nknown, but comparatively recent researches by Sir W. Crookes have shown\nthat there are possibly in existence minute particles which are even\nlighter than an atom of hydrogen. Thus Sir W. Crookes has suggested that\nthere are certain particles associated with an atom of hydrogen which\nare 700 times less in weight than the atom itself.\n\nProfessor J. J. Thompson has further suggested that if we could divide\nan atom into a thousand parts, and could take one of those parts, we\nshould find that this corpuscle, as he has termed it, would be the\ncarrier of the charges in an electric current, so that it will be seen\nthat we are moving into the direction of the continuity of Matter. Let\nus now look at the question as to what is meant by an atom more fully.\n\n\nART. 32. _What is an Atom?_--Clerk Maxwell's definition of an atom is,\n\"a body that cannot be cut in two.\" An atom is the smallest part of a\nsimple substance which can enter into combination with another element,\nand is incapable of being further subdivided.\n\nAn atom of hydrogen is the smallest part of that particular gas which\ncan enter into combination with any other element, as oxygen, to form a\nchemical compound as water, which is composed of two atoms of hydrogen\nand one of oxygen.\n\nFurther, an atom of any kind or sort, retains its identity and remains\nthe same throughout all chemical combinations or physical changes which\nit may undergo. By spectroscopic analysis, it has been ascertained, for\nexample, that hydrogen exists in the sun and stars, and the conclusion\nis arrived at in connection therewith, that an atom of hydrogen in any\nsun or star is the same as an atom of hydrogen in our atmosphere, or in\nany of the compounds, as water, in which it is found. Thus it has come\nto be received as an accepted fact, that every atom of any substance, as\noxygen, nitrogen, and hydrogen, whether they exist in the earth or sun,\nin meteorites or the farthest stars or nebulae, wherever they are found,\npossesses the same identity and the same physical properties.\n\nAtoms attract one another, and this atomic attraction is known as\naffinity. There is not the least possible doubt that affinity is a form\nof universal attraction, except that the affinity of atoms is selective.\nThis affinity of atoms for each other gives rise to the combination of\natoms known as molecules and chemical compounds.\n\n_Size of Atoms._--It has been computed by Lord Kelvin and others, that\nan atom may be as small as 1/50,000,000 of an inch in diameter, so that\nif 50,000,000 of them were put side by side, they would just measure one\ninch in length. Atoms are not all of the same size or weight. An atom of\noxygen weighs 16 times as much as an atom of hydrogen. It has been\nproved by Kirchhoff and Bunsen, that the 3/1,000,000 part of a\nmilligramme of sodium chloride is sufficient to give a yellow colour to\na gas-jet. Faraday prepared some sheets of gold, so thin that he\nestimated they only measured the 1/100 part of the length of a\nlight-wave. We have to remember that each sheet of gold must have\ncontained molecules of gold composed of atoms. What must have been the\nsize of the atoms therefore of which the sheet was composed?\n\n\nART. 33. _The Atomic Theory._--The Atomic Theory was revived by Dalton\nin 1804, in order to account for the fact that elements unite in certain\ndefinite proportions. From that time to the present, the theory has\ngrown and developed until at the present time it is looked upon as a\nwell-established theory. It is, however, simply a theory, and from the\nvery nature of the hypothesis is incapable of proof. No one has ever\nseen an atom of hydrogen or oxygen, or an atom of any solid, liquid, or\ngaseous matter. The Atomic Theory suggests, therefore, that there is a\nlimit to the divisibility of matter. All chemical experiments lend\nsupport to the theory, and by it we are able to give an intelligible and\neasy method of expression to what would otherwise be difficult phenomena\nto explain.\n\nAncient philosophers were divided on the question of the infinite\ndivisibility of matter. The Epicureans were of the opinion that matter\nwas incapable of infinite division, and that even if we were able to\nmake the smallest possible division, it would be impossible for us to\nreach the smallest particle termed \"Atom.\"\n\n\nART. 34. _Kinds of Atoms._--Various forms of atoms have been conceived\nby philosophers from time to time, ranging from the Hard Atom, and the\nsimple point-centres of Boscovitch, until we come to the more modern\nVortex Atom of Lord Kelvin, or the Strain Atom of Dr. Larmor, which will\nbe looked at separately. Democritus conceived a hard atom as long ago as\n500 B.C., while the notion of a hard atom is not absent from the works\nof Newton himself. We find that Newton suggested that the particles of\nair might be hard spherical bodies, at a distance from one another of\nabout nine times their diameter.\n\nThe hard atom, however, seems to be refuted by spectroscopic analysis,\nwhich reveals to us in a manner that has never been revealed before,\nsomething of the sizes and vibrations of atoms.\n\nFrom the phenomenon of heat, which is simply matter in motion, we feel\ncompelled to accept the fact that an atom is not a hard particle, but\nthat it is something which is more closely allied to the Vortex Atom, or\nthe Strain Atom of Dr. Larmor.\n\n_Boscovitch Atom._--According to Boscovitch's theory, each atom is\nsimply an indivisible point in space capable of motion, and possessing a\ncertain mass whereby a certain amount of energy is required to produce a\ncertain change of motion. In addition to this, any two atoms could\nattract or repel each other with a force depending upon their distance\napart. The Law which regulates these forces for all distances greater\nthan 1/1000 of an inch is an attraction varying inversely as the square\nof the distance, and a repulsion for less distances.\n\nWe have, therefore, to suppose that in place of the hard atom, there is\nmerely a geometrical point which can exert attractive or repulsive\nforces to, or from, the central point. So far as external particles are\nconcerned, they would behave just the same as a hard atom would do. This\nconception was largely entertained in recent times by Faraday. It is\nmore a mathematical explanation than a physical one, but has been found\nconvenient in explaining what takes place in the interior of bodies in\ntheir three states, namely: solid, liquid, and gaseous.\n\n_Lord Kelvin's Vortex Atom._--Another hypothesis which has been\nsuggested for the constitution of an atom, is that known as the Vortex\nAtom, which received its birth at the hands of Lord Kelvin. The\nunderlying principle of this Vortex Atom is, that matter may be entirely\ndue to the rotating parts of a fundamental medium, the Aether, which\nfills all space.\n\nThe properties of vortex motion were first mathematically calculated by\nHelmholtz, but it was left to Sir Wm. Thompson, now Lord Kelvin, to give\na physical idea of the Vortex Atom.\n\nBefore entering further into the question of the Vortex Atom, it may be\nas well to explain how vortex smoke rings may be made.\n\n[Illustration: Fig: 3.]\n\nAll that is required is a wooden box, about one cubic foot in size, with\na round hole perforated in one of the sides, and the opposite side\ncovered with a piece of linen in place of the wooden side. The bottom of\nthe box should then be covered with some strong solution of ammonia, and\nsome hydrochloric acid poured into a saucer and put into the box. The\ncombination of these two will cause thick clouds to form in the box, and\nif the linen is sharply tapped by the hand, a ring of this cloud will be\nforced through the hole on the opposite side of the box. The ring so\nformed will be circular in shape, and will go sailing through the room\nin which it is made.\n\nWhen the hole is circular, the rings will be found circular also, but if\nthe hole is square, then the rings will be irregular in shape. One\nremarkable characteristic about these rings is, that when two of the rings\nare travelling in the same straight line, the one behind will overtake the\nfront one, and while so doing, the diameter of the front one is enlarged,\nwhile that of the one behind contracts. The front one will also travel\nslower, while the one behind travels faster until it has caught up the\nformer, and then the latter, having contracted sufficiently, will pass\nthrough the diameter of the former as illustrated in the figure. This\nalternation of contraction and expansion is continued as long as the two\nrings move in the same plane and until they are destroyed. When, however,\nthe two rings are moving in opposite directions, and meeting each other in\nthe same straight line, they will repel one another, instead of attracting\neach other.\n\nTheir rate of progress is gradually reduced as they approach together,\nand they begin to expand and enlarge, but they never touch each other.\nAnother peculiar feature about the rings consists in the fact, that the\ncentral core of air in the ring remains the same all the time the ring\nis in motion through the room, so that it has the same core of air at\nthe end of its journey as it had when it left the box.\n\nAs Lord Kelvin pointed out, if there were no friction of the air, the\nring once created would rotate for ever. If, therefore, there were such\na thing as a perfect fluid, and there were vortex rings in it, nothing\ncould destroy these rings when once they were created, and this is one\nof the most striking suggestions with reference to the Vortex Atom\ntheory of matter. It remains to be seen whether in the universe we have\nsuch a medium as a perfect fluid.\n\nSir Wm. Thompson has applied the Vortex Atom theory of matter to the\nAether, but from mathematical calculation he was unable to arrive at a\nsatisfactory conclusion as to the Aether being composed of vortex atoms.\n\nAnother remarkable property belonging to these rings, lies in the fact\nthat they cannot be cut in two. It will be found that when the knife is\nbrought near to them, they seem to recoil from the knife. In that sense,\nit is literally an atom, a thing which cannot be cut in two.\n\nThe Vortex Atom has many recommendations in its favour. Many of the most\nimportant properties of matter are possessed by it, as for example\nindestructibility, elasticity, inertia, compressibility, and its\nincapability to be cut in two. Further, it may be linked with another\nring, and so give the basis to the combining properties of atomic\nweights.\n\nThe Vortex Atom theory is simple in character, as it does not postulate\nany extravagant hypothesis, but makes use of the Aether as the common\nbasis for all matter, simply stating that this property of rotation may\nbe the basis of all that we call matter. We shall further consider the\nrelation of the Vortex Atom to matter, when we deal with the\nconstitution of matter and the unity of the universe.\n\n\nART. 35. _Elements of Matter._--As is well known, modern chemistry has\nsucceeded in reducing all the complex forms of matter in Nature into a\nnumber of simple substances, which are called elements. Of these\nelements about seventy are at present known, some of which, however, are\nvery rare. An element therefore is a simple substance which cannot be\ndecomposed by any known force or process, as heat or electricity, into\nother elements.\n\nThere are, however, only about fourteen of these elements that enter\nlargely into the constitution of the earth, the most common being oxygen\nand silicon. By the use of the spectroscope, it has been proved that\nmany of these elements, as for example oxygen, hydrogen, sodium and\ncalcium, exist in the sun and stars, as well as in the most distant\nnebulae. Most of the elementary bodies are to be found in a gaseous form\nas hydrogen, oxygen, fluorine and chlorine, though it has been found\npossible to liquefy even these gases. Thus we see that matter may be\nroughly divided into three states, viz. solid, liquid, or gaseous.\n\nThe condition in which the substance is found depends upon its\ntemperature and pressure. An example of matter in its three stages is\nbest shown in the case of water, where in the solid condition we have it\nas ice, in the liquid condition as water, and in the gaseous condition\nas steam.\n\nBy recent researches it has been found possible to liquefy gases at a\nvery low temperature and increased pressure, with the result that now\nnearly all known gases as hydrogen, oxygen, and carbonic acid are to be\nobtained in liquid form. By still more recent experiments made by\nProfessor Dewar, it has even become possible to liquefy the air we\nbreathe, with the result that at a temperature of about 270 degrees\nbelow freezing-point and at an increased pressure, the otherwise\ninvisible and gaseous air may be changed into a liquid, and poured out\nfrom one vessel into another in the same way that water can be poured\nout. A vessel, however, at the ordinary temperature into which such\nliquid air is poured, would be so hot compared with the coldness of the\nliquid air, that as soon as the exceedingly cold liquid air came into\ncontact with the vessel, the comparatively hot vessel would make the\nliquid air to boil.\n\n\nART. 36. _Three Divisions of Matter._--Matter has been divided into\nthree divisions, viz. solid, liquid, and gaseous. These divisions are\neach known by characteristic qualities, which separate the one division\nfrom another. At the same time, it is possible for matter to pass from\none division into another, as for example in the case of water, which\nmay exist in solid, liquid, and gaseous form. In view of the recent\nresearches of Sir. Wm. Crookes and Professor J. J. Thompson, it is very\nprobable that before long we shall have to add a fourth division to\nmatter, which we should have to call ultra-gaseous form, or it may\npossibly be the aetherial form. If it should prove to be true that\nAether is matter, and possesses the essential qualities of matter as\nsuggested by Lord Kelvin, then certainly we shall have reached the\nboundary of another great division of matter, and our conception of the\ndivisions of matter will have to be enlarged to take in that form, so\nthat matter would then be divided into four great divisions, viz. solid,\nliquid, gaseous, and aetherial.\n\nWe will now consider the three groups as at present recognized.\n\n_Solid._--Examples of solid bodies are common and familiar, and are\ntypified by such things as iron, silver, copper, and lead. The chief\ncharacteristic of this condition of matter is that its condition or\nstate is fixed, and cannot be altered without the expenditure of heat or\nelectricity or some other form of energy.\n\nAll solid elementary substances, with the exception of carbon, can be\nmelted or reduced to a molten condition, although some of them require a\nvery high temperature to effect this reduction, as, for example,\nplatinum. When a still higher temperature is applied, the metals may be\nvaporized, or reduced from a molten state to that of a vaporous\ncondition. In the case of solids, the atoms have not a free path in\nwhich to move. It must not be thought, however, that the atoms of a\nsolid are motionless, as there is nothing absolutely motionless in the\nuniverse. In the case of the solid, the molecules which compose it,\npreserve their relative position and are linked together in relation to\neach other by the force of Cohesion.\n\n_Liquid._--When matter is in a liquid condition, as, for example, water\nand oil, the condition of its molecules are not so fixed and stable as\nthey are in the solid state. The molecules can move freely about one\nanother, and their freedom is increased compared with their condition\nwhen in the solid state.\n\nAs already indicated, the reduction of a solid body to a liquid or\nmolten state may be effected by heat. When heat is applied to a solid\nbody, several results follow, each of which is the outcome of the other.\n\n1. There is an increase of temperature which is due to the increased\nenergy of the molecules, through the added heat.\n\n2. There is an enlargement of the volume or size of the body, and if the\naddition of heat be continued, the molecular forces which hold the\nmolecules together are broken down, and then the molecules, loosened\nfrom those forces which in the solid state have bound them together,\nbegin to move about with greater freedom, and thus give rise to the\nmolten condition of metals, or liquid condition of water. Thus, it is\nthe heat which has set the atoms which compose the molecules in motion.\nThe atoms of the solid have absorbed the heat, and the heat which has\nthus been absorbed has imparted vibratory energy to the atoms, which\nthey did not possess before. Now when a substance is in the liquid\nstate, the atoms of that substance have not only a vibratory motion, but\nhave also a translatory motion, so that they can move in and out among\none another. This is proved by the phenomenon of diffusion, where we\nhave the case of two different-coloured liquids, for example,\nintermingling with each other, which is conclusive evidence of the\ntranslatory motion of the atoms in liquids.\n\n_Gaseous._--The third state in which matter is found is the gaseous\nstate. In this condition, the particles of matter which form the gas\nhave the greatest possible freedom of movement, and are able to move\nabout with inconceivable velocity. There is abundant evidence to prove\nthat gases consist of particles of matter which are perfectly free, and\nare able to fly about in all directions. The simplest proof is obtained\nby mixing two gases together, as, for example, when any gaseous\nsubstance is allowed to mix with the air of a room, when we find that\nthe particular gas soon mixes itself thoroughly with all the air in the\nroom. This process of mixing is known as Diffusion, and the lighter a\ngas is, the more quickly does it diffuse itself. The rate of movement of\nthe various particles is varied, by reason of the encounters which each\nparticle undergoes from time to time. Through experiments made by Joule,\nhe arrived at the conclusion that particles of hydrogen attained a\nvelocity of 6055 feet per second at 0 deg. C., which is a velocity much\ngreater than that of a cannon-ball. In spite of the enormous velocity\nwith which a particle of hydrogen would move, there are such a large\nnumber of particles in a single cubic inch of space, that no one\nparticle has an absolutely free path from the one side of the enclosed\nspace to the other. To this constant movement of the individual\nparticles is due the elasticity or pressure of gases. The outward\npressure which they exert on any body which encloses the gas is caused\nby the total effect of the impact of the particles, and is proportional\nto the sum of their masses multiplied into the square of their\nvelocities. If we halve the enclosed space, then we should double the\nnumber of impacts in a given time, so that the number of impacts is\ninversely as the volume of the gas. This is equivalent to the statement,\nthat the pressure of a gas varies inversely as its volume, which is\nBoyle and Marriotte's Law.\n\n\nART. 37. _Matter is Gravitative._--If there is one property which is\nessentially characteristic to all matter, it is that all matter is\ngravitative. To this rule there is no exception, as the universal Law of\nAttraction states that \"every particle of matter attracts every other\nparticle.\" Thus, wherever in the whole universe there is a particle of\nmatter of any kind or sort, whether such matter be solid, liquid, or\ngaseous, there the force of attraction will be exerted with a force\nproportionate to the mass of the particle, and inversely as the square\nof the distance between the attracted particles.\n\nGravitation, then, is a property which is essentially inherent in\nmatter, and any substance which is termed matter, or fulfils the\nconditions that govern matter, must be gravitative, whatever other\nproperty it may, or may not, possess. Unless this be so, we should have\na violation of the universal Law of Gravitation, which would cease at\nonce to be a universal law, for instead of reading \"every particle of\nmatter attracts every other particle,\" we should have to say that \"some\nparticles of matter attract some other particles,\" which would be a\nviolation of that universal law which, through the genius of Newton, has\ngiven to the universe an unity from the philosophical standpoint that it\ndid not possess before.\n\nSome matter may, or may not be elastic; it may, or may not be solid, or\nliquid, or gaseous; but there is this fact regarding matter which is\nabsolutely undeniable, and that is, \"All matter is gravitative.\"\n\nThat this is true of each and all kinds of matter has been proved by\ndirect experiment times without number, and the constant application of\nthe law to all forms of matter is a fact observable from the phenomena\nincidental to every-day life. Astronomical observation teaches us also,\nthat all stars, suns, planets, satellites, and comets are subject to\nthis great Law of Gravitation, as indeed they must be if they are\ncomposed of matter. That they are all composed of exactly similar\nelements of which the earth is composed, has been proved again and again\nby spectroscopic analysis, which teaches that hydrogen, iron, and\ncalcium, etc., are to be found in distant stars and nebulae, as they are\nequally to be found in the composition of the earth. Thus throughout the\nwide universe so far as observation and experiment can teach us, we\nlearn that without any exception, everything that is termed matter is\nsubject to this universal Law of Gravitation.\n\n\nART. 38. _Matter possesses Density._--Density is that property of matter\nwhich decides the weight of a body per unit of volume.\n\nThe density of any substance may be shown in several ways. It may\ndenote, first of all, the number of molecules in a given body. Let us\ntake as an illustration, the case of air being forced into a vessel of a\ngiven size, say one cubic foot capacity. We will suppose that in such a\nvessel there are 1,000,000 molecules. If we pump in a quantity of air\nequal to the amount it contained at first, then it is obvious that we\nhave doubled the number of molecules in the same vessel, and therefore\nwe say we have doubled the density. Not only so, but the weight of the\nair in the vessel will have been doubled. Looked at from this\nstandpoint, density means the number of molecules in unit volume such as\na cubic inch, or cubic centimetre.\n\nAgain, as has already been shown in Art. 35, the different elements have\ndifferent atomic weights. Thus an atom of carbon weighs twelve times as\nmuch as an atom of hydrogen, that is to say, there are twelve times as\nmuch matter by weight in an atom of carbon as there is in an atom of\nhydrogen, so that it would take twelve times as many hydrogen atoms to\nweigh a pound as compared with the number of atoms of carbon. This is\nonly another way of stating that carbon has twelve times the density of\nhydrogen. If we compare lead and silver with hydrogen in the same way,\nwe find that the density is 206 times and 107 times greater than that of\nhydrogen.\n\nThus, it may be seen, that all matter possesses density, and that that\ndensity depends partly upon its atomic constitution. If the molecule of\nmatter is composed of atoms whose atomic weights are very large compared\nwith that of hydrogen, as iron, silver, lead and gold, then the\nmolecules will have a much greater density, than a molecule formed of\noxygen and hydrogen, _i. e._ water. This property of the density of\nmatter plays a most important part in the transmission of any kind of\nwave-motion.\n\n\nART. 39. _Matter possesses Elasticity._--Matter possesses elasticity.\nElasticity is that property of matter which enables all bodies to resume\ntheir original shape, when the pressure which has caused the alteration\nof shape has been removed.\n\nFor example, suppose an ivory ball be dropped upon a marble table, or\nany other hard surface. It will then rebound, and rise almost to the\nsame height from which it was dropped. If the surface upon which it fell\nwas first covered with blacklead, a circular spot of lead will be found\non the ivory ball. From this fact, we arrive at the conclusion that when\nthe ball came into contact with the table, at the moment of contact it\nwas flattened, and then owing to its elasticity it rebounded into the\nair again.\n\nNow the measure of the elasticity of a body is proportionate to the\nvelocity of the wave-motion which it can transmit. A good illustration\nof the transmission of wave-motion may be shown with a number of ivory\nbagatelle or billiard balls. If eight or more of these be put in a row,\nall touching each other, and a single ball be placed about an inch or so\naway from the others in a straight line with them, then when the single\nball is struck with a cue against the other eight, the motion of the\nsingle ball is transmitted by each one of the eight successively with\nsuch rapidity, that the end ball would be set in motion in a quicker\ntime than a single ball would take to reach the end ball, if it had been\nfree to move along without encountering any opposition.\n\nIt is a fact capable of demonstration, that the smaller the particle of\nmatter, the greater will be its vibratory motion. Thus the particles of\nair are very, very small, and consequently air is found to be very\nelastic, and allows sound to be transmitted through it with\ncomparatively great velocity, some sounds travelling at the rate of over\n1000 feet per second.\n\nA most important factor in determining the propagation of any\nwave-motion, through a gas or solid, is the relationship of the\nelasticity of the gas or solid to its density. Suffice to say, that the\nvelocity of any wave-motion is determined by the relation of the\nelasticity to the density. For example, sound, which is a wave-motion of\nthe air, can not only be transmitted through gaseous bodies as air, but\nalso through liquids and solids. Sound travels faster through solids\nthan through liquids, and faster through liquids than through gases. In\nliquids, the relation of the elasticity to density is greater than in\nair, and in solids the relation is greater still. Therefore sound\ntravels much faster in liquids than in gases, and faster in solids than\nin liquids.\n\nThis is the reason why a train can be heard coming if the ear is put to\nthe railway-line, when no indication of its approach is given to the ear\nby the atmosphere. Some examples of the velocities of sound through\ndifferent substances are as follows--\n\n    Gases O. C.             Liquids.                         Solids.\n       FEET                   FEET                            FEET\n\nAir    1090 per sec. Water   4708 per sec. (8 deg. C.).  Gold   5717 per sec.\nOxygen 1040  \"   \"   Alcohol 4218  \"   \"   (20 deg. C.). Silver 8553  \"   \"\n\n\nART. 40. _Matter possesses Inertia._--Inertia is that property of\nmatter, by which matter cannot of itself alter, or change its state of\nmotion, or of rest.\n\nNewton's first law of motion states that a body at rest remains at rest\nuntil some force or motion acts upon it. If a stone be dropped from a\nballoon, the stone does not fall because of any property which it\npossesses, but because the force of gravity acts upon it. If it were\npossible to eliminate this force of gravity, then if there were no other\nforce which could act upon the stone, it would remain suspended in\nspace.\n\nThe inertia of a body is equal to the mass of that body, or the amount\nof matter in the body as measured by gravity, so that if a body is\nhalved, its inertia will be halved also, and if doubled, its inertia\nwill be doubled also. As the inertia of matter opposes all kinds of\nmotion, the amount of force required to overcome the inertia of a body\nis proportionate to its mass. So that if the mass of a body is doubled,\nthen twice the force would be required to move it, while if the body\nwere halved, half the force would suffice to do it.\n\nInertia is possessed quite as much by a moving body as a body at rest.\nThe definition given points this out, as it states that matter cannot of\nitself change its state of motion. If a body therefore is in motion, it\nrequires a certain amount of resistance to bring the body to a state of\nrest, or the loss of an equal amount of energy, by friction or\notherwise, equal to the quantity which it absorbed in order for it to be\nset in motion.\n\nWe get numerous examples of this property of the inertia of bodies in\nour daily experience. Many of the accidents that befall people in\nvarious ways are due to this property of the inertia of matter. A\ncyclist is riding a machine down-hill, and loses control over his\nmachine, with the result that he runs into a wall, and is killed. Now\nwhat has happened? The cyclist has participated in the motion of the\nmachine, with the result that when the machine has been suddenly\nstopped, the body has been thrown forward owing to the momentum it had\nacquired.\n\nWe are constantly being affected by the property of inertia of matter,\nin tram and train and bus. Whenever any of these are suddenly stopped,\nor suddenly started, we are thrown either backward or forward, owing to\nthe body either not having acquired the motion of the train, or, having\nacquired it, is unable to lose its motion as quickly as the train, and\nis therefore thrown forward.\n\n\n\n\n                               CHAPTER IV\n\n                             AETHER IS MATTER\n\n\nART. 42. _Aether is Matter._--The hypothesis of an Aether which fills\nall space was made in order that scientists might be able to account for\ncertain phenomena of Light, which otherwise were difficult to account\nfor. Its existence is demanded not only for the phenomena of Light, and\nHeat, but, in view of the comparatively recent researches of Hertz on\n\"Electric Waves,\" of Electricity also.\n\nThe Aetherial Medium is generally assumed to be that fundamental medium,\nby means of which possibly all the properties of matter, and all the\nphenomena of motion of the universe are to be explained. Light and Heat\nhave been proved to be due to the periodic wave-motion of this universal\nAether, while from the investigations and researches of such men as\nClerk Maxwell, Poynting, Thompson and Hertz, it has been proved that\nelectro-magnetic phenomena are due to this same medium.\n\nSeveral different forms of Aether have been postulated by various\nphilosophers from time to time, but the only Aether that has survived,\nis that which was first conceived by Huyghens to explain the phenomena\nof Light, though it was Thomas Young who finally succeeded in placing\nthe conception of the Aether on a sound basis. Each discovery of science\nhas only strengthened the hypothesis and existence of the Aether, the\nlatest discovery, that of wireless telegraphy so successfully developed\nby Signor Marconi, being attributed to the electro-magnetic properties\nof this self-same Aether.\n\nIt has already been pointed out that Newton endeavoured to account for\nGravitation by the pressure of the Aether. If, therefore, Gravitation be\nreally due to this universal medium it becomes necessary to ask\nourselves, What are the properties and characteristic qualities of this\nwonderful medium? What then is Aether, and what its properties?\n\nIt has already been pointed out in Art. 29 that Aether is matter. Such\nan assumption is strictly in accordance with the Rules of Philosophy,\nquoted in Chap. I.\n\nNot only is this hypothesis a simple one, but it is also in accord with\nall our experience and observation.\n\nIt is a simple supposition, because, unless Aether is assumed to be\nmatter, then, instead of the universe being composed of two classes of\nthings, matter and motion, we have to add a third class, which we call\nAether. It can be readily seen, that by the introduction of a third\nclass into the composition of the universe, such an addition, instead of\nsimplifying the constitution of the universe, adds greater complexity to\nthe same.\n\nBy accepting the hypothesis that Aether is matter, we do away with the\nthird class of essentials in the universe, and so reduce the number to\ntwo classes. If we could go one step further, and prove that instead of\nthere being two classes of things in the universe, there was only one\ngroup, and show that all material things, and all phenomena could come\nunder the head of either matter, or motion, then we should have reduced\nthe universe to the simplest conception possible. As, however, it is not\npossible, at least in our present state of knowledge, for us to come to\nthis fundamental and simple hypothesis of unity for the entire universe,\nwe must accept the next simpler solution, and affirm that the universe\nis composed of two classes of things, viz. matter and motion, and this\nas I have already shown is a simpler classification than by putting\nAether into a class by itself, and therefore is in accord with our first\nRule of Philosophy.\n\nAgain, it is entirely in accord with our second Rule of Philosophy, as\nit in no way violates the results of experiment, experience, or\nobservation. Look where we will, or at what we will, whatever we see,\ntouch, taste, or smell is termed matter. The burning sun, the glowing\nstar, the flying meteor, the glowing comet, the earth, our own island\nhome, the towering rock, the wide ocean, the running river, the green\ntrees of the forest, the tiny insect, the lordly elephant, all animals,\nplants, and our own physical body, all are composed of matter, either in\nsolid, liquid or gaseous form. Therefore when we affirm that Aether is\nmatter, the affirmation is strictly in accordance with the elementary\nprinciples of Philosophy, and in no way violates their rules or laws. To\naffirm that Aether is not matter, is to affirm something contrary to all\nexperience, unless it be affirmed that Aether is motion, for which\nassumption the evidence is not nearly so strong or conclusive as that it\nis matter. Therefore the objector to this assumption is himself\nunphilosophical, in that he postulates or supposes that the Aether is a\nmedium, with qualities which lie altogether outside the range of our\nexperience and observation.\n\nThere is a growing conviction in the minds of scientific men, that\nAether belongs to that group of things which we describe by the term\nmatter. Lord Kelvin in giving an address to the British Association,\n1901, on \"Clustering of Gravitational Matter in any part of the\nUniverse,\" said: \"We are all convinced with our President (Professor\nRucker) that _Aether is Matter_. Aether we relegate to a distinct\nspecies of matter which has inertia, rigidity, elasticity,\ncompressibility, but not heaviness.\"\n\nDr. Larmor in _Aether and Matter_ writes: \"Matter must be constituted of\nisolated portions, each of which is of necessity a permanent nucleus\nbelonging to the Aether, of some such type as is represented for example\nby a minute vortex ring in a perfect fluid.\"\n\nFaraday in relation to this subject writes (_Exp. Res._, vol. ii.): \"The\nview now stated of the composition of matter would seem to involve the\nconclusion that matter fills all space, or at least all space to which\nGravitation extends, _including the sun and its system_, for Gravitation\nis a property of matter dependable on a certain Force, and it is this\nForce which constitutes matter.\" As the Aether fills all space,\nincluding the solar system, therefore, according to Faraday, \"Aether\nmust also be Matter.\"\n\nBy the hypothesis that Aether is matter, with all the properties that\nsuch a hypothesis logically gives to Aether, I venture to premise that\nthe third Rule of Philosophy will be fulfilled, and that there is no\nphenomenon of the astronomical world, and no part of the universal Law\nof Gravitation which such a hypothesis will fail to account for on a\nsatisfactory physical basis. For the first time a physical explanation\nwill be given to Newton's Laws of Motion, at least to those laws which\nare strictly in accordance with the first and second Rules of\nPhilosophy. For the first time a physical conception will be given to\nall Kepler's Laws, and what the mathematical Laws of Gravitation have\ndone to Kepler's Laws, in giving them a mathematical basis, the simple\nhypothesis that Aether is matter, with all that is logically involved\ntherein, will do for the same laws from the physical standpoint. For the\nfirst time a physical conception will be given to the Centrifugal and\nCentripetal Forces, which are the complement and the counterpart of each\nother, that physical conception being the outcome of the same hypothesis\nthat Aether is matter.\n\nIn addition to this, light is thrown upon such problems as are referred\nto by Lord Kelvin (_Phil. Mag._, July 1902) in his paper on \"Clouds on\nthe Undulatory Theory of Light,\" and further light is given to some\ntheories of Electricity advanced by such men as Faraday, Clerk Maxwell,\nand Professor Thompson. I venture to think, therefore, that the\nhypothesis advanced, and the conception put forward that Aether is\nmatter, is philosophically correct, and is warranted by the results that\narise out of such a hypothesis.\n\nIt may be thought by some that the hypothesis that I have advanced is\nalready conceded, and that the fact that Aether is matter is already\nadmitted by scientists and advanced thinkers generally. But such an idea\nis only partly correct. It is already admitted by some of our most\nadvanced scientists that Aether is matter, but that admission is only\ncarried partially to its logical conclusion.\n\nLord Kelvin in an address to the British Association, 1901, gave\nutterance to the following remarks on the relation of Aether to Matter:\n\"We are convinced with our President (Professor Rucker) that Aether is\nMatter, but we are forced to say that the properties of Matter are not\nto be looked for in Aether, as generally known to us by action resulting\nfrom force between atoms of Matter and atoms of Aether. _Here I am_\nILLOGICAL _when I say between Matter and Aether_, as if Aether were not\nMatter. Aether we relegate to a distinct species of Matter which has\ninertia, rigidity, elasticity, compressibility, but NOT HEAVINESS.\"\n\nFrom a quotation of this kind, which is from the lips of one of the\nkeenest intellects of the present time, I think I am justified when I\nmake the statement, that it is not conceded that Aether is matter, with\nall that that concession logically involves. Because, as Lord Kelvin\npoints out, though it is admitted that Aether is matter, yet that\nadmission is only a qualified admission, and not one which carries with\nit all the properties that essentially belong to matter, or an admission\nwhich includes the fact that Aether is gravitative, that is, subject to\nGravitation. To be strictly logical and philosophical, in the statement\nthat Aether is matter, it must be conceded not only that Aether is\nsubject to such properties as elasticity, inertia, and compressibility,\nbut that it is also gravitative or possesses weight. For either Aether\nis matter, or it is not matter.\n\nIt cannot be both at one and the same time. Such a conception is\naltogether opposed to that simplicity which is the chief characteristic\nof Nature as pointed out by Newton.\n\nIf therefore Aether be matter, then, to be strictly logical and\nphilosophical, it must be conceded that Aether is gravitative, as well\nas having the other properties of matter, as elasticity and inertia,\netc. Unless this is conceded, then we have the anomaly in Nature of\nmatter, which is not matter, because it violates the very principles\nwhich above all others decide what is matter, viz., \"That every particle\nof matter attracts every other particle,\" etc., that is, that it is\ngravitative. Thus by supposing that the Aether is matter, and yet not\nbeing gravitative, all the Rules of Philosophy are violated, as such a\nhypothesis is opposed to both the first and second Rules of Philosophy,\nand is contrary to all observation and experience. If Aether therefore\nbe matter, as is conceded by the most advanced thinkers of the time,\nthen it follows that the only logical and philosophical conclusion that\ncan be arrived at is, that it is also subject to those properties which\nare the chief characteristics of all matter. These properties may be\nclassified as follows: atomicity, gravitation, density, elasticity,\ninertia, and compressibility.\n\n\nART. 43. _Aether is Universal._--Young in his first Hypothesis on the\nAether medium states that, \"A Luminiferous Aether pervades the Universe\nrare and elastic in a high degree\" (_Phil. Tran._, 1802).\n\nAs Young points out, this invisible and elastic Aether fills all space\nand floods the universe at large. In it suns blaze, stars shine, worlds\nand planets roll, meteors flash, and comets rush in their mysterious\nflight. In it all material and physical things exist, for it is to them\nnot only the primary medium of their existence, but, just as the\ninfinite and ever-active energy of the Divine is to the universe in its\nentirety and fulness, the exciting and stimulating spirit of its\nenergies and powers, so this aetherial ocean is to the material and\nphysical universe, the exciting and stimulating medium of all its\nactivities, energies, and powers; and without which, though all material\nand physical things were endowed with the varied capacities of their\nkind or life, yet they could neither exert nor exercise them, nor even\nexhibit the simple activity of motion. Hence everywhere, where material\nand physical things are, there, as the medium of their existence and\nenergy, the Aether is; and where the Aether is not, no material or\nphysical thing is, or can be. That the Aether is universal is proved by\nthe phenomena of light. Light-waves have a velocity of about 186,000\nmiles per second. Now the distance of the sun from the earth is about\n92,000,000 of miles, so that light takes about eight minutes and a half\nto travel from the sun to the earth.\n\nA ray of light from the nearest fixed star takes about three and a half\nyears to reach the earth, while there are some stars so far away that\nastronomers tell us, that though light travels with so great a velocity,\nyet it would take several thousand years to reach the earth. This fact\nimplies that throughout boundless space there is to be found this\naetherial medium. Thus interplanetary and interstellar space is not\nempty, but is filled with this ever-present, all-pervading Aether; and\nnot only so, but every particle of matter in the universe is surrounded\nby this universal Aether, which forms the exciting and stimulating\nmedium of all the activities, energies, and motions of all Matter. Thus\nthe Aether is both universal and infinite in its extent.\n\nClerk Maxwell, in his paper on \"Action at a Distance\" (_Collected\nWorks_, by Niven), with reference to the universality of the Aether,\nwrites: \"The vast interplanetary and interstellar regions will no longer\nbe regarded as waste places in the universe, which the Creator has not\nseen fit to fill with the symbols of the manifold order of His Kingdom.\nWe shall find them to be full of this wonderful medium, so full, that no\nhuman power can remove it from the smallest portion of space, or\nproduce the slightest flaw in its infinite continuity. It extends\nunbroken from star to star, and when a molecule of hydrogen vibrates in\nthe Dog Star, the medium receives the impulses of those vibrations, and\ntransmits them to distant worlds. But the medium has other functions\nbesides bearing light from world to world, and giving evidence of the\nabsolute unity of the material system of the universe. Its minute parts\nmay have rotatory as well as vibratory motions, and the axes of rotation\nform those lines of magnetic force which extend in unbroken continuity\ninto regions which no eye has seen, and which, by their action on our\nmagnets, are telling us in language not yet interpreted what is going on\nin the hidden world from century to century.\" Now I premise, that in the\ntheory of the Aether to be submitted in this work, the physical\ninterpretation of this statement of Maxwell's will receive its literal\nfulfilment.\n\n\nART. 44. _Aether is Atomic._--If there is one fundamental truth which is\napplicable to all matter, it is, that all matter is atomic.\n\nProfessor Rucker, in his Presidential Address to the British Association\nof 1901, in dealing with this question, said: \"The believer in the\natomic theory asserts that matter exists in a particular state, that it\nconsists of parts which are separate and distinct from one another, and\nas such are capable of independent movement. It is certain that matter\nconsists of discrete parts in a state of motion, which can penetrate\ninto spaces between the corresponding parts of surrounding bodies. Every\ngreat advance in chemical knowledge during the last ninety years finds\nits interpretation in Dalton's Atomic Theory.\"\n\nFrom such an authority as this, and from the facts which he gave in his\ndealing with the question, we are bound to admit that all matter is\natomic. That being granted, when the statement is made, therefore, that\nAether is matter, the only logical conclusion that can be arrived at,\nwith reference to the question of the atomicity of the Aether, is, that\nAether is also atomic. Unless this be conceded, we have the first and\nsecond rules of our Philosophy violated, as an atomless Aether is\nopposed to that simplicity of conception, which is an essential\nrequirement of all hypotheses, and is moreover contrary to that\npresumptive evidence gathered from observation and experiment, which\nteaches us that all matter is atomic. If it be argued, that it is\nimpossible to decide upon a question as to the atomicity of the Aether,\nmy reply is that the same argument may reasonably be applied to all\nmatter. But, as Professor Rucker stated, all the evidence on matter\npoints out and supports the theory of its atomicity, and, therefore, the\nonly logical and philosophical conclusion is, that Aether is atomic\nalso. Again, it may be suggested that we cannot see or touch an atom of\nAether, and that it is not only invisible, but apparently incapable of\nbeing made sensible to our senses. In reply to that, as I have already\nshown in Art. 31, that objection can be equally used against an atom of\nhydrogen, or an atom of oxygen. Does any one doubt the existence of the\nhydrogen atom or the atom of oxygen, because it is invisible to the\nsense of sight, or cannot be revealed to the limited sense of touch?\nCertainly not! By the same reasoning, it is just as illogical to deny\nthe existence of an atom of Aether because it cannot be seen or felt, as\nit is to deny the existence of an atom of hydrogen or oxygen. An atom of\nAether reveals itself to the senses in the same way that an atom of\nhydrogen or oxygen does, that is, by the force or energy which it\nexerts. Its vibrations can be manifested to the body in the form of\nheat, while the undulatory motion which the aetherial atoms transmit in\nthe form of light, reveal the presence of the aetherial atom to the\nsense of sight. The question at once arises as to what constitutes an\naetherial atom, what are its properties and motions?\n\nNow, in order for us to enter successfully into this speculative region,\nit is essential that we should, as far as possible, conform to the Rules\nof Philosophy, and endeavour to gain some conception of an aetherial\natom from the results of experience and observation. In doing this, we\nare at once confronted with the difficulty, that no one has ever seen an\natom, or analyzed the properties of one. Actual experiment has revealed\nnothing absolutely certain as to the ultimate character of an atom, and\nif this be true of the atoms of matter, then it must also be true of an\naetherial atom. It would seem at first, therefore, that we have no\nresults of experiment, or observation, by which we may be guided in\nformulating a right conception as to the constitution of an aetherial\natom, and therefore we are thrown simply into the regions of speculation\nas to its constitution and properties.\n\nBut I venture to suggest, that there is a method which is strictly\nphilosophical in its application, by which we may possibly arrive at a\nclear conception of an aetherial atom. All great discoveries of science\nhave been the outcome of applying the principle, that what is true of\nthe visible and seen, is true of the invisible and unseen; that what is\ntrue of the known, is true of the unknown; that the principles and laws\nwhich govern the small also govern the large and the great. It was thus\nthat Newton discovered his great Law of Gravitation, as he was able from\nthe falling of an apple, to rise to the application of the same\nprinciple to our satellite the moon, and this led him on to the\ndiscovery of the Law of Gravitation.\n\nIf, therefore, in Philosophy, the laws governing the small things are\nalso applicable to the great things, then the converse equally holds\ngood, that the laws governing great things are the reflex of the laws\nwhich govern the small things. For example, the laws which govern the\nlight and heat of the sun are the same which govern the light and heat\nof a candle or a glow-worm; and the laws which govern a planet or world\nare the same as those which govern an atom. Thus a planet or world,\nwhich is simply an agglomeration of atoms, may reveal to us in its\nmotions and laws, what are the motions and laws which govern the atomic\nworld.\n\nIn looking at the properties and motions of a planet, therefore, as our\nearth for example, we find that a planet is a sphere, or more correctly\nan oblate spheroid; that the earth or planet is a magnet possessing\npolarity, having a north and south pole; that it has rotation on an\naxis, in addition to translation in an orbit, and that it is subject to\nthe universal Law of Gravitation.\n\nIf, therefore, it holds good in Philosophy, that the small things are\nthe index to the greater, and that the laws governing the small things\nalso govern the greater, then the converse holds good, that what is true\nof the large is true of the small, and that the laws governing the great\nalso govern the small.\n\nSo that gathering up those chief properties of the earth to which I have\nalready referred, and applying them to an aetherial atom, or any other\natom if necessary, we arrive at the conclusion that an atom must be\nspherical in shape, must possess rotation, and must have an orbit, must\npossess polarity, and also be subject to the universal Law of\nGravitation.\n\nHere, then, we have given to us certain data by which we are enabled to\nform our conception of an atom, aetherial or otherwise. The question\narises, whether, among the forms of atoms which have been devised by\nscientists, any of the atoms so conceived fulfil all, or nearly all of\nthese requirements. We have Boscovitch's Atom, the Hard Atom of\nLucretius, and the more recent conception of the Vortex Atom of Lord\nKelvin. Of all the hypotheses in regard to the ultimate nature and\nconstitution of an atom, the Vortex Theory probably is the one which\noffers to the mind the simplest conception of an aetherial atom.\n\nThe Vortex Ring Atom, however, which has been so fully developed by Lord\nKelvin, hardly fulfils all the requirements of an aetherial atom. In the\nfirst place it is not spherical in shape, and I hold that to be one of\nthe fundamental bases of the aetherial atom. Then, in the next place it\ndoes not, so far as I can read, possess polarity; that is, it does not\npossess a north and south pole, through being a magnet in the same way\nas the earth is a magnet. We must therefore look for a modification of\nthe vortex ring to discover the constitution of our aetherial atom, and\nI venture to think that such a modification is to be found in Professor\nHill's conception of a Spherical Vortex Atom (_Phil. Trans._, 1894).\n\nIn the conception there put forward, and mathematically worked out,\nProfessor Hill showed that his spherical vortex atom possessed similar\nproperties and characteristics to the vortex rings of Lord Kelvin. So\nthat the spherical vortex atom would possess rotation on an axis, and it\nwould be a magnet, as I shall prove later on, because it rotates in an\nelectro-magnetic medium. It would possess elasticity, compressibility,\ninertia, and, further, would possess a certain amount of mass. That mass\nmight be infinitely small, but nevertheless it would possess mass of an\ninfinitesimal order.\n\nFurther, if we are to be strictly correct, in our analogy between the\nearth and the aetherial atom, its polar diameter must be shorter than\nits equatorial diameter, as that is one of the facts observable\nregarding the shape of our earth, so that the shape of the aetherial\natom will not be strictly spherical, but its actual shape would be that\nof an oblate spheroid, being flatter at the poles, and bulging out in\nthe equatorial regions.\n\nThis exact analogy between the earth and an aetherial atom may not at\npresent seem of very great importance, but its importance will be seen\nlater on, when we come to deal with the phenomena of heat, light, and\nelectricity.\n\nHere, then, is our conception of an aetherial atom in the rough, based\nnot upon any imaginative hypothesis, but rather upon that strict\nconformity to observation and experience, which is the very groundwork\nof all true Philosophy.\n\nFor, after all, what is the earth but an atom on a large scale? In\ncomparison with illimitable space, with its infinite distances, that can\nalone be measured by the velocity of light, our own earth is but a speck\nof dust, a very atom that helps to make up the universe, and, as such,\nshould teach us the shape and properties of other atoms of which the\nsame universe is composed.\n\nWe have therefore to conceive of the all-space-pervading Aether as being\ncomposed of infinitesimal portions of Aether, which are nearly spherical\nin shape, and ever in a state of rotation; this state of rotation\ndifferentiating the atom of Aether from the free Aether, if such an\nentity exists. So that an atom of Aether would simply be an\ninfinitesimal portion of the Aether in a state of rotation.\n\nIf, by any means, we could stop the rotation, we should at once destroy\nthe atom, in the same way that the smoke vortex ring would cease to be a\nring, if its rotation were stopped. The cessation of the rotation I,\nhowever, believe to be impossible. So that even in the ultimate atom of\nthat universal medium the Aether, we have an illustration of the\ncombination of those two forms which are inseparably connected\nthroughout the whole universe, viz. matter and motion, and it is the\ncombination of these two that gives to the aetherial atom its form, and\nits very existence, without which it has no life, and ceases to exist.\n\nIt may be necessary in the development of this work as we proceed, to\nslightly modify our conception of the aetherial atom, but that\nmodification will rather be of a constructive character, than a\ndestructive one. There may also be certain objections to meet and\nexplain away when we deal with the phenomena of light, heat, and\nelectricity, and Gravitation, and the part which the aetherial atom\nplays in those phenomena, but these objections I hope to meet and answer\nas they arise.\n\nThe atomicity of the Aether has already been suggested by such\nscientists as Clerk Maxwell, Lord Kelvin, Dr. Larmor, and Professors\nLodge and J. J. Thompson. Clerk Maxwell, in an article on \"Action at a\nDistance,\"[3] referring to the atomicity of the Aether, writes: \"Its\nminute parts may have rotatory as well as vibratory motions, and the\naxes of rotation may form those lines of magnetic force which extend in\nunbroken continuity into regions which no eye has seen.\" I premise that\nI will conclusively prove that this statement finds its literal\nfulfilment in the theory of the Aether that will be developed in this\nwork.\n\nLord Kelvin, in several articles on \"Vortex Motion\" in the Philosophical\nMagazines of recent years, has mathematically dealt with the Aether from\nthe atomic standpoint, and has endeavoured to prove that the Aether\nmedium is composed of vortex rings, but he was unable to come to any\nsatisfactory conclusion. With the theory that Aether is matter, and\ntherefore possesses mass, his conception is now brought within the range\nof physical explanation, as well as mathematical calculation.\n\nDr. Larmor, in his _Aether and Matter_, has successfully applied the\nprinciple of the atomicity to the Aether, on what is termed the\n\"Electron\" basis. He states that an electron is nothing more or less\nthan \"a point singularity in the electro-dynamic and optical Aether.\" So\nthat our aetherial atom is practically synonymous with Dr. Larmor's\nelectron. Again, Dr. Larmor, in the same work, states that \"the\natomicity of electricity is coming within the scope of direct\nexperiment.\"[4] But Professor Lodge, in his _Modern Views of\nElectricity_, states that \"the Aether is composed of positive and\nnegative electricity, the combination of these two forming the Aether\nmedium.\"[5] Now, if the Aether is composed of positive and negative\nelectricity, and the atomicity of electricity is coming within the scope\nof direct experiment, it follows as a matter of necessity that the\natomicity of Aether and the atomicity of electricity are one and the\nsame, and therefore the atomicity of Aether is coming within the scope\nof direct experiment. Professor J. J. Thompson, who has also attacked\nthe problem of the atomicity of electricity, speaks of \"corpuscles\"\nwhich are the actual carriers of the positive and negative electricity,\nin the atoms of the various elements. These corpuscles therefore\nindicate the fact that electricity has an atomic basis.\n\nNow if there is any such identity between Aether and electricity, as\nthere undoubtedly is, and electricity has an atomic basis, then the\natomicity of the Aether follows as a matter of course, otherwise we\nshall have a medium composed of atoms which is itself not atomic, which\nconclusion is absurd and therefore unphilosophical. So that the most\nrecent researches into electricity confirm and establish the atomicity\nof the Aether.\n\n[Footnote 3: _Collected Works_, by Niven.]\n\n[Footnote 4: Preface to _Aether and Matter_.]\n\n[Footnote 5: Page 348.]\n\n\nART. 45. _Aether is Gravitative._--Young, in the _Philosophical Trans._\nof 1802, in regard to this question, states in his Fourth Hypothesis:\n\"All material bodies have an attraction for the aetherial medium, by\nmeans of which it is accumulated within their substance, and for a small\ndistance around them, in a state of greater density, but not greater\nelasticity.\" He adds that \"this fourth hypothesis is opposed to that of\nNewton's.\"\n\nScientific research has justified the conception of his first three\nhypotheses with respect to the universality, elasticity and vibrations\nof the aetherial medium, but up to the present I am not aware that\nscience has accepted his fourth hypothesis.\n\nI propose to show how, from a strictly philosophical and logical\nstandpoint, his fourth hypothesis is just as true as his first three\nhypotheses, and that it henceforth passes out of the realm of the\nhypothetical into the realms of fact and science, not only by\nphilosophical reasoning, but by actual experiment made by some of the\nmost advanced scientists of the present time.\n\nLet us consider the question first from the standpoint of the Rules of\nPhilosophy. Our first Rule of Philosophy states, that any hypothesis\nmust be simple in connection. Now I put it to any intelligent man, and\nask him which is the simpler conception of Aether? To affirm that Aether\nis matter, and therefore subject to the properties of matter, as\nelasticity, density, inertia and Gravitation, or to affirm that Aether\nis matter, but while it is subject to some of the properties of matter,\nas elasticity, density and inertia, it is not subject to the very\nproperty which of all properties is the most fundamental, viz.\nGravitation. There can, in my opinion, only be one answer to the\nquestion, so that, when we affirm that Aether is matter, we are\ncompelled to affirm, in order to conform to the first Rule of\nPhilosophy, that it is gravitative also. Faraday was also of the opinion\nthat Aether was subject to the Law of Gravity, for, writing in\n_Experimental Researches_, he states: \"The view now stated of the\nconstitution of matter, would seem to involve the conclusion, that\nmatter fills all space, or at least all space to which Gravitation\nextends, INCLUDING THE SUN AND ITS SYSTEM. For Gravitation is a property\nof matter, dependable on a certain force, and it is this force which\nconstitutes matter.\"\n\nLet us also test the question by our second Rule of Philosophy, and we\nshall find greater evidence still for the statement that Aether is\ngravitative. What do experience and observation teach us with reference\nto matter? As we have already seen (Art. 37), if there is one truth that\nthey teach us regarding matter, it is that it is gravitative.\n\nThere is not the slightest evidence throughout the universe, as far as\nour observation can lead us to form an opinion, that there is any kind\nof matter which is not subject to the Law of Gravitation. Therefore to\nassume that Aether is matter, and yet not to assume that it is also\nsubject to Gravitation, is to assume that which is directly opposed to\nthe most fundamental principle of all philosophical teaching and\nscientific research. If Aether be matter, therefore, and yet is not\ngravitative, we shall have an anomaly in an otherwise universal law, as\nwe shall have some kind of matter which fails to come within the scope\nof the universal Law of Gravitation.\n\nTo be consistent, therefore, we must either cease to call Aether matter,\nor else admit that Aether, like all other matter, is gravitative. It is\nabsolutely impossible to be strictly logical and admit that Aether is\nmatter, and not to admit that it is subject to the most universal law\nthat governs matter, as the Law of Gravitation distinctly states that\n\"every particle or atom of matter attracts every other particle.\" This\nuniversal law in view of a gravitationless Aether would have to be\namended to \"Some particles of matter attract some other particles.\" Thus\nthe universal Law of Gravitation ceases at once to be a universal law,\nand such a result is opposed to all experience and experiment. Again,\nlet us apply our third Rule of Philosophy to this supposed\ngravitationless Aether, and see what the result is.\n\nOur third rule states, that any hypothesis put forward must satisfactorily\naccount for the phenomena sought to be explained and accounted for. The\nAether was conceived in order to explain the phenomena of light, and one\nof the properties it was conceived to possess was elasticity, yet that\nvery conception was devoid of the most fundamental property of matter,\nwithout which there is no elasticity, that is, that it was not atomic.\n\nI have already shown in Art. 44, that Aether is atomic, and therefore\nthere is given to the Aether a structure which is capable of exhibiting\nelasticity, inertia, density, and even Gravitation, while at the same\ntime, the conception is fully in harmony with philosophical reasoning\nand Newton's Rules of Philosophy.\n\nLet us consider the question whether Aether is, or is not gravitative,\nfrom another aspect. For several hundred years, the physical cause of\nGravitation has been outstanding, while the world has held the\nconception that Aether is a gravitationless and frictionless medium. The\nearth has been rolling on in her orbit year in, year out, together with\nall the other planets in their annual march round the sun, and yet\nthrough all that time no one has been able to suggest, or give any\nsatisfactory or adequate physical explanation, as to what moves the\nearth along.\n\nI am fully aware that Newton suggested and proved, that it was because\nof the Law of Gravitation. But I look upon that as a mathematical\nexplanation and not as a physical one.\n\nNow I venture to predict this, that on the assumption of a\ngravitationless medium, the physical explanation so longed for will\nalways be outstanding, as a gravitationless Aether is synonymous with a\nfrictionless medium, and so long as we admit that there is a\nfrictionless medium, so long will the physical cause of Gravitation, and\ntherefore the physical cause of all the movements of the planets and\ncomets, be outstanding and unexplained.\n\nIf, however, instead of being illogical in our reasoning, we become\nlogical, and affirm that Aether is matter, and because all matter is\ngravitative, therefore Aether is gravitative; and if, instead of being\nunphilosophical, we become philosophical, and affirm that because a\ngravitationless Aether violates both the first and second Rules of\nPhilosophy, such a conception must be put away, and in its place a more\nphilosophical conception must be forthcoming, which is that Aether is\ngravitative; then, upon such a logical and philosophical basis, I\nventure to premise that the great problem which is still outstanding of\nthe cause of Gravitation, will remain outstanding no longer, and the\nphysical cause of all the movements of all celestial bodies will be put\nupon a physical basis, in addition to a mathematical one.\n\nIf such a result can be arrived at by the logical and philosophical\nconception of a gravitative Aether, then the three Rules of Philosophy\nare fully satisfied, and the assumption of a gravitative Aether is\nwarranted on a strictly philosophical basis.\n\nSo that Thomas Young is strictly correct from a philosophical standpoint\nin his fourth hypothesis, when he states: \"That all material bodies have\nan attraction for the aetherial medium, by means of which it is\naccumulated within their substance and for a small distance around them\nin a state of greater density but not greater elasticity.\" He is not,\nhowever, correct when he states that though there is a greater density\nnear the body, there is not a greater elasticity, as such an assumption\nis opposed to experiment and observation in relation to perfect gases,\nas I shall show when dealing with the elasticity of the Aether.\n\nAgain, in view of the fact that the Aether is atomic, it can now be\neasily understood how it may be subject to Gravitation. The very essence\nof Gravitation is that atoms, or particles, attract each other. If there\nwere no particles, or atoms, it is obvious that there would be no\nattraction, and therefore no Gravitation. Wherever, therefore, there are\nto be found atoms of any kind or sort, whether they be atoms of\nhydrogen, oxygen, silver or aetherial atoms, there the Law of\nGravitation holds good, and attraction between these atoms is to be\nfound. In other words, any substance which is atomic, is also\ngravitative. Now Aether is atomic as has been shown, and therefore from\nthat standpoint it is also gravitative. It may, however, be objected\nthat the assumption of gravitative properties for the Aether is after\nall but a speculation, and that Young's fourth hypothesis was only a\nhypothesis, and that the gravitating properties of the aetherial medium\nhave never come within the scope of direct experiment, without which no\nhypothesis can be fully accepted.\n\nIf such an argument be advanced against a gravitating Aether, then I\nmust differ from those scientists who advance such an objection. My\ncontention is that the gravitating properties of the Aether have already\nbeen made the subject of some of the most refined and delicate\nexperiments that have been made during the past few years.\n\nI refer to the experiments of Michelson and Morley of America.\n\nFor an outline and explanation of such experiments I must refer the\nreader to the _Phil. Mag._ of December 1887.\n\nNow what is the result of these experiments?\n\nI believe it is almost unanimously conceded by all scientists, that\ntheir experiments prove that the Aether is carried along by the earth.\nLet us carefully look at this conclusion and see what it implies in\nrelation to the question at issue.\n\nIf the Aether is carried along by the earth, it necessarily follows that\nthere is some governing law or principle which holds it to the earth,\nwhile the earth moves through space with its velocity of 68,000 miles per\nhour.\n\nNow what is that governing principle or law, which is capable of holding\nsuch an aetherial atmosphere to its central body? If we wish to be\nstrictly philosophical, it is necessary, according to our second Rule of\nPhilosophy, that we should not go outside experience and the analogy of\nNature.\n\nWhere is there a similar analogy in Nature to that of the Aether being\ncarried along through space by the earth? I know of only one analogy\nwhich can be used, and that is the analogy of the atmosphere, which is\nalso carried along by the earth through space, as it rushes on in its\norbit round the sun.\n\nThat being so, the question arises, what principle or law holds the\natmosphere to the earth? for, whatever be the law which governs the\natmosphere, to be consistent with the second Rule of Philosophy, we must\ninfer that the same law also holds the Aether in its place. There is\nonly one answer to the latter question, and that is the Law of\nGravitation. If it were not for that law, and the fact that the\natmosphere is subject to that law, the atmosphere would simply be swept\noff from its central body, the earth, as the latter rushed through space\nwith its comparatively enormous velocity.\n\nThe only legitimate and philosophical conclusion that we can arrive at,\ntherefore, is that the Aether must be carried along with its central\nbody, the earth, through being acted upon by the self-same Law of\nGravitation, and for it to be so acted upon it must obviously be\ngravitative. It would be unphilosophical to suggest that it was held in\nits place by any other force, as that would be introducing a new force\nor law into Nature, contrary to our experience in relation to an exactly\nsimilar phenomenon of Nature.\n\nWe have therefore, it seems to me, direct proof by actual experiment\nthat Young's fourth hypothesis was correct, and that not only in\nrelation to the atomic world, but also in relation to the planetary\nworld, and the stellar world, all bodies exert an attractive influence\nupon the surrounding Aether, by means of which the Aether is accumulated\nnear the surfaces of all bodies in a state of greater density, and\ntherefore of greater elasticity.\n\nLet us apply this truth to the solar system, and see what we get. If it\nis true that the earth exerts an attractive influence upon the\nsurrounding Aether by means of which it is held in its place relatively\nto the earth, then it is equally true that Mercury, Venus, Mars,\nJupiter, Saturn, Uranus and Neptune also exert gravitating or attractive\ninfluences upon the surrounding Aether, in the same way that they do\nupon their own atmospheres. So that in their cases also, the surrounding\nAether is carried along by them through space. Professor Stokes has\nsuggested that this is so, in order to account for the aberration of\nlight, as we shall see later on.\n\nNot only so, but the sun also would have an attractive power over the\nAether by means of which its aetherial atmosphere would be carried\nthrough space, as it moved along in its progress at an estimated rate of\n17,000 or 18,000 miles per hour.\n\nI would like to point out here, that this explanation of the effect of\nthe planets' attractive power over the surrounding Aether is only a\npartial one, as there are other effects directly involved in the fact\nthat the Aether is subject to the gravitating influence of all\nsatellites and planets.\n\nThis is not the place, however, to go fuller into the matter, the\nconsideration of the subject being taken up in a later chapter.\n\nThus I have tried to show a gravitating Aether is strictly in accord\nwith the three Rules of Philosophy, for it is simple in conception, is\nnot contrary to experience, and by it I premise that it is possible to\nexplain the physical cause of Gravitation, with all that is involved in\nthat law.\n\nOnce more, if Aether is gravitative, then every atom and particle in the\nuniverse, as well as every planet, and sun, and star, exert an\nattractive power over the Aether, so that every atom is enveloped in an\natmosphere of Aether, in the same way that every planet, and sun, and\nstar is enveloped by the aetherial atmosphere.\n\nThe Aether, however, while it may flow through the spaces that exist\nbetween the molecules of bodies, yet is held bound to those molecules in\nthe same way, and by exactly the same force, that holds the atmosphere\nto a planet or world.\n\nFurther, if the atoms possess different masses or weights, as they do,\nthen each atom would possess an aetherial atmosphere proportionate to\nits mass, with the result that an atom of carbon, with its atomic weight\nof 12, ought to possess a denser aetherial atmosphere than an atom of\nhydrogen, and so on right through the atomic scale. I need hardly point\nout that this conception of the Aether in relation to atoms, and\nmolecules of bodies, will solve certain problems relating to the density\nof Aether in connection with matter, which problem up to the present\ncannot be solved by the present conception of a frictionless medium.\n\nThat problem may be stated as follows: Does the presence of matter\naffect the Aether in any way, so as to load or make it denser? Professor\nLodge, in _Modern Views of Electricity_, in relation to the density of\nthe Aether, writes: \"The neighbourhood of gross matter seems to render\nAether more dense. It is difficult to suppose that it can really\ncondense an incompressible fluid, but it may load it, or otherwise\nmodify it, so as to produce the effect of increased density.\"\n\nIn view of the fact that Aether is gravitative, the reply is to be found\nin the Law of Gravitation, \"Every particle of matter attracts every\nother particle of matter, etc.,\" and as Aether is matter, it will be\nattracted by the other matter irrespective of whether that matter be in\nthe atomic, molecular, or planetary or stellar form. We shall see that\nthis is so when we come to deal with the density of the Aether.\n\nIt may be objected in relation to this aspect of Aether, that Young also\nasserted that the Aether flows as freely through matter, as the air\nflows through the trees of the forest, and that such a statement\ntherefore contradicts his fourth proposition regarding the gravitating\nproperties of Aether. A little reflection will, however, put a different\nconstruction on this objection.\n\nLet us consider the analogy from the standpoint of experience, and see\nwhat that analogy teaches us. From experience we learn that the air is\ngravitative, but we also learn that it is possible to be moved from\nplace to place as winds, and that as such it can move freely between the\ntrees of the forest, causing their boughs and leaves to tremble and bend\nbeneath its energy and power.\n\nI have yet to learn, however, that while it moves between the trees as\nseparate and distinct objects, such a movement militates or destroys its\ngravitating properties.\n\nDoes the air cease to be any less gravitative, or subject to the Law of\nGravity, when it is subject to certain movements, which give rise to\ncertain currents as winds? Such an assumption is altogether opposed to\nphilosophical reasoning.\n\nWhether the air is stationary or in motion, it is ever subject to the\ngreat Law of Gravitation, and accepting that as an analogy, the apparent\ncontradiction between the oft-quoted simile of Young and his fourth\nhypothesis is at once removed, and from analogy we learn that it is\nquite possible for Aether to move between bodies because of certain\ncurrents which may be originated by heat, light or electricity, yet at\nthe same time the existence of such currents does not violate its\ngravitating tendency.\n\nYoung's fourth hypothesis is therefore in perfect harmony with his\noft-quoted simile, that the Aether flows through the interstices of\nbodies as the wind flows through a group of trees, but like the\nair-currents it does not so flow unless the currents are generated by\nsome form of energy, as heat or light, electricity or magnetism.\n\nFrom these considerations therefore we are compelled to come to the\nconclusion that Aether, like all other matter, is subject to the same\nuniversal Law of Gravitation. If further evidence of the gravitating\ntendency of the Aether were required, I would refer the reader to Lord\nKelvin's utterance on this subject.\n\nLord Kelvin, _Phil. Mag._, November 1899, in relation to the Aether\nwrites: \"We are accustomed to call Aether imponderable. How do we know\nthat it is imponderable? If we had never dealt with air except by our\nsenses, air would be imponderable to us, but we know by experiment that\na vacuum glass tube shows an increased weight when air is allowed to\nflow into it. We have not the slightest reason to believe that Aether is\nimponderable. It is just as likely to be attracted by the sun as air is.\nAt all events the _onus of proof rests with those who assert it is\nimponderable_. I think we shall have to modify our ideas of what\nGravitation is, if we have a mass spreading through space with mutual\nattraction between its parts, without being attracted by other bodies.\"\n\nWe have already seen in the previous article that Faraday was of opinion\nthat the Law of Gravitation extended throughout the whole of the solar\nsystem, and as Aether fills the solar system, then obviously Aether must\nalso be subject to the Law of Gravitation.\n\n\nART. 46. _Aether possesses Density._--That matter possesses density has\nalready been shown in Art. 38, and on the hypothesis that Aether is\nmatter, Aether must possess density also. This property has already been\npostulated for the Aether, in order to account for certain phenomena in\nconnection with the reflection and refraction of light. Young assumed\ndifferent densities for the Aether near bodies owing to its being\nattracted by those bodies (Art. 45). Reflection and refraction of light\nare produced by a change of density of the Aether. It is now generally\naccepted that the optical difference of bodies depends mainly on the\ndifferent densities of Aether in association with those bodies.\nProfessor Tyndall, in his _Lectures on Light_, writes on the density of\nthe Aether as follows: \"The density of the Aether is greater in liquids\nand solids than in gases, and greater in gases than in vacuo. A\ncompressing force seems to be exerted on the Aether by the molecules of\nthese bodies.\"\n\nApart, however, from the atomicity and gravitative properties of the\nAether, it is difficult to understand how there can be density of the\nmedium, and still more difficult to give a satisfactory explanation of\ndifferent degrees of density for the same medium, which some scientists\nassume it to have.\n\nIf, however, all that is logically included in the statement that Aether\nis matter, and therefore is atomic and gravitative, is conceded, then,\nfrom the analogy of our own atmosphere in relation to the earth, the\ndensity of the Aether, and different degrees of density also, is at once\nput upon a logical and philosophical basis, as it is brought into\nharmony with all experience and observation, and is simple in its\nconception.\n\nOn the other hand, an Aether which is not atomic or gravitative cannot\npossess different degrees of density, except by assuming the existence\nof some unknown law of which we have no knowledge, which conception is\naltogether opposed to the fundamental principles of simplicity,\nobservation, and experiment as laid down not only by Newton but by every\ntrue philosopher.\n\nTherefore, that Aether can possess different degrees of density, is only\nthe logical outcome of the statement that Aether is matter, seeing that\nsuch a statement without the shadow of a doubt must at least imply that\nit is gravitative.\n\nI need hardly point out, that it is much more philosophical to be able\nto account for the density of the Aether in a reasonable and\nphilosophical manner, than simply to postulate for the Aether certain\nproperties and qualities, because certain phenomena demand the existence\nof such properties.\n\nThe Aether has been such a hypothetical medium, that it has been easy to\npostulate for it certain properties, if certain phenomena have demanded\nthe existence of those properties.\n\nThus if the Aether were required to be elastic, then elasticity was\npostulated for it; if more elastic, then greater elasticity was added.\nIf density were demanded, then density was postulated, and if less or\nmore density, less or more density was given to it.\n\nThat method of speculation may be satisfactory up to a certain point,\nbut no one will admit that such a method is wholly philosophical. It\nwill be a far better method to adopt, if, in dealing with the universal\nAether, we can make it conform to certain recognized laws and\nprinciples, and from the application of those well-known laws, be able\nto infer the exact constitution of this space-filling Aether medium.\n\nNow the question arises, if Aether is gravitative, what effect has the\nGravitation of any body, be it an atom, or a meteor or planet, sun or\nstar, upon the Aether in which it moves, and which surrounds it?\n\nThat we may have some light thrown upon the matter, I would like now to\ntake the reader to Newton's _Optics_, in order that he may give us his\nopinion as to this property of density of the Aether. In his nineteenth\nquery Newton (_Optics_) asks this question--\n\n\"Is not this medium much rarer within the dense bodies of the sun,\nstars, planets and comets than in the empty spaces between them, and in\npassing from them to great distances, doth it not grow denser and denser\nperpetually, and thereby cause the gravity of those great bodies towards\none another, and of their part towards the bodies, every body\nendeavouring to go from the denser parts of the medium towards the\nrarer?\"\n\nHere then we have given to us an indication of what is the possible\nstate of things in relation to the gravitation of the Aether, and all\nbodies in solar and stellar space. The only mistake that Newton made,\nwas in inverting the right order of comparatively dense and rarer parts\nof the aetherial medium, by putting the rarer parts of the medium near\nto the bodies, and supposing the denser parts to be farther away in\nspace.\n\nAs a matter of fact, the correct view is exactly the opposite, that is,\nif we are to form our conception by following out those philosophical\nrules that Newton laid down. For either the rules are right, or his\nsupposition is right. They cannot both be right, as his supposition is\ncontrary to the second Rule of Philosophy, as all experience and\nobservation from the analogy of Nature teach us that a medium enveloping\nany body, as planet, star or sun, is densest nearest to the body,\nbecoming rarer the further that medium gets away from the central body.\nLet us take for our illustration the best example, that experience and\nobservation afford, that of the atmosphere surrounding the earth. The\nanalogy is so perfect, that one is almost tempted to believe that the\natmosphere and the Aether are in some way intimately associated with\neach other. Some years ago Lord Kelvin was of the opinion that the\nAether was but an extension of the atmosphere, though I am not certain\nwhether he holds that view at the present time. Clerk Maxwell, writing\nin the _Phil. Mag._ in May 1861, writes: \"I have deduced from this\nresult the relation between statical or dynamical electricity, and have\nshown that the elasticity of the magnetic medium in air is the same as\nthat of the luminiferous medium, _if these two coexistent, coextensive,\nand equally elastic media are not rather one medium_.\"\n\nNow for the comparison. Both the atmosphere and Aether are matter. Both\nare atomic, both are gravitative, both possess elasticity, and both\npossess density. The atmosphere also possesses different degrees of\ndensity, so does the Aether. In the case of the atmosphere, however,\nexperience and experiment teach us that the atmosphere is denser nearer\nthe earth than farther away.\n\nWhen we ascend mountains, it is a matter of common knowledge that the\nhigher we ascend, that is the further we get from the earth, the rarer\nthe atmosphere becomes. When we ascend in balloons, we find that the air\nbecomes so rare and so light, that the blood will flow from the nose, on\naccount of the reduced pressure exerted on it, the pressure inside the\nbody being greater than that outside. Now in accordance with our second\nRule of Philosophy, if experience is to be any guide at all, then it\nmost conclusively teaches us that the Aether being subject to the same\nlaws as the atmosphere, the same results inevitably follow. Therefore\nthe Aether nearest the earth is denser than any layer immediately above\nit, and that layer denser than the one above it, and so on for great\ndistances, with the result that the only conclusion we can come to in\nregard to the density and rarity of Aether in relation to all\ngravitating bodies is, that the densest part of the Aether is nearest to\nthem, and the rarest, the farthest away from them. So that while\nNewton's suggestion in his nineteenth query is correct in principle, it\nis incorrect in application to space.\n\nI would like to point out here, that what is true of the earth in\nrelation to the density of the surrounding Aether, must also be true,\naccording to our second Rule of Philosophy, of every other planet, or\nsun, or star. So that every planet, satellite, every sun or star has its\natmosphere, if I may so term it, of Aether, which obeys and follows the\nsame laws as the earth's atmosphere does.\n\nThis is a most important fact, and has a most important bearing upon the\nphysical cause of Gravitation as applied to each planet, and sun and\nstar, as I shall afterwards show.\n\nI wish now to bring the reader into contact with a Theory of Gravitation\nthat was given to the world by Professor Challis of Cambridge, 1872. In\nthe _Philosophical Magazine_ of June of that year he writes: \"I assume\nthat all the active forces of Nature are different modes of pressure\nunder different circumstances of a universal elastic Aether, which\npresses always proportionately to its density.\"\n\nNow what I wish to point out is, that while Prof. Challis admits the\ndensity of the Aether, and also varying degrees of density, as he states\nthat the Aether presses proportionately to the density, he does not show\nhow that varying density is accounted for. If there is this varying\ndensity, then there must be some underlying principle which governs the\nvariation in density, and I know of only one principle or law which can\nregulate that variation in density, and that is that Aether is\ngravitative, and being gravitative it not only possesses density, but\nalso variations in density.\n\nThus by admitting that Aether is gravitative, because it is matter, we\nhave at once a satisfactory explanation for the density of the Aether\nand also for different degrees of density both in the atomic world, and\nin the planetary and stellar world.\n\n\nART. 47. _Aether is Elastic._--In Art. 39, matter was shown to be\nelastic, and on the assumption that Aether is matter, the elasticity of\nthe Aether, which has been postulated for it by various scientists, can\nbe logically and philosophically accounted for.\n\nIn view of the transmission of light through space with a definite and\nfinite velocity, we are compelled to regard Aether as possessing\nelasticity, similar to that of an elastic solid body.\n\nIf we take the analogy of sound, we find that sound is transmitted and\npropagated through matter, by waves of alternate condensation and\nrarefaction, and that transmission is regulated by the relation of the\ndensity of the medium to its elasticity. Light has been proved to be due\nto the undulatory wave-motions of the Aether, and in order to account\nfor the transmission of the wave-motion, it is essential that the Aether\nshould possess the property of elasticity.\n\nAs Young points out in his First Hypothesis,[6] the Aether possesses\nthis property of elasticity, but with the advance of scientific\nknowledge and research, the elasticity of the Aether may be said to have\npassed out of the hypothetical stage, into the state of actual fact and\nexperiment. Both McCullagh and Fresnel have assumed this property of\nelasticity for the aetherial medium in order to account for certain\nphenomena of light.\n\nApart, however, from the atomicity of the Aether, it is exceedingly\ndifficult to understand how such a property can belong to it. Atoms are\nexceedingly small particles, possessing the property of elasticity, or\nthe power to recover their original shape after distortion or change of\nshape. If the Aether therefore be atomic, as is pointed out in Art. 44,\nit can at once be readily understood how the Aether as a whole can\npossess the property of elasticity. The atoms of the Aether must be\ninconceivably small, as the light-waves travel with the enormous\nvelocity of 186,000 miles per second.\n\nWhat must therefore be the atomic vibration which such a statement\nimplies? If, on the other hand, the Aether is assumed to be continuous\nand non-atomic, it must be seen how exceedingly difficult it is to\naccount for the elasticity of the Aether, as it seems absolutely\nimpossible for a medium which is continuous, and non-atomic, to be able\nto transmit the waves of light with a finite velocity.\n\nApart, therefore, from atomicity of some kind or other, elasticity of\nthe Aether is an assumption philosophically incorrect, as it is contrary\nto that simplicity of conception laid down by Newton, and is also\ncontrary to all experience, and thus violates the second Rule of\nPhilosophy.\n\nAether therefore must be said to be perfectly elastic; so perfectly\nelastic, that it is susceptible to the least touch of any natural thing,\nso that even an atom, so small that it cannot be seen with the most\npowerful microscope, yet so elastic is this Aether medium, that the\nleast motion or vibration of one of these atoms, though the motion did\nnot exceed the 20- or 40-millionth part of an inch, yet even this would\ncreate in the aetherial ocean, Aether-waves, just as a body moving in\nwater creates water-waves, which, radiating from the place of their\nbirth, beget and create others, the process continuing until they reach\nthe margin of the water in which they were generated. It is precisely\nso with these Aether-waves, when once generated and set in motion. They\ncreate others, the process being continued and perpetuated; and, unless\narrested in their course, may continue until they reach the very limits\nand confines of material immensity and space.\n\nIt is, perhaps, only necessary to say, regarding the perfection of the\nelasticity of the Aether medium, that though it takes from 40,000 to\n69,000 waves to complete the space of one inch in extent, yet it is done\nwith such miraculous rapidity, as to speed the distance of 186,000 miles\nin the short space of a second of time; or, taking the number of\nAether-waves to complete an inch as 50,000, its elasticity is such that\nit makes 50,000 x 186,000 x 12 x 5280 vibrations in one second of time.\n\nWe have already seen in Art. 39, that according to Boyle and Marriotte's\nLaw, the velocity of a wave-motion, as sound in the air, is determined\nby the relation of the elasticity of the medium to its density. If the\ntemperature of the atmosphere remains the same, then the _elasticity_\nvaries in the same proportion as its density.\n\nAccording to Art. 45, Aether is gravitative, and that fact produces\ndifferent degrees of density in the aetherial atmosphere of an atom or\nplanet or meteor, sun or star; that part of the Aether being densest\nnearest the central body, and rarer the further we go away from that\nbody.\n\nNow the question at once arises, what is the effect of the increased\ndensity of the Aether near the body upon the elasticity of the Aether?\n\nFrom the analogy of sound in air, we arrive at the conclusion that Boyle\nand Marriotte's Law equally applies to the Aether, as it does to the\natmosphere of any planet. That is, if the temperature of any stratum or\nlayer of the Aether remains the same, then the elasticity of the\naetherial medium in that layer is proportionate to its density, so that\nwhile the gravitating property of the Aether makes it denser nearest the\ncentral body, the fact that the elasticity is proportionate to the\ndensity, does not affect the transmission of any wave-motion.\n\n[Footnote 6: _Phil. Trans._, 1802.]\n\n\nART. 48. _Aether possesses Inertia._--From Art. 40 we have seen that all\nmatter possesses inertia, inertia being that property of matter by which\nit cannot of itself change its state of motion or of rest.\n\nIf Aether be matter, therefore, then it must also possess inertia. This\nproperty of inertia is already postulated for Aether by scientists, and to\nthat extent is conformable to the Rules of Philosophy. Professor Tyndall,\nwith reference to the inertia of the Aether, writes: \"The motion of\nAether communicated to material substances throws them into motion. It\nmust be therefore itself a substance. Aether is a substance endowed with\ninertia, and capable, in accordance with the established laws of motion,\nof imparting its motion to other substances.\"[7]\n\nAgain, Lord Kelvin in his Address to the British Association, 1901, on\nthe \"Clustering of Gravitational Matter in any part of the Universe,\"\nstates: \"Aether we relegate to a distinct species of matter which has\ninertia, etc.\" Aether, therefore, according to Tyndall, \"is a substance\nor medium endowed with inertia, and capable, in accordance with Newton's\nLaws of Motion, of imparting its motion to other substances.\"\n\nIf, however, the Aether is frictionless, as has generally been supposed,\nthen it cannot possess inertia, because to the extent that a body\npossesses inertia, to that extent it is opposed to being frictionless.\n\nInertia is really the equivalent of mass, or the amount of matter\nmeasured by gravity, and if Aether possesses mass in any sense at all,\nas it must do if it is matter, then, possessing mass or weight, it must\noffer resistance to any body moving through it, and to that extent\ncannot be frictionless. To suppose that the Aether is frictionless, and\nyet possesses inertia, is to suppose something altogether opposed to all\nthe Rules of Philosophy and therefore of experience.\n\nI have already shown that a frictionless medium is opposed to all\nphilosophy and experience, and is an anomaly in the universe.\n\nOn the strictly philosophical assumption that Aether is matter, and\ntherefore atomic and gravitative, the whole question of the inertia of\nthe Aether is reduced to one of common experience. It is, at least to my\nmind, difficult to conceive of mass without weight or without atomicity,\nand yet that is the unphilosophical position of the present state of\nscience in relation to the Aether. In other words, while the Aether is\nsupposed to possess inertia, which is dependent upon mass, as measured\nby gravity, yet it is supposed not to be gravitative, that is, that the\nmass of the Aether has no weight at all, and therefore is not mass,\nwhich assumption contradicts itself. From Arts. 44 and 45, however, we\nhave seen, to be strictly philosophical, that Aether must be atomic and\nalso gravitative. It can now be easily understood how it can possess\ninertia like any other matter, and is therefore capable of receiving\nmotion from other matter, and also of imparting that motion to other\nmatter.\n\nSo that, wherever there is motion of any kind in the Aether, either in\nthe form of vibratory motion as heat, or undulatory motion as light, or\nrotatory motion as electricity, those motions will affect adjoining\nmatter in the same way that the motion of any other moving matter\naffects any body with which it comes into contact.\n\nFrom the fact that Aether possesses inertia, and is also gravitative, we\nhave now to alter our conception of this universal space-filling medium,\nand in place of a frictionless medium, which is incapable of imparting\nmotion to any body, we have now to remember henceforth that the Aether\nis matter, which possesses inertia, and therefore has the capacity not\nonly of offering resistance to any body moving through it, as a comet or\nmeteor, but also of imparting the motion which it may receive in any\nmanner to any other matter, as a planet, satellite, or sun, that may be\nfloating in it.\n\nWith this philosophical view of the Aether, which is entirely in harmony\nwith our first and second Rules of Philosophy, we shall be able to give\na physical explanation of the Law of Gravitation, as we have now a\nphysical medium existing in all atomic, solar, and stellar space, which\ncan both accept motion, and transmit that motion to other bodies. In\nother words, we have a medium which can both push and pull.\n\n[Footnote 7: _Lectures on Light._]\n\n\nART. 49. _Aether is Impressible._--Another characteristic property of\nthis Aether medium is, that it is as perfectly impressible as it is\nelastic. So perfectly impressible, that it receives, retains, and\nperpetuates for thousands of years, and for distances to human mind\nincalculable, every impression given to it of light, form, colour, tint,\nand shade; and that, too, with a perfect fidelity that nothing mars,\neven to the least and most infinitesimal detail.\n\nTherefore, irrespective of distance, wherever there is matter to arrest\nand reflect the impressions received, there those impressions of light\n(and all that in the luminosity is involved and contained) become\nvisible and revealed, and wherever there is power of vision to receive\nand concentrate these Aether- or light-waves, there, not only luminosity\nor light, but all that constitutes and is involved in that luminosity,\nbecomes at once visible and seen.\n\nIt is by this means we see the colour, tints, shades, and forms of suns\nand planets; of stars, constellations, etc., with all the varied forms,\nconfigurations, and movements of the celestial phenomena. Each and every\none, small or great, glittering or blazing, sun or planet, are ever\ncreating or generating Aether-waves, and impressing them with all the\ndetails and particulars of their nature and existence; and these\nAether-waves ever bear upon their mystic wings the impressions received,\ncarrying the information given with lightning speed to the very confines\nand limits of infinite space or the material universe; beyond which\nexists nothing but the ever-living and active energy of the Divine, the\nonly unlimited, unbounded, and absolute infinitive.\n\nIt is by the interception and concentration of these waves by our\nperceptive powers, aided with the giant powers of the telescope, that we\nobtain the information given, or become cognizant of the nature and\nexistence of the varied lights, colours, tints, and shades of the\ncelestial bodies.\n\nThe vision, assisted by the giant power of the telescope, collects and\nconcentrates these Aether-waves into a perfect image of those things\nthat gave them birth, and by this means reveals to us the knowledge of\nthings afar, their existence, nature, characteristics, properties, and\npowers.\n\nThus it is we see the solar orb, with its huge fires all aglow, obtain a\nknowledge of its character and powers, see its huge spots, its quivering\nfringe of flame, and high-leaping prominences, or watch its slowly\nrevolving form.\n\nThus we see the planets that around it sweep and roll; swift-footed\nMercury with his wondrous speed, and dazzling Venus with her silver\nsheen; Mars the god of war with his ruddy glow, and mighty Jupiter with\nhis orange hue, and the yellow Saturn with her mysterious rings, the\nblue Uranus, and the more distant Neptune, with all the satellites that\nto it belong.\n\nThen far far away the brilliant Sirius--the Dog Star, Cygnet, Centauri,\nthe Great Bear, and a thousand others.\n\nThe Pleiades and the twenty millions of suns that form our own galaxy\nand the Milky Way, with all their varied colours, tints, and hues of\nwhite, golden, orange, ruby, red and blue, green and grey, silver,\npurple and yellow, buff and fawn, emerald and green, lilac and coppery.\nThus we see the distant Orion, so far away that swift-footed Light, with\nits speed of more than eleven million miles per minute, has to travel\nfor more than thirty thousand years before it spans the gulf that\nintervenes between it and us, and brings to us the news of its existence\nthere.\n\nThen the spectroscope with its revealing power literally tears asunder\nwave from wave, and reveals the mystic message which each doth bear, of\nthe distant things from which they come, of each and every sort and\nkind.\n\nThus we know, that in the solar fires there ever burn such things as\nhydrogen, oxygen and nitrogen, and also, in a vaporous state, aluminium,\nsodium, iron, magnesium, cobalt, calcium, chromium, copper, manganese,\nzinc, and others.\n\nThus light-waves are speeding everywhere, and from all material things.\nThey come from our own sun, and rush in, and flood the earth's aerial\nveil, the atmosphere; and \"Each little atom of matter, like a mirror,\nreflects and re-reflects them as if in sport, buffeting each luminous\nray from one to another, increasing and amplifying it by an infinity of\nrepercussions\" (Herschel), and then in their entirety and whole, like a\nhuge multi-mirror, so blend and mingle them that they come to earth's\nsurface in that soft radiance we call Light, and bathe it as in a sea\nof mellowed glory.\n\n\nART. 50. _Aether: its Motions._--The question of the exact motions of\nthe Aether is a question which has involved the attention of scientific\nmen for many years, and which is at the present time receiving the\nattention of some of our most advanced scientists, not only in this\ncountry but in other countries also.\n\nWhether the Aether in space is at rest, or is moving along with all the\nbodies that float in it, so to speak, is a question of the greatest\nimportance to scientists and philosophers generally, as the particular\ncharacter of the motions of the Aether, which are either suggested or\nascribed to it from the analogies of Nature, are sure to have a most\nimportant bearing not only on the motions of all the planets and\nsatellites, but also upon such questions as the aberration of light, and\nsuch difficulties as presented by Lord Kelvin in his paper on \"Clouds on\nthe Undulatory Theory of Light\" (_Phil. Mag._, July 1902).\n\nI need hardly point out that the hypothesis that Aether is gravitative,\nis bound to play a most important part in the consideration and\ndevelopment of this phase of the study of the universal aetherial\nmedium. It is not my intention, however, at this stage of the work to go\nfully into the development of this aspect of the subject.\n\nThe application of this principle will be considered at the right time,\nand in the right place. It is, however, generally assumed, that the\nAether is at rest in space, and that the earth, the planets, and the sun\nand all stars, move through it with varying velocity, although, as Lord\nKelvin points out, such an assumption is covered with a cloud which up\nto the present is \"as dense as ever.\" Of course, if the Aether be at\nrest, and the planets and other heavenly bodies move through it with\nvarying velocity, then the only assumption regarding the Aether is, that\nit is frictionless, but, as I have shown in Art. 45, this is opposed to\nall philosophical reasoning, and therefore to experience and\nobservation.\n\nWe have, therefore, to postulate for the Aether such motions as shall\nfulfil all the Rules of Philosophy, that is, shall be simple in\nconception, shall be in harmony with our experience and observation, and\nwhich shall satisfactorily account for the phenomena sought to be\nexplained, that is, the universal Law of Gravitation; for it is by the\nproperties, combined with the motions of the Aether, that the physical\ncause of Gravitation is alone to be explained.\n\nLet us revert to the question of a stationary Aether for a moment or\ntwo, and let us ask ourselves, where is the evidence for such an\nassumption? Has the sun ever ceased to shine, or to send its light-waves\nwith their enormous velocity speeding through the solar system? So far\nas experience and observation go, I have never read of any record of\nsuch a fact, or that light-waves have ceased to proceed from the sun and\nfill the solar system with Aether-waves.\n\nNot only is this true of the sun, but it is equally true of every planet\nand satellite, every meteor or comet, every star and sun that exist or\ndwell in this aetherial medium; for, as has already been shown (Art.\n49), every body emits Aether-waves, and these waves spread out in all\ndirections in a spherical form.\n\nThe truth is, that the universal Aether is in eternal motion, and that\nmotion forms the physical life of the universe. If it were possible to\ndestroy the motion, then the whole fabric of the universe would fall to\npieces, and the beauty, order, and harmony of the celestial mechanism\nwould be replaced by disorder, confusion, and ultimate ruin. Take any\nanalogy of Nature, and see what such an analogy teaches us. Look at any\nplanet, sun, or star. Do we find any one of these stationary or at rest?\nWhy from the smallest meteorite or satellite, to the largest star that\nshines in the firmament of heaven, there is nothing but motion; each\nsatellite, planet, sun, and star moving on and on, ever and ever through\nthe countless ages of time until its course is run and its existence\nended. But rest, never! Such a thing as rest is unknown in the entire\nuniverse, whether it be in the atomic systems of matter, or the systems\nof stars and suns that form the universe of worlds.\n\nTake another illustration--that of the ocean! Is that ever at rest, with\nits unceasing wave and tidal motion? Has the reader ever stood on the\nshore and seen the ocean when it has been absolutely still, or when the\ntide has ceased to flow? Such a possibility is almost absurd to\ncontemplate. The same argument applies to the air with its regular flow\nof winds. Now in regard to the aetherial and universal medium, there are\njust as regular motions as the flowing of the tide round the earth, or\nthe revolving of a satellite round a planet, or a planet round the sun.\n\nAnd what is as important, all the motions can be as satisfactorily\nexplained and accounted for from the physical standpoint, as the flow of\nthe tide, or the revolution of a planet.\n\nYear in and year out, the motions of the Aether remain the same, governed\nby the same laws and producing the same effects. Age after age, the Aether\nhas been moving, producing by its various motions the continuity of that\nbeauty, order, and harmony that govern the universe as a whole.\n\nI have already indicated in Art. 45 the effect of Gravitation on the\nAether surrounding each satellite, or planet, or star, or sun. As each\nsatellite, or planet, or star moves through the universal Aether, it\ntakes with it its surrounding Aether as indicated in Art. 45, in the\nsame way that each planet or sun takes with it its own associated\natmosphere, which is held in contact with it by the self-same force of\nGravitation.\n\nIn addition to this motion of the aetherial atmosphere through space,\nthere are other motions of this same gravitating Aether that have to be\ntaken into consideration, before a complete and adequate conception of\nall the motions of the Aether can be arrived at.\n\nI do not intend, however, at this stage to go fully into such motions,\nbut rather wish to lead up to them from a consideration of hypotheses\nput forward by such men as Rankine, Challis, Maxwell, Lord Kelvin,\nMcCullagh, and Helmholtz, and from a consideration of such hypotheses in\nthe realm of heat, light, and electricity to be able to form a\nscientific conception of the proper motions of the Aether, as well as a\nphilosophical one.\n\n\n\n\n                               CHAPTER V\n\n                                 ENERGY\n\n\nART. 51. _Energy._--In the days of Newton, and for a long time afterwards,\nall energy went by the name of \"Force.\" Thus Newton in his Laws of\nMotion refers to the action of forces on stationary or moving bodies,\nand shows how the motion of any body is effected by the impressed force.\n(Art 13.)\n\nAs science advanced, and scientific research was carried into the fields\nof heat, light, and electricity, we find that the various forces began\nto be particularized, with the result that such terms as electrical\nforce, magnetic force, chemical force, etc., became common and familiar\nterms. As gradually it became known that one particular kind of force\nwas the outcome of another kind, there was given to the world such terms\nas the Correlation of Forces (Grove), in which he proved that whenever\none kind of force appeared as heat or light, it was at the expense of\nanother kind of force, as electricity.\n\nOf later years, however, another term has crept into Philosophy, and\ninstead of the term Force, which is very indistinct and indefinite in\ncharacter, there appeared the term Energy, although Force and Energy are\nnot exactly synonymous terms. Thus electricity, heat, and light are\nforms of energy, and are convertible into one another, in the same way\nthat the forces were convertible. Thus we get transformations of energy\nin the same way that we had transformations of force, and conservation\nof energy in the same way that we had conservation of force.\n\nEven the term Energy, however, is being replaced in the present times by\nsomething more definite and simple, and instead of the term Energy, we\nshall find, in the development of this phase of natural phenomena, that\nthat term is being replaced by the simple idea of motion, or modes of\nmotion, and that all forms of energy, as light, heat, magnetism, and\nelectricity, and even Gravitation itself, are due to motion of some kind\nor other. We will, however, lead up to this truth by looking briefly at\nthe term Energy, and see what it implies and embodies.\n\nEnergy, therefore, is that property which a body possesses, by which it\nis capable of doing work. Thus our ideas of work give us our conception\nof energy. For example, when a weight is lifted, work is done, and a\ncertain amount of energy is expended in the process. Further, the amount\nof work done is proportionate to the weight lifted, and the height to\nwhich the body is raised. Work is done against resistance, so that\nwhenever resistance is overcome, then work is the result. For example,\nsuppose one pound is lifted one foot high, in opposition to the force of\ngravity, then work is done, and this amount of work is known as a\nfoot-pound.\n\nIf a body weighs ten pounds, and is lifted ten feet, the work done is\nequal to ten pounds multiplied by ten feet (10 x 10 equals 100), so that\none hundred times the amount of work has been done in comparison with\nthe lifting of the one pound one foot high.\n\nAs all weight is essentially a gravitational measure, depending upon the\nintensity of gravity at the place, then, whenever a body is raised or\nlifted, the work so done is done against the gravity of the earth.\n\nWork is also done, as Newton points out in the first and second laws,\nwhenever we apply force to any body, either stationary or already in\nmotion. The results of all observation and experiments prove, that\nwhenever we have two bodies upon which work is being done, the amount of\nwork is determined by the amount of energy transferred from one body to\nthe other, and that the actual amount of energy gained by one is equal\nto the amount of energy lost by the other.\n\nEnergy is always found in association with matter, so that matter has\nsometimes been termed the Vehicle of Energy. Wherever, therefore, we\nfind energy of any kind or sort, there we find matter also, as the two\nare inseparably connected together. Thus, wherever we have heat, we have\nmatter in a particular state of motion, generally understood as\nvibratory motion Wherever we have light, which is also a form of energy,\nwe also have matter in motion, that is the Aether, in a state of\nperiodic wave-motion; and wherever we have electricity, we have again\nmatter possibly in a state of rotatory motion, as we shall see later on.\nEnergy, therefore, is the power which a body possesses to do work.\n\n\nART. 52. _Conservation of Energy._--The principle of the Conservation of\nEnergy was first enunciated by Mayer in 1842. The principle may be\ndefined as follows: The total amount of all the energy, as light, heat,\nelectricity and magnetism, Gravitation, etc., in Nature is unchangeable;\nso that, according to this law, the universe possesses a store of energy\nwhich is unchangeable in quantity throughout all time. The energy may\npass from one form to another, yet the total amount ever remains the\nsame. It is almost unnecessary to say, that this is a principle which,\nlike the conservation of matter, is incapable of absolute proof, but its\nassumption has greatly helped scientific thought and speculation from\ntime to time. Clerk Maxwell says (_Theory of Heat_) on this point: \"The\ntotal energy of any body is a quantity which can neither be increased\nnor decreased by any mutual action of the bodies, though it may be\ntransformed into those forms of which energy is susceptible.\"\n\nThe conservation of energy is inseparably connected with the\nconservation of matter (Art. 30). They cannot be divided, because, if\nenergy is only to be found in association with matter, then if the law\nof the conservation of matter falls to the ground, the principle of the\nconservation of energy falls with it. Energy, therefore, like matter,\ncannot be destroyed or created by any process known to man. As there is\nno process known, either in the chemical or in the physical world, by\nwhich new matter may be created by man, so, in relation to energy of any\nkind or sort, there is no process known by which man can create or even\ndestroy the smallest form of energy that exists. If energy appears in\nany body or in any particular form, it is solely because of the loss of\nenergy in some other body, or in some other form.\n\nAll changes of energy, therefore, are simply changes due to the\ndifference in form in which the energy is manifested. At one time it\nwill be manifested in the form of light, then of heat, then in\nmechanical motion, and so on. Joule gave us some good illustrations of\nthis principle of the conservation of energy. He showed us how\nelectricity could be changed into heat, and the heat into work. When\nlight, which is a form of energy, is absorbed by any opaque body, it is\nfound that the body which has absorbed it has become hotter. The energy\nof light has not been destroyed, but as its energy cannot pass through\nthe opaque body, it has been employed in agitating the particles and\natoms of that body, which becomes hotter in consequence.\n\nThus from the principle of the conservation of energy, which is in\noperation not only in our planetary world, but throughout the whole of\nthe solar and stellar space, and indeed throughout the whole universe,\nwe arrive at the conclusion that the total quantity of energy throughout\nthe universe is unchangeable. In the evolution and development of\nworlds, and in the destruction of those worlds after long periods of\ntime, throughout all the varied manifestations of heat, light,\nelectricity, and magnetism, associated with the development and\ndestruction of each globe, the sum-total of the energy of the universe\nremains the same. Meteors may rush into the atmosphere of planets, and\nbe dissolved into Aether through the friction, comets may be dissolved\ninto their component gases as they near the sun, water may be changed\ninto vapour by the heat of the summer sun, vegetation may be produced\nfrom apparently dead matter, and then that vegetation may itself decay\nand return to the dust by which it had been built up, but throughout all\nthese processes of birth and death, of evolution and devolution, the\nsum-total of active living energy which is associated with all the\nphenomena, remains unalterable and unchangeable. Such is the teaching of\nthe great principle of the Conservation of Energy as enunciated by Mayer\nand Helmholtz.\n\n\nART. 53. _Transformation of Energy._--One of the chief characteristics\nof energy is, that we can transform it, and it is chiefly of use to us\nbecause of its capability to be transformed, but in all its\ntransformations, the total quantity of energy remains the same. The\ntransformation of energy renders it necessary to the existence of all\nlife, and to all physical change in the universe. Mayer showed us that\nall energy in the solar system primarily derives its existence from the\nsun, and that all plant life and physical life owe their continued\nexistence to the energy which is poured out from the sun upon the\nplanetary worlds. So that energy is always flowing from the sun into the\nsurrounding space in the form of light, heat, and electricity, the\nmedium of its passage being the universal Aether.\n\nThis principle of transformation teaches us, that heat may be converted\ninto electricity; that light may be converted into heat, or electricity\nmay be converted into either heat or light or both. This principle of\ntransformation naturally follows from the principle of the conservation\nof energy; because, if energy cannot be destroyed in any way, but is\nmade to disappear by any process, it must reappear in some other form,\nand therefore has been transformed from its original state. So that,\nwhenever one kind of energy disappears, then it is absolutely necessary,\naccording to the principle of conservation of energy, that some other\nkind shall be produced. There cannot be any real loss or destruction.\n\nThat leads us to the next point regarding this principle of\ntransformation, which is that all transformations of energy take place\nin fixed proportions. When a certain quantity of coal is burned, a\ncertain quantity of heat, or thermal energy as it is sometimes called,\nis produced, and the quantity of heat so produced is definitely\nproportionate to the quantity of coal consumed.\n\nIf a certain quantity of coal were burned in a perfect steam-engine,\nthat is one in which there would be no loss of heat, then also a\ndefinite amount of mechanical work would be done, which would be\nstrictly proportionate to the heat generated by the consumption of the\ncoal. So that when coal is put into an engine, the potential energy of\nthe coal is transformed into kinetic energy of the steam, and that is\nagain transformed into actual mechanical energy of the engine itself, by\nwhich work is done in driving or pushing or pulling the train along, and\nthe amount of work done is proportionate to the coal consumed.\nIllustrations of transformation are common, and may be seen by any\nperson living in a large town. Thus at any electrical station or\nelectric tram terminus, these transformations of various forms of energy\nare very familiar sights. We have first the transformation of the coal\nin the furnace into heat. This heat converts water into steam, whose\nmotion is communicated by proper machinery into a dynamo, the product of\nwhich is electricity. That electricity is then conveyed along wires, and\nwork is done by it, by moving trams along the connected tram system, or\nit may be converted into heat in the carbon filament in the car itself,\nwhich, if heated enough, will then produce the electric light. So that\nstarting from the coal, we have several transformations therefrom into\nthe forms of heat, light, motion, and finally mechanical energy, which\nresults in Work. The question arises as to what is the law of\nequivalence in regard to the transformation of energy. That is, if we\nhave a certain amount of energy of a given sort, how much of any other\nsort can be produced by it? The answer is partly to be found in a\nstatement made by Joule in 1843, which practically embodies what is\nknown as the first law of Thermo-dynamics, and is as follows: \"When\nequal quantities of mechanical effects are produced by any means\nwhatever, from purely thermal sources, or lost in purely thermal\neffects, then equal quantities of heat are put out of existence or are\ngenerated, and for every unit of heat measured by raising a pound of\nwater one degree F. in temperature, you have to expend 772 foot-pounds\nof work.\" From this law we learn that heat may be used to do work, but\nthat a certain amount of heat is always used up in the process. It can\nalso be demonstrated that electric currents can do work, but to generate\nthe currents a certain amount of work must be done.\n\nThis equivalence and transformation prevail in all forms of energy,\nwhether it be mechanical energy, thermal or heat energy, or electrical\nenergy.\n\n\nART. 54. _Potential Energy._--Energy has been divided into two classes,\nwhich are termed respectively Potential Energy and Kinetic Energy. We\nwill look at the former first.\n\n_Potential Energy_ may be briefly defined as energy of position.\n\nThus if we lift a body from the ground, the energy which has been\nimparted to it is energy of position, or potential energy. A glacier\nhigh up the mountain possesses potential energy, because of its\nposition. By the mere fact that it is situated high up the mountain, it\nhas a capacity for doing work by its descent, and if that descent be\nvery sudden, the work done will be destructive work, as it may sweep\naway all houses and villages in its sudden descent. Thus, by the mere\nfact of its elevation, it possesses a power of doing work, which it has\nlost when it has descended. Again, work done in winding up the spring of\na clock is stored up in the form of potential energy, and gradually runs\nout in the form of motion or kinetic energy.\n\nPotential energy is really the complementary principle of kinetic\nenergy. That is to say, the amount of potential energy lost by any body,\nis equal to the amount of kinetic energy gained by the other body, to\nwhich the energy has been transferred. In the case of a body falling, as\nthe potential energy diminishes, the kinetic energy increases, but the\ntotal amount of the two combined always remains the same. This is well\nillustrated in the case of a swinging pendulum. When a pendulum is at\nthe highest point of its swing, its velocity or kinetic energy is zero,\nbut at that point its potential energy is greatest. As it descends, the\npotential energy decreases, but the kinetic energy increases. When the\npendulum is at the lowest point its energy is wholly kinetic, the\npotential energy being zero at that point, while it has sufficient\nkinetic energy to raise it to the highest level again. Throughout the\ncycle of these operations, the sum-total of the two energies always\nremains the same.\n\nProfessor Tait points out, in his _Recent Advances in Physical Science_,\nthat the available sources of all potential energy may be divided into\nfour classes--\n\n    1st. Fuel.\n    2nd. Food of Animals.\n    3rd. Water-power.\n    4th. Tidal Water-power.\n\nAll these are different forms of potential energy. Under the head of\nfuel he includes not only wood, coal, but also all forms of matter that\nmay be used or burnt up by heat, or dissolved by chemical agencies. Thus\nzinc and lead, which are used in batteries, are merely forms of fuel.\nThat potential energy resides in such things as wood and coal is a\nmatter of common experience. All our coal-fields are stores of energy,\nwhich received their energy when in plant form, ages ago, from the sun,\nand this energy is now being used to drive our machinery, to warm our\nhouses, and to give light to our homes and our cities. It has been\ncalculated that a pound of coal would give out 14,000 heat units, which\nis equal to 11,000,000 foot-pounds of work, which is also equal to the\namount of work a horse can do in five hours. Again, all food, whether it\nbe the food of animals, as vegetables and plants, or of man, as bread,\nmeat, etc., are all forms of potential energy, or energy which is stored\nup in matter. All forms of food have a certain amount of energy in them,\nwhich is used up in the body in building up waste tissue and imparting\nenergy to the physical frame.\n\nAgain, all forms of water-power, whether it be in the form of the\nflowing river or the tidal motion of the sea, possess a large amount of\npotential energy which may be used up to do mechanical work. They also\npossess kinetic energy, or energy of motion. We find illustrations of\nthe possession of potential energy by rivers and tides, in the fact that\nby their fall from a higher to a lower level they may be made to do\nmechanical work, as in the case of the turning of the water-wheel by the\nfall of the water, which motion is communicated to machinery, and\nvarious forms of work are the result. In Switzerland and America\nadvantage is being taken of the energy of falling water to generate\nelectricity, by means of which villages and towns are being supplied\nwith electric light at a very small cost.\n\n\nART. 55. _Kinetic Energy._--Kinetic energy may be defined as energy of\nmotion, and is the energy which a body possesses in consequence of its\nmotion. A body in motion thus possesses kinetic energy, which it must\nimpart to some other body before it can be brought to a state of rest.\nThe body may be simply an atom, as a vortex atom, but if it be in\nmotion, as all atoms are, then it must possess kinetic energy, which may\nbe transferred to another atom by collision, or by some other method. As\nhas already been pointed out in previous articles, kinetic and potential\nenergy are complementary to one another, the sum-total of the two\ncombined always remaining the same in any cycle of work, according to\nthe principle of the conservation of energy. We get a good example of\nthis oscillation from kinetic to potential, and _vice versa_, in the\nplanetary system. When the earth is farthest from the sun, its velocity,\nand consequently its kinetic energy, is at its lowest point; but there\nthe potential energy is at its greatest. As the earth turns round in its\norbit, however, and begins to approach the sun again, its potential\nenergy decreases, while its kinetic energy increases with its increased\nvelocity. So that by the time it has reached the nearest part of its\norbit to the sun, its velocity, and consequently its kinetic energy, is\nat a maximum, while the potential energy is at a minimum. Then as the\nearth passes round its perihelion, the kinetic energy is used up in\nassisting the earth to overcome the attraction of the sun. Thus there is\nthis oscillation from kinetic to potential, and from potential to\nkinetic, year in and year out, as the earth performs its cycle round its\ncentral body the sun.\n\nProfessor Tait, in the work referred to in the previous Article, gives\nexamples of kinetic forms of energy under the following heads--\n\n    1st. Winds.\n    2nd. Currents of Water.\n    3rd. Hot Springs and Volcanoes.\n\nIt can be readily seen that winds are a form of energy, as we have\ninnumerable instances of the power and energy which they exert.\nAdvantage is taken of that kinetic energy by means of windmills, in\nwhich the energy of the wind is imparted to the revolving sails, and\nthence to the machinery, various forms of mechanical work being the\nresult, as, for example, the grinding of corn, or the pumping of water.\nThe pressure or energy of winds has even been calculated, the following\nfigures being examples--\n\nVELOCITY IN MILES PER HOUR.   FORCE IN LBS. PER SQ. FOOT\n\n           1 mile.               .005 lb. per sq. foot.\n           5  \"                  .123  \"   \"     \"\n          10  \"                  .496  \"   \"     \"\n          15  \"                 1.11   \"   \"     \"\n          20  \"                 1.98   \"   \"     \"\n          30  \"                 4.5    \"   \"     \"\n          40  \"                 7.9    \"   \"     \"\n          50  \"                12.5    \"   \"     \"\n\nIn the case of currents of water, whether they are in the form of river\ncurrents or ocean currents, as has already been pointed out in the\nprevious article, the question of potential energy, or energy of\nposition, is associated with their kinetic energy. Water is taken at a\ncertain elevation, and then allowed to fall to a lower level, and in its\nfall from the high level to the lower level, its kinetic energy is used\nto drive mill-wheels, and thus work is done, the kinetic energy of the\nwater being transformed into the motion of the machinery. This machinery\nmay be used to work a dynamo, and thus electric light may be generated,\nor it may drive an electric motor which may perform all sorts of\nmechanical work. The great underlying principle of either kinetic or\npotential energy rests in the fact, that wherever we have energy of any\nkind or sort, whether it be associated with water, wind, or Aether,\nthere we have the capacity to do work, the amount of work depending upon\nthe amount of energy that exists in the matter which is the vehicle of\nenergy.\n\nIn Art. 50 it has been indicated that the Aether possesses several kinds\nof motions. From the sphere of light and heat, we learn that the Aether\npossesses certain motions which are always exerted in a direction from\nthe central body, which gives rise to the light- and heat-waves. That\nbeing so, it conclusively follows that the Aether possesses kinetic\nenergy, and therefore, possessing this energy, it also possesses the\npower to do work. It must be remembered we are no longer dealing with a\nfrictionless medium, but with a gravitating medium, possessing mass and\ninertia, and, that being so, wherever we have the Aether in motion,\nthere we have kinetic energy or the power to do work; and that work will\ncorrespond to the particular kind of motion which is exerted on any body\nby the aetherial motions, and will be equally subject to Newton's Laws\nof Motion.\n\n\nART. 56. _Energy and Motion._--An advance, however, as to the meaning of\nthe term Energy has been made within recent years, which brings it more\ninto harmony with that simplicity of conception, and accordance with\nexperience which are the very foundation of all philosophy. Instead of\nthe term Energy, there is now being used another term to denote the\nforces which form the life of the universe, and that term is the word\n\"Motion.\"\n\nProfessor Poynting says: \"All energy is energy of motion\" (_British\nAssociation Report_, 1899).\n\nThus motion is the fundamental principle of all phenomena. If we analyze\nall forms of energy with which we are familiar, we shall soon find that\nthey are only changes of one form of motion into another. Thus we shall\nsee that heat is a mode of motion, as has been proved by Tyndall, that\nlight is another mode of motion, and that electricity is also a mode of\nmotion. I need hardly point out that this advance in our conception of\nenergy is strictly in accord with the Rules of Philosophy. First, it is\nsimple in conception. When we say that a body possesses energy, whether\nthat energy be potential energy or kinetic energy, it does not convey to\nthe mind some definite concrete fact, as does the statement that a body\npossesses motion. Every one, whether familiar with scientific teaching\nor not, understands and is familiar with the word Motion, as it is a\ncommon phenomenon of everyday life and experience. As Energy was simpler\nin conception than Newton's term Force, so Motion is simpler in\nconception than the rather vague and indefinite term Energy; therefore\nwhen we say that all energy is energy of motion of some kind or sort, we\nstate that which is philosophically correct.\n\nIt is also in accord with the second Rule of Philosophy, in that it is\nstrictly in harmony with experience and observation. Look where we will,\nor at what we will, there we find motion of some kind or other, whether\nit be among the innumerable stars, or in our own solar system, or any\nphenomena on the earth, or even among the world of atoms in their minute\nand atomic systems. Such a thing as absolute rest, or stagnation, is\nunknown in the universe. Wherever there is matter, there we find motion\nof some kind or other. It may be vibratory motion as heat, or wave\nmotion as light, or rotatory motion as electricity, but motion of some\nsort is inseparably connected with all matter. So that when we say that\nall energy of the universe is the energy of motion, and motion only, we\nstate that which according to the second Rule of Philosophy is\nabsolutely correct.\n\nFurther, I wish to premise that by the use of the term modes of motion,\nin lieu of energy, the third Rule of Philosophy will be fulfilled. For\nif all phenomena of the universe, whether it be heat, light,\nelectricity, be due to different modes of motion, then Gravitation\nshould be explained from the physical standpoint by some kind of\naetherial motion also. This I can safely premise will be done, and in\nthe later chapters of this work, Gravitation will be shown to be due to\nthe motions of the aetherial medium which floods all space. By so doing,\nall the Rules of Philosophy will be fully satisfied, and Gravitation\nwill then be brought into line with all the other forms of motion, as\nheat, light, electricity, and magnetism, which are in themselves modes\nof motion, as will be shown in subsequent articles.\n\n\nART. 57. _Conservation of Motion._--If it be true that all energy is the\nenergy of motion, then the principle of the conservation of energy ought\nalso to apply to all the modes of motion, and in its place we should\nthen have the principle of the conservation of the various forms of\nmotion. This defined would be, that the total amount of all motion in\nthe universe, as heat and light, electricity, magnetism, and Gravitation\nalso, if that be due to the motion of the Aether, is unalterable and\nunchangeable.\n\nThere may be changes from one form of motion to another, from heat to\nlight, and light back to heat; heat into electricity, and electricity\ninto light or heat; from Gravitation into heat or into light, or even\ninto electricity; but the sum-total of the whole remains the same.\n\nAgain, as the principle of the conservation of energy is inseparably\nconnected with the conservation of matter, so the principle of the\nconservation of all the modes of motion is also inseparably connected\nwith the conservation of matter. They cannot be divided, so that\nwherever we get matter of any kind or sort, there we get motion of some\nkind, either in the form of heat, light, or electricity, or those\naetherial motions which produce those phenomena associated with\nGravitation.\n\nAs matter cannot be destroyed by any known process to man, so motion\ncannot be destroyed either. On the vortex atom theory of matter, this\nprinciple of the conservation of any mode of motion is perfectly\nintelligible, especially if added to that theory we have Dr. Larmor's\nelectron theory as the basis of the vortex atom. An atom in its ultimate\nstate is nothing more or less than Aether in rotation, and as Aether is\nmatter, we see that on the assumption of this atomic basis, we have even\nin the atomic world an illustration of this conservation of matter and\nmotion, as in such an atom we have nothing but matter (_i. e._ Aether)\nand motion. Carrying the idea upwards in the atomic scale, if atoms of\nhydrogen or oxygen are multiples of these vortex atoms, then again we\nhave nothing in all the elements, or combination of the elements, but\nmatter and motion. Again, as all planets and satellites, suns and stars,\nare but agglomerations of elements, we have still the same two classes\nof things, matter and motion, and so from the most infinitesimal atom in\nexistence, up to the most ponderous star that exists in the universe, we\nhave running through them all the principle of the conservation of\nmotion, which is to matter the source of all its activities, energies,\nand powers. Motion, therefore, might almost be said to be eternal. We\nhave heard from time to time of the term perpetual motion. Philosophers\nhave from time to time endeavoured to discover some application of this\nperpetual motion, but all efforts in this direction up to the present\nhave proved futile. In one sense there is no such thing as perpetual\nmotion. In another sense, that is from the standpoint of the\nconservation of all modes of motion, as motion cannot be destroyed, it\nmust therefore be perpetual.\n\nIt is an absolute impossibility to obtain motion except from some\nantecedent energy, which is itself a form of motion. It would require\nthe distinctive fiat of an Almighty Creator to produce motion from\nnothing, and I question whether such a result is obtainable, as I hold\nthat if the Creator, at any time in the history of the universe, set any\nsubstance in motion, the source from which that motion was derived, was\nHis own Divine Energy, and in that sense the physical motion was not\nproduced from nothing. Such an assumption is altogether opposed to all\nphilosophical reasoning and experience. I hope to deal with the question\neither in the last chapter of this book, or in another work.\n\n\nART. 58. _Transformation of Motion._--Again, if energy be the energy of\nmotion, and the principle of the transformations of energy holds good,\nthen it is equally true that all modes of motion are also transformable.\nThus heat is a mode of motion, being due to the vibration of the atoms\nwhich go to make up any body. Light is also a mode of motion, being due,\nas far as solar light is concerned, to the periodic wave motion of the\nAether. While electricity, as we shall see later on, is also due to some\nform of rotatory motion. It has already been shown (Art. 54) that light\ncan be converted into heat, so that the periodic wave motion of light\ncan be transformed into the vibratory motion of heat.\n\nHeat can also be converted into electricity, and if electricity be\nrotatory motion, then the vibratory motion of heat can be transformed\ninto the rotatory motion of electricity. Again, as electricity can be\nconverted into light, the rotatory motion of electricity can thus be\ntransformed into the periodic wave motion of light. Thus through all the\nforms of motion with which we are familiar, we find this principle of\ntransformation holds good, so that each form of motion may be directly\nor indirectly transformed into any one of the other kinds. Whenever,\ntherefore, one kind of motion disappears, it is absolutely necessary,\naccording to the principle of the conservation of motion, that some\nother kind shall be produced. There cannot be any real loss or\ndestruction of the motion. It may be transformed, but not lost. By the\nuse of proper apparatus, therefore, any form of motion with which we are\nfamiliar may be converted into another form, and in the process not the\nleast quantity of any form of motion is lost. Heat may be changed into\nlight, and light into heat; electricity into light, and light into\nelectricity; heat into electricity, and electricity into heat. Indeed,\nstarting from any one form, any of the other modes of motion may be\nproduced, either directly or indirectly, and mechanical effects or work\nmay be produced by each and all. Then, again, the order can be reversed,\nas by doing work which is simply applied motion, any of the other modes\nof motion can be produced. Thus heat can be produced by friction, and if\nthe friction which is the outcome of muscular energy be continued long\nenough, a light will be the result, in the form of fire. When certain\nforms of work are done, as the turning of the handle of an electrical\nmachine, frictional electricity will be produced. So that not only are\nall the modes of motion convertible into work, but work itself can be\ntransformed into the modes of motion known as heat, light, electricity,\nand magnetism.\n\nNow, if Gravitation be due to motion of the Aether, and if it is true\nthat all modes of motion are convertible, then the application of this\nprinciple should also hold good in relation to Gravitation. It has been\ndemonstrated by Joule and others that Gravitation can be converted into\nheat, light, and electricity. It can be converted first into heat. Joule\nmade a number of experiments to ascertain what quantity of heat is\nproduced by falling bodies, that is bodies under the influence of\nGravitation. From experiments he has calculated that if one lb. of water\nfalls through a space of 772 feet, it would raise the temperature of\nthe water one degree Fahrenheit--that is, the water after its fall will\nbe one degree hotter than when it started to fall. Here, then, we have\nthe exact equivalence of a certain amount of gravitational motion\nexpressed in terms of heat. So that, whenever motion of a falling body\nproduced by gravity is arrested, heat is generated, and as heat is a\nmode of motion, it follows that the motion of Gravitation has been\nconverted into the motion of heat. Again, the motion of gravity may be\nconverted into that of light. This may be demonstrated as follows: Lord\nKelvin has suggested that the light and heat of the sun are maintained\nby the falling into the sun of meteorites. Now the cause of the falling\nof these meteorites into the sun is the Attraction of Gravitation, and\ntherefore if the falling of these meteorites produces light and heat, it\nnecessarily follows that the motion of Gravitation, whatever that may be\ndue to, is converted into the motion known as light and heat. Thus it\ncan be seen that Gravitation, looked at from the standpoint of a mode of\nmotion, is itself conformable to the principle of the transformation of\nmotion, and this is an indirect argument in favour of the fact that\nGravitation is itself due to certain motions of the universal Aether.\n\n\nART. 59. _Motion and Work._--In Art. 52 we have seen that energy is the\npower which a body possesses to do work, the amount of work which a body\ncan perform being regulated by the amount of energy which such a body\npossesses. In Art. 57 we have further seen that all energy is the energy\nof motion, and that wherever we have energy of any kind or sort, whether\nit be in the form of light, heat, or electricity, there we have motion\nof some kind or other. That being so, we arrive at the conclusion, that\nwherever in the universe we have motion of any kind or sort, whether it\nbe the motion of Aether, or wind, or water, there we have the power of\ndoing work, and the work so done will be proportionate to the motion\nwhich the medium possesses. The amount of work that air in motion can do\nhas been measured, as we have already seen (Art. 55) that air which\nmoves at the rate of 30 miles per hour exerts a force of 4-1/2 lb. per\nsquare foot.\n\nThe amount of work that water in motion can do has also been measured.\nThe carrying and erosive powers of a river depend on the rapidity of its\ncurrents. It has been calculated that a velocity of three inches per\nsecond will transport fine clay; eight inches per second coarse sand;\nwhile three feet per second will transport stones as large as eggs.\n\nIf, therefore, air moving at the rate of 30 miles an hour can exert a\nforce of 4-1/2 lb. per square foot, what must be the force or pressure\nof aetherial motion, as light-waves for example, which move with a\nvelocity of 186,000 miles per second? The amount of work which such an\naetherial motion can perform has actually been measured by Professor\nLebedew of Moscow, and will be dealt with in the chapter on \"Light, a\nMode of Motion,\" when the application of the work done on a body, as a\nplanet for example, will also be considered. Work, therefore, can always\nbe done by motion against resistance. This is a fundamental principle in\nthe sphere of dynamics, which is incontrovertible, as all experience,\nobservation, and experiment teach us, that wherever we get motion of any\nkind or sort, there we have the capacity or power to do work. The work\ndone may be either in the form of pushing a body along, or pulling a\nbody towards a centre. All experience and observation teach us that no\nbody moves (whether it be an atom, or moon, or planet, or sun, or star),\nunless some other body or medium, which is in direct contact with the\nmoving body, exercises some pressure or pull upon the moving body. The\naction is purely and simply a mechanical one. So that if this be true,\nthen the earth and the planets, the sun and stars, comets and meteors,\nare moved through space solely because they are being pushed by some\nmedium, or pulled to the centre by the motions of the same medium. If\nthis can be proved to be true, then, as can be readily seen, our\nphilosophy will then be made to agree with our experience, and the\nsecond Rule of Philosophy fully satisfied. As has already been pointed\nout, there is no such thing as action at a distance, therefore the Law\nof Gravitation demands a medium for its operation, production, and\ncontinuity. Newton distinctly points this out in his Letters to Bentley,\nwhere he says: \"That one body should act upon another through empty\nspace without the mediation of anything else, by and through which their\naction and pressure may be conveyed from one to another, is to me so\ngreat an absurdity that I believe no man who has in philosophical\nmatters a faculty for thinking can ever fall into it.\" It has already\nbeen pointed out (Art. 42), that the only medium which is universal is\nthe Aether medium, and we have therefore to look to the motions and\nproperties of that medium for the solution of the problem as to the\nphysical cause of Gravitation. That such a medium has motions which are\nas regular as the tides of the sea, or the trade winds of the\natmosphere, will be proved later on, when it will be found that\nGravitation, with all that that law implies, is due, as Newton and\nChallis suggested, to the pressure, properties, and motions of the\naetherial medium, which is as universal as Gravitation itself. This\nbeing so, it is essential that we should set ourselves to find out from\nthe analogies of Nature, what are those properties and motions of the\nAether which give rise to the universal Law of Gravitation. This I\npropose doing by a consideration of three different modes of\nmotion--viz. Heat, a mode of motion; Light, a mode of motion; and\nElectricity, a mode of motion. I venture to premise, from a careful\nconsideration of these three truths, that we shall be able logically and\nphilosophically to arrive at the simple, yet grand truth which reveals\nthe physical source of all motion of the universe.\n\n\n\n\n                              CHAPTER VI\n\n                            HEAT IS MOTION\n\n\nART. 60. _Heat is Motion._--On the phenomena of Heat, Newton in his\neighteenth query in _Optics_ asks the questions: \"Is not the heat of a\nwarm room conveyed through the vacuum by the vibrations of a much\nsubtler medium than air, and is not the medium the same as that medium\nby which light is reflected and refracted, or by whose vibrations light\ncommunicates heat to bodies? And do not the vibrations of this medium in\nhot bodies, contribute to the intenseness and duration of their heat?\nAnd do not hot bodies communicate their heat to contiguous cold ones by\nthe vibrations of this medium propagated from them into the cold ones?\nAnd is not this medium exceedingly more rare and subtle than air, and\nexceedingly more elastic and active?\" Thus it can be seen that Newton\nwas of the opinion that heat consists in a minute vibratory motion of\nthe particles of bodies, and that such motion was communicated through\nwhat he calls a vacuum by the vibrations of an elastic medium, the\nAether, which was also concerned in the phenomena of light.\n\nOne of the first experimental investigations into the real nature of\nHeat was made in 1798 by Count Rumford.\n\nWhile he was engaged in boring brass cannon in the arsenal at Munich, he\nwas struck with the degree of heat which the brass gun acquired, and\nwith the still more intense heat which the metallic chips, which were\nthrown off, possessed. Of the phenomena he says: \"The more I meditated\non these phenomena, the more they appeared to me to be curious and\ninteresting. A thorough investigation seemed even to bid fair to give us\na farther insight into the hidden nature of Heat.\" Rumford therefore set\nhimself to find out by actual experiments what the nature of Heat was.\nFor this purpose he constructed a cylinder, and mounted it so that it\ncould be made to rotate by horse-power. At the beginning of the\nexperiment the thermometer stood at 60 deg. Fahrenheit, and after\nhalf-an-hour, when the cylinder had made 900 revolutions, the\ntemperature was found to be 130 deg. Fahrenheit, so that there had been\nan increase in the temperature of the cylinder of 70 deg. Fahrenheit.\nThe experiment was again repeated in another form with similar results.\nRumford in dealing with the results of his experiments said: \"It appears\nto me to be extremely difficult, if not quite impossible, to form any\ndistinct idea of anything capable of being excited and communicated, in\nthe manner the Heat was excited and communicated, in these experiments,\nexcept it be Motion.\"\n\nOnly a year later, Davy gave to the world some results of experiments\nwhich he had performed, by which he had arrived at a similar conclusion\nto that of Rumford, viz. that \"Heat is motion of some kind.\" His\nexperiment consisted of rubbing two pieces of ice together, and by so\ndoing showed the ice could be melted. He then caused two pieces of metal\nto be rubbed together, keeping them surrounded by ice, and still he\nfound that the two pieces of metal when rubbed together, produced heat,\nand melted the ice. He therefore rightly concluded that heat was\nproduced by friction, and of the experiment adds: \"A motion or vibration\nof the corpuscles of bodies must necessarily be generated by friction.\nTherefore we may reasonably conclude that this motion or vibration is\nHeat. Heat then may be defined as a peculiar motion, probably a\nvibration of the corpuscles of bodies tending to separate them. It may\nwith propriety be called a repulsive motion. Now bodies exist in\ndifferent states, and those states depend upon the action of the\nattractive and of the repulsive powers on their corpuscles, or in other\nwords, on their different quantities of repulsion and attraction.\" It\nwas not, however, till 1812 that Davy confidently stated that \"The\nimmediate cause of the phenomena of Heat is motion, and the laws of its\ncommunication are precisely the same as the laws of the communication of\nmotion.\"\n\nThe question therefore confronts us, if heat be motion, what is the\nparticular character of that motion? Is it a vibratory motion as Davy\nsuggested, or is it similar to the undulatory wave motion of light? I\nneed hardly point out, that we have evidence in favour of the hypothesis\nthat light is due to some form of periodic wave motion in the Aether,\nthe hypothesis being that known as the undulatory theory. We have also\nsimilar evidence in favour of the hypothesis, that heat is also due to\nsome form of motion of the same aetherial medium. Indeed, it can be\nshown that heat possesses all the properties of light, and is subject to\nthe same laws, with the exception that it cannot affect the sense of\nsight.\n\nHeat, then, is due to some motion in the universal aetherial medium,\nthat not only fills all space, but also forms an atmosphere around every\natom or particle of matter that exists in the universe, and that motion\nis generally known as a vibratory or backward and forward motion.\n\nHeat, then, may be said to be due to the vibrations of the Aether that\nsurrounds all atoms and molecules, and of which those very atoms are\ncomposed, that is if we accept the aetherial constitution of all matter.\nSo that, whenever a body, whether it be an atom or a molecule, or a\nplanet or sun or star, is heated in any way whatever, such bodies excite\nwaves in the surrounding Aether, and these waves travel through the\nAether towards us from the heated body with the velocity of light. When\nthese waves fall upon any other body, they become more or less absorbed\nby the body on which they fall, and cause corresponding vibratory\nmotions in the same, which give rise to the phenomenon of heat in that\nparticular body.\n\nIt has to be remembered that nothing definite is actually known as to\nthe character of this vibratory motion. It is called a vibratory motion\nbecause it possesses a periodic vibratory movement, but as to its exact\ncharacter, that has not yet been discovered. I hope, however, to\nindicate what the motion is that produces heat before the completion of\nthis work.\n\n\nART. 61. _Heat and Matter._--If it be true that heat is due to the\nvibrations of the aetherial medium, the question now arises, as to how a\nbody may become heated, and by so doing be transformed into the three\nstages in which matter is found. We have already seen (Art. 36), that\nmatter may be found in three forms, viz. solid, liquid, and gaseous, and\nthat all these different forms of matter are composed of minute parts\ncalled atoms. In the case of the solid, the atoms are held closely\ntogether by some strong attractive power, termed cohesion; in the case\nof the liquid, the atoms have a greater freedom; while in the gaseous\nform they have a greater freedom of movement than when in either the\nliquid or the solid state. According to Young's Fourth Hypothesis (Art.\n45), we find that all matter, and therefore all atoms have an attraction\nfor the Aether, by means of which it is accumulated within their\nsubstance, and for a small distance around them in a state of greater\ndensity, and therefore of greater elasticity. In other words, as Aether\nis gravitative, every atom possesses an atmosphere of Aether in the same\nway that the earth has its atmosphere of air; and further, the aetherial\natmosphere of each atom is densest nearest to the atom, gradually\ngetting rarer and rarer the further the atmosphere recedes from the\nnucleus or centre, the elasticity or pressure being always proportionate\nto the density. Professor Challis, in his Dynamical Theory of Light and\nHeat, states that all the forces in Nature are different modes of\npressure under different circumstances of the universal Aether, and as\nheat is a Force, and therefore a mode of motion, that also must be due\nto some form of pressure due to the vibrations of the Aether.\n\nProfessor Challis[8] on this point says: \"According to this theory, the\natoms of any substance are kept in position of equilibrium by attractions\nand repulsions resulting from the dynamical action of the vibrations of\nthe Aether which have their origin at the atoms. Each atom is the centre\nof vibration propagated equally from it in all directions, and that part\nof the velocity of the vibration which is accompanied by change of density\n(of the Aether) gives rise to a repulsive action on the surrounding\natoms. This action is the repulsion of heat, which keeps the individual\natoms asunder.\"\n\nWith all these facts before us, we are now in a position to account for\nthe changes of matter which take place when heat is applied to either\na solid or a liquid body. We have already seen (Art. 36) that it is by\nthe application of heat that matter in its solid form is changed into a\nliquid, and from a liquid into a vaporous or gaseous form. It is now for\nus to endeavour to form a mental picture as to how this is done.\n\nFor example, let us take an iron ball, and apply heat to it, either by\nputting it in a furnace or suspending it in some way over an intense\nheat. As the heat, which is vibratory motion of the Aether, begins to be\nabsorbed by the iron ball, it sets the atoms which compose the ball in\nmotion, urging them to separate, and thus cause the iron ball to expand\nand increase in volume. As greater heat is absorbed, so greater motion\namong the atoms is the result. So that the motion of heat is tending\nall the time to expand the body, while they are held together by the\nattraction of cohesion, whatever that may be. As the heat is further\nincreased, the iron ball begins to assume a liquid or molten form, its\natoms beginning to move about with greater freedom, though held together\nby a decreased attractive power. In this condition we now say that it is\nin the molten state. Now during all this time, what has the Aether been\ndoing, or what part has it played in the expansion and changing of the\nsolid to a liquid? We have to remember, from Art. 60, that wherever\nthere is motion of any kind or sort, there we have a capacity to do\nwork, and that the aetherial motion which we term heat is no exception\nto this rule. We are now no longer dealing with a frictionless medium,\nbut with a medium which possesses weight, because it is gravitative, and\nconsequently possesses inertia also. So that whenever the Aether is set\nin motion by flame or heat, its motion would be transmitted by waves of\nsome kind to the iron ball. These periodic waves, acting upon the mass\nof the ball, attack the molecules of the ball and begin to set them in\nmotion. It is supposed that they are already in motion, as nothing is\nabsolutely cold, and the motion of the aetherial waves imparts a greater\nmotion still to the molecules, with the result that the agitation\nbecomes greater and greater, until at length the agitation becomes so\ngreat, that the molecules break away from the power of attraction that\nholds them together, and so begin to move about with greater freedom and\nwith greater rapidity. It is this state which we call molten. Now if\nAether be frictionless, as has hitherto been supposed, and if heat be\ndue to the vibratory motions of Aether, the problem confronts us, as to\nhow the motion of a frictionless medium can do work in expanding a body,\nand urging the molecules of a body further and further apart. If the\nAether be frictionless, then the waves of Aether known as aetherial heat\nwaves ought to pass between the atoms as water passes through a sieve,\nor wind passes through a forest. Yet it is assumed that the vibratory\nmotions of a hot body are caused by vibrations of the periodic waves of\nthe Aether, which act upon the molecules of the body; and, in order for\nsuch an assumption to be consistent with the results, the only possible\nconception that can be accepted of the Aether, is that it is\ngravitative, and consequently possesses mass and inertia, and therefore\nhas a capacity not only to accept motion, but also to transmit motion to\nanother body, and impart the motion which it has accepted to a colder\nbody.\n\nBy imparting such motion, it increases the motion of the cold body, and\ngradually changes its state from a solid to a liquid condition. Here,\nthen, from the realm of heat we have another argument in favour of the\nfact that Aether is gravitative, and therefore possesses mass and\ninertia.\n\nIn the experiment of reducing the iron ball from a liquid state, so to\nspeak, to a vaporous condition, we have practically a continuation of\nthe same process, only that greater heat or greater aetherial motion is\nrequired, and whereas in the previous experiment the molecules of the\nball were acted upon, in this case the atoms are more directly acted\nupon by the Aether waves. In all these processes it suggests itself to\nme that the aetherial atmosphere must take its share in the expansion\nand transformation of the liquid form into a gaseous form, or the solid\ninto a liquid form. Taking the analogy of our atmosphere in its relation\nto the earth, we know that when heat is absorbed by it, it expands, the\nresult being that a greater pressure is exerted by the expanding\natmosphere, than would be exerted if it remained at the same temperature\nall the time. If, therefore, each atom has an aetherial atmosphere,\nwhich is capable of expansion, then the effect of the absorbed aetherial\nmotion of the heat waves on each atomic atmosphere must be to expand it,\nand thus there will be a pressure _away from_ the atom, because of the\nincreased elasticity acquired by the heated aetherial atmosphere. So\nthat the expansion of the liquid is due to the increased elasticity of\nthe aetherial atomic atmosphere, which has been expanded by heat, and\nwhich exerts an increased pressure on neighbouring atoms, thus seeking\nto push them farther away from each other. There are other motions of\nthe atoms themselves in addition to this to be considered, but I am now\nseeking to show only the effect of the aetherial atmosphere of each atom\nupon the neighbouring atoms. This would give each atom a larger sphere\nof freedom in which to move, and that state would then be called a\ngaseous and not a liquid one. This assumption of the part which the\naetherial atmosphere plays in the expansion of a body is therefore in\nagreement with Professor Challis' theory of heat already referred to, in\nwhich he states that heat gives rise to aetherial vibrations which act\nrepulsively on the neighbouring atoms. In further confirmation of the\nexistence of these aetherial atmospheres that exist around atoms, I\nwould like to draw the attention of the reader to a theory of heat given\nto the world by Rankine, _Phil. Mag._, 1851. His theory is known as the\n\"Hypothesis of Molecular Vortices.\"\n\nHe assumed that \"each atom of matter consists of a nucleus or central\npoint, enveloped by an elastic atmosphere, which is retained in its\nposition by attractive forces, and that the elasticity due to heat\narises from the centrifugal force of those atmospheres revolving or\noscillating about their nuclei or centres.\"\n\nNow in this assumption we find that he admits that each atom has an\natmosphere, such atmosphere evidently being an aetherial one, and in\nthat case the hypothesis would agree with the statement in Art. 46, that\nevery atom possesses an aetherial atmosphere. He further points out that\nthe atmosphere is retained in its position by attractive forces. This is\nalso in harmony with the hypothesis given in Art. 45, which proves that\nAether is gravitative, and therefore the atmosphere of the atom would be\nheld in its position by the attractive force of Gravitation, as\nsuggested by Young in his Fourth Hypothesis.\n\nFurther, he goes on to show that the elasticity of the atomic atmosphere\nis proportionate to its density, which is also in conformity with the\nstatement made in Art. 47, and is also in accordance with Boyle's Law.\nThen he goes on to prove that the quantity of heat in a body is measured\nby the molecular revolutions of the vortices.\n\nHe does not clearly define the exact character of those molecular\nvortices, but I take it to mean that each atmosphere is in a state of\nrevolution around its atomic centre, in the same way that the atmosphere\nof a planet is in a state of revolution around its central body.\n\nSuch an assumption is entirely in harmony with experience, as there is\nan analogy for its assumption from the planetary system; and if an atom\nis a world in miniature, as I believe it to be, then the atmosphere of\nthe atom ought to revolve around its central nucleus in the same way\nthat the atmosphere of a planet revolves around its nucleus or central\nbody.\n\nHe then deals with temperature, and with the pressure of gases caused by\nheat, showing the relation of elasticity and pressure to temperature in\na table of results given in the _Phil. Mag._ for 1851. I must refer the\nreader to the paper itself for fuller details. Thus from one of the\ngreatest thinkers of modern times we have further testimony to the\nhypothesis that Aether is matter and is therefore gravitative, and\nbecause of its gravitating tendency, it forms around every atom and\nmolecule elastic envelopes or atmospheres, whose pressure is always\nproportionate to their density.\n\n[Footnote:8 _Phil Mag._, 1859.]\n\n\nART. 62. _Radiation and Absorption._--We have already seen (Art. 31)\nthat all matter is made up of atoms and molecules, each of which is\nsurrounded by its atmosphere of Aether. By means of the Aether, motion\nin the form of light and heat may be transmitted from one atom and\nmolecule to another. The transmission of heat from one body to another\nis termed Radiation, while the acceptance of heat is termed Absorption.\nTyndall defines Radiation as \"the communication of molecular motion from\nthe heated body to the Aether in which it is immersed,\"[9] and\nAbsorption, therefore, would be the acceptance of motion by the body\nfrom the Aether. So that in Radiation, the atom, molecule, or body parts\nwith motion to the Aether, while in Absorption it gains motion from the\nAether.\n\nNow in order for us to understand this theory of Radiation and\nAbsorption, it will be well for us if we look at a similar effect in the\nsphere of music and sound. Let us suppose that we have two tuning-forks\nof the same pitch, placed on a table at a distance of a foot from each\nother. If we set one of the forks vibrating, the waves which it radiates\nthrough the air will fall upon the other one, and will also set it in\nvibration, because they are of the same period or size as those waves\nwhich it would itself give off when sounded. Thus while one is losing\nits motion, the other is gaining it, or while one is radiating motion,\nthe other is absorbing motion. This can readily be proved by stopping\nthe vibration of the first fork, when it will be found that the second\nfork is now giving out a similar note to the first, although it was\nsilent at the commencement. Thus we have here an example of radiation\nand absorption of sound, the success of the experiment depending upon\nthe fact that both forks shall have the same pitch. Again, it must be\nnoted, that if we have two tuning-forks both of which are of the same\npitch, and both vibrating at the same time, then, while one is radiating\nsound and consequently losing motion to the other, yet at the same time\nit is absorbing motion from the other. Because, if fork A can transfer\nmotion to fork B, the latter can equally transfer its motion to fork A,\nand when both are vibrating together, each is the recipient of part of\nthe other's motion, while at the same time giving off motion in the form\nof sound waves itself. So that the power of a fork to radiate sound\nwaves equals its power to absorb sound waves. If now we apply this\nsimile to the atomic and molecular world, we shall be able to form a\nmental picture as to what takes place in radiation and absorption.\n\nAll atoms and molecules are ever in a state of ceaseless motion, ever\nmoving, never still. All are creating Aether waves which move away with\nthe velocity of light. If, in the transmission of the waves by the\nAether, they fall upon another atom which can emit a wave of similar\nlength, in the same way that two tuning-forks emitted sound waves of the\nsame length, then the atom upon which the waves strike will be set in\nvibration, as the second tuning-fork was set in vibration by the first.\nWe shall look again at the principle of wave motion in the next chapter.\nFurther, from the simile of the two forks, which absorb sound at the\nsame time that they radiate sound, we learn that an atom or body\nradiates heat waves at the same time that it is absorbing heat waves.\nSuppose that we have two bodies at equal temperatures, it must not be\nthought that the radiation or absorption has ceased, for, according to\nthe simile used, they both still continue to vibrate and emit the\naetherial heat waves; but where we get equality of temperatures, there\nwe get equality of radiation and absorption. Before this equality of\ntemperatures, however, is reached, the hotter body will radiate more\nheat waves than it absorbs, while the colder body will absorb more heat\nwaves than it emits. All bodies, whatever their temperature, are\nincessantly radiating heat waves. This may be proved experimentally with\nproper apparatus, as for example with an instrument known as the\nthermopile. When, however, the total heat waves radiated out by a body\nare less than it absorbs, the body gets gradually colder, and the\ntemperature decreases. So long as this is continued, so long will the\nbody continue to get colder and colder, until it arrives at the same\ntemperature as the surrounding bodies, at which point the total heat\nwaves radiated out will equal the total heat waves absorbed, and at that\npoint the temperature of the body will remain constant.\n\nThis aspect of temperature was first introduced by Prevost of Geneva in\n1792, in an article in which he tried to explain the radiation from a\ncold body. According to his reasoning, a body is not simply regarded as\nradiating heat when its temperature is falling, or absorbing heat when\nit is rising.\n\nWhat he tried to make clear was, that both radiation and absorption were\ngoing on at one and the same time; the radiation depending upon the body\nitself, but the absorption depending upon the nature of the body. While\nradiation and absorption are thus reciprocal, which implies that a good\nradiator is a good absorber, and a bad radiator is a bad absorber, it\ndoes not follow that all bodies radiate and absorb alike.\n\nThe capacity of bodies to radiate and to absorb differ considerably. Dr.\nFranklin made several simple experiments to prove the relative powers of\nradiation and absorption with several pieces of cloth. These were put\nout on the snow, and exposed to the heat of the sun. He found that the\npieces which were dark in colour sank deepest into the snow, while those\nwhich were lightest in colour sank the least. From this he inferred that\nthe darkest pieces were the best absorbers, and therefore the best\nradiators, while the light-coloured cloths were the worst absorbers, and\ntherefore the worst radiators.\n\nRadiation, therefore, may be said to be the propagation of a wave motion\nthrough the Aether; and, as all motion is a source of power or energy,\nwe have in the radiation of heat from one body to another by the\naetherial waves, the transmission of a motive power capable of doing\nwork, either internal work as increasing the temperature of the molecule\nor body, or external work as separating the atoms, or driving them\nfurther apart. It can readily be seen that if the Aether were\nfrictionless, as has generally been supposed, the Aether could not have\nany motive power at all, and therefore could not transmit heat from one\nbody to another. Professor Tyndall[10] on this point says, referring to\nthe cooling of a red-hot ball: \"The atoms of the ball oscillate in a\nresisting medium, which accepts their motion and transmits it on all\nsides with inconceivable velocity.\" Now in the previous quotation given\nin this article from the same authority, he states that the atoms are\nimmersed in the Aether. So that evidently in his opinion the Aether and\nthe resisting medium are one and the same. So that our assumption of the\ngravitative property of the Aether is perfectly in accord with Professor\nTyndall's conception of the Aether, in so far as it concerns the\npropagation of heat waves; and, as will be shown later on, heat and\nlight waves are due to the same physical agent--that is, the Aether;\ntherefore, wherever we get heat and light, there, according to Professor\nTyndall's statement, we must have a resisting medium, and as Aether\nfills all space, the resisting medium must fill all space. This is\nperfectly in accord with our assumption that the Aether is gravitative\nand possesses inertia--that is, the capacity to receive and to impart\nmotion, and being gravitative it possesses mass or weight, which is the\nvery quality necessary for the existence of a resisting medium.\n\n[Footnote 9: _Heat, a Mode of Motion._]\n\n[Footnote 10: _Heat, a Mode of Motion._]\n\n\nART. 63. _Heat is a Repulsive Motion._--Whatever be the particular\ncharacter of the vibratory motion of the Aether termed heat, there is\none fact regarding the same that is very patent and obvious to all; and\nthat is, that the vibratory motion of heat is essentially a repulsive\nmotion, or a motion from a centre and not one to a centre.\n\nProfessor Davy points this out (Art. 60) where he says of heat, \"It may\nwith propriety be called a repulsive motion,\" while Professor Challis\n(Art. 61) states that \"Each atom is the centre of vibrations propagated\nfrom it equally in all directions, which give rise to a repulsive action\non the surrounding atoms. This action (he adds) is the repulsion of heat\nwhich keeps the individual atoms asunder.\"\n\nThere have been many experiments undertaken which go to prove that a\nrepulsive action between atoms and molecules is produced by heat. It has\nbeen demonstrated that certain coloured rings, known as Newton's rings,\nchange their shape and position when the glasses between which they\nappear are heated, thus indicating the presence of a repulsive power due\nto the increased heat. If we consider the change of state that heat\ninduces in matter, as, for example, from solid to a liquid, or liquid to\na gaseous form, we are compelled to admit that heat possesses an\nexpanding and therefore a repulsive motion. It is almost an universal\nlaw that heat expands and cold contracts, and the greater the heat\nabsorbed, the greater the expansion. In the case of a solid being\nconverted into a liquid, a much greater heat or repulsive motion is\nrequired to separate the particles, on account of the power of cohesion\nbeing greater in the solid than in the liquid. As Professor Tyndall[11]\nstates when dealing with the stability of matter from the molecular\nstandpoint: \"Every atom is held apart from its neighbour by a force of\nrepulsion. Why then do not the mutually repellent members of the group\npart company? The reason of this stability is that _two_ forces, the one\nattractive and the other repulsive, are in operation between every two\natoms, and the position of every atom is determined by the equilibration\nof these two forces. The points at which attraction and repulsion are\nequal to each other is the atom's position of equilibrium. When the\natoms approach too near each other, repulsion predominates and drives\nthem apart; when they recede to too great a distance, attraction\npredominates and draws them together.\" If, therefore, there are TWO\nforces at work in the atomic world, viz. attraction and repulsion, then\nthe question arises, Can that repulsive power be increased in any way,\nand if so, by what means? Such repulsive motion, as experiment and\nexperience teach us, can be increased, and such increase may be derived\nfrom the absorption of heat which gives rise to increased atomic motion,\nand so to increased aetherial motion away from the atom, by which the\nrepulsive action of one atom upon another is increased. Thus an atom's\nrepulsive power may be increased by heat; the greater the heat absorbed,\nthe greater the repulsive power that any atom or body exerts upon a\nneighbouring atom or body. We can therefore understand how it is, that a\nbody when changed from a solid to a liquid condition occupies a larger\nspace in the latter condition than in the former; or why a body when\nchanged from a liquid to a gaseous condition occupies a still larger\nvolume in the latter than in its previous condition. The expansion in\nboth cases is essentially the result of the increased repulsive motion\nthat has been imparted to its atoms or molecules by the increased heat,\nand this increased repulsive power has overcome the attractive power of\nthe atoms or molecules, with the result that they have been driven\nfurther and further apart, until, in the gaseous state, the atoms may\nbe very far apart indeed. Wherever, therefore, we have heat of any kind,\nthere we have a repulsive motion, such motion being proportionate to the\nheat radiated, that is, the aetherial waves propagated by the body. If,\ntherefore, in the atomic world we find a repulsive motion, which is due\nto the vibratory motions of the Aether generated by heat, the question\nnow confronts us, as to whether in the solar system, and indeed all\nthrough the universe, there is not the same repulsive motion from a\ncentral body due to the wave motions of the Aether termed Heat.\n\nMay we not find in the repulsive power of heat in the atomic world, an\nindication of that very power for which we are seeking in the solar\nsystem--that is, a Centrifugal Force or motion which is the exact\nopposite of the Centripetal Force or attractive power of Gravitation?\nFor if heat be a repulsive motion at all, then to be strictly logical it\nmust be equally repulsive in relation to large masses, the sun and the\nplanets for example, as it is in the atomic world, otherwise we have a\nphenomenon in Nature which contradicts itself, which assumption would be\ncontrary to the simplicity which is to govern our philosophy, and also\ncontradictory to experience, which is the primary factor of\nphilosophical reasoning. Now what are the facts with reference to the\nsun, which is the central body of our solar system, and the source of\nall light and heat in that system? We will look at this aspect of the\nquestion under the heading of Radiant Heat.\n\n[Footnote 11: _Heat, a Mode of Motion._]\n\n\nART. 64. _Radiant Heat._--The source of all light and heat, not only of\nour earth, but also of all the other planets, is to be found in the sun.\nWe have therefore to deal, not with an atom which is generating heat\nwaves on every side, but with a globe about 860,000 miles in diameter,\nand with a circumference of over 2,700,000 miles. This huge orb consists\nof a central body, molten or partly solid, with a temperature so hot\nthat it is almost impossible to conceive its intensity. The quantity of\nheat emitted by the sun has been ascertained by Sir John Herschel from\nexperiments made at the Cape of Good Hope, and by M. Pouillet in Paris.\n\nSir John Herschel found that the heating power of the sun when it was\ndirectly overhead was capable of melting .00754 of an inch of ice per\nminute. According to M. Pouillet the quantity was .00703 of an inch,\nwhich is equal to about half-an-inch per hour. From these results it has\nbeen calculated that if the direct heat of the sun were received upon a\nblock of ice one mile square, 26,000 tons would be melted per hour by\nthe heat which would be absorbed. Again, as Herschel[12] puts it:\n\"Supposing a cylinder of ice, 45 miles in diameter, to be continually\ndarted into the sun with the velocity of light, the heat given off\nconstantly from the sun by radiation would be wholly expended in\nliquefaction on the one hand, while on the other, the actual temperature\nat the sun's surface would undergo no diminution.\" Sir John Herschel\nfurther says: \"All the heat we enjoy comes from the sun. Imagine the\nheat we should have to endure if the sun were to approach us, or we the\nsun, to a point the one hundred and sixtieth part of the present\ndistance. It would not be merely as if 160 suns were shining on us all\nat once, but 160 times 160 suns according to the rule of inverse\nsquares--that is, 25,600. Imagine a globe emitting heat 25,600 times\nfiercer than that of an equatorial sunshine at noonday, with the sun\nvertical. In such a heat there is no solid substance we know of which\nwould not run like water, boil, or be converted into smoke or vapour.\"\n\nLockyer points out that the heat radiated from every square yard of the\nsun's surface is equal to the amount of heat produced by the burning of\nsix tons of coal on that area in one hour. Now the surface of the sun\nmay be estimated at 2,284,000,000,000 square miles, and there are\n3,097,600 square yards in each square mile; what therefore must be the\nnumber of tons of coal which must be burnt per hour to represent the\namount of heat radiated from the sun into space? The approximate result\nmay be calculated by multiplication, but the figures arrived at fail to\ngive any adequate conception of the actual result.\n\nFrom these facts it may be seen that the sun has a temperature far\nexceeding any temperature that can be produced on the earth by\nartificial means. All known elements would be transformed into a\nvaporous condition if brought close to the sun's surface. It may readily\nbe seen, therefore, that the sun is constantly sending forth an\nincessant flood of radiant heat in all directions, and on every side\ninto space. Now if heat be motion, and be primarily due to the vibratory\nmotion of Aether, what must be the volume and the intensity of the\naetherial waves, known as heat waves, generated by the sun? When we\nremember its ponderous mass, with its volume more than 1,200,000 times\nthat of our earth, its huge girth of more than 2-1/2 millions of miles,\nand this always aglow with fire the most extensive known--fires so\nintense that they cover its huge form with a quivering fringe of\nflames which leap into space a distance of 80,000 miles, or even\n100,000 miles, or over one-third of the distance of the moon from the\nearth,--remembering all these facts, what must be the volume and\nintensity of the aetherial heat waves which they generate and send upon\ntheir course into space on all sides! What a very storm of energy and\npower must there be in this aetherial atmosphere which exists around the\nsun's huge form, and with what volume of power must the aetherial heat\nwaves speed away from so great a generating source! Some idea as to\ntheir velocity of motion may be gained by the fact, that these aetherial\nheat waves traverse the distance of 92,000,000 miles between the sun and\nour earth in the short space of 8-1/2 minutes. With such a velocity of\nmotion as that, and with the fact before us that all motion is a source\nof energy or power, what must be the energy possessed by these heat\nwaves! There must, therefore, be a power in these aetherial heat waves\nwhich is strictly proportionate to their intensity and flow. So that,\nwhenever they come into contact with any body, as a planet, as they flow\noutwards from the sun, they must exert a power upon such a planet which\nis directed _away_ from the sun, and therefore act upon that planet by\nthe energy of their motion away from the sun, the source of the\naetherial heat waves. Therefore, not only in the atomic world is heat a\nrepulsive motion, but equally in the solar world, which is but an atomic\nworld on a large scale, the same principle prevails, and the effect of\nradiant heat is essentially a repulsive, that is, a centrifugal motion,\nas it is always directed from the central body, the sun.\n\nFurther, it can be shown that the repulsive power of heat in the solar\nsystem has already received the attention of scientists, especially in\nFrance. This will be seen more fully when we come to deal with the\nphenomena of comets' tails. One remarkable feature about comets' tails\nis, that they are always directed away from the sun, and various\nhypotheses have been advanced to account for that fact. Among them is\nthe hypothesis of M. Faye, in which he assumes that there is a repulsive\nforce which has its origin in the heat of the sun. This repulsive force\nis not propagated instantaneously, but the velocity of propagation is\nthe same as that of a ray of light. By means of this repulsive power due\nto the heat of the sun, M. Faye explains how it is that the tails of\ncomets are always turned away from the sun. Here, then, we have an\nindication of the existence of this repulsive force of heat which we are\nconsidering--a repulsive power which finds its source in the aetherial\nwaves, which give rise to the phenomena of Heat, and to which we must\nlook for the ultimate source of that repulsive power or Centrifugal\nForce which is to form the complementary power to the attractive force\nof Gravitation.\n\n[Footnote 12: _Lectures on Scientific Subjects._]\n\n\nART. 65. _Direction of Ray of Heat._--The question as to the path which\na ray of heat takes may best be attacked by finding out what is the path\nwhich a ray of light takes in its progress through the Aether. When we\ncome to deal with light, we shall find that it has been experimentally\nproved that the path of a ray of light is that of a straight line\nthrough space; so that if we have any body emitting light, the rays of\nlight will proceed from that body in straight lines, with decreasing\nintensity, according to the law of inverse squares, the same as\nGravitation.\n\nIt can readily be shown, that wherever there is light there is heat. For\nexample, the radiant heat from the sun proceeds through space along with\nthe light from the sun, and when one set of waves, the light waves for\ninstance, are intercepted, the heat waves are also intercepted. Or, to\ntake another illustration, when the sun is eclipsed, we feel the sun's\nheat as long as any portion of the sun is visible, but as soon as the\nsun is totally eclipsed, then the light waves disappear, and with it the\nheat waves. From this we can readily see, that not only do the heat and\nlight waves from the sun proceed in the same straight line, but that\nthey also travel at the same rate through space, at the rate of 186,000\nmiles per second. Then again the common lens, which is so familiar to\nevery one, will prove the same fact by concentrating the rays of light\nto a focus, and by so doing will produce sufficient heat to burn a piece\nof paper, or even set fire to wood. If, therefore, the path of a ray of\nlight be that of a straight line, proceeding from the luminous or\nlighted body, and the path of a ray of heat coincides with the path of a\nray of light, the path of the ray of heat must also be in the direction\nof a straight line from the heated or luminous body, which, as we shall\nsee in a subsequent article, also decreases in intensity according to\nthe law of inverse squares the same as Gravitation Attraction.\n\nProfessor Tyndall, on the direction of a ray of heat,[13] states his\nopinion on the matter as follows: \"A wave of Aether starting from a\nradiant point in all directions in a uniform medium constitutes a\nspherical shell, which expands with the velocity of light or of radiant\nheat. A ray of light or a ray of heat is a line perpendicular to the\nwave, and in the case here supposed, the rays would be the radii of the\nspherical shell.\" From this it can be seen that a ray of light or heat\ncorresponds to what is known as the radius vector of a circle (Art. 20),\nand therefore a ray of light and heat takes exactly the same path\nthrough space (if we consider the sun as the source of the light and\nheat) as the path of the attractive power of Gravitation. Collecting,\ntherefore, our results from the preceding articles of this chapter, we\nlearn that heat is due to vibrating wave motion of the Aether, and that\nthat motion is a motion which is always directed from the central body\nwhich is the source of the heat; and further, that this motion amounts\nto a repulsive motion acting in an opposite direction to the attractive\npower of gravity or to the centripetal force of Gravitation. What is\nmore remarkable still, the path of a ray of heat corresponds with, and\ntakes up exactly the same direction through space, whether it be atomic\nspace, solar space, or interstellar space, as the attractive force of\nGravitation.\n\nLooking at the subject from the standpoint of the solar system, with the\nsun as the central body, we see that while we have the sun, which acts\nas the controlling centre of the particular system of planets, holding\nall the planets in their orbits by its attractive power, yet at the same\ntime it is also the source of all light and heat. Now heat being due to\nthe wave motion of the aetherial medium, such motion being always\nexerted from the central body, we arrive at the only legitimate\nconclusion that can be arrived at, viz. that the sun is also the source\nof a repulsive motion, which motion coincides with the path that the\nattractive power of Gravitation takes, that is, along the radius vector\nof the circle, as shown in Art. 20.\n\n\nART. 66. _Law of Inverse Squares applied to Heat._--The law of inverse\nsquares which governs not only the Law of Gravitation Attraction (Art.\n22), but also electricity and light, is equally applicable to the\nphenomena of heat, so that we say the intensity of heat varies inversely\nas the square of the distance. Thus, if we double the distance of any\nbody from the source of heat, the amount of heat which such a body\nreceives at the increased distance is one-quarter of the heat compared\nwith its original position. If the distance were trebled, then the\nintensity of the heat would be reduced to one-ninth; while if the\ndistance were four times as great, the intensity of the heat would only\nbe one-sixteenth of what it would receive in its first position. This\nmay be proved from experiments as given by Tyndall in his _Heat, a Mode\nof Motion_.\n\nLet us apply the law of inverse squares in relation to heat to the solar\nsystem, and see what the result gives. In our solar system, we have the\nsun as the central body, the source of all light and heat, with the\neight planets, Mercury, Venus, the Earth, Mars, Jupiter, Saturn, Uranus,\nNeptune, describing orbits around the central body, and at the same time\nreceiving from it the light and heat which the sun is ever pouring\nforth into space. The mean distance of Mercury from the sun is about\n36,000,000 miles, while that of the Earth is about 92,000,000 miles, so\nthat reckoning the distance of Mercury as unity, the distance of the\nEarth is a little more than 2-1/2 times that of Mercury from the sun.\nNow the square of 2-1/2 is 25/4, and that inverted gives us 4/25, so\nthat according to the law of inverse squares, the intensity of heat at\nthe Earth's distance from the sun is 4/25 of what the intensity of heat\nis at the mean distance of Mercury. Again, the mean distance of Mars is\n141,000,000 miles, while the mean distance of Saturn is 884,000,000\nmiles, and taking Mars' distance from the sun as unity, the distance of\nSaturn would be represented by 6-1/4. Now the square of 6-1/4 is\n(25/4)^{2} which gives 625/16 and the inverse of that is 16/625, so that\nthe intensity of heat at the distance of Saturn's mean distance from the\nsun, in comparison with the intensity of heat at Mars' mean distance,\nwould be about 16/625; or in other words, the heat received by Saturn\nwould be only 16/625 of the intensity of heat received by the planet\nMars. In Art. 63 we have seen that heat is a repulsive motion, being a\nwave motion of the Aether which is propagated from the heated and\ncentral body, which in this case is the sun. Therefore, according to the\nlaw of inverse squares from the standpoint of heat, we find in the solar\nsystem a repulsive motion, due to the wave motion of the Aether, which\nis always exerted away from the sun in the same path that the\ncentripetal force takes, and which like that force diminishes in\nintensity inversely as the square of the distance. So that, wherever the\ncentripetal force, or the attractive force of Gravitation, is diminished\non account of the increased distance from the sun, the repulsive motion\ndue to heat is also diminished in exactly the same proportion and along\nexactly the same path. If at any point in the solar system the\nattractive force is doubled, then according to our repulsive theory of\nheat, and the law of inverse squares, the repulsive motion is also\ndoubled. If the attractive force is halved, then the repulsive motion is\nhalved also, the repulsive motion being always and at all places exactly\nproportional to the increase or decrease of the attraction of\nGravitation.\n\n[Footnote 13: _Heat, a Mode of Motion._]\n\n\nART. 67. _First Law of Thermodynamics._--The Law of Thermodynamics is\nbased on two fundamental truths which have reference to the conversion\nof Heat into Work, and Work into Heat. In Art. 54 we have already seen\nthat energy in the form of heat, light, electricity and magnetism is\ncapable of being converted into other forms of energy, while in Art. 59\nwe have seen that Joule gave us the exact relation in foot-pounds\nbetween heat and work. He showed that when 1 lb. of water fell through\n772 feet its temperature was raised one degree Fahr. Thus the principle\nunderlying the first law of thermodynamics states, that whenever work is\nspent in producing heat, the amount of work done is proportionate to the\nquantity of heat generated; and conversely, whenever heat is employed to\ndo work, a certain amount of heat is used up, which is the equivalent of\nthe work done. This principle is also in accord with the conservation of\nEnergy and Motion (Arts. 52 and 57), which assert that whenever energy\nor motion disappears in one form, it is manifested in some other form.\nThus, from the first law of thermodynamics, we learn that wherever we\nhave heat we have the power to do work, and the amount of work so done\nis proportionate to the heat used up. Heat, then, has a capacity to\nperform work, and that power is known as the mechanical equivalent of\nheat. Both Mayer of Germany, and Dr. Joule of Manchester, have worked\nout this problem, and have given us the mechanical value of heat. By\nexperiments Mayer found out that a quantity of heat sufficient to raise\n1 lb. of water one degree Fahr. in temperature was able to raise a\nweight 771.4 lb. one foot high. Dr. Joule of Manchester, after making a\nnumber of experiments which lasted over many years, came to the\nconclusion that the mechanical equivalent of a unit heat was 772\nfoot-pounds, a unit of heat being the quantity of heat which would raise\n1 lb. of water one degree Fahr. So that if a 1-lb. weight fell from a\nheight of 772 feet, an amount of heat is generated which would raise 1\nlb. of water one degree Fahr.; and conversely, to lift 1 lb. 772 feet\nhigh, one degree Fahr. of heat would be consumed.\n\nNow if this law of thermodynamics is true, it must not only be true in\nrelation to terrestrial heat, or heat produced by artificial means on\nour earth, but it must equally hold good in relation to the solar\nsystem; and not only the solar system, but equally true throughout all\nthe systems of worlds that flood the universe. So that wherever we get\nheat in the universe, in the solar system for example, there, according\nto our first law of thermodynamics, we should have the capacity to do\nwork of some kind or other. That work may take either the form of\nexpanding a body, as the atmosphere of a planet for example, or it may\ntake a mechanical form, that is, actually moving a body by the increased\npressure due to aetherial heat waves generated by the sun. We have\nalready seen in Art. 64, on Radiant Heat, what a store of heat the sun\nhas. For thousands and millions of years the sun has been pouring forth\nits heat rays into space, and yet its temperature does not seem to be\ndiminished. The great Carboniferous or coal period of past geological\ntimes is an indication of the heat and light of the sun, which it must\nhave radiated out millions of years ago; and year by year, these\naetherial heat waves are still being poured forth by the sun on every\nside into space, so that no matter where a planet may be in its orbit,\nthere it may be the recipient of these aetherial heat waves which break\nupon its surface. Now if there be this quantity of heat existing in the\nsun, and heat according to the first law of thermodynamics has a\nmechanical value, which is that it can push or lift a body through\nspace, the question arises, as to what is the mechanical value of this\nheat of the sun? Are we to suppose that if one unit of heat can lift 1\nlb. 772 feet, the millions and millions of units of heat which are\nconstantly being poured out of the sun into space are doing no work at\nall? Such an assumption is not only contrary to that simplicity which\ngoverns our Philosophy, but is entirely opposed to experience, which is\nthe very foundation of all philosophical reasoning. If, therefore,\nexperience is to be any guide at all, we are compelled to come to the\nconclusion that the heat poured forth into space does do work on the\nbodies, as comets, meteors, planets, upon which the aetherial heat waves\nfall. The problem is, what is the character of the work done? I have\nalready indicated part of the work, viz. in the expansion of the\natmosphere of the planets. Then there is also the reception of the heat\nby the animal and vegetable life of the planet, but these do not account\nfor all the motive power of the aetherial waves, which break upon the\nplanet or its atmospheres.\n\nThe true solution of the first law of thermodynamics, in its relation to\nthe solar system, seems to me to be found in the fact already stated in\nArt. 63, viz. that heat is a repulsive motion, and the law of\nthermodynamics confirms that statement, and shows that the work done on\na planet by the aetherial heat waves is that of pushing it, or urging it\nby their very energy and motion away from their controlling centre, the\nsun. This would practically amount to a repulsive force which had its\nhome in the sun, and this conception would bring our Philosophy into\nharmony with our experience, which teaches us that wherever there is\nheat there is the capacity of doing work, the amount of work being\nproportionate to the heat generated and consumed.\n\n\nART. 68. _Second Law of Thermodynamics._--This law was enunciated by\nSadi Carnot in 1824, when he wrote an essay on the Motive Power of Heat.\nPrevious to the time of Carnot no definite relation seems to have been\nsuggested between work and heat; Carnot, however, discovered what were\nthose general laws which govern the relation between heat and work. In\narriving at his conclusion, he based his results on the truth of the\nprinciple of the conservation of energy already referred to (Art. 52).\n\nCarnot started his reasoning on the assumption that heat was matter, and\ntherefore indestructible. The two great truths in relation to heat and\nwork, enunciated by Carnot, are known as, first, a Cycle of operations;\nand, secondly, what he termed a Reversible Cycle. In order to be able to\nreason upon the work done by a heat-engine, say a steam-engine for\nexample, Carnot stated we must imagine a cycle of operations, by which,\nat the end of such operations, the steam or water is brought back to\nexactly the same state in which it was at its start. He calls this a\ncycle of operations, and of it he says, that only at the conclusion of\nthe cycle are we entitled to reason upon the relation between the work\ndone and the heat spent in doing it. His other idea of the reversible\ncycle implies that an engine is reversible when, instead of using heat\nand getting work from it, the engine may be driven through the cycle of\noperations the reverse way, that is, by taking in work, it can pump back\nheat to the boiler again. Carnot showed that if you can obtain such a\nreversible engine, it is a perfect engine. All perfect engines, that is\nall reversible engines, will do exactly the same amount of work with the\nsame amount of heat, the amount of work being strictly proportionate to\nthe amount of heat consumed. I need hardly point out that the reversible\nengine, or the perfect engine of Carnot, is only the ideal one, as there\nis no engine in which all the heat is converted into work, as a great\ndeal of the heat is radiated away and not converted into work at all.\nAgain, working from the standpoint that heat is matter, Carnot reasoned\nthat in the heat-engine the work is performed, not by the actual\nconsumption of heat, but by its transportation from a hot body to a cold\none. Thus, by the fall of heat from a higher to a lower temperature,\nwork could be done in the same way that work could be done by allowing\nwater to fall from a higher to a lower level. The quantity of water\nwhich reaches the lower level is exactly the same as that which leaves\nthe higher level, as none of the water is destroyed in the fall. He\nargued, therefore, that the work produced by a heat-engine was produced\nin a similar manner, the quantity of heat which reaches the condenser\nbeing supposed to be equal to that which left the source. Thus the work\nwas done by the heat flowing from a hot body to a cold one, and, in\ndoing this work, it lost its momentum like falling water, and was\nbrought to rest. One of the most important points noted by Carnot is\nthe necessity that, in all engines which derive work from heat, there\nmust be two bodies at different temperatures, that is, a source and a\ncondenser, which correspond to a hot and cold body, so that there may be\nthe passage of heat from the hot to the cold body. In order to get work\nout of heat it is absolutely necessary to have a hotter and a colder\nbody. From this reasoning we learn, therefore, that work is obtained\nfrom heat by using up the heat of the hotter body, part of which is\nconverted into actual work, while part is absorbed by the colder body.\nSo that wherever we have two bodies at different temperatures, according\nto the second law of thermodynamics, there we have the power of doing\nwork by the transmission of heat, from the body of higher to the one of\nlower temperature.\n\nThat Carnot ultimately came to believe in the dynamical theory of heat,\nis proved by the following passage taken from his notes on the Motive\nPower of Heat: \"It would be ridiculous to suppose that it is an emission\nof matter, while the light which accompanies it could only be a\nmovement. Could a motion produce matter? No! undoubtedly, it can only\nproduce a motion. Heat is then the result of motion. It is plain then\nthat it could be produced by the consumption of motive power, and that\nit could produce this power. Heat is then simply motive power, or rather\nmotion which has changed its form. It is a movement among the particles\nof bodies. Wherever there is a destruction of motive power, there is at\nthe same time production of heat in quantity exactly proportional to the\nquantity of motive power destroyed. Reciprocally, whenever there is\ndestruction of heat there is production of motive power.\"\n\nLet us apply this principle to the solar system, and endeavour to find\nout whether in that system we have, in relation to the heat thereof,\neither a cycle of operations or a reversible cycle. We have again to\nconsider the sun as the source of all light and heat in the solar\nsystem, radiating forth on every side, year by year, the countless units\nof heat which go to form the continuance of all planetary life and\nexistence. One of the problems that has confronted scientific men for\nmany years is this, Where does the sun get its supply of heat from? When\nwe remember the incessant loss of heat which the sun suffers through its\nradiation of heat into space, we are compelled to ask, How is that\nsupply maintained, and how has it been kept up through the countless\nages of the past? Several suggestions have been made, and several\ntheories advanced to account for the fact. Mayer, of Germany, suggested\nthat the heat is partly maintained by the falling into the sun of\nmeteors, which, like comets, pursue a path through the heavens, and are\nsubject to the attractive influence of the sun. In the combustion of\nthese meteorites, or meteors, he contended there were the means by which\nthe light and heat of the sun might be maintained. Whatever theory,\nhowever, may be suggested as to the maintenance and the source of the\ncontinuity of the sun's heat, I do not think it has been suggested by\nany scientist that the heat emitted and radiated by the sun is ever\nreturned in any way back to the sun from infinite space, whether by\nreflection or by any other method. So far as I can learn, there are no\nfacts in connection with the solar system which would lead us to make\nthat assumption. On the contrary, experience and experiment teach us\nthat radiation implies loss of heat, and that the body, which so\nradiates, ultimately becomes cold, unless its internal heat is kept up\nby some means or other. So that the terms introduced by Carnot in the\nsecond law of thermodynamics, viz. that of a Cycle of Operations and of\na Reversible Cycle, do not apply to the solar system, and the solar\nsystem, viewed from the standpoint of a machine, with the sun as the\nsource of the heat, does not represent a perfect engine, that is, all\nthe heat is not used up in doing work, some of it being radiated out\ninto space. Wherever, however, the heat, that is the aetherial heat\nwaves generated by the sun, comes into contact with a planet, as\nMercury, Venus, or Jupiter, then, in accordance with Carnot's reasoning,\nwork is done. Carnot points out that, in order for work to be done, we\nmust have a source and a condenser, that is, two bodies at different\ntemperatures, a hot body and a cold one. Now these conditions of work\nare satisfactorily fulfilled in the solar system, and as a result work\nis performed. We have the sun with its huge fires, and its intensity of\nheat, representing the source or the hot body, while every planet and\nevery meteor and comet, that come under its influence, represent the\ncold body, and between the two work is always going on. That work is\nrepresented by the repulsive power of heat, which I have already\nindicated, so that, viewed from Carnot's standpoint with relation to the\nmotive power of heat, we find that there are in the solar system those\nconditions which govern work, and by which, from a mechanical\nstandpoint, work is performed; further, that work takes the form of a\nrepulsive power on every planet or other body upon which the aetherial\nheat waves fall. Therefore, from the second law of thermodynamics we\nhave another proof of this repulsive power of heat already indicated and\nreferred to in Art. 63.\n\n\nART. 69. _Identity of Heat and Light._--We have seen from the preceding\narticles of this chapter, that heat is due to a periodic wave motion of\nthe Aether, and in the succeeding chapter we shall also see that light\nis due to some kind of periodic wave motion in the Aether. So that not\nonly heat, but light also, it would appear, is due to certain periodic\nwave motions that are set up in the Aether by the vibrations of hot or\nluminous bodies. The question therefore arises, how many wave motions\nare there in the Aether? Are there different wave motions which in one\ncase produce light, and in the other case produce heat, or are light and\nheat both produced by the same set of aetherial waves? The identity of\nlight waves with heat waves is manifested by the fact that wherever we\nget light we get heat, as can be proved in many ways. One of the\nsimplest proofs is found in the common lens or burning-glass, by which\nthe light waves are brought to a focus, and as a result, heat is\nmanifested. Although there is this close identity between light and heat\nwaves, yet there must be some distinction between the heat and light\nwaves, because while light waves affect the eye, heat waves do not.\nThere is actually a difference between the two kinds of waves, and that\ndifference is one of period or length. It must not, however, be thought\nthat there are really two classes or sets of waves in the Aether, one of\nwhich could be called light waves, and the other heat waves, but rather\nthe same wave may be manifested in two different forms because of its\ndifferent wave lengths. In one case the waves may affect the eye, and we\nhave the sensation of sight, but in the other case they affect the body,\nand we experience the sensation of warmth. An analogy from the waves of\nsound may make these facts much clearer. We know that sound travels\nabout 1100 feet per second. If, therefore, we have a bell which vibrates\nabout 1100 times per second, we should have a wave one foot long. If it\nvibrated 100 times per second the waves would be 11 feet long, while if\nit vibrated only 11 times per second, the waves would be 100 feet long.\nNow the impression made upon the ear depends upon the number of\nvibrations the bell makes per second, and from the rate of vibration we\nget the idea of pitch. If the vibrations are very rapid, then we get a\nnote of high pitch, and if the vibrations are slow, then we get a note\nof low pitch. A note of high pitch, therefore, will correspond to waves\nof short length, while a low note will correspond to waves of a greater\nlength; so that the greater the rapidity with which a sounding bell\nvibrates, the shorter will be the length of the sound waves which it\ngenerates, and _vice versa_. The range of the ear however for sound\nwaves is limited, so that if the vibrations be too rapid or too slow,\nthe ear may not be able to respond to the vibrations, and so no distinct\nimpression of the sound will be conveyed to the brain. It need hardly be\npointed out, that both the very short and long waves are of exactly the\nsame character as those of a medium length, which the ear can detect,\nthe only difference being one of rapidity. We do not therefore suggest\nthat in the case of sound, where the vibrations lie outside the compass\nof the ear, those which lie outside are not sound waves, or that they\nare different from those which lie within the compass of the ear, and\nwhich the ear can detect. Whether the sound waves are long or short,\nwhether they can be detected by the ear or not, we still say that all\nare sound waves, and that all are due to the vibrations of the sounding\nbody, which vibrations are transmitted through the air, in waves, that\nfall upon the tympanum or drum of the ear, and set that vibrating, which\nvibrations are transmitted to the auditory nerve and so give rise to the\nsensation of hearing. In a similar manner, every atom and every particle\nof matter, every planet, every sun and star, is constantly in a state of\nvibration, sending off aetherial waves on every side. Nothing in Nature\nis absolutely cold, nothing is absolutely still. Therefore all matter,\nwhether in the atomic form, or in the planetary or solar world, is\nconstantly generating aetherial waves, which travel from their source or\norigin with the velocity of light. If these aetherial waves so generated\nfall within certain limits, then they affect the eye, and we get the\nsensation of sight. To do this they must vibrate 5000 billion times per\nsecond, and if they fail to do this, they fail to give rise to the\nsensation of sight. If the aetherial waves fall below this limit, then\nthey affect the body, and give rise to the sensation of heat. For it\nmust be remembered, that as the ear has a certain compass for sound\nwaves, which may vary in different individuals, so the eye has also a\ncertain compass for aetherial waves, with the result that some waves may\nbe too slow or too rapid to affect the eye, and consequently fail to\ngive rise to the sensation of sight. When that is so, the sensation of\nwarmth helps us to detect these longer waves, so that the longer waves\nwould warm us and make their presence felt in that manner. We shall see\nin the next chapter that there are both shorter and longer waves, which\nmay be detected in other ways. From these facts it can be readily seen,\nthat we have a common origin for both light and heat, and that they are\nboth due to periodic waves in the Aether, and therefore all the laws\nthat govern heat should also govern the phenomena of light. Further, if\nheat possesses a dynamical value, and if there be such a truth as the\nmotive power of heat, then there ought equally to be a motive power of\nlight; and further, if heat possesses a repulsive motion, then because\nof the identity of light and heat, light should equally possess this\nrepulsive power, because it is due to similar periodic wave motions in\nthe Aether. With regard to the same laws governing both light and heat,\nwe shall see that this fact also holds good. We have already seen (Art.\n66) that the intensity of heat is inversely as the square of the\ndistance, and we shall also see in the succeeding chapter that the same\nlaw holds good in relation to light. We have seen (Art. 65) that the\npath of a ray of heat is that of a straight line; we shall see in the\nsucceeding chapter that the path of a ray of light is that of a straight\nline also.\n\nIndeed, there is no law applicable to heat which is not applicable to\nlight. The law of reflection and refraction of heat equally holds good\nin relation to light; and further, Professor Forbes has shown that heat\ncan be polarized in a similar manner to the polarization of light. This\nlast fact is considered the most conclusive argument as to the identity\nof light and heat, and proves that the only difference between the two\nis simply the difference corresponding to the difference between a high\nnote and a low note in sound. That being so, I hope to be able to show\nthat as heat possesses a dynamical value, so light equally possesses a\ndynamical value, and that as heat is a repulsive motion, then light must\nequally possess a similar repulsive motion, that motion always being\ndirected from the central body, being caused by the same agency, viz.\nthe waves of the Aether, the common source of both light and heat. I\npurpose to address myself to this subject in the following chapter,\nwhich I have termed Light, a Mode of Motion.\n\n\n\n\n                              CHAPTER VII\n\n                        LIGHT, A MODE OF MOTION\n\n\nART. 70. _Light, a Mode of Motion._--No subject has in the past received\ngreater attention from philosophers and scientists than that involved in\nthe question as to \"What is Light?\" Indeed, it may truthfully be said,\nthat even to-day its exact character is not positively known. That it is\ndue like heat to some periodic wave motion in the Aether is known, but\nthe exact character of that wave motion has yet to be determined. As in\nthe case of heat, so in the case of light, there have been two theories\nwhich have contended with each other for supremacy in endeavouring to\nanswer the question as to \"What is Light?\" Those two theories are known\nas the Emission or Corpuscular Theory, and the Undulatory or Wave\nTheory. The corpuscular theory was introduced and developed by Newton in\nhis work on _Optics_, which ranks second only to the _Principia_ as a\nwork revealing masterly research and scientific genius. Newton supposed\nthat a luminous or lighted body actually emitted minute particles, which\nwere shot out from the body with the velocity of light, that is, at the\nrate of 186,000 miles per second. These minute particles he termed\ncorpuscles. In the work just referred to regarding this matter, he asks\nthe question, \"Are not rays of light very small bodies emitted from\nshining substances?\" These small particles or corpuscles were supposed\nby him to actually strike the retina of the eye, and so produce the\nsensation of Sight, in the same way that odorous particles entering the\nnostril, come into contact with the olfactory nerves and produce the\nsensation of Smell. In order, however, to account for certain phenomena\nof light, he was compelled to postulate an aetherial medium to fill all\nspace, in which his luminous corpuscles travelled, and which would\nexcite waves in that medium. In his eighteenth query on this point he\nasks: \"Is not the heat of a warm room conveyed through the vacuum by the\nvibration of a much subtler medium than air, and is not this medium the\nsame with that medium by which light is reflected or refracted, and by\nwhose vibrations light communicates Heat to bodies, and is put into fits\nof easy reflection and easy transmission?\" The corpuscular theory,\nhowever, received its death-blow when, in competition with the wave\ntheory of light, as developed by Young, it was found that the latter\ntheory satisfactorily accounted for certain phenomena as the refraction\nof light, which the corpuscular theory did not adequately account for.\nEven while Newton was developing his theory, Huyghens, a contemporary of\nNewton, was developing another theory which is now known as the\nundulatory or wave theory. Huyghens drew his conclusions from the\nanalogy of sound. He knew that sounds were propagated by waves through\nthe air, and from the region of the known, endeavoured to carry the\nprinciple into the region of the unknown, a strictly philosophical\nmethod, and one in accordance with the second Rule of Philosophy. He\nsupposed that light, therefore, like sound, might be due to wave motion,\nbut if it were wave motion, there must have been a medium to propagate\nthe waves. In order to account for this wave motion, he supposed all\nspace to be filled with a luminiferous Aether, which would be to his\nlight waves what air is to sound waves. In this conception he was\nsupported by Euler the mathematician, and in 1690 he was able to give a\nsatisfactory explanation of the reflection and refraction of light, on\nthe hypothesis that light was due to wave motion in the Aether. It was\nnot, however, till the advent of Thomas Young, that the undulatory or\nwave theory reached its perfection, and finally overthrew its competitor\nthe corpuscular theory. Young made himself thoroughly acquainted with\nwave motion of all kinds, and applied his knowledge and experience to\nthe phenomena of light, and from the analogies so obtained, he gradually\nbuilt up the undulatory theory, and gave to it a foundation from which\nit has not yet been moved. Young made use of the same aetherial medium\nin order to propagate the wave motion of light in the same way that\nHuyghens did. From that conception, the Aether has been gradually\nperfected, until we have the conception which has been presented to the\nreader in Chapter IV., in which I have endeavoured to show that this\naetherial medium is matter, but infinitely more rarefied and infinitely\nmore elastic, but notwithstanding its extreme rarefaction and\nelasticity, it possesses inertia, because it is gravitative. It is this\nAether, then, that is concerned in the propagation of light, and is the\nuniversal medium which is to light what air is to sound. Young,\ntherefore, having applied himself to the wave motion of sound, from such\nresearches was able to explain the physical cause of colour, and that\nphenomenon termed interference.\n\nWe will therefore look at wave motion, in order to understand the wave\ntheory of light.\n\nNow in all wave motion, whether it be water waves or sound waves, that\nwhich is propagated or conveyed from place to place is energy, or\nmotion. If a stone is thrown into water, a series of concentric circles\nof waves are generated, which spread out with increasing size, but\ndecreasing power or motion, regularly on all sides. The water, however,\ndoes not move away from the generating source. There is a motion of the\nwater, but it is simply a wave motion, so that the propagation of a wave\nis the propagation of motion, rather than the transference of the actual\nwater which constitutes the wave. In the case of sound waves, we have\nagain an illustration of the same principle. For example, suppose we\nstrike a bell, and so set the particles of that bell in a state of\nvibration. These vibrations give the air in contact with the bell a\nforward movement, and then, owing to the elasticity and inertia of the\nair, a backward movement is set up, with the result that a series of\nwaves are set in motion from the bell on every side, which gradually\ndiminish in intensity the farther they recede from the generating body.\nAccording to the wave theory, therefore, we have to picture all heated\nand luminous bodies in a state of vibration, and the atoms of such\nluminous bodies imparting the vibrations to the atoms of the Aether, in\nthe same way that the atoms of a bell impart their vibrations to the\natoms of the air in contact with it. These vibrations are then\npropagated through the Aether in waves, which, entering the eye, impinge\nor strike upon the retina at the back of the eye, and being transmitted\nto the brain give rise to the sensation of sight. It must not be\nforgotten that the waves of Aether, as pointed out in Art. 64 in\nrelation to heat, really form spherical shells which radiate out in all\ndirections from the central body which gives rise to them. Thus it can\nbe seen, that all points in the spherical wave which are at equal\ndistances from the vibratory or luminous body, must possess the same\nintensity, and possess equal lighting powers. Light, therefore, like\nheat, is due to a periodic wave motion set up in the Aether by the\nvibrating atomic motion of heated or luminous bodies. It must be also\nnoticed, that if we could see the air through which the sound waves are\npassing, we should see that each atom or particle of the atmosphere was\nvibrating to and fro in the direction of propagation. If, however, we\ncould see an atom of Aether in vibration, accepting the principle that\nAether is atomic, we should see that each aetherial atom is not\nvibrating in the direction of propagation, but across the line in which\nthe wave is travelling. Thus the vibration of the air is said to be\nlongitudinal, but the vibrations of the Aether are transversal. An\nillustration of the transverse motion of a light wave may be obtained by\ntaking a rope and imparting to it a series of undulations by shaking it\nup and down, when it will be observed that the wave motion of the rope\nis transverse to the straight line in which it is propagated. The\nphysical explanation of the transverse vibration of light will be dealt\nwith in a subsequent article.\n\nNow the question suggests itself to our mind, as to what effect the\natomicity of the Aether has upon the undulatory theory of light. Does it\nestablish it upon a firmer basis, or does it in any way destroy its\ntruth as a theory? I venture to think that the atomicity of the Aether\nin no sense destroys any part of the undulatory theory of light, but\nrather tends to confirm and establish it upon a logical and\nphilosophical basis.\n\nFor instance, as has been pointed out in Art. 47, in order for the\nundulatory theory to have any existence at all, it is essential that the\nAether should possess the property of elasticity. But how the Aether\npossessed the property of elasticity while at the same time it was\nfrictionless, and therefore possessed no mass, has been a problem that\nhas taxed the ingenuity and resources of scientists for a century past,\nand up to the present is a problem which still remains unsolved. Now,\nhowever, with our atomic Aether, it is just as easy to conceive Aether\ntransmitting a wave as it is for air to transmit sound waves, or water\nto transmit water waves.\n\nTyndall, in his _Lectures on Light_, seems to have appreciated the\ndifficulty, and to avoid confusion, again and again refers to a\n_particle_ of Aether. While Huyghens himself in speculating upon the\nelasticity of the Aether in his _Traite de la Lumiere_, 1678, makes a\nsuggestion as to its origin, which practically amounts to the fact that\nthe aetherial atom which gives rise to this elasticity is the core or\ncentre of a vortex ring. Thus it can be seen that the elasticity of the\nAether, so essential to the undulatory theory, is a problem that cannot\nbe solved apart from recognizing the hypothesis of an atomic Aether.\n\nThen, again, in the undulatory theory of light, the density of the\nAether around molecules of bodies has to be taken into consideration to\naccount for such phenomena as the refraction and reflection of light,\nbut, as we have seen in Art. 46, such a property as density is\ninconceivable in connection with a medium which is neither atomic and\npossesses no mass. On the assumption, however, of an atomic and\ngravitative Aether, the difficulty is at once solved, and the density of\nthe Aether, and different degrees of density are at once placed upon a\nlogical and philosophical basis. So that in relation to the elasticity\nand density of the Aether upon which the transmission and reflection of\nwave motion depend, an atomic and gravitative Aether establishes and\nconfirms the undulatory theory.\n\nThere is also another aspect of the subject that is worthy of notice. I\nrefer to the effect of an atomic and gravitative Aether upon Newton's\ncorpuscular theory of light. Newton's corpuscular theory failed in not\nbeing able to account for the relative velocity of light in rare and\ndenser media, and if by an atomic Aether in conjunction with the\nundulatory theory, the phenomenon can be accounted for, as I believe it\ncan, then our aetherial vortex atoms are analogous to Newton's\ncorpuscles. This distinction will, however, have to be made, viz. that\nNewton supposed his luminous corpuscles to be emitted by the luminous\nbody, whereas in the conception of our aetherial atoms, we conceive them\nto be stationary relatively in space, and only subject to those\nvibrations and oscillations that give rise to the aetherial waves\nrecognized in the undulatory theory.\n\nIt would indeed be a consummation to be desired, if, by an atomic\nAether, it can be proved that Newton's Corpuscular Theory was made to\nharmonize with the Undulatory Theory, and that it can be I am profoundly\nconvinced. Professor Preston is also of this view, for in his _Theory of\nLight_, writing on this subject, he says, page 19: \"In conclusion, we\nmay state that we believe an ingenious exponent of the emission theory,\nby suitably framing his fundamental postulates, might fairly meet all\nthe objections that have been raised against it.\"\n\nWe will now apply the hypothesis of an atomic and gravitating Aether to\nHuyghens' principle of wave propagation, and see if this atomicity in\nany way destroys that principle, or whether it simplifies and confirms\nit.\n\nLet us briefly review our conception of the Aether before making the\napplication. In the first place, because Aether is gravitative, we\nlearned from Art. 45 that it surrounds all bodies in the universe, from\nthe smallest atom to the largest sun or star in the firmament of heaven.\nOur sun, then, which is to our system the source of all its light, will\nbe surrounded by what are practically spherical aetherial envelopes or\nshells which decrease in density as they recede from the sun (Art. 46).\nThese aetherial shells are, according to our conception, made up of\nminute aetherial spherical vortex atoms possessing polarity and rotation\n(Art. 43), and these atoms will be closer together the nearer they are\nto the central body, because of the increased density of the Aether due\nto the attractive influence of the sun. Thus, when a wave motion is set\nup in the Aether around the sun by the intense atomic activity of that\nincandescent body, each atom of that aetherial spherical shell or\nenvelope participates in the motion or impulse received, at one and the\nsame time, so that the wave is transmitted from envelope to envelope, by\nthe elasticity of the aetherial atoms which compose the envelope or\nshell. Thus the light wave is always spherical in form, or nearly so, as\nthe rotational and orbital motion of the sun affect the exact shape of\nthe aetherial envelope as we shall learn more fully later on.\n\nFurther, the wave front always takes the form of a sphere, as the waves\nare radiated out from the luminous body in all directions, and we shall\nlearn, in the next article, that the vibrations are always in the wave\nfront, that is, take place on the surface of each of these envelopes,\nand these vibrations are also transverse to the propagation of the wave.\nAs these aetherial envelopes extend right into space, the wave is\ntransmitted from envelope to envelope by means of the aetherial atoms\nwith the velocity of 186,000 miles per second, but as each succeeding\nenvelope possesses a larger surface than the preceding one, the\nintensity of the light is proportionally decreased. The surface of such\nenvelope is always proportionate to the square of the radius, the other\nquantities remaining equal. So that the intensity of the light waves,\nwhich are coincident with the surface of each spherical envelope, will\nalways vary inversely as the square of the distance from the luminous\nbody, which agrees with the law of inverse squares that governs light\nand heat.\n\n[Illustration: Fig: 4.]\n\nWe have considered the wave motion as a whole, that is, we have viewed\nit from the standpoint of the whole of the aetherial elastic envelope.\nNow we will look at the subject from the atomic standpoint, and see if\nit is in accordance with Huyghens' principle of wave propagation.\n\nWe will suppose that an undulatory movement is started by a luminous\nbody at point _A_ situated in the Aether, and surrounded by that medium.\n_A_ may represent a part of any luminous body, as the sun or star, while\n_B_ _C_ and _B'_ _C'_ represent a segment of the aetherial envelopes\nalready referred to, which exist around the sun. We will further suppose\nthat the small dots surrounding the luminous body represent the\naetherial atoms forming the envelope, which transmit the impulse or\nenergy received from the atomic vibrations of the luminous body. As each\naetherial atom is moved or pushed forwards, each atom directly in\ncontact with it accepts and transmits the impulse. But each of these\natoms stands in relation to those in front of them, as they did in\nrelation to the first row of atoms, so to speak, and therefore exert a\ncorresponding impulse on the front row.\n\nBut the third row stands in relation to the fourth row as the second row\ndid to the third, and so on to infinity. Thus each atom being surrounded\nby other atoms may be looked on as the centre of a new wave system, so\nthat every particle of the wave system is itself a centre of a new wave\nsystem which is transmitted in all directions. As these innumerable and\nminute wave systems co-operate with one another, they form a principal\nwave system which is coincident with the surface of the spherical\nenvelope, part of which is represented by _B_ _C_. Then if we conceive of\nall the aetherial atoms in part of the principal wave system _B_ _C_, as\nthemselves becoming the centre of wave propagation, by their wave\nsystems the principal wave will be transmitted further on into space to\nanother aetherial envelope _B'_ _C'_, which represents part of another\nprincipal wave, which again is coincident with the surface of one of the\nspherical aetherial envelopes. So that by the action of the aetherial\natoms which exist on all sides of the luminous body, the aetherial wave\ncan be transmitted from atom to atom in more or less spherical form.\n\nNow let us compare this explanation of the transmission of light by an\natomic Aether with the celebrated Huyghens' principle which is thus\nenunciated. \"When an undulatory movement propagates itself through an\nelastic medium, every _particle_ imitates the movement of the particle\nfirst excited. But every particle stands in relation to the adjoining\nones in exactly the same relation that the first particle did to its\nneighbours, and consequently must exert upon those surrounding it,\nexactly the same influence as the first did. Every vibratory particle is\ntherefore to be regarded as if it were the originally excited particle\nof the wave system; and as the innumerable and simultaneous elementary\nwave systems co-operate with one another at each instant, we obtain\nexactly that principal wave system by which the elastic medium appears\nat any moment to be moved.\" Now here, in this statement, we have the\ndefinite term _particles_ used several times by Huyghens. But in the\ngenerally accepted theory of the Aether, such a term is unknown and\nunrecognized, with the obvious result that the definite and simple\nstatement of Huyghens loses all its simplicity and meaning. Replace,\nhowever, the non-atomic Aether as at present recognized, by an atomic\nand gravitating Aether, and then Huyghens' exposition or principle\nstands out in all its simplicity and clearness, and finds in an atomic\nAether its literal fulfilment and complete verification.\n\nIn conclusion on this point, viz. that light is a mode of aetherial\nmotion, let us endeavour to form a mental picture of our atomic and\naetherial world. We have to remember that every particle and atom of\nmatter in existence are ever vibrating, and by their vibrations are ever\ncreating and generating Aether waves in the aetherial medium. These\nwaves, begetting others, the process is continued until they are either\nintercepted and brought to rest by other matter, or else speed away\nuntil they reach the boundary of space.\n\nNow it is scarcely necessary for me to say, that if one atom can create\nand generate these Aether waves, a thousand atoms can create them in\ngreater abundance still, and millions of atoms in even still greater\nabundance, and so on in proportion to the quantity or bulk of the matter\nvibrating. Further, as it is with quantity, so will it be with\nintensity, or activity of vibration. The more intensely an atom\nvibrates, the more intense would be the movement of the generated Aether\nwaves, and the intensity would be in exact proportion to the intensity\nof the motion of the atoms vibrating. In regard to the power of atomic\nmotions or vibrations, those are the greatest and most intense in energy\nor motion, which are produced by combustion or burning. The chemical\nactivity by which the burning is brought about arouses and excites the\natoms of matter subject thereto, into an intensity of motion, thousands,\nit may be millions of times greater than can be produced by any other\nknown means. Therefore it can be readily seen, that the Aether waves\ngenerated by this means will be greater and more abundant, both in their\nvolume and intensity, than the Aether waves produced merely by a cold\nbody. For example, take a candle at night-time when the light has\ndisappeared; look at it and feel it. Though its atoms are all in motion,\ngenerating Aether waves which are impressed with its own particular form\nand colour, yet it can scarcely be seen even at a short distance; but\nlight it, and what a change takes place! We can both see it, and are\nenabled by its light to see other things also. By the power of\ncombustion, its atoms have been excited into greater energy or motion,\ngenerating and speeding Aether waves on every side, and these Aether\nwaves being reflected and re-reflected by the atoms of the air, and the\nwalls of the house, give light to all that are in the house. I must now\nask the reader to refer to Art. 64 on Radiant Heat, in order that we may\nrecall facts regarding the heat of the sun. Remembering the intensity\nof the heat of the sun as calculated by Herschel and others, and\nremembering that the sun is 1,200,000 times larger in volume than our\nearth, the question naturally suggests itself to our mind, what must be\nthe volume and intensity of the light waves as they flow from the sun\ninto space? What a storm of fury and of motion must there be within the\naetherial atmosphere around the sun, and with what volume and power must\nthese light waves speed away from so mighty a source! Some idea may be\ngained from the fact that they speed away to the distant Neptune, a\ndistance of nearly three thousand millions of miles, and impart to that\nplanet the energy of light and heat which to the planet forms the\nphysical source of all its life and activities. Thus from the sun, the\ncentre of the solar system, there are ever being poured forth into space\nthese aetherial light waves. The solar fires are ever glowing, and their\nflames ever burning, robing the solar disc with its quivering fringe, or\nmadly leaping on every side to a distance of one hundred thousand miles,\nand by their madness lashing the aetherial atmosphere into fury,\ncreating aetherial waves, myriads upon myriads, and sending them with\nlightning speed across the intervening space. As swift-footed messengers\nthey come, the bearers of life and beauty to distant planets. They come\nto this our island home in space, these aetherial light waves, like rich\nargosies freighted with the treasures of light, of life, of beauty, and\nof glory, and the transmission of this life and beauty is effected by\nthe incessant wave motion generated in the Aether by the central body of\nour solar system, the sun. Let us therefore endeavour to form a mental\npicture of this aetherial wave motion with its transverse vibrations.\n\n\nART. 71. _Transverse Vibration of Light._--In the previous article we\nsaw that the vibration of light was transverse to the line of\npropagation. If we could see the particles of air which are vibrating\nwhen sound waves are produced, we should find that each particle or atom\nis vibrating backwards and forwards in the direction of propagation.\n\nIn the case of an aetherial atom, however, which, according to our own\ntheory, participates in the vibration, we have to try to conceive of\neach atom as vibrating across the line of propagation. So that if _A_\n_B_ represents a ray of light proceeding from a luminous body, as the\nsun (Fig. 5), then the vibration must be across the line, as up and down\nand across that line as shown in the figure, each phase of the vibration\nbeing at right angles to the line of propagation--that is, to _A_ _B_.\nHow can we form a physical conception of this phenomenon? There must be\nsome physical explanation to it, for if it be an effect there must be a\ncause for its existence and production. Up to the present, however, no\nphysical explanation has been forthcoming, so that for over 200 years a\nfrictionless medium has failed to account for, or to explain, the\ntransverse vibration of light as suggested by Fresnel.\n\nIf, therefore, by the hypothesis of an atomic and gravitative Aether, we\nsucceed in accomplishing a result that a frictionless Aether has failed\nto accomplish, then the explanation will be a most important factor in\nproving the atomicity and consequent gravitative property of the Aether.\n\nLet us therefore revert to our hypothesis of the Aether as given in Art.\n45. From that we learn, because Aether is atomic, it is also\ngravitative, and therefore forms around every atom and molecule, every\nsatellite, planet, sun and star, an aetherial atmosphere--such aetherial\natmosphere being doubtless proportionate to the mass of the atom or\nmolecule or planet as the case may be, in accordance with the Law of\nGravitation. We shall consider this view of the subject later on.\n\n[Illustration: Fig: 5.]\n\nThus we learn that every particle of matter, and every body in the\nuniverse has its aetherial atmosphere so to speak, to which it is held\nbound by the universal Law of Gravitation. In the case of a satellite\nor planet or sun or star, that atmosphere will be more or less spherical\nin shape, decreasing in density as it recedes from the attracting body.\nAs we saw in the previous chapter, Tyndall stated that the waves of\nlight really formed spherical shells which surrounded the luminous body.\nIn the conception of an atomic and gravitating Aether we can form a\nphysical conception of these aetherial shells, which can be pictured as\nelastic envelopes, or rather series of envelopes surrounding each\nparticle of matter, and also surrounding each satellite, planet, sun,\nand star; each envelope getting gradually less and less dense as the\ndistance from the central body is increased.\n\nNow we learn from experiments that the vibration is always in the wave\nfront, but the wave front is coincident with the surface of each\naetherial spherical shell, therefore the vibration must be in, and\ncoincide with, the surfaces of the spherical shells that are formed\naround every body in the universe.\n\nWe are now, however, dealing specially with one body which is the source\nof light, viz. the sun, and have therefore to picture the sun as being\nsurrounded by these aetherial elastic envelopes, which gradually get\nless and less dense as they recede from it. What, therefore, will be the\neffect of the heat of that body as it is poured forth into space? We\nhave already learned (Art. 63) of the untold quantity of heat that is\ncontinually being poured forth into space from the sun with its diameter\nof 856,000 miles, and its circumference of over 2-1/2 million miles.\nWhat intense activity it must generate in the Aether near its surface!\nand what must be the direct effect of that heat upon the aetherial\nelastic envelopes or shells which surround it?\n\nPerhaps the answer can be best illustrated by a simple experiment. Let\nus take an ordinary toy balloon, with its elastic envelope, and fill it\nmoderately full with air, and observe what the effect on it is when we\nput it near the fire. Gradually, as heat is imparted to the air in the\nballoon, the air which is also elastic expands, with the result that the\nenvelope of the balloon is extended, and its size enlarged. Now withdraw\nit from the fire and note what happens.\n\nAs the air inside gets cold again, the elastic envelope of the balloon\ngradually shrinks, until it has been reduced to its former size. What\nhas been taking place during this experiment with regard to the elastic\nenvelope and the atoms thereof? May we not say that there has been a\nvibration or oscillation, among the particles which go to make up the\nelastic envelope, that forms the surface of the balloon? Certainly there\nhas been some form of motion, and that motion took first the form of an\nexpansion, and then contraction of the individual particles; and we have\nonly to conceive of this process being repeated quickly and\ncontinuously, to form a mental picture of what takes place in any\naetherial elastic envelope or shell that surrounds the sun.\n\nThe illustration is not, however, perfect, because we have made the\nsource of heat to be outside instead of inside the elastic envelope, as\nis the case with the sun and its aetherial atmosphere or envelope. We\nwill therefore slightly modify the experiment, and take two balloons,\n_A_, _B_, one smaller than the other, and put the smaller one _A_ into\nthe interior of the larger one, inflating the smaller one, so that it\ncan be situated in the middle of the larger one, the latter having twice\nthe diameter of the smaller one, as in the diagram (Fig. 6). To the neck\nof the smaller balloon _A_ we will attach an india-rubber tube which\nends in a closed bulb _C_. We have now the two balloons inflated. Let us\npress the bulb _C_ and notice what happens. The effect will be exactly\nthe same as it was when we brought the balloon in contact with the heat\nof the fire in the first experiment--that is, the elastic envelope will\nbe again expanded. As soon as we take the pressure from the bulb _C_ the\nenvelope, being elastic, seeks to recover its original position, with\nthe result that it springs back to its original size. If we pressed the\nbulb _C_ 20 times per minute, we should get 20 vibrations of the\nparticles of the envelopes per minute, and if we pressed it 1000 times\nper minute, we should get 1000 vibrations among the particles of the\nelastic envelope, so that the number of vibrations would correspond to\nthe number of times we pressed the bulb. Now how did this vibration\nreach the elastic envelope of the balloon _B_ from the balloon _A_?\n\n[Illustration: Fig: 6.]\n\nThe reply is, by means of the particles, or atoms of air that exist\nbetween the two surfaces of the balloons, and that transmission would\ntake the form of a wave propagated from particle to particle, so that we\nmight put dots on the right side of _A_ to represent the atoms of air\nwhich transmit the wave from _A_ to _B_.\n\nBut the vibration which takes place in the surface of the envelope of\nthe outer balloon is _across_ this line of propagation, because as the\nwave proceeds from _A_ to _B_, the elastic envelope expands and\nstretches always _across_ the line of propagation--that is, it stretches\nup and down, left and right, as it is expanded outwards, so that the\nvibration or oscillation of the particles always takes place in the\nsurface of the elastic envelope across the line of propagation. Let us\ntherefore apply the result of this simple experiment to our solar system\nand the Aether, and see if it can be made to explain the transverse\nvibration of light. Let _A_ represent the sun (Fig. 7) and _B_ an\naetherial elastic envelope surrounding the sun. In this case we dispense\nwith the bulb _C_, as the sun possesses within itself the power to\ngenerate heat, and so to produce the required expansion of the elastic\naetherial envelopes _B_, _G_, _H_, etc.\n\n[Illustration: Fig: 7.]\n\nInstead, however, of having air particles between _A_ and _B_, we will\nput in their place our aetherial atoms which we have conceived according\nto Art. 44. These surround the sun, represented by _A_, forming elastic\nspherical shells or envelopes. As the sun radiates its heat into space,\nit urges the aetherial atoms against each other, with the result that\nthey transmit the energy from atom to atom, or particle to particle,\ntill they come to the elastic aetherial envelopes of _H_, _G_, _B_.\n\nThe effect on _B_, or on any other aetherial envelope, is to expand it\noutwardly, and thus set the atoms of which it is composed into\nvibration. The wave, which is now an aetherial wave travelling with a\nvelocity of 186,000 miles per second, may be represented by the line _D_\n_E_. But while it is travelling from _D_ to _E_ the same energy is being\nradiated out in all directions, so that a wave reaches the whole surface\nof the elastic envelope _B_ at the same time, with the result that the\nwhole of the shell or envelope is set in vibration as it expands\noutwardly.\n\nThus the vibration is always in the wave front, and the wave front is\nalways coincident with the surface of one of these envelopes, and as\nthese aetherial envelopes are themselves formed by aetherial atoms, the\nwave is spread outwardly from any central point in a spherical form as\nproved by experiment. Not only, therefore, is the vibration in the wave\nfront, but it is always transverse to the line of propagation, for the\nsimple reason that the surface of the spherical shell or envelope is\nalways at right angles to the radius vector or straight line which joins\nany centre to the surface of a spherical envelope.\n\nAs soon as the aetherial atom which forms the spherical aetherial\nenvelope has reached the limit of its expansion, it seeks to recover its\nformer position because of its elasticity, with the result that the\nwhole envelope contracts again, and arrives at its original position in\nspace ready to accept motion again and transmit it onwards in the same\nmanner as before.\n\nThus, by the acceptance of an atomic and gravitating Aether, we may form\na physical conception of one of the greatest problems in optical\nphenomena, viz. the transverse vibration of light which always takes\nplace in the wave front, and across the line of propagation. Whether\nthis explanation is exactly correct in detail, or not, I am convinced\nthat the true physical explanation of the problem is to be found in an\natomic and gravitating Aether, as hitherto a frictionless Aether has\nfailed even to suggest to any scientist how such a transverse vibration\ncan take place.\n\n\nART. 72. _Reflection and Refraction._--A ray or wave of light is said to\nbe reflected when it meets with an obstacle which opposes its free\npassage and turns it back. We have illustrations of this law of\nreflection in the case of water waves striking against a breakwater, or\na sound wave striking against the wall of a room. In either case the\nwave is turned back, and reflection is the result. A ray or a wave of\nlight is said to be refracted when, in passing from one medium into\nanother, it is turned from the straight path in which it was going\nbefore it entered the refracting medium. An illustration of the\nrefraction of light is to be found in the case of the glass lens, so\noften used to converge the light waves into one focus. We have up to the\npresent dealt with only two theories of light, the Corpuscular theory\nand the Undulatory or Wave theory. We have seen how both harmonize with\nHuyghens' principle, and the question arises as to whether both can be\nmade to harmonize with the phenomena of reflection and refraction.\n\nIn the Corpuscular theory we have luminous particles emitted by luminous\nbodies. These particles we have learned are practically synonymous with\nour aetherial atoms.\n\nIn the Wave theory it is impossible to conceive of a wave without\nconceiving of particles which transmit the wave; even Huyghens refers to\nparticles of Aether, and so does Tyndall in his _Notes on Light_.\n\nIn the Electro-magnetic theory of light we have again to think of atoms,\nwhich are termed electrons by Dr. Larmor and Sir William Crookes; while\nProfessor J. J. Thompson calls them corpuscles.\n\nSo that in all three theories we have the same fundamental idea of\natoms, either expressed or imagined, underlying all the three theories.\nNow what is the property of the Aether on which all reflection and\nrefraction is based? Is it not the property of density? Fresnel assumes\nthat reflection and refraction of light are dependent upon different\ndegrees of density of the Aether associated with any body, and has given\na mathematical formula, which decides the index of refraction, such\nformula being entirely dependent upon the relative density of the Aether\nin association with the refracting medium.\n\nBut with a frictionless medium, it is an absolute impossibility to\nconceive of different degrees of density of the Aether in association\nwith matter.\n\nIf the Aether does possess different degrees of density which decide the\nrefractive index of the substance, then of a certainty there must be\nsome law to govern and decide the density, and that law can only be the\nLaw of Gravitation.\n\nAs Young points out in his Fourth Hypothesis, every particle of matter\nhas an attraction for the Aether by which it is accumulated around it\nwith greater density. Now on the basis of our conception of a\ngravitative Aether, every atom and molecule, and indeed every body in\nthe universe, possess aetherial atmospheres, which possess varying\ndegrees of density, the denser layers being nearest to the nucleus of\nthe atom or molecule as the case may be, the elasticity of each layer or\nenvelope being always proportionate to its density.\n\nWhen we apply the corpuscular theory to the reflection of light we find\nthat it satisfactorily accounts for the phenomenon.\n\nAccording to Newton's corpuscular theory, each luminous particle travels\nin a straight line through a homogeneous medium. When, however, it comes\nalmost into contact with a reflecting surface, which in our case we\nconceive to be a layer of one of the aetherial elastic envelopes\nsurrounding the atoms or molecules of the reflecting body, then,\naccording to Newton, the light particle is repelled, or reflected by the\nmedium; the angle of reflection or repulsion being always equal to the\nangle of incidence. So that the emission theory harmonizes with the wave\ntheory in regard to reflection.\n\nWhen, however, we come to deal with the refraction of light, the\ncorpuscular theory apparently breaks down, and it was in relation to\nthis phase of the phenomena of light that the undulatory theory\noverthrew the corpuscular theory.\n\nAccording to the corpuscular theory, when a luminous particle or\ncorpuscle is nearing the surface of a denser medium, as glass or water,\nit was attracted by the denser medium, with the result that the velocity\nof the particle in the denser medium was greater than its velocity in\nair. But direct experiments prove exactly the opposite, as it is found\nthat when light passes from a rare into a denser medium, the velocity of\nlight in the denser or more refracting medium is less than it was in the\nair. Here then was a test to decide the respective merits of the two\ntheories. As the undulatory theory was able to give a satisfactory\nexplanation of the phenomenon, the corpuscular theory was rejected, and\nthe undulatory theory was accepted. Now the question suggests itself, as\nto whether it is possible to reconcile the two theories in relation to\nthe refraction of light by our conception of an atomic and gravitative\nAether. I believe it is possible. Let us look at the case for a moment.\nWe have, according to our theory of the Aether, to conceive of all atoms\nand molecules, of all planets and suns and stars, being surrounded by\naetherial elastic atmospheres, or envelopes, which, like the atmosphere\nin association with the earth, are always the densest nearest the\nnucleus of the atom, getting gradually less and less dense the further\nthey recede from the central point. Further, according to our theory,\nwith regard to the elasticity or pressure of these elastic envelopes,\nthey exert a pressure proportionate to their density. So that the nearer\nthe aetherial atmosphere or envelope is to the central point or nucleus\nof the atom, the greater will be the elasticity or pressure.\n\nNow what I wish to call the reader's special attention to is, that the\npressure in each and every case of the aetherial elastic envelopes which\nsurround the central nucleus, is always directed _away from_ the central\npoint, and here it seems to me is the solution of the difficulty which\nNewton failed to solve. For when a luminous corpuscle enters any medium,\nassuming it to do so, it would have to overcome the pressure due to the\nincreased elasticity of the denser aetherial envelopes, and as the two\nmotions, viz. that of the incident ray, and the pressure due to the\nelasticity of the elastic envelope, would be in opposition to each\nother, the result would be that the luminous corpuscle, if it entered\nthe medium at all, would be retarded and not accelerated as suggested by\nNewton, and such a result is perfectly in harmony with experiment. So\nthat by our theory of an atomic and gravitating Aether, it seems to me\nthat it now becomes possible to reconcile the two theories.\n\nThere is another difficulty that the emission theory had to contend\nwith, and that was, how was it possible for the same surface of any\nsubstance to reflect and refract a corpuscle at one and the same time?\nNewton overcame this difficulty by suggesting, from the results of his\nobservations on certain coloured rings, that each particle had what he\ncalled certain phases or fits, of easy reflection or refraction, so that\nat certain times they would be refracted, and at other times they would\nbe reflected.\n\nBoscovitch has suggested that the fits were due to the fact that each\nluminous corpuscle possessed polarity; which, by rotating, alternately\noffered their different sides to the refractive and reflecting surfaces,\nso that sometimes they would be reflected or repelled, and at other\ntimes attracted or refracted.\n\nA similar hypothesis has also been suggested by Biot. Now if such a\nhypothesis will satisfactorily account for the fact that the same medium\nwill reflect or refract the luminous corpuscles, as the case may be,\nthen in our aetherial atom we have the very conditions which would\nsatisfy both Boscovitch and Biot's hypothesis. For one of the properties\nthat we suggested regarding our aetherial atom was, that it possessed\nrotation like our own earth, and that it also possessed polarity.\n\nThe harmonizing of the two theories, therefore, seems to rest upon the\natomicity or non-atomicity of the Aether.\n\nIt is absolutely certain that the electro-magnetic theory of light\ndemands the recognition of some form of atomicity for the Aether. For if\nlight be really an electro-magnetic phenomena, as has been proved by\nMaxwell and experimentally demonstrated by Hertz, then, in view of the\nfact that the atomicity of electricity is coming within the scope of\ndirect experiment as asserted by Dr. Larmor, unless we accept atomicity\nof the Aether in some way, we shall be in the unphilosophical position\nof having the Aether of space not being composed of atoms, while the\nelectricity associated with that Aether in some unknown way is composed\nof atoms. In other words, we shall have a non-atomic body composed of\natoms, which conclusion is absurd. Therefore, from the electro-magnetic\ntheory of light, we are again compelled to postulate atoms of some kind\nfor the Aether.\n\nIf there are electrical atoms in association with the Aether, then they\nmust be of two kinds, positive and negative, as it is impossible to find\npositive electricity disassociated from negative. Therefore, from the\nelectro-magnetic theory of light we get further evidence of the polarity\nof the aetherial atom, by which Newton's fits of easy reflection or\nrefraction may be physically conceived.\n\nI am convinced, that with the hypothesis of an atomic and gravitative\nAether as suggested by Young in his Fourth Hypothesis, all three\ntheories of light in relation to the phenomena of reflection and\nrefraction can be harmonized. I wish only to point out the direction in\nwhich to look for the solution, and must leave it to scientists to work\nout the problem.\n\n\nART. 73. _The Solar Spectrum._--When a ray or beam of solar light is\npassed through a prism, it is broken up or decomposed into its\nconstituent parts. This is called dispersion, and conclusively proves\nthat the light from the sun is not a simple, but a compound colour. We\nhave illustrations of this decomposition of pure white light in the\nrainbow, where the colours of the sunlight are revealed against the sky\nwith clearness and precision. A simple experiment to prove that the\nsolar light is a compound one may be made by boring a small hole in a\nshutter, and then allowing the sunlight that passes through the hole to\nfall upon a prism, such as the pendant of a candelabrum. When this is\ndone, then on the opposite wall of the room will be seen, not one\ncolour, but seven colours, ranged in the following order: Red, Orange,\nYellow, Green, Blue, Indigo, Violet. This is termed the Visible\nSpectrum.\n\nIt may be asked, What is the cause of the various colours in the\nspectrum? We have already seen that light is due to a wave motion of the\nAether, and it can be demonstrated that the various colours of light are\ndue to different wave lengths. Colour is to light what pitch is to\nsound. As has been shown in Art. 62, the pitch of a note depends upon\nthe number of air waves which strike upon the tympanum of the ear in a\ngiven time. The more rapid the vibration, the higher the note. The more\nrapidly a sounding body vibrates, the shorter will be the length of each\nwave. If a violinist wants to produce a note of higher pitch, he presses\nhis finger on the string, thereby shortening it, and by so doing\nincreases the rapidity of vibration, and raises the pitch of the note.\nNow the colours of the spectrum are to the eye what the notes are to the\near. The aetherial waves which produce the red colour are slower in\ntheir vibrations, and are longer than those which produce the orange\ncolour. Those which produce the orange colour are of slower vibrations,\nand longer than those which produce the yellow colour, and so on through\nall the other colours; until we get to the violet and to the\nultra-violet, or invisible violet rays, which are the most rapid in\ntheir vibrations, and consequently their wave lengths are the shortest\nof the whole group. It has been ascertained that it takes about 39,000\nwaves of red light to measure an inch if placed end to end. Now light\nhas a velocity of 186,000 miles per second. If this is reduced to\ninches, we find that there are 11,784,960,000 in that distance. Let us\ntherefore multiply this number by 39,000, and we shall then find how\nmany waves of red light must enter the eye to produce the sensation of\nred colour. That number is 459,613,440,000,000, so that all these waves\nenter the eye in one second of time, and must strike the retina of the\neye in order to produce the sensation of redness. In the same way, the\nnumber of waves that must strike the retina of the eye to produce the\nsensation of violet can be determined. It takes about 57,500 waves of\nviolet to measure an inch, so that a violet wave is only 1/57000 part of\nan inch in length. All the other colours of the spectrum which lie\nbetween the violet and the red waves gradually get longer and longer in\ntheir wave lengths, and slower and slower in their vibrations, until at\nthe red end of the spectrum and beyond it we have the longest waves,\nwhich are from 1/39000 part of an inch in length to 1/10000 part of an\ninch.\n\nThe seven colours seen in the spectrum are called the Visible Spectrum.\nThere are, however, rays of light beyond both ends of the spectrum which\ndo not affect the optic nerves of the eye, and therefore are invisible\nto sight. The rays in the spectrum which lie beyond the red are termed\nultra-red rays, while those beyond the violet are called ultra-violet\nrays. It can be proved the former are rich in heating power, while the\nlatter possess great chemical power. By means of an instrument known as\nthe thermo-electric pile, or thermopile, the various heating power of\nthe whole spectrum, visible and invisible, can be determined.\n\nLet us look for a moment at these invisible or dark rays. Strictly\nspeaking, all light is invisible, as we cannot see light itself, we can\nonly see it by reflection. We have seen that light is due to a wave\nmotion in the Aether, but we cannot see that wave motion, neither can we\nsee the Aether itself, so that it is not strictly correct to call a ray\nvisible or invisible. We have, however, accepted the terms in relation\nto the rays of the spectrum, to distinguish between the invisible or\nobscure rays of the spectrum and the visible rays. It was Sir W.\nHerschel who first discovered the existence of these invisible waves. He\npassed a thermometer through the various colours of the solar spectrum,\nand then noted the temperature of each colour. He did not, however, stop\nat the limit of the visible spectrum, but experimented with his\nthermometer beyond its limits, and then found that beyond the red rays\nthere were other rays, the ultra-red rays, which possessed greater\nheating power than any other rays of the spectrum. Thus his experiments\nproved, that side by side with the luminous or light waves, there were\nother rays, which, though they possessed greater heating power, yet were\nnot able to excite the optic nerve, and so produce the sensation of\nsight.\n\nFrom these facts we learn that the solar spectrum may be divided into\nthree parts--\n\n1. The red or ultra-red end of the spectrum which possesses the greatest\nheating power.\n\n2. The central part, yellow and green, which is the greatest in luminous\npower or light waves.\n\n3. The violet or ultra-violet end, which possesses great chemical or\nactinic power as it is sometimes termed.\n\nWe have already seen (Art. 69) that the same aetherial waves which give\nrise to heat, also give rise to light, and that the only physical\ndifference between heat and light is, that the waves which cause the\nphenomena of heat are of slower period, and of greater length, than\nthose which cause the phenomena of light. From the solar spectrum we\nlearn that there are a third class of Aether waves, which are of more\nrapid vibration, and therefore shorter in length than either the\naetherial heat waves or the aetherial light waves. As already stated,\nthese are called chemical or actinic waves, because they possess a\ngreater chemical power than either the heat or the light waves that form\nthe central part of the spectrum.\n\nNow this question suggests itself to us in relation to these chemical\nwaves. What are these so-called chemical waves that are produced in the\naetherial medium by the activity and heat of the sun? It must be\nremembered that the aetherial waves which give rise to both light and\nheat, and also these chemical waves, are first set in motion by the sun,\nat least as far as our solar system is concerned. We are perfectly\nconversant with the phenomena and characteristics of both heat and\nlight. We are able to exactly determine what their particular effect\nwill be on matter, and to describe that effect in a perfectly\nstraightforward manner. The same, however, cannot be said of these\nso-called chemical waves that lie chiefly in the violet and ultra-violet\nend of the solar spectrum. What, then, is a chemical wave, its\nparticular nature, and its exact properties? That we know it can\ndecompose certain compounds, as Carbonic Acid Gas, CO_2, and so give\nrise to chemical decomposition, has been proved by Professor Tyndall and\nothers, but I have never yet seen any record of any attempt to find out\nwhat these chemical waves are. There may have been such attempts made to\ndiscover their origin and character, but I have not seen any such\nrecord. I purpose, therefore, to offer an explanation as to the\ncharacter and origin of these chemical or actinic waves, which I hope to\nprove by philosophical reasoning. We have already seen (Arts. 54 and 59)\nthat both heat and light are convertible, or can be transformed into\nelectricity, so that the same aetherial wave motion which can produce\nlight can also produce heat, and that in its turn can produce\nelectricity. Thus we learn that there is a very close identity between\nlight, heat, and electricity; indeed it can be demonstrated that the\nsame aetherial wave motion which produces electricity can produce the\nother two.\n\nLorentz,[14] in an article on \"The Identity of Light Vibrations with\nElectric Currents,\" states that \"the vibrations of light are themselves\nelectric currents.\" Now if this is true, and I believe it to be true, as\nI hope to prove later on from Clerk Maxwell's works, then it necessarily\nfollows, that wherever we get aetherial light waves, we must at the\nsame time also get aetherial electric waves. If that be so, then in the\nsolar spectrum we ought to have revealed to us, not only indications of\nthe presence of the heat and light vibrations, but equally so the\npresence of electric waves. This, I believe, is actually the case, and\nthe electric waves are the so-called chemical waves in the violet and\nultra-violet end of the spectrum. I think that we shall find sufficient\narguments and analogy to support this hypothesis, as we look further\ninto the matter. One of the greatest scientists of the past century,\nClerk Maxwell, has given to the world the genesis of what he termed the\nElectro-Magnetic Theory of Light, in which he proved that light was\nnothing more nor less than an electro-magnetic phenomenon. He pointed out\nthat the same Aether which was concerned in the propagation of light and\nheat through space, must therefore be equally concerned in the\npropagation of electric displacements in the free Aether; as he states,\nit would be philosophically wrong to assume that there was one aetherial\nmedium for light, and another for electric phenomena. If, therefore,\nthere is such a theory as the Electro-Magnetic Theory of Light, and\nthere undoubtedly is, as has been proved by the researches of Hertz on\nelectric waves, then it follows, either that light waves are themselves\nelectric currents, as suggested by Lorentz, or that the light waves are\ndirectly associated with electric waves in the same way that they are\nassociated with heat waves. So that the only difference between them\nwould be one of period of vibration and of length, the electric waves of\nthe Aether being of greater rapidity and therefore of shorter length\nthan either the light or heat waves. The only conclusion, therefore,\nthat it seems possible to come to regarding these chemical waves is,\nthat they are the electric waves of the spectrum. Thus, in the solar\nspectrum, there are three classes of waves indicated by the various\ncolours, and beyond the limits of these colours, viz. (1) Thermal or\nHeat waves in the red or ultra-red end of the spectrum; (2) Luminous or\nLight waves at the middle of the spectrum; and (3) Electric or Chemical\nwaves in the violet or ultra-violet end of the spectrum. Now in looking\nat this hypothesis from the standpoint of our Rules of Philosophy, I\nventure to assert that all the three rules are satisfactorily fulfilled,\nand that being so, the hypothesis advanced is philosophically correct.\nIn the first place, such a conception that the chemical waves or violet\nwaves are really electric waves is simple in its hypothesis, and so\nfulfils our first Rule of Philosophy. It is simple, because it puts in\nthe place of unknown chemical waves, a certain kind of aetherial waves\nwith whose action we are definitely familiar, and whose origin and\neffect can be satisfactorily accounted for, as proved by Hertz. Chemical\nwaves are not simple in conception, because we do not know exactly what\nthey are, or how they are originated. Besides, as Newton points out,\nthere is nothing superfluous in Nature. If one cause can effect the\ndesired end, as electric waves, then another cause as chemical waves is\nsuperfluous and unnecessary. Further, in our hypothesis of the electric\ncharacter of these chemical waves, we have a solution which\nsatisfactorily fulfils the second Rule of our Philosophy. Experience and\nexperiment teach us, that there are electric waves constantly being\ngenerated in a thousand ways. Indeed, it is an absolute impossibility to\nperform the simplest act of ordinary life, as brushing a hat, or wiping\nthe boots on a mat, cutting an orange, or any other act of simple\neveryday life, but that these aetherial electric waves are generated.\nBut as for these so-called chemical waves, experience has little to say\nabout them, and experiment still less. If we decompose water, dividing\nit up into two gases, Oxygen and Hydrogen, we do it by passing a current\nof electricity through the water. If we want to decompose or split up a\nbinary compound, as HCl, into its two elements, Hydrogen and Chlorine,\nthen we can do it by electricity--that is, by the decomposing action of\nthese electric waves. In all these experiments and results we know\ndefinitely what we are doing, and what the effect will be. There is no\nvagueness about the terms used. When we speak of chemical action we look\nto a definite source for that action, and we do not say that such action\nis produced by chemical waves, but rather by electricity. So that all\nexperience teaches us, and all experiments made by such men as Faraday,\nDavy, Maxwell, and Hertz confirm the statement, that these aetherial\nelectric currents can accomplish all that the so-called chemical waves\naccomplish, and that being so, the third Rule of our Philosophy is also\nfulfilled, as we have in the aetherial electric waves a satisfactory\nexplanation for the fact which we seek to explain, viz. the character\nand origin of the chemical waves that exist in the violet end of the\nspectrum. Thus, we learn, that not only is the sun the source of all\nheat and light, in that it gives rise to the vibrations of the Aether\nwhich are propagated through it in waves, but that it is also the source\nof all electric waves in the solar system, in that electric currents are\nprimarily due to the wave motion set up in the Aether, those electric\nwaves also traversing space with the velocity of light.\n\n[Footnote 14: _Phil. Mag._, 1867.]\n\n\nART. 74. _Direction of Ray of Light._--In Art. 65 it was shown that the\ndirection of a ray of heat was that of a straight line from the heated\nor luminous body from which the Aether waves proceeded. We have also\nseen in Art. 69 that the aetherial waves which give rise to the\nphenomena of heat are identical with those that give rise to light, so\nthe direction of a ray of light must also be that of a straight line\nproceeding from the luminous body. A ray of light is a line\nperpendicular to the Aether waves which are propagated through space in\nconcentric spheres from the luminous body, which, by its atomic\nvibrations, gives rise to the light waves. It must, however, be\nremembered that rays have no physical existence, for it is the waves\nthat are propagated, and not the ray, which simply indicates the\ndirection that the light takes, this truth being known as the\nrectilineal propagation of light. That light proceeds in straight lines\nmay be proved in several ways. For example, we cannot see round corners,\nwhich would be possible if light took a curved path instead of a\nstraight one. A better proof, however, may be obtained by making a small\nhole in the window-shutter, and allowing the sunlight to pass into the\ndarkened room. The beam of light which passes into the room will then be\nseen to take a straight course, its presence being revealed by the\nparticles of dust that float about the room.\n\nAnother conclusive proof that light proceeds in straight lines is to be\nfound in the fact, that all images formed on any screen by the rays of\nlight after passing through a small hole are inverted. For example,\nsuppose we have a window-shutter with a small hole in it, while in the\ngarden fronting the window there stands a tree. Now if the rays of light\nwhich pass from the tree through the hole in the window-shutter are\nallowed to fall upon a screen in the darkened room, it will be found\nthat the image is inverted.\n\nThis is accounted for by the fact, that the rays cross each other at the\nhole, and proceeding in straight lines, form an inverted picture on the\nscreen. It can further be proved, that the path of a ray of light\nthrough space as it proceeds from the sun is also that of a straight\nline. Whenever there is a solar eclipse we have light so long as we can\nsee the smallest part of the sun's surface. The instant, however, that\nwe have a total eclipse, at that instant the whole of the light of the\nsun is shut off, and for a brief space there is darkness, until the\nplanet which is causing the eclipse has passed on in its orbit and the\nsun's surface reappears again. Now if light did not proceed in straight\nlines, such an event as a total eclipse would be impossible; because, if\nthe light proceeded in curved lines instead of straight ones from the\nsun, then even when the planet which causes the eclipse got directly\nbetween the earth and the sun, the rays of light being curved instead\nof straight would bend round the eclipsing planet, and so would not all\nbe intercepted, and thus such an event as a total eclipse would be an\nimpossibility. From this we learn, therefore, that the path of a ray of\nlight as it proceeds from the sun through space is that of a straight\nline, and that the path corresponds to the radius vector of a circle,\nwhich is also the path that the centripetal force takes.\n\nViewing the matter from the standpoint of the solar system, we find the\nsun, which is the centre of that system, exerting an attractive force\nalong the radius vector of all the orbits of the planets, with a force\nwhich decreases in intensity inversely as the square of the distance. At\nthe same time, being the source of all light, it is constantly\npropagating into space aetherial light waves with a velocity almost\ninconceivable; which also decrease in exactly the same ratio as the\nattractive power of the sun decreases. If, therefore, it can be shown\nthat there is such a truth as the dynamical value of light, in the same\nway that it has been shown that there is a dynamical value of heat, then\nit follows, that not only is the sun the centre of an attractive power\nwhich proceeds in straight lines, but it is equally the centre of a\npower whose influence and motion are exerted along exactly the same path\nas the centripetal force, but in an opposite direction, that is, away\nfrom the sun. I hope to be able to show that the aetherial light waves\ndo possess such a dynamical value, and if that is accomplished, then not\nonly from the realm of heat, but also from the realm of light, we shall\nhave conclusive evidence of a power or motion whose influence is\ndirected away from the sun, which, therefore, would correspond to a\ncentrifugal force--that is, a force or motion directed from a central\nbody as the sun.\n\n\nART. 75. _Intensity of Light._--The intensity of light diminishes with\nthe distance from the luminous body, according to the same law that\ngoverns sound, and heat, and electricity. We have already seen (Art. 67)\nthat the intensity of heat diminishes inversely as the square of the\ndistance, so that if the same law holds good for light that holds good\nfor heat, then, according to the law of the inverse squares, if we\ndouble the distance from the luminous body, the intensity of light is\nonly 1/4 of what it was in its first position. If the distance be\ntrebled, then the intensity will be decreased 1/9. This can easily be\nproved by the following experiment: Suppose we have a lighted lamp, and\nat a distance of 1, 2 and 3 feet respectively, we have three square\nsurfaces. It can then be demonstrated that the light which falls on the\nsquare 1 foot away, if allowed to fall upon the square 2 feet away,\nwould cover four times the area of the first square; and if allowed to\nfall on the square 3 feet away, it would cover nine times the area.\nTherefore the intensity of the light on the square 2 feet away, covering\nfour times the area, would only be 1/4 of what it is on the square 1\nfoot away, while the intensity of light on the square 3 feet away, which\ncovers nine times the area, would only be 1/9 of the intensity received\nby the first square.\n\nIf the difference in the distances therefore be represented by the\nfigures 1, 2, and 3 feet respectively, the intensity would be\nrepresented by the figures 1, 1/4, 1/9. The decrease in the intensity of\nlight is really a decrease in motion. The intensity of a note in sound\ndepends upon the vibration of the particles of air, while the intensity\nof light also depends upon the vibrations of the aetherial atom.\n\nIf, therefore, we get a decrease in the vibration of the aetherial atom,\nthe further we get from the luminous body, it can be readily seen that\nthe intensity of light really implies a decrease of motion.\n\nNow let us apply the law of inverse squares in relation to light to the\nsolar system. We have the sun with its huge form all aglow with fires,\nas the source of all light to the planetary worlds that revolve around\nit. Year in and year out, for many ages past, the sun has been pouring\nout its light into space on every side, lighting up the planets or other\nbodies that revolve round it on that side only which is presented to the\nsun. Thus Mercury, at its distance of about 36,000,000 miles, obtains a\nlight from the sun which is of far greater intensity than the light\nwhich Venus receives, while Venus receives a light of greater intensity\nthan the light which the Earth receives, and the Earth receives light of\ngreater intensity than any of the planets outside its orbit in the solar\nsystem, as Mars, Jupiter, Saturn, Uranus, or Neptune. This decrease in\nthe intensity of light is according to the inverse square of the\ndistance from the central body, the sun. So that if we have one planet\nat twice the distance from the sun, as compared with another planet, the\nintensity of light at that distance will be only 1/4 of the intensity\nreceived by the nearer planet. This decrease of the intensity of light,\nhowever, may be compensated for by a difference in the constituents of\nthe planets' atmosphere, by means of which it may be possible that the\noutermost planets enjoy climatic conditions similar to our own.\n\nNow we have proved, in the previous chapter, that heat is a repulsive\nmotion, and as the same aetherial waves give rise to the phenomena of\nlight, then it ought to follow that light has equally a repulsive power\non the planets with which it comes into contact. If that can be proved,\nand I submit that it can, then from the phenomena of light, we learn\nthat there is a force, or rather a motion, ever proceeding from the sun\nin straight lines, as shown in the previous Art., which decreases in\npower or intensity inversely as the square of the distance. So that not\nonly is the sun the centre of an attractive Force, the Centripetal\nforce, or the attractive Force of Gravity, which proceeds in straight\nlines through space, decreasing in intensity inversely as the square of\nthe distance, but at the same time it is also the centre of a motion,\nthat is, the aetherial wave motion of light, which takes exactly the\nsame path as Gravitation Attraction, and which is subject to exactly the\nsame laws. Unlike Gravitation Attraction, however, its power and motion\nis ever directed away from the central body, the sun; and if such motion\nexerts any power on any planet with which it comes into contact, that\npower or motion can only be a repulsive motion in the same way that heat\nis a repulsive motion. Assuming, therefore, that light, through the\nmedium of the aetherial waves, does exert this repulsive motion, then,\naccording to the law of inverse squares, it can be seen that if a\nplanet's distance be doubled, the repelling power of the aetherial light\nwaves would be decreased 1/4, while at the same time the attractive\npower of the centripetal force would be decreased 1/4 also. If, on the\nother hand, the planet's distance from the sun be reduced to 1/2 of its\nformer distance, then the repelling power of the aetherial light waves\nwould be increased four times, but contemporaneously with the increase\nthere would be an increase in the attractive power of gravity, which\nwould exactly counterbalance the increased repelling power of the light\nwaves. So that in assuming that there is this repelling power in the\nlight waves, there are thus two forces in existence in the solar system\n(which is a type of all other systems), or rather two motions, as all\nforces resolve themselves into motions of some kind, one motion ever\ntending from the central body, that is, the motion of the aetherial\nlight waves, and the other tending to the central body, that is, the\nforce of gravity, which we shall see later on is also a motion of the\nAether, whose influence is ever towards the central body, be it a sun,\nstar, or planet. These two motions, therefore, are subject to the same\nlaw, viz. that their power or intensity is not only directed in straight\nlines from the central body, but their intensity is regulated exactly by\nthe same law of inverse squares. If the repelling motion be doubled,\nthen the attractive motion or power would be doubled also; if the\nrepelling motion be quadrupled or halved, then the attractive force of\ngravity would be quadrupled or halved in the same way, the two forces\nbeing exactly increased or decreased in the same ratio according to the\nlaw of inverse squares.\n\n\nART. 76. _Velocity of Light._--The transmission of light is not\ninstantaneous, as it requires time for its propagation through space,\nfrom the luminous body which gives rise to all light, as the sun for\nexample, until it reaches the body which it lights up. The velocity of\nthe light waves, however, is so great, that it is almost impossible to\ngive any comparative idea of their rate of transmission. The velocity of\nthe light waves was first established by Roemer, a Danish astronomer, in\n1675. He ascertained the velocity of light by observations made on the\nsatellites of Jupiter. His methods of reasoning can easily be understood\nby reference to the following diagram.\n\n[Illustration: Fig: 8.]\n\nLet _S_ represent the sun, and _A_ and _B_ the orbit of the earth round\nthe sun; _C_ _E_ _D_ part of Jupiter's orbit round the sun; while _D_\n_E_ _F_ represents the orbit of Jupiter's satellite. When the earth,\nJupiter, and the satellite are in a straight line with each other, the\nsatellite suffers an eclipse through passing into the shadow thrown by\nJupiter. Now Roemer found that there was a difference in the time of the\neclipse when the earth was at _B_, that is, when it was nearest to\nJupiter, and when it was at _A_, which is that part of the earth's orbit\nfurthest away from Jupiter. That difference was accounted for by the\nfact, that when the earth was at _A_ the light had to travel further\nfrom Jupiter than when the earth was nearest to Jupiter, that is at\npoint _B_. Thus, when the earth was nearest to Jupiter, the light had a\nshorter journey to travel than when it was furthest from Jupiter. The\ndifference, he found, was about 16 minutes, and he reasoned that this\ndifference was caused by the light having to cross the earth's orbit\nfrom _B_ to _A_, in its longer journey, than when it only had to reach\nthe earth at _B_. The mean distance of the earth from the sun, that is,\nthe radius of the earth's orbit, is about 92-1/2 million miles, so that\nthe diameter of the earth's orbit is about 185,000,000 miles, and if it\ntakes about 16 minutes for light to traverse this distance, we find that\nlight has a velocity, according to Roemer, of 192,500 miles per second.\nThe result, however, arrived at by Roemer was not generally accepted at\nthat time, and it was not till 1728 that Bradley discovered what is\nknown as the Aberration of Light, and from that discovery proved that\nlight was not transmitted instantaneously through space, but that it was\ntransmitted with finite velocity; and that that velocity corresponded\nfairly well with the velocity given by Roemer. Bradley, in his\nastronomical observations, noticed that some of the fixed stars, so\ncalled, did not appear to be really fixed, but that they described small\ncircles in the heavens each year. This fact greatly perplexed him, until\nat last he hit upon the true solution by taking into account the motion\nof the earth in its orbit, together with the fact that light had a\nfinite velocity. This result showed that the light from the stars\ntravelled with the same velocity as that which travelled from Jupiter's\nsatellites. The Aberration of Light, as his discovery was termed, may be\nillustrated in the following way--Suppose that you are standing still,\nand that it is raining, the rain descending vertically on the umbrella\nthat you hold up to cover you. As soon as you begin to walk, the\nrain-drops will apparently begin to slant, and if the walk is changed\ninto a run, the greater apparently will be the slanting direction that\nthe rain-drops take. In the same way, the rays of light from a star\nwould fall vertically upon the earth if it were motionless, but as the\nearth is moving through space with varying velocity, it gives to the\nrays of light a slanting direction. By calculating the speed of the\nearth, and ascertaining the exact slanting direction of the rays, the\nvelocity of light may be ascertained. This Bradley did, and showed that\nit coincided almost with the result arrived at by Roemer. Various other\nmeans have been adapted to test the results arrived at by these two\nastronomers. Fizeau, in 1849, was able to measure the velocity of light\nby using, not planetary or stellar distances, but by simply using\ndistances in the city of Paris; while Foucault, in 1860, devised a\nmethod of measuring the velocity of light in air or any other medium.\nThe results arrived at by these men leave no doubt as to the exact speed\nof light, which may now be reckoned to have a velocity of 186,000 miles,\nor 300,000,000 metres per second. Notwithstanding this great speed at\nwhich light travels, the nearest stars are so far off that their light\ntakes about 3-1/2 years to reach the earth, while scientists tell us\nthat some of the most distant stars are so remote, that their light\ntakes thousands of years to reach our earth, travelling at the rate of\n186,000 miles per second. From considerations like these we get a dim\nconception of the almost illimitable extent of the universe. Now let us\ntry to understand what this rate of motion really means. We have to\nremember that light is caused by wave motions in the Aether, so that we\nhave here a wave motion which is travelling through the Aether at the\nenormous rate already quoted. Light takes about 8-1/2 minutes to travel\nfrom the sun to the earth, a distance of 92,000,000 miles. Our fastest\ntrains do not travel 80 miles an hour, and if a train left the sun and\ncontinued its journey through space at that rate, it would take over 130\nyears before it reached our earth, while the light would perform the\njourney in 8-1/2 minutes. We have some idea of the velocity of a train\ntravelling at 80 miles an hour; what, however, must be the velocity of a\nwave motion which travels 22,500 times as fast? In Art. 56 we have seen\nthat all energy is the energy of motion, and therefore wherever we get\nmotion of any kind or sort, there we must have energy accompanying it,\nor the power to do work. We have here, then, a source of energy in the\naetherial waves known as light waves, with their enormous velocity which\nis almost inconceivable and illimitable. What must be the energy which\nexists in space due to the wave motion of the Aether? We have to\nremember on this point that we are no longer dealing with a frictionless\nmedium, but that we are dealing with matter, only in a far more rarefied\nand far more elastic form than ordinary matter, but nevertheless matter\njust as air is considered matter, and, being matter, its very motion\nimparts to the light waves a power and a force which make them capable\nof doing work. The kind of work done will be considered later on, when\nwe deal with the dynamical value of light. That we do not feel the power\nand energy of the light waves is due to the well-known fact that their\npower is broken by the activity of the atmospheric particles, each of\nwhich, in their myriads, is ever moving with great velocity, and\ntherefore bombard the light waves, as they endeavour to strike the\nearth. Thus the aetherial light waves are broken up and shattered, and\nfall to the earth not with their full energy or power, but in a blended\nform, or with that reflected energy which we call light. If they were to\ncome unbroken and unchecked upon us, and on the earth, in the same way\nthat they apparently do upon our satellite the moon, we doubtless should\nexperience very different effects of their energy and power due to their\nenormous velocity.\n\n\nART. 77. _Dynamical Value of Light._--We have already learned (Art. 68)\nthat heat possesses a dynamical value, such value being measured by\nJoule, and its equivalent in foot-pounds being exactly ascertained. We\nhave further seen (Art. 69, on the identity of light and heat), that the\nsame aetherial waves which produce heat are also concerned in the\nproduction of light. If, therefore, the aetherial waves which give rise\nto heat possess a dynamical action and equivalent, it follows that light\nmust also possess a dynamical action and equivalent, and such action\nshould be capable of being expressed in terms of foot-pounds. Clerk\nMaxwell has recorded the exact dynamical equivalent of light. On this\nmatter he writes:[15] \"If in strong sunlight the energy of light which\nfalls upon a square foot is 83.4 foot-pounds per second, the mean energy\nof one cubic foot of sunlight is about .0,000,000,882 of a foot-pound,\nand the mean pressure on a square foot is .0,000,000,882 of a pound\nweight.\" We have here then the exact dynamical equivalent, according to\nMaxwell, of a cubic foot of sunlight near the earth's surface, and of\nthe pressure exerted by light on a body with which it comes into\ncontact.\n\nAgain, Lord Kelvin[16] has measured the exact dynamical equivalent of a\ncubic mile of sunlight, both near the surface of the sun and then near\nthe surface of the earth, and in a note adds that the relation of the\ntwo values is as 46,000 to 1. So that if the dynamical value of a cubic\nmile of sunlight near the earth's surface be represented by unity, then\nthe value of a cubic mile of sunlight near the sun's surface would be\n46,000 times greater, while he further adds that it would take 4140\nhorse-power every minute, as the amount of work required to generate the\nenergy existing in a cubic kilometre of light near the sun, a kilometre\nbeing equal to about 1093 yards.\n\nProfessor Challis[17] stated in 1872 that \"Light is to be ranked with\nthe physical forces, and its dynamical action is equally to be ascribed\nto the pressure of the Aether.\" Now I want to put this question to the\nreader: If light possesses this dynamical action, that is, if it\npossesses a motive or driving power, what must be the exact effect of\nthe dynamical action of the light waves from the sun upon all the\nplanets and meteors that revolve round it? We know that the sun is\n324,000 times the mass of our earth, and that it has a diameter of about\n856,000 miles and a circumference of over two million and a half miles.\nWhat, therefore, must be the energy of the aetherial light waves that it\nspeeds on their way through space on every side? Stokes,[18] in regard\nto the mechanical energy of Light, states that \"the amount of energy\npoured forth into space corresponds in round numbers to 12,000\nhorse-power per square foot,\" and that every square foot of the sun's\nsurface supplies energy at the above rate. The number of feet in the\nsun's surface can be approximately determined. Roughly, there are\n2,284,000,000 square miles of surface on the sun's huge form, and there\nare 27,878,400 square feet in a mile. By multiplying these two numbers\nwe can ascertain the exact number of square feet on the surface of the\nsun. If, therefore, every square foot possesses a mechanical value equal\nto 12,000 horse-power, what must be the mechanical equivalent of the\nsun's radiation of light that it pours forth into space?\n\nI want to call the attention of the reader to another fact, and that is,\nthat light always proceeds in straight lines from the sun (Art. 76), and\ntherefore if there be any mechanical action in light at all, that action\nmust be one which is always directed from the sun in straight lines. Now\nexperience universally teaches us, that if a body is pushed, and pushed\nwith such a force as has been indicated, then that body not only moves,\nbut moves in the direction that the supposed horses would push. I have\nalready shown (Art. 76) that the path of light is that of a straight\nline corresponding to the path of the attractive force of gravity;\ntherefore these horses must ever push in a direction _from_ the sun\nalong the same path that the sun's attractive power takes. In other\nwords, the mechanical action of these supposed horses will be a\nrepulsive one, that repulsion being due to the dynamical action of the\nlight waves upon the body that they come into contact with. If this is\ncorrect, then not only is heat a repulsive motion, as stated in Art. 63,\nbut light is equally the possessor of a repulsive motion, because its\naction is ever directed from the sun. We might continue to follow the\nsupposed horses as they continued their course through space, and we\nshould find that their energy decreased inversely as the square of the\ndistance, partly because the further they proceeded into space the\nlarger the area would be they would have to cover, and therefore their\nenergy would be decreased proportionately.\n\nProfessor Stokes, in the same work[19] already referred to, in\ncontinuation of the same idea, states: \"At the distance of the earth the\nenergy received would correspond to about one horse-power for every\nsquare of 5 feet, on that side of the earth's surface facing the sun,\nsupposing the rays to fall perpendicularly.\" That being so, we can\nexactly calculate in horse-power the energy received from light on that\nside of the earth facing the sun, at its distance of 92,000,000 miles.\nThe area of the earth's surface is, roughly, 200,000,000 x 5280 square\nfeet, and if the energy received is equal to one horse-power for every 5\nsquare feet, then the amount of energy received by the earth on that\nside facing the sun would be equal to 200,000,000 x 5280 x 1/2 x 1/5\nhorse-power. This power, it must be remembered, is ever directed _away\nfrom_ the sun, and upon that side of the planet that faces the solar\norb. So that we have virtually a repulsive force ever directed against\nthe earth, estimated by Professor Stokes to be equal to the estimated\nhorse-power.\n\nThis assumption of the repulsive power of light brings the phenomena of\nlight into harmony with that of heat, because we have already seen (Art.\n63) that heat is essentially a repulsive motion, as indicated by Davy,\nRumford and others; and, as heat and light both have a common origin,\nthen light should possess a repulsive power also.\n\nAs further proof of this statement, let me again quote from Clerk\nMaxwell. In the quotation already given in this Art. we have seen that\nthe pressure of sunlight on a square foot is equal to 83.4 lb. He adds\nthe following words to those already quoted: \"A flat body exposed to\nsunlight would experience this pressure on its illuminated side only,\nand would therefore be repelled from the side on which the light falls.\"\n\nNow if more conclusive proof of the correctness of the argument I am\nadvancing were required, I do not think it could be given from any\ngreater authority than that just quoted. Coming from the pen of one of\nthe most brilliant scientists that the past century has known, I venture\nto think the opinion will be received with that due weight which it\ndemands.\n\nThis statement of Clerk Maxwell's has received, however, definite and\nexperimental proof from Professor Lebedew of Moscow University, and by\nNichols and Hull of America. The former has given, in the _Annalen der\nPhysik_ for November 1901, the results of his experiments in relation to\nthe pressure of light. The following are the results: He proved, 1st,\nthat the incident beam of light exerts pressure both upon an absorbing\nand a reflecting body; 2nd, that the pressure of light is proportionate\nto the amount of incident energy, and is independent of the colour of\nlight; 3rd, that the pressure of light corresponds with the forces of\nradiation as calculated by Maxwell.\n\nAbout the same time, Nichols and Hull of America were engaged upon\nexperiments relating to the pressure of light waves, and their results\nwere published in the November _Physical Review_, 1901. Thus, from two\nseparate and independent sources, Maxwell's equations as to the pressure\nwhich light waves exert upon any body on which they fall received\ndefinite experimental confirmation.\n\nThe repulsive power of the light waves receives further confirmation from\nthat theory known as the electro-magnetic theory, which supposes light to\nbe nothing more or less than an electro-magnetic phenomenon; that is to\nsay, it is directly or indirectly due to the action of electric currents.\n\nAs already indicated, Lorentz was of the opinion that the light waves\nwere themselves electric currents, and whether this is the actual fact\nor not, certainly it is true that the electro-magnetic theory of light\nis no mere fable or myth, but that it ranks as one of the most advanced\nand correct hypotheses in regard to light that has ever been given to\nthe world. According to that theory, which we shall look at\nsubsequently, we find that the aetherial medium is not only the medium\nfor the light waves, but that it is also the medium which conveys and\ncarries the electric currents through space, and even through all\nmatter. Further, from that theory we shall have good reasons for\nassuming that the aetherial light waves are either themselves electric\ncurrents, or closely identified with them, in the same way that the\nlight waves are identified with heat waves. If these facts should be\nfound to hold good relative to the identity of aetherial light waves and\nthe aetherial electric waves, then it can very readily be seen that such\na hypothesis gives added weight to the repulsive power of light. One of\nthe very commonest facts regarding electricity and its currents is, that\nwherever we get electricity, we not only get attraction, but there is\nalways associated with that attractive force a repulsive force, which is\nequal in amount to the attractive force. So that if, wherever we get\nelectric currents, we find associated with those currents a repulsive\nforce, then, in view of the electro-magnetic theory of light, it should\nalso follow that on that hypothesis we ought also to find a repulsive\npower in light. From the dynamical aspect of light on the bases of facts\ngiven to the world by such men as Professor Stokes, Clerk Maxwell, Lord\nKelvin, and Professor Lebedew, we are compelled, therefore, to come to\nthe conclusion that light does possess such a repulsive force, such\nforce being due to the dynamical action of the aetherial light waves.\n\nThus we learn from the dynamical action of light, that not only is the\nsun the centre of an attractive force, but that it is equally the centre\nof a repellent or repulsive power or motion; which repulsive power\nalways follows the path of the radius vector, and diminishes with an\nintensity which is inversely as the square of the distance. What we have\nto ask ourselves therefore is, whether the repulsive power of light is\nthe Centrifugal Force that we are trying to discover? In Art. 24 we\nfound out what were the necessary characteristics of the Centrifugal\nForce, which is to form the companion law to the attractive law of\ngravity, or the Centripetal Force. We there saw that this centrifugal\nlaw must be universal in character; that it must coincide with the path\nof the centripetal force; that it must also be subject to the same law\nof intensity, viz. the law of inverse squares; and further, that the\nforce must be proportional to the product of the two masses concerned.\nWe find in the repulsive power of light three at any rate of these\nconditions fulfilled. Light is universal because Aether is universal.\nIt is always subject to the law of inverse squares, and what is more,\nits repelling power coincides exactly with the path which the\ncentripetal force takes, that is, the radius vector. We have not,\nhowever, discovered that light fulfils the remaining necessary\ncondition, which is, that the repelling powers of light emitted by any\ntwo bodies are equal to the product of their masses. So that until this\nis done, it cannot be said that the aetherial light waves form the\ncentrifugal force or motion from a central body that we are seeking for.\nBut while that may be true, yet if light be not the centrifugal motion,\nit certainly indicates in what direction we are to look for that force,\nand that is to the Aether, whose periodic waves give rise to the\nphenomena of light. For, after all, light is due to aetherial wave\nmotion, and, therefore, while light from certain standpoints may be\nconceived to be the cause of other phenomena, yet primarily the real\ncause of all phenomena which are due to light are due to the aetherial\nwaves which themselves give rise to the phenomena of light. Thus light\nacts as a guide-post to us, pointing out the direction we should take in\norder to find out the real centrifugal force or motion, and as plainly\nas it possibly can, it indicates to us that the true solution of our\ncentrifugal motion that we are seeking for is to be found, and alone\nfound, in that universal aetherial medium which, by its vibrations and\nwave motions, gives rise to that which we term Light. In conclusion of\nthis point, it may be pointed out that Professor Challis[20] also took\nthis view of light, as he distinctly states that \"Light is to be ranked\nwith the physical forces, and its dynamical action is equally to be\nascribed to the pressure of the Aether,\" and then proceeded to show how\nrepulsion could be exerted on atoms by the periodic wave motion of the\nAether.\n\n[Footnote 15: _Magnetism and Electricity._]\n\n[Footnote 16: _Phil. Mag._, 1902.]\n\n[Footnote 17: _Ibid._, 1872.]\n\n[Footnote 18: _Burnet Lectures._]\n\n[Footnote 19: _Burnet Lectures._]\n\n[Footnote 20: _Phil. Mag._, 1872.]\n\n\nART. 78. _The Electro-Magnetic Theory of Light._--We have seen (Art.\n71) that light is due to a periodic wave motion of the Aether, and we\nhave previously seen that heat is also due to a periodic wave motion of\nthe Aether. Thus in the phenomena of light and heat, Aether is the\nmedium in which the energy of light is stored, and by which it is\ntransmitted in its passage from a luminous body, as the sun, until it\ncomes into contact with a planet or satellite from which it is\nreflected, thus giving rise to light and heat. When, however, we come to\ndeal with electro-magnetic phenomena, which are the results and effects\nproduced by electricity and magnetism, we find certain phenomena similar\nto those that we find in relation to light and heat. Thus, when light is\nemitted by a luminous body, a certain amount of energy is given out by\nthat body, and if such light is absorbed by another body, the latter\nbecomes heated, a clear proof that it has received energy or motion from\nsome outside source. From the time it left the luminous body till it\nreached the lighted or absorbing body, it must have existed as energy,\nthat is, motion in the Aether. As we have already seen, Newton thought\nthat the transference of energy was accomplished by the actual\ntransference of certain small corpuscles or atoms given out by the\nluminous body, which conveyed the energy of the one body to the other.\nAccording to the wave theory of light, however, we find that the\ntransference of energy is accomplished by a wave motion in the Aether,\nwhich is periodic both in time and space, by which wave motion the\nenergy is transferred from the luminous to the illuminated body. Now\nevery one is familiar with the effects of magnetism and electricity in\nsome form or other, and such familiarity teaches that various kinds of\nwork may be done by electricity. If an electric current be generated and\nallowed to flow through any circuit, as the ramifications, for example,\nof an electric-tram system, it can readily be seen that by the action of\nthe current large masses or bodies as trams may be moved. To generate\nthe current requires the expenditure of energy, and for the tram to be\nmoved requires the transmission of that energy from the generating\nstation till it reaches the body to be moved. By what means is such\nenergy transmitted? because if it disappears at one place and reappears\nat another, it must have passed through a medium during the interval. It\nhas been demonstrated that the medium which conveys the current from\nplace to place is the Aether, so that as light is transmitted through\nspace by the Aether, in a similar manner electric currents are\ntransmitted through space also by the same medium. The discoverer of\nthis great truth was Clerk Maxwell, and it was from the consideration of\nelectro-magnetic phenomena that he was able to lay the foundation of\nthat theory known as the Electro-Magnetic Theory of Light. In paragraph\n781 of his greatest work[21] he says: \"In several parts of this treatise\nan attempt has been made to explain electro-magnetic phenomena by means\nof mechanical action from one body to another by means of a medium\noccupying space between them. The undulatory theory of light also\nassumes the existence of a medium. We have now to show that the\nproperties of the electro-magnetic medium are identical with those of\nthe luminiferous medium.\" He then points out that, \"to fill all space\nwith a new medium, whenever any new phenomenon is to be explained, is by\nno means philosophical\"; and further adds, that \"If it should be found\nthat the velocity of propagation of electro-magnetic disturbances is the\nsame as the velocity of light, and this not only in air, but in other\ntransparent media, we shall have strong reasons for believing that light\nis an electro-magnetic phenomena.\" In the wave theory of light we have\nseen (Art. 70), that two properties are necessary to any medium before\nit is capable of transmitting wave motion of any kind. Those two\nproperties are elasticity and inertia. Water possesses these properties,\nand so can transmit ocean waves; air also possesses these properties,\nand so can transmit sound waves; and Aether, being matter, also\npossesses these properties (Arts. 47 and 48), and is therefore capable\nof transmitting light waves. The elasticity is essential in order for\nthe medium to store up energy, and also to enable it to resume its\noriginal shape after deformation, while the inertia is necessary in\norder that the medium may transmit the impulse, and oscillate to and fro\nuntil the impulse received has been passed on. This elasticity and\ninertia may be well illustrated by the bending of a lath or cane. If we\npull one end down, holding the other end quite still, we shall see that\nthe lath oscillates to and fro until gradually it comes to rest. The\nelasticity of the lath allows it to be pulled out of its original\nposition, and also enables it to rebound, while its inertia causes it to\nswing back again past its original position. Both combined together\ncause it to swing backwards and forwards till its energy is used up. If\nsuch a series of springs could be set in motion at equal intervals of\nspace and time, we should then have a good illustration of a wave\nmotion.\n\nWhat analogy, may be asked, is there in electro-magnetic phenomena to\ncorrespond to this elasticity and inertia of the Aether, so essential to\nthe propagation of light? Let us look at the familiar illustration of\ncharging a Leyden jar. In charging a Leyden jar with electricity a\ncertain amount of energy is spent, work is done, and the result is found\nin the electrified state of the jar. That which has actually been\naccomplished is the storing up of energy in the Aether around the jar.\nThis storing up of energy is analogous to pulling aside the lath, and is\nthe making use of the elasticity of the Aether, in order to produce a\ntendency to recoil. When the jar is discharged, which is analogous to\nletting go the lath, the Aether seeks to recover its former condition by\ndischarging the energy it received. In these operations the elasticity\nof the Aether is called into play. After the jar is discharged, however,\nthe recoil of the Aether produces a current, and the inertia of the\ncurrent causes it to overshoot its original position, and for an instant\nthe charge of the jar is reversed. The current now flows backwards in\nthe same way that the lath returned back, and charges the jar as at\nfirst. This discharging and recharging continue backward and forward, so\nto speak, until all the energy which was originally given to the jar has\nbeen expended, and it resumes its normal condition. In this experiment\nthe elasticity and inertia of the Aether have both been called into\nplay, so that we see in this electrical experiment a similar\nillustration of the elasticity and inertia of the Aether, as manifested\nin the undulatory or wave theory of light. The question now arises, what\nare the corresponding properties as given by Maxwell in his\nelectro-magnetic theory? In Art. 782 he writes: \"In the theory of\nelectricity and magnetism adopted in this treatise two forms of energy\nare recognized--the electro-static and the electro-kinetic--and these\nare supposed to have their seat, not merely in the electrified or\nmagnetized bodies, but in every part of the surrounding space where\nelectric or magnetic force is observed to act. Hence our theory agrees\nwith the undulatory theory in assuming the existence of a medium which\nis capable of becoming a receptacle of two forms of energy.\" Faraday, in\nhis _Experimental Researches_, paragraph 3075, in referring to the\ncharacter of magnetic phenomena external to the magnet, writes: \"I am\nmore inclined to the notion that in the transmission of force there is\nsuch an action external to the magnet, than that the effects are merely\nattraction and repulsion at a distance. Such a function may be a\nfunction of the Aether if it should have other uses than simply the\nconveyance of radiations\" (light and heat). From this extract we learn\nthat Faraday was also of the opinion that the Aether around a magnet or\nany electrified body was directly concerned in the propagation of the\nelectric and magnetic forces, these forces according to Maxwell being of\ntwo kinds. From the illustration of the charging and discharging of the\nLeyden jar, we learn that aetherial electrical waves can be produced by\nelectric means, and from the alternate charging and recharging of the\njar we learn that these aetherial waves travel to and from the jar with\na periodic wave motion. Here, therefore, we have an aetherial wave\nmotion which is produced wholly by electricity, and yet which answers\nour definition of a wave motion of light, in that it is periodic both\nin time and space, and in that aetherial wave motion Maxwell states that\ntwo forms of energy are called into play, which he calls Electro-Static\nand Electro-Kinetic. These correspond respectively to the elasticity and\ninertia in the older theory of the wave motion of light. It was upon\nthis basis that Maxwell built up his electro-magnetic theory. Even this\ntheory does not tell us what is the exact character or nature of the\nperiodic wave motion of the Aether. All it tells us is, that the\nelectro-magnetic wave motion of the Aether is the same in nature and\ncharacter as the wave motion which produces light and heat. Thus it\nshows that light and electricity have a common origin, and proves that\nlight is nothing more or less than an electro-magnetic phenomenon.\nMaxwell gave a number of proofs in support of his theory. He showed that\nthe velocity of the electro-magnetic waves was almost identical with the\nvelocity of light waves, his results being as follows--\n\n  VELOCITY OF ELECTRO-MAGNETIC            VELOCITY OF LIGHT IN\n             WAVES.                         METRES PER SEC.\n\n  Weber      310,740,000 metres per sec.   Fizeau    314,000,000\n  Maxwell    288,000,000   \"       \"       Foucault  298,360,000\n  Thompson   282,000,000   \"       \"\n\n\nFrom these figures it can readily be seen that the velocity of an\naetherial wave, generated by electric means, is approximately the same\nas an aetherial wave generated by a luminous body. Thus one of the most\nimportant results of Maxwell's theory was to show that electro-magnetic\ndisturbances produced in the Aether by an electrified or magnetic body\nmight be propagated through space with a velocity equal to that of\nlight.\n\nIt was left, however, for Professor Hertz to place the electro-magnetic\ntheory of light upon a sure and certain foundation. The results are to\nbe found in his work on _Electric Waves_, translated by Professor Jones,\n1893.\n\nIn his paper on \"The Velocity of Propagation of Electro-dynamic Action,\"\nhe gave definite and experimental proof of the hitherto theoretical fact\nthat the velocity of the electric waves in air was exactly the same as\nthat of light, whereas he found that in wires the ratio was not the\nsame, being 4 to 7. This was afterwards found out to be an error by some\nexperiments made at Geneva, when it was discovered that the propagation\nin wires was the same as in the air. Among his experiments Hertz\nsucceeded in producing very short electric waves of 30 centimetres in\nlength, that is, about one and one-fifth of an inch. According to\nMaxwell's theory, such a wave ought to behave exactly as a beam of\nordinary light does. Hertz proved that this was the case, and published\nhis proofs in his paper on \"Electric Radiation.\" In that paper he showed\nhow such electric radiation was propagated in straight lines, like\nlight, and that it could also be refracted and reflected. Thus he gave\nto Maxwell's electro-magnetic theory experimental demonstration, and\nplaced it on a solid and immovable foundation. In summing up the results\nof this theory, we learn, therefore, that Hertz has conclusively proved\nthat electric and magnetic effects are propagated through the Aether\nwhich fills all space with the same velocity that light is propagated.\nFurther, he has conclusively proved the identity between light and\nelectricity, and shown that electric and light radiations are\nessentially one and the same, and that they are both propagated by\nperiodic wave motions of the Aether. Further, he has proved that the\nvelocity of the propagation of light is the same as that of the\nelectro-magnetic waves, and that these waves obey all the laws that\ngovern light and heat. We have here, therefore, experimental proof of\nthe identity between electricity and light, and in Art. 69 we have also\nproved the identity of light and heat, so that we have now experimental\nproof that light, heat and electricity are all due to the periodic wave\nmotions and vibrations of the universal Aether, which not only fills all\nspace, but which surrounds every atom and every particle of matter\nthroughout the whole universe. Having established, therefore, the\nidentity of heat, light and electricity, and having proved that they are\nall due to the periodic wave motions or vibrations of the universal\nAether, it must follow as a matter of necessity that wherever in\ninterplanetary or interstellar space we find light or heat waves we must\nalso find electricity. We have already seen that aetherial light waves\nflood all space, both interplanetary and interstellar space, so that in\nview of the identity of the aetherial light waves and aetherial electric\nwaves, it follows that the aetherial electric waves flood all space in\nthe same way, and at the same time. Wherever, therefore, we find the\nlight waves, there we find the electric waves also; and it will be\nimpossible to find the one without the other. Thus, throughout all\nspace, and indeed throughout the universe, light waves will not be found\napart from electric waves. They are as incapable of being dissociated as\nare light and heat waves. Now we have already seen (Art. 64), so far as\nthe solar system is concerned, that the sun is the generator of all\nlight and heat, and that these light waves speed from the sun on every\nside with a velocity of 186,000 miles per second. From the identity of\nlight and electric waves, therefore, given to us by the electro-magnetic\ntheory of light, it must follow that the sun is equally the source and\ngenerator of the electric waves. Not only so, but as the light waves\nflood all solar space, these electric waves, being identical with the\nlight waves, must flood the solar system also. Thus we learn from\nMaxwell's theory as developed by Hertz, that not only is the sun the\ngenerator of light and heat waves which are poured forth into space\ncontinually with a velocity almost inconceivable, but at the same time\nthe sun is pouring forth into space electric waves which travel outwards\nin spherical shells in the same way as light waves do, and with a\nsimilar intensity, as we shall see in the next chapter. Now let me ask\nthe reader to ponder over the fact given to us by this electro-magnetic\ntheory in its relation to the solar system, and endeavour to find out\nwhat such an application teaches us. Let it be remembered that we are\nlooking for a Centrifugal force or motion, that is, a motion from a\ncentre, which is to be the exact counterpart of the Centripetal force,\n_i. e._ motion to a centre; and further, that the Centrifugal motion\nmust be a repulsive motion acting in the opposite way to the attractive\npower of the Centripetal force, that is, the attractive power of\ngravity. We have seen (Art. 77) that light possesses a repulsive power.\nWe have now only to prove that electricity or the aetherial electric\nwaves have a repulsive motion, which will be the easiest of all to\nprove, and then we shall have proved beyond the possibility of\ncontradiction, the existence of that repulsive force referred to by\nHerschel in Art. 24, which is to form the complementary and counterpart\nof the attractive power of gravity. If it can be proved that electricity\ndoes possess such a power, that is, a repulsive power, ever acting from\na centre, then in view of the identity of light, heat and electricity,\nthe correctness of the views we have advanced as to the repulsive power\nof light and heat will be proved beyond the shadow of a doubt, otherwise\nMaxwell's electro-magnetic theory of light is a fable and a myth, and\nHertz' experiments were never performed. Further, if all\nelectro-magnetic phenomena are due to the same aetherial medium which\ngives rise by its wave motions to light, heat and electricity, then we\nshall have discovered a medium which throughout the universe can by its\nwave motions transmit and propagate both repulsions and attractions,\nthat is, the aetherial medium which is to be the physical cause of\nUniversal Gravitation. In order to further develop and establish this\npoint we will now consider the subject of Electricity as a Mode of\nMotion.\n\n[Footnote 21: _Mag. and Elec._]\n\n\n\n\n                              CHAPTER VIII\n\n                         AETHER AND ELECTRICITY\n\n\nART. 79. _Electricity, a Mode of Motion._--The question as to What is\nElectricity? is one of the greatest problems of modern times. In view of\nthe electro-magnetic theory of light, however, science is able to give a\nbetter definition as to what electricity is, than it was able to do\nprevious to the introduction of the theory by Maxwell, and its practical\nestablishment by Hertz.\n\nIf that theory teaches us anything at all with regard to the nature of\nelectricity, it teaches us that electricity is due to certain motions of\nthe universal Aether, that not only fills all so-called Space, but\nsurrounds all particles and atoms of all Matter.\n\nThe question has been asked by various scientists, \"Is Aether\nElectricity, or, in other words, are Aether and Electricity one and the\nsame?\" Let us look at the question from the standpoint of the analogy\nfrom the phenomena of light and heat. As we have already seen (Art. 61),\nheat is due to a particular kind of motion of the universal Aether,\ngenerally known as vibratory motion, which motion is communicated to the\nAether by a luminous or heated body.\n\nSo that we learn that heat at any rate has an aetherial basis, as it is\na particular kind of aetherial motion. From Art. 70 we learn also that\nlight is due to an undulatory or wave motion in the Aether; the waves,\nhowever, in this case being shorter, and of more rapid vibration than\nthose waves which give rise to heat.\n\nThus light and heat both have an aetherial basis, being due to\nvibrations of that medium. From these analogies, therefore, we come to\nthe conclusion that electricity and magnetism have an aetherial basis,\nand are also due to certain kinds of motion in the Aether.\n\nThat motion may be rotatory motion or vibratory motion, as the case may\nbe, but whatever definition we give of electricity, we cannot as yet say\ndefinitely that Aether is electricity.\n\nWe may assume, and indeed prove, that Aether has an electrical and\nmagnetic basis, in the same way that it has a thermal or heat basis, or\na luminiferous or light basis; but while we admit such a hypothesis, we\ncannot admit as yet that Aether and electricity are one and the same\nthing. It is not within the province of this work, however, to prove\nwhat electricity is, or show the relation of Aether to all the various\nforms of electricity with which we are conversant, but I think I may\nventure to make this statement, that all forms of electricity, whether\nit is electro-static, that is electricity at rest, or current\nelectricity, or electro-magnetism, are due to certain forms of motion\nof the universal Aether, in the same way that light and heat are also\nparticular forms of motion of the same medium. I need hardly point out\nthat it is an absolute impossibility for me to deal with such a subject\nas Electricity in all its details and various aspects in one chapter; so\nthat I shall have to assume that the reader is familiar with some of the\nelementary truths of the subject.\n\nAt the same time, I will endeavour to make clear most of the technical\nterms used as we proceed. From the Electro-Magnetic theory of light,\ntherefore, we learn that Aether has an electrical or electro-magnetic\nbasis, so that, wherever we get Aether, there we have the bases and\nconditions which will produce all the phenomena with which we are\nconversant in the sphere of electricity. Given the required motions in\nthe Aether necessary to produce any particular form of electricity, then\nthat form is produced as soon as the motions of the Aether are generated\nby any charged or electrified body. Produce a circular current in any\nway in the Aether, and you will have a circular current of electricity;\nproduce radiations from a radiating body, and you will get electric\nradiations which speed away with the velocity of light.\n\nThis phase of the Aether is entirely in harmony with Dr. Larmor's\nHypothesis of Electrons, which has already been referred to in Art. 44.\nDr. Larmor in his work indicates that electricity has an atomic basis,\nand further states that \"the atomicity of electricity is coming within\nthe scope of direct experiment.\"[22]\n\nNow, if electricity, as I have indicated, be due to certain motions in\nthe Aether, then it can easily be seen that postulating atomicity for\nelectricity will be the same as postulating atomicity for the Aether.\nDr. Larmor[23] definitely and clearly states, \"that each electron has an\neffective mass of aetherial origin, which forms part, and may be the\nwhole, of the mass of matter to which it is attached;\" and again points\nout (p. 64) that \"an electron is nothing more than a point singularity\nor pole in the electro-dynamic and optical Aether.\" Thus we see that Dr.\nLarmor's hypothesis as to the atomicity of electricity is a further\nproof of the atomicity of Aether, and is also in harmony with the\nelectro-magnetic theory of light.\n\nNow in dealing with electricity as a mode of motion, it will be\nnecessary to show that electricity is also a form of energy in the same\nway that heat and light are forms of energy.\n\nIf it can be demonstrated that electricity is a form of energy, then it\ncan easily be demonstrated that work can be done by it, and that that\nwork may take a mechanical form in the same way that the energy of heat\nand light may produce mechanical results. Clerk Maxwell has given us, in\nhis greatest work, his conception of the two kinds of energy due to\nelectricity and magnetism. On the subject he writes: \"In the theory of\nElectricity and Magnetism accepted in this treatise, two forms of energy\nare recognized, the Electro-Static and Electro-Kinetic (paragraphs 630\nand 636), and these are supposed to have their seat not merely in\nelectrified or magnetized bodies, but in every part of surrounding\nspace, wherever electric or magnetic force is observed to act. Hence our\ntheory agrees with the undulatory theory of light in assuming the\nexistence of a medium which is capable of becoming susceptible to two\nforms of energy.\"[24] The question has arisen many times as to what is\nmeant by the terms Electro-Static and Electro-Kinetic energy used by\nMaxwell, and various hypotheses have been advanced to explain the same.\n\nElectro-static energy is said to be that phase of electricity in which\nwe deal with stresses set up in the Aether by an electrified body at\nrest, whether that body be small or large. It further deals with the\nprocess of induction, that is, the action of an electrified body upon\nanother body, such action taking place through the medium between the\ntwo bodies. Electro-kinetic energy is the energy due to electricity in\nmotion. On this point Maxwell says: \"A conducting circuit in which the\ncurrent has been set up has the power of doing work in virtue of the\ncurrent, for it is really and truly energy. It appears, therefore, that\na system containing an electric current is a seat of energy of some\nkind; and, since we can form no conception of electric current except as\na kinetic phenomenon, its energy must be kinetic energy, that is to say,\nthe energy which a moving body has in virtue of its motion.\" (Arts. 551\nand 552.)\n\nIt is not our purpose to deal with the electro-kinetic form of energy\nreferred to by Maxwell in this chapter. We shall deal with that form of\nenergy due to electricity in the succeeding chapter. We will consider\nfirst the effect of the electro-static energy in relation to\nelectrified bodies, but I wish it to be distinctly understood, that in\nall the different kinds of electric phenomena manifested, the Aether\nplays the chief part, and without it, none of the phenomena observed\ncould be produced; because, what Aether is to light and heat, so it is\nto electricity, being that medium which by its motions propagates and\ngives rise to all electrical phenomena.\n\nThis being so, we have now to apply some of the facts taught us by\nelectricity, and especially by the electro-magnetic theory of light, to\nour solar system, with the hope that we shall find further evidence of a\nCentrifugal Force which is physical in character, and whose action can\nbe traced throughout the whole realm of space. Let us, in starting to\napply some of the truths already learned, recall some of the facts\nconcerning light, its production and its propagation. We recall the fact\nthat light is produced by the action of the sun upon the Aether, giving\nrise to waves which speed away from the generating source with a\nvelocity of 186,000 miles per second. We further remember that Hertz has\ndefinitely proved that these light waves are identical with\nelectro-magnetic waves, as they ought to be if the Aether possesses an\nelectrical basis, as Dr. Larmor and Professor Lodge suggest.\n\nIn order that there may be no mistake on this point, let me quote from\none of Hertz' papers, where, in his conclusion, he says: \"The\nexperiments described appear to me, at any rate, eminently adapted to\nremove any doubt of the identity of light, radiant heat, and\nelectro-magnetic wave motion.\" Now, what I want to point out regarding\nthis fact is this. If the sun gives rise to the aetherial light waves,\nand these light waves are identical with electro-magnetic waves as\nproved by Hertz, then the sun must either be an electrified body or else\na magnet.\n\nIt must be one or the other, because, if it were not, we should then\nhave an anomaly in Nature of a body emitting electro-magnetic waves\nwhich is itself neither electrified nor a magnet. Therefore, according\nto our second Rule of Philosophy, such a body would be incapable of\ngiving rise to these waves, as such a result would be contrary to\nuniversal experience and experiment.\n\nWe know that the earth is a magnet, but up to the present it has never\nbeen proved that the sun is a magnet, although, as I shall show later\non, Lord Kelvin and others have suggested such a possibility. If we\nassume that the sun is a magnet, our grounds for assumption would not be\nso strong at this point, and our reasons so philosophical, as they are\nif we assume that the sun is an electrified body.\n\nWe have philosophical reasoning to prove that the sun is an electrified\nbody in the fact that it emits or gives rise to electro-magnetic waves\nin the Aether, and no other hypothesis can be made other than that the\nsun is an electrified body, in order to prove the connection between the\ntwo.\n\nThus we affirm that the sun is an electrified body, which like any\nother electrified body is capable of generating electric waves, and\nspeeding them through the Aether with similar velocity to that of light.\nNot only so, but, like any other electrified body, it must have its\nelectric field and possess the ability to electrify any other body by\ninduction, that may happen to be in its electric field, as we shall see\nlater on.\n\nFurther, being an electrified body, the electric density will be\ngreatest near the sun's surface, and this fact fully accords with our\nstatement in Art. 45, that Aether is gravitative. As pointed out in that\nArt., if Aether be gravitative, it must be densest nearest to the\nattracting body; and, as Aether has an electric basis, then with the\ndenser Aether there must be an increased electric density, which can\nonly happen provided the sun is an electrified body.\n\nSir G. Stokes was also of this opinion, for in his Burnet Lectures on\nLight he writes (p. 212): \"There is nothing, therefore, unreasonable\nin supposing that the sun may be a permanently charged body.\"\n\nSo that all the reasoning that has led to this result seems to harmonize\nand confirm each several hypothesis which has been advanced. There can\nbe little doubt, therefore, that the sun is an electrified body, and it\nis for us now to carry out this fact to its logical and philosophical\nconclusion, by applying all the truths which circle round it to the\nsolar system, when we shall find greater confirmation of the statement\njust advanced than any we have yet adduced.\n\nAccording to Professor Young of America, the sun is not only an\nelectrified body, but is also the abode of living and sentient beings.\nThis astronomer has suggested that the sun is the centre of electric\nforce, and that converging streams of Electricity are ever flowing to it\nas a centre; but on meeting with the atmosphere they give rise to\nbrilliant discharges, which thus gives the appearance of a solid\nincandescent body.\n\nNow, whether this hypothesis is correct or not, it is absolutely\ncertain that the sun is an electrified body, as it gives rise to\nelectro-magnetic waves in the Aether, as philosophically proved by\ndirect experiments.\n\n[Footnote 22: _Aether and Matter_, p. 8.]\n\n[Footnote 23: _Ibid._, p. 64.]\n\n[Footnote 24: _Magnetism and Electricity_, by C. Maxwell, Art. 782.]\n\n\nART. 80. _Aether and Electric Fields._--Before proceeding to apply some\nof the facts of Electricity to the solar system, let us find out what is\nmeant by an Electric Field. An electric field is to an electrified body,\nwhat a thermal or heat field is to a heated body, or a luminous or\nlighted field is to a luminous body. If a lamp, for example, be lighted,\nits light waves spread out on every side, and extend for a considerable\ndistance unless impeded by such obstacles as the wall of a room.\n\nThe extent to which the light waves reach and flow might well be called\nthe lighted or luminous field, and in that field the effect of the\naetherial light waves would be manifested and seen.\n\nNow, in a similar manner, when any body is electrified, the electric\nwaves spread out on every side of the electrified body, and the extent\nto which the waves spread out form what is known as an electric field.\n\nSo that an electric field may be defined as any region or space in which\nelectric energy is manifested by means of the aetherial electric waves,\nand across which induction may take place.\n\n[Illustration: Fig: 9.]\n\nThus, for example, let _E_ be an electrified body (Fig. 9), then it will\ngenerate electric waves which will speed from the body with a velocity\nequal to that of light. If the body be a sphere, then the waves will be\nspherical in shape, and will proceed from the generating source in the\nshape of concentric spheres as indicated in the figure. Before\nproceeding any further, it is necessary that we should look at the\nelectric field from the physical aspect, with a view to discover\nsomething of what takes place therein. As has already been indicated,\nall electric phenomena are due to motions of the universal Aether.\n\nIt was left for Faraday to give us a true conception of an electric\nfield, and for Maxwell to perfect that conception and give us a physical\naspect of the same. Faraday conceived that stretching out from a magnet\nor electrified body through space, that is, through the Aether, were\nwhat he called \"Lines of Force,\" and that these lines of force indicated\nnot only the direction of the magnetic and electric forces, but also\ntheir intensity or power.\n\nWhere the lines of force were closest together, there the electric or\nmagnetic energy was the greatest and most intense; and where they were\nthe farthest apart, there the field was weakest in energy. An\nillustration of the magnetic lines of force may be obtained by placing a\npiece of paper over a magnet, and then strewing iron filings over the\nsame, when it will be seen that the iron filings will arrange themselves\nin certain curved lines, which Faraday called Magnetic Lines of Force.\nIn this way Faraday mapped out the lines of force, relative not only to\nsingle magnets, but also to magnets with poles placed in various\npositions relatively to poles of other magnets.\n\nNow as there are lines of force which reveal the intensity and direction\nof the magnetic energy, so there are lines of force radiating out from\nelectrified bodies which reveal the intensity and power of the electric\nfield. The electric lines of force are radial, and are shown in the\nfigure (Fig. 9) by the straight lines _D_ _F_, _D_ _H_, _D_ _K_.\n\nIf an electrified pith ball, for example, be hung up in a room, then the\nlines of force, which extend from the ball, indicate the stress in the\nAether surrounding the pith ball, so that if a hair be placed across\nthese lines of force, any movement of the pith ball will be indicated by\nthe motion of the hair.\n\nIt was Clerk Maxwell, however, who gave to the world a true physical\nconception of Faraday's Lines of Force, in his paper on \"Physical Lines\nof Force.\"[25]\n\nIn the opening words of that paper he writes as follows: \"We cannot help\nthinking that in every place where we find these lines of force, some\nphysical state or action must exist in sufficient energy to produce the\nactual phenomena.\" Maxwell then went on to show what these physical\nactions were, which took place in the dielectric--that is, the medium\nsurrounding the electrified body which we now know to be the Aether.\n\nThis electric field, he pointed out, was \"in a state of stress, which\nconsisted of pressures or tensions different in different directions at\nthe same part of the medium. The relation of these forces were\nthreefold, and consisted in the most general type of stress of three\npressures or tensions in directions at right angles to each other.\"\n\nThus, in Maxwell's opinion, the existence of a medium, which by its\nphysical character was able to exert energy on material bodies, was one\nof the fundamental hypotheses of his theory as to the physical character\nof Faraday's Lines of Force.\n\nThis physical medium was to be capable of certain motions, and both\nelectric and magnetic forces were produced by its motions and its\nstresses. Maxwell's conception, however, of the physical lines of force\nwas more or less hypothetical, and up to the present, as far as I can\nlearn, has not received that authority from science that such a\nhypothesis requires to make it an accepted theory in science.\n\nBut what I venture to point out is, that with the view of the aetherial\nmedium that is submitted in this work, Maxwell's hypothesis remains a\nhypothesis no longer, and that the hypothetical character of his theory\nceases to exist. For, by our conception of an atomic and gravitative\nAether, we are able to see that his physical lines of force are indeed\nphysical, and that his brilliant hypothesis now receives a true physical\nfoundation which otherwise it would not receive from a frictionless\nAether.\n\nThere is nothing, I venture to predict, in Maxwell's hypothesis which\ncannot be accounted for on a truly physical basis, by the conception of\nthe Aether as given in this work. So that when Faraday saw in his mind's\neye lines of force traversing space, he saw by his imagination that\nwhich was actually the real state of affairs, and when Maxwell enlarged\nthe conception by giving to those lines of force a definite atomic and\ncellular structure, he, too, but anticipated the real nature and\ncharacter of the Aether as given in Chapter IV., which theory is the\ndirect outcome of Newton's philosophical rules, and the result of\ndiscarding everything that is not in accordance with experience and\nobservation. Thus the lines of force which exist and surround a magnetic\nor electrified body are as real as ocean currents, or the waves of the\nsea, in that they are the manifestations of the motions of the universal\nAether, which is as truly matter as air or water.\n\nLet us look at the analogy which exists between the lines of force and\nthe gravitative Aether, and we shall see that a gravitative Aether fully\nagrees with the conception of an electric Aether as revealed to us by\nthe lines of force in an electric field.\n\nAs is well known, the lines of force are closer together in that part of\nthe electric field where the intensity of the field is greatest; and the\nintensity of a field being greatest at the surface of an electrified\nbody, the lines of force are therefore closer together nearest to the\nsurface of such a body than further away.\n\nNow according to Art. 45 Aether is gravitative, therefore the Aether\nnearest the surface of a body is densest, and the aetherial atoms are\ntherefore more pressed upon than the layer immediately above it. Such a\nresult is exactly what should happen provided that Aether has an\nelectric basis, and that Aether is gravitative. For, in Art. 45, we have\nseen that because Aether is gravitative, therefore it must possess\nvarious degrees of density, being densest nearest the surface of an\nattracting body.\n\nIn electricity we find a similar phenomenon which corresponds to\naetherial density, which is known as Electric Density, by which term is\nmeant the amount or quantity of electricity spread over a certain area\nor surface. If we double the quantity of electricity on that given\nsurface, then we double the density, and we say that the electric\ndensity is doubled, while if we halve the quantity of electricity, then\nwe say the electric density is halved, and so on.\n\nBut this is exactly what happens in the case of aetherial density, as\nproved in Art. 46. We have only to picture the number of aetherial atoms\nbeing doubled on a given area, and at once the physical conception of\nelectric density is furnished, if we remember that Aether has an\nelectric basis as suggested by Maxwell and proved by Hertz. Thus we see\nat once why it is the lines of force should be closer together nearer\nthe electrified body than farther away.\n\n_Electric Potential._--There is another aspect of the electric field\nthat I wish to call the reader's attention to, and that is the Electric\nPotential of such a field.\n\nElectric potential is to electricity what temperature is to heat, or\npressure is to any medium of different densities. We have already seen,\naccording to the laws of thermodynamics, that heat will flow from a\nhigher temperature to a lower one, with the result that work is done. In\nthe case also of water at two different levels, work can also be done by\nthe water flowing from a higher to a lower level.\n\nA similar thing happens in electricity; where we have two conductors or\ntwo parts of an electrical fluid at different potentials, electricity\nwill flow from the place of higher potential, until the potentials are\nequalized, in the same way that the temperature of two bodies at\ndifferent temperatures would be equalized by the flow of heat.\n\nSo that electric potential agrees with our conception of a gravitative\nAether in that, being gravitative, it is denser in those parts nearest\nto the attracting body than farther away, and as the elasticity or\npressure is proportionate to the density (Art. 47), therefore we learn\nthat the electric potential of the Aether, and the thermal condition of\nthe Aether, if I may use such a term, both agree and coincide with the\ndensity and elasticity of the Aether.\n\nAny equipotential surface which represents a particular aetherial\ndensity, would also correspond with a particular elasticity or pressure\nof the Aether, while it would further correspond with a particular\ntemperature, if such a term is applicable to the Aether.\n\n_Equipotential Surfaces._--The fact that in an electric field there are\ndifferent points at different potentials, leads us to the truth that in\nan electric field there are also equipotential surfaces; that is to say,\nthere are surfaces where the electric density or the aetherial density\nare equal at all points on such a surface. If, for example, _E_ be an\nelectrified body (Fig. 9), and _A_ _A'_, _B_ _B'_, represent equipotential\nsurfaces around the body, then all the points on _A_ _A'_ would be of\nequal potential--that is, of equal energy, or pressure.\n\nWe have to remember that _A_ _A'_, _B_ _B'_, are sections of a sphere, so\nthat when the body as _E_ is a sphere, then the equipotential surfaces\nare spheres also. This agrees with Art. 77, in which we saw that the\npressure around any body due to aetherial density also possessed\nequipotential surfaces.\n\nIt could equally be shown that there were equipotential surfaces so far\nas the phenomena of heat and light are concerned, as these also are\nsubject to the same laws. Having now very briefly considered the meaning\nof the Electric Field, Electric Potential, Electric Density, and\nEquipotential Surfaces, we are now in a position to apply these facts to\nour solar system, at least as far as the sun is concerned.\n\nIn the foregoing Art. we arrived at the conclusion that the sun was an\nelectrified body, therefore, in accordance with all experiment and\nobservation, it, too, must have an electric field. Not only must it have\nan electric field; but that field must possess different potentials,\npossessing a higher potential the nearer the field gets to the sun, and\na lower potential the farther away the field is.\n\nFurther, around the sun there must also exist not imaginary but real\nphysical lines of force which indicate the electric and magnetic forces,\nand which are made real by the atomic character of the Aether that\nsurrounds it; and those lines of force would be closer together the\nnearer they got to the sun on account of the electric density of the\nelectric Aether, which coincides with the density of the Aether from the\ngravitative standpoint. There would also be aetherial equipotential\nspheres, or rather oblate spheroids around the sun, as the sun is not\nstrictly a sphere, its polar diameter being less than its equatorial\ndiameter.\n\n[Illustration: Fig: 10.]\n\nLet us therefore endeavour to picture the sun under these conditions as\nthe centre of our solar system. Let _S_ be the sun (Fig. 10), and the\nlines _A_ _A'_, _B_ _B'_, _C_ _C'_, etc. represent Equipotential\nSurfaces, Fig. 11 being a vertical section and Fig. 10 being an\nequatorial section. In Fig. 11 the sections of the equipotential\nsurfaces would be vertical, while in Fig. 10 the sections of the\nequipotential surfaces would be horizontal, while the electric lines\nof force would be radial, as all electric radiations take place in\nstraight lines, as we shall see was proved by Hertz, later on. We\nwill suppose that the sun is stationary, as the question of the\nmovement of the sun, both axially and through space, will be\nconsidered in a subsequent article.\n\n[Illustration: Fig: 11.]\n\nThen the question arises, How far does the sun's electric field extend?\nThat is rather a difficult question to answer, but the correct answer\nwould be, \"As far as the sun's light extends, so far does the sun's\nelectric field extend.\" From the electro-magnetic theory of light we\nknow that wherever there are light waves, there are electro-magnetic\nwaves, though at the present moment we are only dealing with the\nelectric aspect of those waves.\n\nWe know that the aetherial light waves reach at least as far as Neptune,\na distance of 2,750,000,000 miles, therefore we know that the sun's\nelectric field must also extend to that distance. How much further in\nspace it extends we cannot tell, because the data on which to form a\nbasis is inadequate.\n\n[Illustration: Fig: 12.]\n\nThus we learn that the sun's electric field extends east and west for\nthat enormous distance, but we cannot say that it extends the same\ndistance north and south. Now why is that? The first reason I should\ngive is the well-known experiment of a revolving body, by which we learn\nthat when a body is revolving, as the sun for example, the atmosphere\naround it would seek to extend itself east and west, owing to the\nCentrifugal Force so called. But a better reason than that will be found\nfrom an analogy of a magnetized body. Faraday has shown in his drawings\nillustrating lines of force, that if a spherical body is magnetized, the\nmagnetic lines of force extend in circles east and west, but go out into\nspace in almost straight lines north, and south as the preceding figure\nshows.\n\nTherefore, accepting Faraday's experiment as the basis for our\nconception of the magnetic lines of force in the sun's electric field,\nwe come to the conclusion that the electric field around the sun extends\neast and west, while the lines of force, north and south, are more or\nless radial into space as depicted in the figure.\n\nThroughout the whole of the field, the electric potential, at different\ndistances from the sun, would differ in accordance with all experiment\nand observation. The greatest electric potential would therefore be\nnearest the sun's surface, and would be greatest in the equatorial\nregions of the sun, in accordance with a well-known rule which\ndetermines electric density and electric potential on conductors.\n\nAs we proceed from the sun's surface east and west into space, we should\npass equipotential surfaces of different potentials. Thus the pressure\non every point of equipotential surfaces would be regulated by the\nelectric density of the Aether, which would coincide with the actual\naetherial density at that point; and as the aetherial density is the\nmeasure of its elasticity or pressure, so the electric potential would\ncorrespond with the elasticity or pressure at the same point.\n\nThus it is possible to map out the electric field east and west by\never-increasing and widening circles which would be at lower potential\nthe further they receded from the sun. So that by carrying out the\nelectro-magnetic theory of light to its logical conclusion, we are able\nto bring the whole of the solar system into line with electric\nphenomena; and, as we proceed, we shall see that all other facts\nrelating to electricity, and magnetism also, are equally as applicable\nthereto, otherwise this theory of light must fall to the ground.\n\nThat this conception of the universal Aether in its application to solar\nspace is not extravagant may be proved from the writings of Prof.\nTyndall and Clerk Maxwell. Tyndall, writing on the subject of Faraday's\nLines of Force, says:[26] \"The aspect of these curves so fascinated\nFaraday that the greater part of his intellectual life was devoted to\npondering over them. He invested the space through which they run with a\nkind of materiality, and the probability is that the progress of\nscience, by connecting the phenomena of magnetism with the luminiferous\nAether, will prove these 'Lines of Force,' as Faraday loved to call\nthem, to represent a condition of this mysterious substratum of all\nradiant action.\"\n\nWhile Clerk Maxwell,[27] writing on \"Action at a Distance,\" says: \"These\nLines of Force _must not be regarded as mere mathematical abstractions_.\nThey are the _directions in which the medium is exerting tension like\nthat of a rope_, or rather like that of our own muscles.\" I therefore\npremise, that both these statements will find a literal fulfilment in\nthe conception of the Aether advanced and perfected in this work.\n\n[Footnote 25: _Phil. Mag._, 1861.]\n\n[Footnote 26: Tyndall on _Light_.]\n\n[Footnote 27: _Collected Papers_, by Niven.]\n\n\nART. 81. _Aether and Induction._--We have seen in the preceding Arts.\nthat the sun is an electrified body, possessing an electric field, which\nfield possesses different intensities at different distances from its\nsurfaces.\n\nIf such be the case, the question at once confronts us, as to what is\nthe effect of such an electrified body with its electric field upon all\nthe planets which revolve around it; for, if its electric field extends\nas far as Neptune, then all the planets and meteors, that revolve\naround the sun, must revolve in the sun's electric field.\n\nSuch a question can best be answered from the consideration of\nexperiments and theories advanced first by Faraday, who gave to the\nworld his theory of Induction, which we shall now consider.\n\nLet _A_ be an electrified body (Fig. 13), and _C_ be a body not\nelectrified, but situated within the electric field of _A_. Then it can\nbe experimentally proved, that _C_ will also become an electrified body\nby induction. As is well known, there are two kinds of electricity,\nPositive and Negative. We will suppose _A_ to be charged with positive\nelectricity. Then it can be proved that _C_ will also be charged with\nnegative electricity on the half nearest to _A_, while the other half\nwill be charged with positive electricity.\n\n[Illustration: Fig: 13.]\n\nNow how has this result been brought about? According to Faraday's\ntheory the particles of air, the dielectric, between _A_ and _C_ play a\nmost important part in the process. As a matter of fact, each atom or\nparticle of air is polarized, as the process of separating the two kinds\nof electricity is termed, so that every atom has one half of it covered\nwith positive electricity, and the other half with negative electricity.\n\nFor example, let _A_ and _C_ be the same brass balls with the particles\nof air between them, _A_ being the positively charged ball and _C_ the\nunelectrified ball, the shaded parts representing positive electricity\nand the unshaded parts negative electricity.\n\nThen _A_ will act inductively on the unelectrified ball _C_ through the\nmedium of the particles of air _d_, _e_, _f_, _g_, _h_. The electrified\nball _A_ will act first on the layer of particles next to it, attracting\ntheir negative electricity and repelling the positive according to the\nwell-known law that \"Unlike electricities attract, like electricities\nrepel each other.\"\n\nThe positive electricity in the first layer then acts in the particles\nof the next layer in the same way, and thus the inductive action is\ntransmitted through the particles, from layer to layer, until we come to\nthe last layer of particles next to the ball _C_.\n\nAs the half of each atom or particle nearest to _C_ is positively\nelectrified, then the half of the ball _C_ nearest to the layer becomes\nnegatively electrified, while the half further away is positively\nelectrified. Thus we say that _C_ has become electrified by induction\nthrough the polarization of the particles of air which lie between the\ntwo bodies. Faraday on this point says: \"Thus induction appears to be\nessentially an action of contiguous particles, through the\nintermediations of which the Electric Force, originating at a certain\nplace, is propagated or sustained at a distance, appearing there as a\nForce of the same kind exactly equal in amount, but opposite in its\ndirection and tendencies.\"[28]\n\nWhile again he states:[29] \"Induction appears to consist in a certain\npolarized state of particles into which they are thrown by the\nelectrified body sustaining the action, the particles assuming positive\nand negative parts which are symmetrically the lines of Inductive\nForce.\" Thus in the case of any electrified body, acting on an\nunelectrified body at a distance, it has to be definitely understood\nthat _the action at a distance_ is alone communicated and propagated by\nthe dielectric or medium which exists between the two bodies. Though in\nthe case of Gravitation it has been mathematically assumed, that action\nat a distance is possible, yet experimentally and physically such an\nassumption is philosophically incorrect, as all experience and\nexperiment go to prove that there is no such thing as action at a\ndistance manifested, except such action is propagated through the\nintervening medium, as stated and proved by Faraday.\n\nIn order to bring Gravitation, therefore, into line with our experience,\nit will have to be demonstrated that it, too, is the result of the\naction of the intervening medium, that is, the Aether, which is a result\nwe are being led up to.\n\nWe have already seen that the sun is an electrified body, possessing an\nelectric field, and as all electrified bodies can act on other bodies in\ntheir field inductively, then a similar result should happen in the\nsolar system, that happens in any electrical experiment on induction,\nwith the result that all the planets should become electrified bodies by\ninduction, such action taking place, as Faraday points out, through the\nmedium which divides the sun and the planets, that is, the Aether.\n\nOf course with a frictionless and non-atomic Aether such a result would\nbe an impossibility, but with our conception of an atomic and\ngravitative Aether the result is now attainable. We have therefore to\nthink of the sun, the centre of the solar system, being an electrified\nbody, and for illustration we will suppose it to be a positively charged\nbody.\n\nAll around the sun is the atomic Aether, which is polarized in the same\nway that the particles of air were polarized; that is, the two kinds of\nelectricities in the aetherial atom are separated, the negative being on\nthat side nearest to the sun, and the positive on the side further away.\nIn this way the whole aetherial medium would be polarized, and any body\nin the field would be electrified by induction, with the result that the\nside nearest the sun would be negatively charged, and the opposite side\npositively charged.\n\nThus let _S_ (Figs. 10 and 11) be the sun, and the circles represent\nequipotential surfaces, then one half of every surface would be\nnegatively electrified and the other half positively electrified, that\nis, assuming the sun to be a positively electrified body.\n\nIf _M_ represents Mercury, _V_ represents Venus, and _E_ represents the\nEarth (Fig. 10), then it can readily be seen that all these would be\nnegatively electrified on the side facing the sun; and, as they rotate\non their axes, each part of the planet would be positively and\nnegatively electrified once each day.\n\nWe are assuming that the medium is at rest, but according to our\nconception in Art. 44, all the aetherial atoms are in rotation on their\naxes, in the same way that the earth rotates on its axis, so that each\nof these aetherial atoms would present different parts of its surface to\nthe sun as it rotates on its axis; but, as that does not affect the\nprinciple of induction, such a fact need not now be fully considered.\n\nLet us now ask, What is the result of all the planets becoming\nelectrified bodies in the same way that the sun is an electrified body?\nArguing from experience, we come to the conclusion that each planet must\nalso possess its electric field, which also must have its lines of\nforce, its different potentials at different distances, and its\nequipotential surfaces. So that Mercury, Venus, the Earth, Mars,\nJupiter, Saturn, Uranus, and Neptune all have their electric fields,\nwith their own lines of force, and with their equipotential surfaces.\n\nIf we carry the analogy further still, then it can also be proved that\nthe Earth, and those planets which have moons or satellites, also act\ninductively on their satellites, with the result that they too become\nelectrified bodies, with their own smaller electric fields and lines of\nforce. This may seem at first sight a little confusing, but the\nconfusion will gradually disappear if we will look at it carefully for a\nmoment or two. Let us endeavour to picture the solar system from this\nnew standpoint, and map out the equipotential surfaces, which this idea\nsuggests. Let _S_ represent the sun (Fig. 14), the initials of all the\nplanets and satellites representing the various planets; then we get the\nfollowing plan of the solar system with the various equipotential\nsurfaces shown by the circular lines.\n\nWe are now supposed to be looking down on all the solar system from\nabove it, so to speak, so that we should be looking at what we call the\nNorth Poles of the sun and planets.\n\n[Illustration: Fig: 14.]\n\nThus we see that the equipotential surfaces around the sun are huge\ncircles which stretch out as far as Neptune or even beyond, but within\nthose circles we find each of the planets revolving round the sun, each\nwith its own equipotential spheres, which are circles also, while around\nthe various planets are the satellites, from the moon of our Earth, to\nthe two satellites of Mars, five of Jupiter, eight of Saturn, each with\nits own lines of force and electric fields.\n\nOf course we must not forget that all these revolve round the sun, and\nthe question may suggest itself to the reader's mind, if such a result\nis possible. I shall prove later on, that according to Maxwell such an\nevent is possible, but at present we will consider them stationary.\n\nNow let us see how such a conception compares with our hypothesis of a\ngravitative Aether. If Aether be gravitative, then the sun must have an\nattraction for the Aether, and its aetherial field would stretch out\ninto space as far as Neptune at least.\n\nSo that it can readily be seen that the aetherial field of the sun's\nattractive power coincides with the electric field which the sun\npossesses as an electrified body. Again, if Aether be gravitative, then\nall the planets must also have an aetherial field, which will be\nco-extensive with their electric field also. The same principle applies\nto each of the satellites, with the result that they too will possess an\naetherial field which will be equal in extent and limit to their\nelectric field.\n\nAs the satellites revolve around their primary planet taking their\nelectric fields with them, so the planets with their associated\nsatellites revolve around the sun taking their electric and aetherial\nfields with them. Thus we get a glimpse, though at this point very\nshadowy and indistinct, of those motions of the universal Aether, which\nhelp to constitute the harmony, beauty, and order of the universe. We\nhave seen, therefore, that as the sun is an electrified body, so all the\nplanets and satellites are electrified bodies also, each possessing its\nown field, with all that such a field implies.\n\nWe shall find that such a conception is borne out by experience and\nobservation, when we come to deal with the Earth as a magnet; because we\nshall afterwards learn that the Earth is an electro-magnet, possessing\nits magnetic field, which is co-existent and equipollent with its\nelectric field.\n\n[Footnote 28: _Exp. Res._, 1297, 1298.]\n\n[Footnote 29: Par. 1298.]\n\n\nART. 82. _Energy of the Field._--We have seen in Art. 79 that every\nelectrified body has an electric field. We have further learned, in\ncarrying the electro-magnetic theory of light to its logical conclusion,\nthat all the planets and satellites together with the sun must be\nelectrified bodies, each possessing its electric field.\n\nWe have now to determine the effect of such a truth from its dynamical\naspect upon the bodies within the field, that is to say, we have to\nconsider the energy of such electric fields, and endeavour to find out\nthe effect of such energy upon other bodies within that field.\nMaxwell,[30] in his introduction to a paper on \"The Dynamical Theory of\nthe Electro-magnet Field,\" writes on the matter thus: \"It appears\ntherefore that certain phenomena in electricity and magnetism lead to\nthe same conclusion as those of optics, namely, that there is an\naetherial medium pervading all bodies and modified only in degree by\ntheir presence; that the parts of this medium are capable of being set\nin motion by electric currents and magnets; that this motion is\ncommunicated from one part of the medium to another by forces arising\nfrom the connection of these parts; that under the action of these\nforces, there is a certain yielding depending upon the elasticity of\nthese connections; and that therefore energy in two different forms may\nexist in the medium, the one form being the actual energy of motion of\nits parts, and the other being the potential energy stored up in the\nconnections in virtue of their elasticity.\"\n\nThe two forms of energy he gives us in his work on _Magnetism and\nElectricity_, where, in the quotation already given in Art. 79, he\nstates them to be electro-static and electro-kinetic energy, while in\nparagraph 792 of the same work he adds: \"The intrinsic energy of the\nmedium is half electro-static and half electro-kinetic, that is, half is\ndue to electricity and half is due to magnetism.\"\n\nWe are, however, only dealing at this point with the electro-static\nenergy in the electric field, as we shall deal with the electro-kinetic\nenergy in the following chapter.\n\nWe have, therefore, to conceive of an electrified body generating\nelectric or electro-magnetic waves, which speed away from the generating\nsource on every side with the velocity of light. Now we have already\nseen that the aetherial waves which give rise to heat and light possess\na repulsive power, that is, they exert a pressure on the body with which\nthey come into contact.\n\nIf, therefore, in the electric field there is this energy manifested as\nproved by Maxwell, and that energy takes partly the form of a pressure\nas stated by Maxwell, then we have in the electro-static energy of the\nelectric field, another indication of that centrifugal force for which\nwe are looking, and whose existence was so satisfactorily demonstrated\nto Herschel by the phenomena of comets' tails.\n\nThat there is this pressure in an electric field was conclusively proved\nby Maxwell, and experimentally demonstrated by Professor Lebedew (Art.\n77). Maxwell distinctly states on this point, \"that the combined effect\nof the electro-static and electro-kinetic stresses is a pressure equal\nto 2 P. in the direction of the propagation of the waves,\" that is, away\nfrom the electrified or charged body.\n\nHe continues: \"Thus, if in strong sunlight the energy of light which\nfalls on one square foot is 83.4 foot-pounds per second, the mean energy\nin one cubic foot of sunlight is about .0,000,000,882 of a foot-pound,\nand the mean pressure on a square foot is .0,000,000,882 of a pound\nweight. A flat body exposed to sunlight would experience this pressure\non its illuminated side only, and would therefore be _repelled_ from the\nside on which the light falls.\"[31]\n\nThis pressure only gives the result due to the pressure of one cubic\nfoot of sunlight. What must be the pressure, therefore, due to the whole\nof the sunlight received by the flat body from the sun? The total\npressure, whatever it may be, would be equal to 2 P. according to\nMaxwell, and half of that is due to electricity, and half due to\nmagnetism. Now such a result is entirely in harmony with the conception\nof the Aether as given in this work. For, if Aether possess an electric\nbasis as suggested by Maxwell, and it is also gravitative as suggested\nin Art. 45, then it must follow, as pointed out in a previous Art., that\nthroughout the field there is a varying difference in the potential of\nthe field; the potential being regulated by the electric density, that\ndensity being equivalent to the aetherial density. Further, as the\nelasticity of the medium which regulates the pressure is proportional to\nthe density, so the pressure must decrease, as the elasticity\ndecreases--that is, as the electric potential decreases, or the electric\ndensity is diminished. Therefore, if the sun be an electrified body,\never generating electro-magnetic waves which speed away from it on every\nside, then, whenever any of these waves come into contact with a planet\nor comet, that planet or comet would be repelled from the sun by the\npressure of these electro-magnetic waves to which the sun gives rise in\nits electric or electro-magnetic field.\n\nThus we again come to the conclusion that the sun is not only the centre\nof a centripetal force due to Gravitation, and subject to certain laws,\nwhose physical cause is unknown, but it is equally the centre and source\nof a centrifugal force, in that it is an electrified body, and gives\nrise to electric waves which produce a pressure on any body upon which\nthey fall, in the sun's electric or aetherial field. It has only to be\ndemonstrated, therefore, that this centrifugal force satisfactorily\nfulfils all the laws required as laid down in Art. 24, that is, that its\ncourse is along the same path as the Centripetal Force of Gravitation,\nthat it is subject to the same law of intensity, which is inversely as\nthe square of the distance; and further (what is the most important at\nthis stage), that the combined effect of the pressure of two bodies is\nequal to the product of their masses, then we shall have discovered that\nwhich we set out to discover, viz. a complementary force to the\nattractive force of Gravitation.\n\nUnlike the centripetal force, however, the centrifugal force will be\npurely a physical one, due to a purely physical medium, the Aether,\nwhose properties and motions can be accounted for on a physical, and not\non a hypothetical basis.\n\nFurther, as the planets are also electrified bodies (Art. 81), they too\nwill possess an electric field, and will generate electric waves, which\nwill also exert a centrifugal force upon all bodies upon which the waves\nfall. So that, like the sun, the planets are not only the centre of a\ncentripetal force, which ever acts towards their centre; but they are\nalso the centre of a centrifugal force, due to the aetherial electric\nwaves to which they give rise in the Aether.\n\nThe application of the same principle may be extended to every satellite\nthat exists in the solar system, and indeed to every particle and atom\nof matter that exist throughout the universe, for wherever we find the\nAether, there we find this centrifugal force, which is due to the\nelectric aetherial waves generated by the atom or particle of matter, or\nby any combination of atoms, as a meteor, satellite, planet, sun or\nstar.\n\n[Footnote 30: _Collected Papers_, by Niven.]\n\n[Footnote 31: _Magnetism and Electricity_, Arts. 791 and 793.]\n\n\nART. 83. _Electric Radiation._--We learn, therefore, that the sun,\ntogether with every planet and satellite in the solar system, is the\ncentre of a centrifugal force, which is due to the radiation of electric\nwaves by an electrified body. We have now to prove that this force\nfulfils all the laws required, in order for it to become the\ncomplementary law to the Centripetal Force of Gravitation. We will first\nshow that this centrifugal force which proceeds from the electrified\nbody is radiated out into space in straight lines with the velocity of\nlight and radiant heat.\n\nAs we have already seen, it was due to the genius of Hertz to show the\nidentity between electric radiation and radiant light and heat. In his\npaper on Electric Radiation he says:[32] \"I have succeeded in producing\ndistinct rays of electric force, and in carrying out with them the\nelementary experiments which are commonly performed with light and\nradiant heat.\" We have seen in Arts. 65 and 76 that radiant heat and\nlight are propagated in straight lines, so that, according to Maxwell's\nelectro-magnetic theory, a ray of electric radiation should also be\npropagated in straight lines.\n\nThis Hertz proved, and gave his results in his paper \"On the Action of a\nRectilinear Oscillation upon a Neighbouring Circuit,\" in which he fully\ndemonstrated that when electric action takes place between two charged\nbodies, the electric force is radiated out into space in straight lines\nin the same way that light and radiant heat are radiated. In his paper\non \"The Finite Velocity of Electro-magnetic Actions,\" he showed that the\nvelocity of the electro-magnetic waves was the same as that of light. In\nthe summary of this paper (paragraph 3) he states: \"There are many\nreasons for believing that the transverse waves of light are\nelectro-magnetic waves; a firm foundation for this hypothesis is\nfurnished by showing the actual existence in free space of\nelectro-magnetic transverse waves which are propagated with a velocity\nakin to light.\"\n\nAgain, in his paper on \"Electric Radiation,\" he not only showed how the\nradiation was propagated in straight lines, like light, but also proved\nthat while it was reflected by metals, the electric beam was able to\npass through doors and stone walls, and adds, \"that it was with\nastonishment that one saw the electric beam appear inside a closed room\nafter its passage through the door.\"\n\nThus Hertz has shown that both electric and magnetic effects are\npropagated through the Aether with finite velocity, and that that\nvelocity is exactly the same as the velocity of light. He further proved\nthat this propagation takes place in straight lines, in the same way\nthat radiant heat and light are propagated. This being so, it is\nnecessary for us to apply these truths to the solar system, with a view\nto find out what such a result teaches us.\n\nWe have seen in a preceding article, that the sun is an electrified\nbody; therefore it, too, must generate these electro-magnetic waves, and\nradiate them into space on every side with the velocity of light. Let us\ntry to picture the scene. Let _S_ represent the sun, and the circle\nround it represent the equipotential spheres which exist round the sun.\n(See Figs. 10 and 11.) As the intensity of the electric force is greater\nnearer the sun than further away, these equipotential surfaces will be\ncloser nearer the sun than further away.\n\nThen let the straight lines which radiate out from the sun represent the\npath of an electric ray. It can be easily seen that these electric rays\ncut the equipotential surfaces at right angles, as they pass from the\ncentre of the sun outwards into space. Now these lines not only\nrepresent the path which the electric ray takes in its journey through\nspace, but exactly coincide with the electric lines of force as\nconceived by Faraday. This great thinker and experimentalist not only\nconceived lines of magnetic forces existing in the dielectric or medium\nbetween two electrified bodies, which in this case is the Aether, but\nalso conceived lines of electric force which started at a conductor, or\nan electrified body, and radiated out into space.\n\nThus a line of electric force has a definite direction, and always\nstarts from an electrified body. If it were possible to move a planet\nalong one of these lines of force, its path would be that of a straight\nline. If on the other hand a planet moved at right angles to one of\nthese lines of force, that is, along the surface of an equipotential\nsphere, then no work would be done against the electric force, as on\nsuch a sphere the electric force would be of the same intensity.\n\nSo that from Hertz' experiments it can be demonstrated, that if there be\nany electric force existent in the Aether, due to the action of the sun\nupon the Aether, then such a force is directed along the path of a\nstraight line into space with the velocity of light, which, as already\npointed out, is the path taken by a ray of radiant heat and light, and\ncoincides with the path taken by the centripetal force.\n\nIt has been demonstrated that such electric force is accompanied by a\nrepulsive force, or more correctly a pressure, so that here we have\nfurther evidence of the existence of a centrifugal force which finds its\ngenerating source in the sun, which is also the centre of the attractive\nforce of Gravitation in the solar system.\n\nThe application of Hertz' experiments may be made not only to the sun,\nbut also to every planet and satellite that exists in space with the\nsame result; and, further, may be extended to every particle and atom\nthat exists throughout the universe. For, according to Art. 43, we have\nlearned that Aether is universal, and we have seen that it is\ngravitative, and have learned from the electro-magnetic theory of light\nthat it has an electro-magnetic basis. Therefore, to be thoroughly\nconsistent, we must not stop in the application of this principle at any\npoint in the whole universe.\n\nEither the whole principle is of universal application, or it ceases to\nbe a universal law. Therefore, if there is this centrifugal force\noperating along a straight line from the centre of an electrified body,\nsuch centrifugal force must be in its application universal, in order to\nbe complete, and in order to satisfactorily form the counterpart of the\ncentripetal force which is also universal, and operates along the\nstraight line joining the centres of gravity of any two bodies.\n\n[Footnote 32: Hertz on _Electric Waves_.]\n\n\nART. 84. _Law of Inverse Squares._--We have learned therefore from the\npreceding Arts., that the solar system may be looked upon as an electric\nfield, with the sun as the electrified body occupying the centre. We\nhave also seen that there is a centrifugal force in all electric fields,\nwhich is due partly to electric waves, and partly to the magnetic waves\nof the Aether.\n\nIt will be interesting to find out, what law governs the intensity of\nthis force in any part of the field, or at a given distance from the\ncentral body. We have seen (Art. 66) that the law governing the\nintensity of heat at any distance from the sun, is the law of inverse\nsquares. Further, from Art. 75 we have also learned that light is\nsubject to the same law of inverse squares, as indeed it should be, if\nit be due to one and the same medium, the Aether.\n\nIf, therefore, electricity is also due to certain motions of the\naetherial medium originated by the action of an electrified body as the\nsun, in the same way that light and heat waves are originated, then it\nought to follow that the repulsive power of electricity is also subject\nto the same law of inverse squares. As a matter of fact, that is exactly\nthe state of affairs, so that we find the intensity of the repulsive power\nin the Aether from any central body, due to the electric waves, or the\npressure due to the wave motions of the electric Aether, in relation to\nthat body, is governed and controlled by the same law that governs light\nand heat.\n\nIt may be suggested that such a coincidence is not a very strong\nargument, as all forces emanating from a central body are subject to the\nsame law of inverse squares. In reply to that, I should like to point\nout, that even that objection only strengthens the conception of the\nAether that we are endeavouring to complete. Our contention is, that all\nphysical forces, whether they be light, heat, electricity, magnetism or\nGravitation, are all due to the motions of the aetherial medium; which\nmotions may be generated by a heated or luminous or electrified body,\nand are radiated from such a body in waves of concentric spherical form,\nand are all subject to the laws of inverse squares.\n\nSo that the fact of the intensity of the centrifugal force due to the\nrepulsive power of electricity falling into line with the law governing\nlight and heat is, to my mind at any rate, only a clearer proof of the\none common origin of all the physical forces. The law of inverse squares\nin relation to electricity may be thus stated. The Centrifugal or\nRepulsive Force between two charged electrified bodies acts inversely as\nthe square of the distance between them.\n\nThis law was proved by Coulomb by means of an instrument known as\nCoulomb's Torsion Balance, and I must refer the reader to any work on\nelectricity for a full establishment of this law. Suffice to say, that\nit has been experimentally demonstrated that the law holds good in\nrelation to the phenomena of electricity; and, wherever we get the two\nkinds of electricity present in any medium or conductor, owing to the\npolarization of its particles, there we have this law operating in\nrelation to the intensity of the repulsions of the two bodies directly\nconcerned.\n\nWe have already learned that the sun is an electrified body, and from\nthat hypothesis we have arrived at the conclusion that the earth and all\nthe other planets are electrified bodies. This being so, it naturally\nfollows that the intensity of the centrifugal force between any two of\nthese bodies, as the sun and the earth for example, or the sun and\nJupiter, is subject to the law of inverse squares; and that the\nrepulsion of the sun and the earth for each other is always regulated by\ntheir distance, being inversely as the squares of the distance between\nthem.\n\nThus, if the distance between the sun and any planet is reduced to\none-half, which is an exaggerated view, the intensity of the centrifugal\nforce is increased four times; if the distance be doubled the force is\nreduced to four times its former intensity, and so on.\n\nWhatever the distance may be between the sun and any of the planets, if\nthat distance be increased or decreased, then the intensity of the\ncentrifugal force due to electric waves is increased or decreased in\naccordance with the law of inverse squares. This agrees with the\ncentripetal law of Gravitation, as the Attraction of Gravitation is also\nsubject to the same law of inverse squares, and, as we have seen (Art.\n83), its path coincides with the path of centrifugal force, as it\npursues the path represented by the straight lines joining the two\nbodies.\n\nSo that, whenever, and wherever, at any point in space in relation to\nthe central body, the sun, the intensity of the attractive force is\nincreased according to the law of inverse squares by the distance from\nthe central body being diminished, at exactly the same time and in\nexactly the same manner, the repulsive force due to aetherial electric\nwaves is also increased. If the attractive force is doubled, then the\nrepulsive force is doubled. If the attractive force is halved, the\nrepulsive force is halved. If the attractive force is lessened\ngradually, then the repulsive force is lessened gradually; and if\nquickly, by the quicker motion of the planet through space, then the\nrepulsive motion is also increased with a quicker motion.\n\nFurther, like the repulsive power of light and heat, the repulsive power\nof electricity takes exactly the same path as the attractive power of\nGravitation.\n\nThus we learn that the sun is the centre of two forces: first, a\ncentrifugal force due to the pressure of the aetherial medium which is\never directed away from the sun, and which may either be produced by\nelectric or thermal or light waves; and second, it is the centre of a\ncentripetal force known as the Law of Gravity, whatever that may be due\nto. Further, the centrifugal force is also subject to the same law of\nintensity as the centripetal force, and moreover takes exactly the same\npath which the centripetal force takes.\n\nSo that we have only to prove that they both agree in another\nparticular, viz. that their power is regulated by the product of their\nmasses, and then we shall have discovered a real physical force, which\nis the exact complement and counterpart of the centripetal force due to\ngravity.\n\n\nART. 85. _Second Law of Electricity. (Product of Masses.)_--We have now\nto prove that the centrifugal force exerted by any electrified body\noperates upon another electrified body in the same proportion and with\nexactly the same force which governs the centripetal force. From Art. 21\nwe learn that the centripetal force which is exerted by one body upon\nanother is equal to the product of their masses. In order, therefore,\nfor any centrifugal force to be the exact counterpart of that force, it\ntoo must be subject to the same law of proportion, that is, the\nrepulsive force between any two bodies must be equal to the product of\ntheir masses.\n\nWe have shown that there is a repulsive force exerted by the Aether from\nthe phenomena of heat, light, and electricity, and that that repulsive\nforce or energy fulfils every condition required by a centrifugal force\nor motion, with the exception of the part referring to the fact that\nsuch a force must be proportionate to the product of their masses. What\nwe were unable to accomplish, however, from the phenomena of heat or\nlight we are now able to accomplish from the phenomena of electricity.\n\nFor in the phenomena of electricity we find a law which runs thus: \"The\nforce of repulsion\" (which is the part of electricity we are now dealing\nwith) \"between two electrified bodies is equal to the quantities of\nelectricity with which the body is charged.\" This law was established\nand proved by Coulomb by means of a delicate instrument known as the\nTorsion Balance, with which he also established the law of inverse\nsquares.\n\nIt will be seen at a glance that there is a slight difference between\nstating the law of proportion with reference to the centripetal force,\nand the centrifugal force or motion. In the former we state the\nproportion is equal to the product of the masses, while in the latter we\nsay that the proportion is equal to the product of the quantities of\nelectricity.\n\nIn the one case we deal with the mass of the body, whether it be atom,\nmolecule, planet or star; in the other case we deal with quantities of\nelectricity. At first sight it may seem that there is little, if any,\nconnection between the two laws, but a careful reflection of the\nhypotheses laid down with regard to the aetherial medium will show that\nthere is not only a close connection between these two laws of\nproportion, but also that the law governing the repulsive power of the\naetherial electric waves is the direct outcome of the law of proportion\ngoverning the centripetal force. Let us restate our case in regard to\nthe aetherial medium.\n\nWe have learned that the Aether is gravitative, and that it also has an\nelectro-magnetic basis is proved from Maxwell's electro-magnetic theory\nof light. Let me ask the reader this question therefore. If the Aether\nbe gravitative, what must be the rule governing the extent and density\nof the aetherial atmosphere surrounding any planet or sun or other body?\nIf the Law of Gravity teaches us anything at all, it distinctly teaches\nus that the gravitating power of any body is regulated by the mass of\nthe body, as the law states that the attraction is proportionate to the\nproduct of the masses. It states nothing about volume or condition of a\nbody.\n\nThe exact size or state of a body has no direct result bearing on\ngravitation attraction; the underlying principle being that the\nattractive force is dependent on the mass, and only on the mass of a\nbody. So that if the volume of any body, whether atom, planet, satellite\nor sun, be doubled, its attractive power remains the same, simply\nbecause the mass of the whole body remains the same. Mass, we are told\nby mathematicians, is equal to the volume multiplied by the density, and\nwhenever we increase the volume of a body we decrease the density, the\ntotal mass of the body remaining the same.\n\nIf the volume be doubled, then the density of the body would be halved,\nand _vice versa_, but through all the changes of volume and density that\nmay arise from the addition of heat or diminution of heat, the total\nmass of a body always remains the same. Looked at from the atomic\nstandpoint, taking hydrogen as unity, an atom of oxygen would always\nweigh sixteen times an atom of hydrogen, and this principle applies\nthroughout the whole realm of the atomic world. Further, the same\nprinciple or law, that the mass is equal to the volume multiplied by the\ndensity, is true of the planetary or even the stellar world. Thus the\ngreat regulating principle of the attractive force of gravity is mass,\nand not volume, or density, or any other condition.\n\nNow as Aether is subject to the attractive force of gravity, the extent\nof the aetherial field, and the density of the Aether near the surface\nof any body, must be subject to the same law regarding mass. That is,\nthe aetherial atmosphere of any atom, or molecule, or satellite, or\nplanet, or star is dependent upon the mass of the atom, the molecule, or\nthe planet, or the star as the case may be.\n\nThus an atom of oxygen would have a larger or denser aetherial\natmosphere than an atom of hydrogen, exactly proportionate to their\nrespective masses. A planet whose mass was represented by 1,000,000 tons\nwould have twice the quantity of Aether around it, compared to a planet\nweighing only 500,000 tons, and so on, the aetherial atmosphere always\nbeing proportionate to the mass of the planet, or the satellite, or the\nsun, or the star. The fact which we learn from these considerations is\nthat the quantity of Aether, which is attracted by any body, is always\nproportionate to the mass of the body attracting it.\n\nBut we have learned from Art. 78 that Aether has an electro-magnetic\nbasis, and that the density of the Aether is co-equal with electric\ndensity, so that the quantity of Aether which is attracted and held\nbound by any body is really equal to the quantity of electricity that\nsuch a body is covered with, or is charged with. If the quantity of\nAether around any body is doubled because its mass is doubled, then the\nquantity of electricity is also doubled, but as long as the mass remains\nunaltered, the quantity of electricity held bound by that mass remains\nunaltered also. The area of the mass may be doubled, and in that case\nthe density of the electricity would be halved, but as long as the mass\nremained the same, the quantity of electricity would remain the same\nalso. So that we learn from this reasoning that the mass of a body, and\nquantities of electricity on that mass, are always proportionate to each\nother, because of the fact that Aether is gravitative, and also has an\nelectro-magnetic basis.\n\nIf we wanted further evidence of the hypothesis that has just been\nadvanced, such evidence is to be found in the hypothesis suggested by\nFaraday as to the electro-chemical equivalents of all elements.\nAccording to this hypothesis every element has its exact\nelectro-chemical equivalent, or definite quantities of electricity are\nto be found in association with each and every particular atom of each\nelement. Writing on the subject in his _Exp. Res._, par. 852, he says:\n\"The theory of definite electro-chemical action appears to me to touch\nupon the absolute quantity of electricity or electrical power belonging\nto different bodies. Although we know nothing of what an atom is, yet we\ncannot resist forming some idea of a small particle which represents it\nto our mind, and though we cannot say what electricity is, so as to be\nable to say whether it is a particular matter or matters, or mere motion\nof ordinary matter, yet there is immensity of facts which justify us in\nbelieving that the atoms of matter are in some way endowed or associated\nwith electrical powers to which they owe their most striking qualities,\nand amongst them their chemical affinity.\" Further, in Art. 857, he\nstates: \"I can have no doubt that, assuming hydrogen as 1, and\ndismissing small fractions for the simplicity of expression, the\nequivalent number or atomic weight of oxygen is 8, of chlorine 36, of\nbromine 78.4, and of lead 103.5, etc., notwithstanding that a high\nauthority doubles several of these numbers.\"\n\nThen, writing upon the definite relationship of these equivalents in\ncompounds, he states (Art. 835): \"Electro-chemical equivalents are\nalways consistent, that is, the same number which represents the\nequivalent of a substance _A_ when it is separating from a substance _B_\nwill also represent _A_ when separating from a third substance _C_. Thus\n8 is the electro-chemical equivalent of oxygen, whether separating from\nhydrogen, tin, or lead; and 103.5 is the electro-chemical equivalent of\nlead, whether separating from oxygen, or chlorine, or iodine.\"\n\nHere, then, from the pen of one of the greatest thinkers and\nexperimentalists of modern times we have confirmatory evidence that the\nmass of any body is practically synonymous with the quantity of\nelectricity associated with that body. For if the principle is true in\nits application to atoms, it is true in its application to molecules;\nand if it is true in relation to molecules, it is equally true in\nrelation to small bodies composed of molecules. And if it holds good in\nrelation to small bodies, the principle is equally true in its\napplication to larger bodies, as the earth, and therefore is of\nuniversal application and proves the statement already made, that the\nmasses of bodies and quantities of electricity in association with that\nmass are always proportionate to each other.\n\nWe are now in a position to compare the proportion of the centripetal\nand centrifugal forces. The attractive power of the former, between two\nbodies, is equal to the product of their masses; the repulsive power of\nthe latter is equal to the product of the quantities of electricity\nbound to them, and that, as we have seen, is regulated by the respective\nmass of each body. Let us apply this fact to the solar system and see\nhow it works.\n\nTaking the mass of the earth as unity, we find that the mass of the sun\nis 324,000 greater, so that the attractive power of the two bodies would\nbe represented by the product of the two numbers; but because the sun is\nthat number of times greater, its aetherial and, therefore, its electric\nfield would be so many times greater, with the result that the\nproportion of the repulsive forces between the two bodies would be\nexactly the same as the attractive forces between the two bodies, that\nis, if the mean distance remains the same.\n\nIn the same way, it can be shown that the attractive forces between the\nearth and Jupiter exactly equal the repulsive forces between the two\nplanets at their mean distance, or the attractive forces between any two\nplanets or satellites are exactly counterbalanced by the repulsive power\nof the centrifugal force at their mean distances.\n\nThus the centrifugal force of every body is the exact opposite of its\ncentripetal force at their mean distance, because the laws governing the\ncentrifugal force are the exact counterpart of the laws governing the\ncentripetal force. A comparison of the two will prove this. From Arts.\n20, 21, and 22 we have seen that the centripetal force is exerted along\nthe straight lines joining the attracting bodies, that the intensity of\nthe attracting body is inversely as the square of the distance, while\nthe total force is proportionate to the product of their masses.\n\nFrom the phenomena of light, heat, and electricity, we learn that the\ncentrifugal force due to aetherial pressure is exerted along straight\nlines, that the intensity is inversely as the square of the distance,\nwhile the total force between two bodies is equal to the product of the\nquantities of electricity, which are regulated by the product of their\nmasses.\n\nThus, if every planet and satellite could be conceived to be motionless\nin space, and these two forces could be set in operation without\nproducing rotation or translation in space, which is impossible, then\nevery planet and satellite would occupy, by the joint exercise of these\ntwo forces, the same position in relation to the sun represented by\ntheir mean distances, as long as the solar system existed as a separate\nsystem in the realm of aetherial space. We have therefore discovered by\nstrict philosophical reasoning, based on Newton's Rules of Philosophy, a\nreal tangible centrifugal force existing throughout the universe;\nbecause it is entirely due to the pressure of an universal Aether, whose\noperation is ever directed from a central body, which force was\nindicated by Herschel, and its existence to his mind was demonstrated by\nthe repulsion exhibited in connection with the tails of comets.\n\nWe have now to go a step further, and show that the same pressure also\nincludes the magnetic phenomena, as indicated by Clerk Maxwell, and that\nmagnetic phenomena are also due to the aetherial medium, and then we\nshall have linked together in one common medium the majority of the\nforms of energy, as light, heat, electricity and magnetism, with which\nwe are familiar.\n\nIf it be demonstrated that these two forces, the centrifugal force and\nthe centripetal force, can conjointly account for all the motions of the\ncelestial bodies, then we shall have conclusive evidence that one of the\nforces is physical and due to the pressure of a physical medium. After\nthat it will be comparatively easy to show that the centripetal force is\nalso due to the same aetherial medium, and then we shall have\naccomplished that which we set out to accomplish, viz. the establishment\nof a physical cause for universal Gravitation, which physical cause is\nalone to be found in the pressures, tensions and motions of an universal\nAether.\n\n\n\n\n                               CHAPTER IX\n\n                          AETHER AND MAGNETISM\n\n\nART. 86. _Electro-magnetism._--We have now to look at the relation of\nmagnetism to electricity, or, in other words, to prove the identity that\nexists between magnetism and electricity. In Art. 78 we have proved the\nidentity between electricity and light, so that if we can now prove the\nidentity between electricity and magnetism, then, wherever we get\naetherial light waves, we must also get aetherial electro-magnetic\nwaves.\n\nAs the light waves due to the vibrations of the Aether are practically\nuniversal in extent, then it must follow, if the identity of the light\nwaves with electro-magnetic waves is established, that the universality\nof electro-magnetic waves is established also, with the natural result,\nthat, wherever we get these electro-magnetic waves, there we shall have\nthe conditions by which all electro-magnetic phenomena are produced.\n\nNow it can be demonstrated by actual experiment that wherever we get a\ncircular current of electricity, there we have magnetic phenomena\nmanifested. The two are inseparably connected, and it is impossible to\nobtain the one without the other. For example, suppose we have a wire\nconveying a current of electricity and make it into a coil as in Figure\n15, what is the result? The result is, that the coil of wire has\nactually been converted into a magnet.\n\nIt will attract iron filings that are brought near it, and also\nmagnetize an iron bar placed in the centre of the coils, and convert\nthat into a magnet. Indeed, there is nothing which can be done by an\nordinary bar magnet which cannot be done by a coiled wire conveying an\nelectric current.\n\nFrom this and similar experiments it can be demonstrated that wherever\nwe get a circular current of electricity, there, associated with that\ncurrent, are all the phenomena incidental to and associated with the\nordinary bar magnet. This leads us to the truth discovered by Ampere,\nthat magnetism is nothing more or less than electricity in rotation, or\nthat it is due to a whirl of electricity circulating round the molecule\nof any body. From certain experiments which he made in relation to the\nmutual action of two circuits on each other, with currents flowing\nthrough them, he came to the conclusion that the magnetism of the\nmolecule of each magnet is due to electric currents circulating round\nit.\n\nThe question arises as to what effect our new theory of the Aether has\nupon Ampere's theory: does it confirm it, or does it destroy it? We have\nlearned that every atom has its aetherial atmosphere, so to speak, which\nis bound to the atom by the Law of Gravitation (Art. 45). We have also\nlearned that Aether has an electrical basis, as proved by Maxwell and\nHertz, so that we learn that every atom has really an aetherial electric\natmosphere in association with it. We have only to conceive of this\natmosphere being set in rotation either by the rotation of the atom or\nmolecule itself, or by outside agencies, and we have at once a physical\ninterpretation of Ampere's theory of magnetism in the rotation of electric\ncurrents around the atom, such currents being due to the circulating or\nrotating motion of the Aether which surrounds the atom or molecule.\n\n[Illustration: Fig: 15.]\n\nThus we learn from experiment, and from Ampere's theory also, that\nmagnetism is directly associated with circulating currents of\nelectricity, and that wherever we get currents of electricity\ncirculating round any atom or body, there we get all the phenomena\nassociated with magnetism. That is to say, we shall have such phenomena\nas magnetic fields, magnetic lines of force, magnetic induction, and the\nproduction of permanent magnets by electricity.\n\nFurther, with reference to the identity of electricity and magnetism,\nFaraday has conclusively proved their relation to each other; and I\nwould strongly advise any reader who desires further light on the\nsubject to carefully read paragraphs 3265-3269 in his _Experimental\nResearches_, where he will find experiments which place the identity of\nelectricity and magnetism beyond the possibility of doubt. In paragraph\n3265 he writes: \"The well-known relation of the electric and magnetic\nforces may be thus stated. Let two rings in planes at right angles to\neach other represent them. If a current of electricity be sent round the\nring _E_ in the direction marked, then lines of magnetic force will be\nproduced. As these rings represent the lines of electro-dynamic force\nand of magnetic force respectively, they will serve for a standard of\ncomparison.\"\n\n\"I have elsewhere called the electric current or the line of\nelectro-dynamic force an axis of power having contrary forces exactly\nequal in amount in contrary directions (517). The line of magnetic force\nmay be described in precisely the same terms, and these two axes of power\nconsidered as right lines are perpendicular to each other,\" etc.\n\n[Illustration: Fig: 16.]\n\nAgain in 3267 he adds: \"Like electric currents or lines of force, or\naxes of power when placed side by side attract each other. This is well\nknown and well illustrated when wires carrying such currents are placed\nparallel to each other. But like magnetic axes of power or lines of\nforce repel each other. The parallel case to that of electric currents\nis given by placing two magnetic needles side by side with like poles in\nthe same direction.\"\n\nThen in 3268 he shows that these effects are not merely contrasts, but\nthey are contrasts which coincide when the two axes of power at right\nangles to each other are considered. Then in 3269 he adds: \"The mutual\nrelation of the magnetic lines of force and the electric axis of power\nhas been known since the time of Oersted and Ampere,\" and further states\nhe is of the opinion that \"the magnetic lines have a physical existence\nthe same as the electric lines,\" and having that opinion, asks whether\n\"the lines have a dynamic condition analogous to the electric axis to\nwhich they are so closely and inevitably associated, or whether they\nconsist in a state of tension of the Aether round the electric axis, and\nmay therefore be considered as static in their nature.\" Thus Faraday\nproved the intimate and close relationship that existed between the\nelectric current and the circles which represent the magnetic force in\nassociation with that current; and, what is more noticeable, he asks\nwhether such magnetic results are due to a state of tension in the\nAether around the axis of the electric current, evidently being of the\nopinion that the Aether played an important part in the phenomena of\nmagnetism, as well as in electricity, as other parts of his writings\nabundantly show.\n\nIf, therefore, there is this close identity between electricity and\nmagnetism, then in view of the fact that all electricity is due to the\nmotions of the universal Aether, it must follow that all magnetism is\nalso due to motions of the same aetherial medium, which is as universal\nas it is invisible.\n\nWhat these motions are has already been indicated by previous statements\nin this article, being comprised of circular or rotatory motions of the\naetherial electric medium about any body, whether that body be an atom,\nplanet, or sun or star. Such a conclusion as this is perfectly in\nharmony with Maxwell's electro-magnetic theory of light, as the\nconclusion that he arrived at in that theory was, that the light waves\nwere identical in nature and character with electro-magnetic waves\nproduced by an electro-magnetic source.\n\nUp to the present we have only dealt with the electric character of\nthose waves, and have therefore now to deal with the magnetic character\nof the same. So that throughout the whole realm of space, and indeed\nwherever there is Aether, there we have the conditions which give rise\nto magnetic phenomena, such as those already indicated.\n\nIt matters not whether it be in the atomic systems whose combinations\ncomprise all material forms of life with which we are familiar, or\nwhether it is in the systems of planets that revolve around their\ncentral sun, or whether it be in the constellations that fill the\nuniverse, wherever we find the Aether, there we find the conditions in\nthat Aether which will produce all the results ordinarily produced by\nmagnetism, or with which magnetism is associated, and it is to the\napplication of these phenomena to our solar system that we will now turn\nour attention.\n\n\nART. 87. _The Earth a Magnet._--If there is any fact in relation to a\nplanet that holds good, it is that the earth, with which planet we are\nmore intimately associated than any other, is a magnet.\n\nThis truth was clearly explained by Dr. Gilbert about the year 1600 in\nhis work on \"De Magnete.\" Not only has the earth geographical North and\nSouth poles, but it has also magnetic North and South poles, and indeed\nhas all the phenomena incidental to a magnet, such as magnetic dip and\nmagnetic lines of force, as we shall see later on.\n\nWe know, however, that the earth is simply one of a system of planets,\nwhich revolves with all the others of that system round its central body\nthe sun; and the question arises, whether the earth is the only one out\nof all the planets that is actually a magnet. Suppose it is affirmed\nthat the earth is the only planet which is a magnet. On what basis would\nsuch a statement be made? The only ground for making such a statement\nthat I can see is, that we have never lived on Mars or Jupiter or\nSaturn, or any of the other planets, and therefore been unable to\nexperiment on them, which reason is totally insufficient and inadequate\nfor such a conclusion.\n\nIf philosophy simply dealt with the results attained by such limited\nreasoning, then the progress of science would be retarded, and would be\nlimited and confined to actual experience obtained on our own planet and\nin relation only to that planet. But philosophy is not satisfied with\nsuch a narrow and limited outlook, but drawing its conclusions from\nactual experience on our own planet, in accordance with the rules of\nphilosophy, it seeks to apply such experience gained to the explanation\nof phenomena of other planets which also revolve round the sun.\n\nBy such reasoning we learn that all the other planets have North and\nSouth geographical poles like our earth, although we have never actually\ntrodden on those planets, or discovered the poles. We also learn that\nMars possesses climatic conditions probably similar to our own earth, as\nthere are certain changes on the surface around the poles, which by\nanalogy we assume to be caused by increase and decrease of snow during\nthe Arctic winter and summer of Mars respectively.\n\nThe analogy between our earth and the other planets is very full and\ncomplete, as the following results show. Our earth has an atmosphere, so\nhave all the rest of the planets. The earth revolves on its axis from\nWest to East, so do all the rest. The earth possesses two geographical\npoles, so do all the other planets. The earth revolves round the sun in\nan orbit of elliptic form, so do the other planets. The earth fulfils\nall the laws of motion as given by Newton, and all the other planets do\nthe same. The earth fulfils all Kepler's laws, and this is also true of\nall the others. Indeed, the only difference apparently that exists at\npresent between the earth and all the other planets is, that our earth\nis a magnet, while at present it is not conceded that all the others are\nmagnets.\n\nNow such a conclusion I venture to say is altogether opposed to every\nrule of philosophy. For if experience be any guide in philosophy, then\naccording to experience and observations made in respect to the only\nplanet that we can actually experiment on, it most conclusively follows,\nthat not only the earth, but every planet, and indeed every satellite\nthat revolves round its primary planet, is a magnet; otherwise the rule\nof philosophy which permits us to formulate hypotheses based on\nexperience is entirely violated, and ceases at once to be an universal\nrule.\n\nSo that either the earth is not a magnet, or else, being a magnet by our\nsecond Rule of Philosophy, all the other planets are magnets also. This\nconclusion has already been arrived at by Lord Kelvin, who in writing in\nhis _Popular Lectures_[33] on the subject says: \"If it is true that\nterrestrial magnetism is a necessary consequence of the magnetism and\nthe rotation of the earth, other bodies comparable in these qualities\nwith the earth, and comparable also with the earth in respect to\nmaterials and temperature, such as Venus and Mars, must be magnets,\ncomparable in strength with the earth; and they must have poles similar\nto the earth, North and South poles on the North and South sides of the\nequator. It seems probable also that the sun, because of its great mass\nand its rotation in the same direction as the earth's rotation, is a\nmagnet, with polarities on the North and South sides of the equator,\nsimilar to terrestrial North and South magnetic poles.\" Further, such a\nconclusion is entirely in harmony with the view of the solar system\nrevealed in Art. 81, where we saw that each planet was an electrified\nbody having its own electric field, with its lines of force, being\ncapable of giving rise to all the phenomena associated with electricity.\nSo that if we combine that view of the subject with the view that we are\nnow coming to, we arrive at the conclusion that each planet and\nsatellite, and indeed all bodies that move or revolve in space, are\nelectro-magnets giving rise to magnetic waves in the Aether, which\nassumption is fully consistent with the electro-magnetic theory of light.\n\nWe must now go one step further and apply a similar line of reasoning to\nthe sun, when we shall arrive at exactly the same result that Lord\nKelvin arrived at, according to the previous extract. All planets\npossess an atmosphere, the sun also possesses an atmosphere. All planets\nrevolve on their axes from West to East, so does the sun. All planets\npossess a North and South pole the same as the sun.\n\nThe equatorial diameter of every planet is greater than its polar\ndiameter, and the same truth applies to the sun. It is hotter at the\nequatorial regions of every planet, and this truth also applies to the\nsun. Now, if the sun agrees with all the planets in these respects, then\nwe may philosophically conclude that it agrees with them in another\nrespect, viz. that the sun is also a magnet possessing its own magnetic\nfield, which is co-equal and co-extensive with its aetherial electrical\nfield. We have already seen that the sun is an electrified body,\npossessing its electric field, with its electric lines of force.\nTherefore the sun is also a magnet, or, to speak more correctly, it is\nan electro-magnet, and as such gives rise to electro-magnetic waves.\n\nThe conclusion to which we have come, that the sun is an electro-magnet,\ncan be arrived at from an altogether different method of reasoning, and\nas that different method of reasoning will tend to confirm the statement\nmade, I will just indicate it, and then leave it for fuller development\nin another article.\n\nIt is a matter of common knowledge to all students, that the magnetism\nof the earth varies in several important particulars from time to time.\nThe magnetic poles of the earth do not always occupy the same place in\nrelation to the geographical poles, so that the magnetic force varies as\nregards intensity or magnitude. The reasons of the variations have never\nbeen satisfactorily accounted for, though various hypotheses have been\nsuggested as a solution from time to time.\n\nThere is, I believe, only one satisfactory solution to the problem, and\nthat is, that the sun is an electro-magnet, and this conclusion may be\narrived at by strictly adhering to Newton's rules of Philosophy. For we\nhave learned that any hypothesis put forward to account for any\nphenomena, must be simple in character, must agree with experience and\nobservation, and, lastly, must satisfactorily account for the phenomena\nsought to be explained.\n\nHere then are the variations in time of the magnetic force of the earth,\nthe variations in intensity, and in the inclination of the magnetic\naxis, together with other variations. What solution shall we offer to\nsuch a problem? The only philosophical solution that can be suggested\nlies in the statement that the sun is an electro-magnet. Such statement\nis simple in conception, does not violate our experience or observation,\nas we find a similar revolving body, the earth, which is a magnet; and\nfurther, such a statement I premise will satisfactorily account for the\nwhole of the variations and changes in relation to the magnetic forces\nof the earth. We shall see that this is so when we consider more fully\nthe sun as an electro-magnet. Therefore, apart altogether from any\nprevious analogies, we can philosophically arrive at the conclusion that\nthe sun is an electro-magnet, as well as all the planets.\n\nThat being so, it will possess its magnetic field, its magnetic lines of\nforce, and be capable of bringing into operation in the solar system all\nthe phenomena or effects associated with any ordinary magnet that we may\nexperiment with on the earth.\n\n[Footnote 33: _Popular Lectures_, Vol. II.]\n\n\nART. 88. _The Sun an Electro-magnet._--If the sun is an electro-magnet,\nas stated in the previous article, then it is necessary for us to apply\nthe phenomena of magnetism to it in order to ascertain what effect such\napplication will have on the solar system as a whole.\n\n[Illustration: Fig: 17.]\n\nThe first thing that we will look at is the magnetic field which is\nalways associated with every magnet. The magnetic field may be defined\nas that region or space around every magnet in which the magnetic force\nacts or is in operation. An illustration of a magnetic field may easily\nbe obtained by taking a bar magnet and bringing near to it a magnetized\nneedle, when it will be found that the needle will set itself in various\npositions relative to the magnet, on account of the lines of force which\nexist in the field. Thus let _A_ _B_ (Fig. 17) be a bar magnet with its\nNorth pole at point _A_ and South pole at point _B_. If a number of\nfreely suspended needles be hung above it, as shown in the figure, they\nassume the positions indicated there. It will be seen that at the North\nand South poles the needles hang vertical, while midway between the two\npoles there is no dip of the needle, as it is parallel to the bar\nmagnet; while between the place of no dip and the place of vertical dip,\nwhich is directly over each pole, the dip gradually changes, becoming\nmore and more vertical as it gets nearer to the pole. If the bar magnet\nbe a strong one, then its magnetic field will be manifested at a great\ndistance; and any magnetized needle brought into the field will be,\naffected by the same, and will tend to set itself along the lines of\nforce.\n\nAs already stated in Art. 80, it was Faraday who originated the term\n\"Lines of Force,\" and gave to the world some idea of the motions of the\naetherial medium, which plays so important a part in electro-magnetic\nphenomena. A visible manifestation of these lines of force which gather\nround every magnet may be made by strewing iron filings over a piece of\nglass, underneath which are several bar magnets, when it will be found\nthat the iron filings will set themselves in well-defined lines or\ncurves, which Faraday termed \"Lines of Force.\"\n\n[Illustration: Fig: 18.]\n\nAs the bar magnets are placed in different positions, North pole to\nNorth pole, or North to South, and so on, the iron filings will change\nthe figures assumed, indicating in, each case the effect of the lines of\nforce of each magnet upon one another. The iron filings strewed over the\nmagnet are magnetized by induction, with the result that the North pole\nof one filing attracts the South pole of the next one to it, and this is\ncontinued along the whole of one line of force, as revealed by the united\niron filings. Faraday believed in the real physical existence of these\nlines of force, and that belief has been perfected by Clerk Maxwell in two\npapers which he wrote on \"Physical Lines of Force,\" which will be\nconsidered in another article. We will simply deal with them at present\nas indications of the existence of the magnetic forces in the medium\nsurrounding any magnet.\n\nLet us apply these facts to the solar system and see what the\napplication yields. We have the sun revolving in the Aether medium\nrepresented by the circle _S_ in Fig. 19. Then we have the lines of\nforce extending in curved lines _E._ and _W._, but in almost straight\nlines North and South. We will suppose the axis of the sun to be\nvertical for the sake of simplicity. It may be asked, how far will these\nlines of force stretch out into space? The reply is that they stretch\nand extend throughout the whole solar system, and far away into the\ndepths of space, though with ever-decreasing intensity according to the\nlaw of inverse squares. Wherever the aetherial light waves are\nmanifested, there the electro-magnetic waves, with all that they imply,\nare manifested also. We know that the light waves are existent at least\nas far as Neptune, a distance of 2800 millions of miles, therefore at\nleast to that extent the electro-magnetic waves are manifested; and\nwherever the electro-magnetic waves to which the sun has given birth are\nmanifested, there we have the existence of the electro-magnetic field,\nwhich is co-existent and co-extensive with the electric field of the\nsun. Further, wherever we get the magnetic field, there we get the lines\nof force which are as real as air or ocean currents, and are caused, as\nMaxwell indicated (Art. 44), by the motions of the atomic Aether.\nWherever these lines of force are closest together, there the intensity\nof the magnetic force is at its greatest.\n\n[Illustration: Fig: 19.]\n\nBy actual experiment, it can be demonstrated that the lines of force are\nclosest together nearest to the magnet, and therefore applying that fact\nto the solar magnetic field, the lines of force should be closest\ntogether nearest to the surface of the sun, which is exactly what we\nhave already learned. For if Aether be gravitative, then it will be\ndensest nearest to the sun than further away, and the vortex atoms which\nrepresent our aetherial atoms will be pressed more closely together near\nto the surface than further away.\n\nWe have learned that Aether has an electro-magnetic basis, and it is\nthat very fact which gives rise to the existence of these lines of\nforce. So that the magnetic phenomena as indicated in the lines of force\nconceived by Faraday harmonize with the fact that the sun is an\nelectro-magnet; and that Aether, which has an electro-magnetic basis, is\nalso gravitative, with the result that the lines of force are closest\ntogether nearest the surface of the sun, where the magnetic force is\ngreatest in its intensity and power.\n\nNow let us apply the principle of the experiment to the solar system by\nbringing a magnet into a magnetic field, and let us see what the result\nis. We have learned from the experiment, that if a magnet is moved along\nany one of the lines of force the dip of the magnet changes, gradually\nchanging from a horizontal to a perpendicular position in accordance\nwith its relation to the two poles of the magnet. From the previous\narticle we have come to the conclusion that not only is the earth a\nmagnet, but that all the other planets are magnets also, so that if any\nof these are brought into the magnetic field of the sun, then the\nmagnetic axis of the planet, which corresponds to the needle in our\nexperiment, must assume a certain dip in relation to the sun, setting\nitself along those lines of force which are in the immediate\nneighbourhood of the planet.\n\nLet us place the earth, for example, at a distance of 90 millions of\nmiles from the sun in the magnetic equator, or that line which exactly\ndivides the magnetic field into two equal halves. According to our\nexperiment, the magnetic axis will now be exactly parallel with the axis\nof the sun, that is, exactly vertical, pointing North and South, as seen\nin position 1 in Fig. 19. But suppose that the earth is to the North of\nthe magnetic equator of the field, what happens then? The result will be\nthat the magnetic axis of the earth will dip towards the magnetic North\npole of the sun (position 2, Fig. 19), while if the earth be to the\nSouth of the magnetic equator, its axis will dip in the opposite\ndirection (position 3), the magnetic axis setting itself in each case\nalong the lines of force which exist in the Aether in that region or\nspace. Thus it can be seen at a glance, that if the earth changes its\nposition at any time in its orbit in relation to the magnetic equator,\nsuch a change will effect the total dip of the magnetic axis. In other\nwords, the magnetic poles which indicate the position of the magnetic\naxis will not occupy the same position in relation to the geographical\nNorth and South poles, sometimes appearing to the East and sometimes to\nthe West, and at other times being coincident with the same as it moves\nto the North or South of the magnetic equator of the sun's\nelectro-magnetic field.\n\nWe have to remember, also, that the earth is constantly varying its\ndistance in relation to the sun, being at a distance of ninety and a\nhalf millions of miles at its perihelion, or that part of its orbit\nnearest to the sun; while it is ninety-four and a half millions of miles\nat its aphelion, or that part of its orbit furthest away from the sun.\nThis implies that as it proceeds from that point in space furthest away\nfrom the sun, and approaches a point nearer to the sun, it will pass\ninto places of greater magnetic intensity, with the result that the\nintensity of the electro-magnetic waves is increased; and the magnetism\nof the earth is accordingly affected by that fact.\n\nWhen we come to deal with the earth as a magnet more directly, we shall\nsee that all the variations of terrestrial magnetism may be\nsatisfactorily explained by the fact that the sun is, as we have\nindicated in this article, an electro-magnet, possessing its magnetic\nfield with its lines of force, and therefore able to give rise to all\nthe phenomena incidental to and associated with any ordinary magnet.\n\n\nART. 89. _Aether and Faraday's Lines of Force._--We have now to face the\nquestion of the physical character of the Lines of Force conceived by\nFaraday. We have seen in Fig. 18 illustration of these lines of force,\nwhich are manifested by the iron filings in the neighbourhood of a\nmagnet, and the question suggests itself to the mind, as to what is the\nrelation of the Aether to those lines of force? Does the Aether play any\npart in their existence, and if so what?\n\nFaraday was of the opinion that the Aether did play some part in the\nexistence of the lines, and that they were no mere hypothetical lines,\nbut were caused by the actual physical state or condition of the\naetherial medium, which existed around every magnet and every\nelectrified body. On this point he says, Art. 3263:[34] \"To acknowledge\nthe action in curved lines seems to me to imply at once that the lines\nhave a physical existence. It may be the vibration of the hypothetical\nAether, or a state of tension of that Aether equivalent to either a\ndynamic or static condition.\"\n\nPar. 3277: \"I conceive that when a magnet is in free space, there is\nsuch a medium, magnetically speaking, around it. That a vacuum has its\nown magnetic relations of attractions and repulsions is manifest from\nformer experimental results (2787). What that surrounding magnetic\nmedium deprived of all material substance may be, I cannot tell, perhaps\nthe Aether.\"\n\nIt was, however, left for Clerk Maxwell to develop the idea as to their\nphysical character, and this he did in his paper on \"Physical Lines of\nForce,\" _Phil. Mag._, 1861. He had previously written a paper on\n\"Faraday's Lines of Force,\" delivered to the Cambridge Phil. Society in\n1855 and 1856, but his more matured conception of Faraday's Lines of\nForce was given in the later article.\n\nWhat Maxwell did was to conceive a physical theory of electricity and\nmagnetism, by which electrified and magnetized bodies could act upon\neach other by means of the stress or strain of some medium, which\nexisted in the space surrounding these bodies. Now Faraday looked upon\nelectro-static and magnetic induction as always taking place along\ncurved lines. These lines may be conceived as atoms or molecules\nstarting from the poles of a magnet, and acting on all bodies in the\nelectro-magnetic field. These atoms or molecules, joined together in a\ndefinite manner, tend to shorten in the direction of their length, that\nis to say, there is a tension along the lines of force while at the same\ntime they swell out laterally or sideways. Thus there is a tension along\nthe lines of force, and a pressure at right angles to them owing to\ntheir bulging out sideways. Maxwell used as an illustration of the\ntension and pressure, the contraction and thickening of a muscle. As the\nfibres of the muscle contract, and the arm or leg is drawn up, the\nmuscle swells in its centre outwardly, and so thickens. Thus there would\nbe a tension along the muscle, and a pressure at right angles to it,\nwhich would cause any body placed on it to move away from it, owing to\nthe pressure of the contracted muscle.\n\nIn the conception of an aetherial atom (Art. 44) drawn purely from\nobservation of the shape of the earth, we came to the conclusion that\nthe aetherial atom was a spherical vortex atom, or, to be more correct,\nthat it was an oblate spheroid with its polar diameter, so to speak,\nshorter than its equatorial diameter, and further, that the aetherial\natom possessed polarity.\n\nNow if we can conceive of these aetherial vortex atoms being joined\ntogether, North pole to South pole, and revolving round their axes, we\nshall then have an exact image of Maxwell's physical conception of\nFaraday's Lines of Force.\n\nWe know that when any liquid body is caused to rotate rapidly about its\naxis, it will expand laterally and contract longitudinally in the\ndirection of the axis; and it was on this analogy that Maxwell worked\nout his physical conception of the lines of force. Maxwell's fundamental\nidea was, that in a magnetic field there is a rotation of the molecule\never going on about the lines of force. For example, let _A_ _B_ be a\nmagnet, and _A_ _C_ _B_ be a line of force composed of spherical vortex\natoms joined end to end, that is, each North pole (assuming the vortex\natoms to be magnets) being directly associated with the South pole of\nthe one next to it, and _vice-versa_ (Fig. 20).\n\nThus it can be readily seen that there will be a tension along the line\nof force, while there will be a pressure at right angles to it owing to\nthe lateral expansion, partly due to the rotation of the vortex atom,\nand partly due to the attraction of the vortices for each other in the\ndirection of the line of force.\n\nMaxwell in his paper says: \"It appears therefore that the stress in the\naxis of the line of magnetic force is a tension like that of a rope.\"\nFurther, he adds: \"Let us now suppose that the phenomena of magnetism\ndepend upon the existence of the tension in the direction of the lines\nof force, combined with a hydrostatic pressure, or in other words, a\npressure greater in the equatorial than in the axial direction. The next\nquestion is, What mechanical explanation can we give of these\ninequalities of pressure in a fluid or mobile medium? The explanation\nwhich most readily occurs to the mind is, that the excess of pressure in\nthe equatorial direction arises from the centrifugal force of the\nvortices or eddies in the medium, having their axes in the direction\nparallel to the lines of force.\" He adds: \"A medium of this kind filled\nwith molecular vortices, having their axes parallel, differs from an\nordinary medium in having different pressures in different directions.\"\n\n[Illustration: Fig: 20.]\n\nHe then goes on to develop the idea in relation to different intensities\nof the magnetic field. I must, however, refer the reader to the paper\nitself for fuller details. In his greatest work,[35] writing on this\nsubject, he says: \"I think we have good evidence for the opinion that\nsome phenomenon of rotation is going on in the magnetic field, that this\nrotation is performed by a great number of very small portions of\nmatter, each rotating on its own axis, being parallel to the direction\nof the magnetic force, and that the rotations of these different\nvortices are made to depend on one another by means of some kind of\nmechanism.\"\n\nFrom the foregoing extracts taken from Maxwell's writings, we learn that\nthe constitution of the Aether, as given in Art. 44, exactly coincides\nwith, and satisfactorily fulfils the conditions that he lays down with\nreference to his physical conception of the lines of force around a\nmagnet or electrified body.\n\nSo that the theory of Maxwell is not merely hypothetical, as is\nsuggested by scientists, but exactly describes the conditions and state\nof the atomic Aether medium which surrounds all magnets. We have,\nhowever, seen that the sun is a magnet, and therefore it possesses\naround it on every side, the same as any other magnet, these aetherial\nlines of force composed of infinitesimal vortices, or mere whirling\npoints which correspond to an aetherial atom.\n\nThese aetherial lines of force stretch out into space on every side of\nthe sun, and in fact form concentric magnetic shells around the sun;\nwhich magnetic shells coincide with the equipotential surfaces of the\nAether viewed merely from the point of elasticity and density of the\nmedium. We learn by experiment, that these lines are closest together\nnearest to the magnet, which fact agrees with the statement that Aether\nis gravitative, and therefore the Aether would be densest nearest the\nsun. That is, the atoms would be pressed closer together, so that the\nlines of force of which these atoms are composed ought also to be closer\ntogether at the surface of the magnet, which we find by experiment is\nthe case. As the sun is an electro-magnet, therefore, it possesses these\nmagnetic lines of force on all sides, forming a series of magnetic\nshells. We have now arrived by the aid of Maxwell's theory to a physical\nconception of the Aether from a magnetic standpoint, which fully agrees\nwith our physical conception of the Aether which was arrived at by\npurely philosophical reasoning, based on Newton's Rules of Philosophy.\n\nThus we are able to combine into one whole by our conception that Aether\nis matter, and therefore atomic and gravitative, not only Faraday's\nLines of Force, but also Maxwell's physical conception of the same,\napart from the solutions given to the other problems of science by the\nself-same conception, which solutions will be dealt with in their proper\norder.\n\nAs further evidence of Maxwell's belief in the physical existence of\nFaraday's Lines of Force, let me again quote from his paper on \"Action\nat a Distance,\"[36] already referred to in Art. 43. He writes: \"Its\nminute parts may have rotatory as well as vibratory motions, and the\naxes of rotation form those lines of Magnetic Force which extend in\nunbroken continuity into regions which no eye has seen.... These lines\nmust _not be regarded as mere mathematical abstractions_. They are the\ndirections in which the medium is exerting tension like that of a rope,\nor rather like that of our own muscles.\"\n\n[Footnote 34: _Exp. Res._]\n\n[Footnote 35: _Magnetism and Electricity._]\n\n[Footnote 36: _Collected Works_, by Niven.]\n\n\nART. 90. _Terrestrial Magnetism._--We have already seen that the earth\nis a magnet, and like any other magnet will therefore possess its\nmagnetic field with its magnetic lines of force. The earth's magnetic\nfield is co-existent and co-equal with its electric field (Art. 80), and\nthat is co-existent with the earth's aetherial atmosphere which is held\nbound to the planet by the force of gravity.\n\nHow far the earth's magnetic field reaches, is impossible to say, but we\nknow that it extends at least as far as 260,000 miles, the distance of\nthe moon; as we find that this satellite of the earth is affected very\nconsiderably by the electro-magnetic attractive power of the earth. Any\nbody which is placed in the earth's magnetic field is affected by the\nlines of force which exist in the magnetic field; for wherever the field\nexists, there the lines of force exist also.\n\nThese lines of force, which are associated with the earth, extend\ntherefore into space, and any body such as the moon would become a\nmagnet, if not already one by the process known as magnetic induction,\nwhich physical process is well illustrated in the action of a magnet\nupon iron filings strewed over it as in the illustration (Art. 88).\n\nAn experiment which well illustrates the inductive power of the earth's\nmagnetism, may be made by placing a poker in one of these lines of\nforce, whose direction can be found at any part of the earth's surface\nby means of proper instruments. When the poker is so placed, it will be\nseen that it has actually become magnetized by the magnetism of the\nearth, and it is itself able to attract iron filings or small needles.\nThese lines of force of the earth are closer together nearest to the\nearth's surface than further away in space, and congregate around the\nNorth and South magnetic poles, where they are greatest in number in a\ngiven area, and there the magnetic intensity is the greatest.\n\nFaraday, writing on the terrestrial lines of force, says: \"The lines of\nforce issue from the earth in the northern and southern parts with\ndifferent but corresponding degrees of inclination, and incline to, and\ncoalesce with each other over the equatorial parts. There seems reason\nto believe that the lines of magnetic force which proceed from the earth\nreturn to it, but in their circuitous course they may extend through\nspace to a distance of many diameters of the earth, to tens of thousands\nof miles.\"[37]\n\nFrom this extract it will be seen that Faraday was of the opinion that\nthe lines of force extended beyond the atmosphere of the earth into the\nAether, which statement is confirmed by other parts of his writings;\nthough he was not able to give any physical explanation of how these\nlines extended beyond the atmosphere on account of the doubtful\nconstitution and character of the Aether, although in another part of\nhis work he definitively refers to the magnetic character of space.\n\nIn writing on the magnetic character of space he says:[38] \"From such\nexperiments, and also from general observations and knowledge, it seems\nmanifest that the lines of magnetic force can traverse pure space, just\nas gravitating force does, and as static electric forces do (1616), and\ntherefore space has a magnetic character of its own, and one that we shall\nprobably find hereafter to be of the utmost importance in natural\nphenomena.\" With the view of the Aether presented in this work, viz. that\nAether is matter, though in an infinitely more rarefied and elastic form,\nwe can now see the physical cause of the lines of force with which by his\nimagination he filled all space.\n\nAgain, from the conception of the Aether presented to the reader in Art.\n45, we learn that around any body in space there are existing aetherial\nconcentric spheres or shells which are equipotential surfaces, or\nsurfaces of equal pressure, and that these surfaces coincide with the\nelectric equipotential surfaces, as shown in Art. 80.\n\nNot only so, but they coincide with the magnetic shells which the lines\nof force actually form around a circular and globular magnet, as the\nearth. For it must not be forgotten that these lines of force exist\nequally on all sides of the earth, and therefore really form a spherical\nshell, or to speak more correctly an aetherial electro-magnetic shell,\nwhich is an oblate spheroid in shape, partaking of the shape of the\nearth or other planet which the lines of force surround.\n\nIf these shells were divided into two equal halves, the line so dividing\nthem would be called the magnetic equator, and on that line any magnet\nwould set itself in a horizontal position, so that all round the earth\non the magnetic equator would correspond to a line of no dip. At the\nmagnetic poles, a magnet would set itself vertically, or at an angle of\n90 deg., and between these two parts, the place of no dip, and that of\n90 deg., the dip gradually changes as illustrated in the figure. Again,\nin relation to the magnetism of the earth we find that there are certain\nvariations in the magnetic force, which not only influence the dip at\nany place, but also the intensity at that place. The variations in\nMagnetic Force are chiefly three--\n\n    1st. Diurnal Variations.\n    2nd. Annual Variations.\n    3rd. Secular Variations.\n\nLet us look at these three variations from the standpoint of the\nmagnetic lines of force which exist around the earth, and around every\nplanet. In relation to the variations of the magnetic forces upon the\nsurface of the earth, Faraday points out that these variations are\ncaused by the action of the sun's rays upon the terrestrial lines of\nforce. He uses the following figure to illustrate his meaning. Let _H_\nbe the sun, _E_ the earth--\n\n[Illustration: Fig: 21.]\n\nHe writes as follows: \"If the magnetic and astronomical poles of our\nearth be supposed to be coincident, then North and South poles will also\nrepresent the North and South magnetic poles, and the different curves\ncutting the earth will sufficiently represent a course of magnetic lines\nas they occur at, or about, the surface of the earth. _H_ represents the\nsun, and _a_ the place immediately underneath it, which is also\ncoincident with the magnetic equator. Point _a_ will be a line of no\ndip, while at point _b_ there will be dip. This dip will be increased by\nthe action of the sun's rays, because the atmosphere under the influence\nof the sun's rays has expanded the air, and has thus acquired a power to\naffect the lines of magnetic force.\"\n\n\"All the lines passing through the heated and expanded air will, because\nof its being a worse magnetic conductor, tend to open out, and the mass\nof heated air will as a whole assume the condition of diamagnetic\npolarity (2923). The case may be more simply stated for the facility of\nrecollection by saying, that the effect of the sun is to raise the\nmagnetic circles over the equatorial and neighbouring parts from their\nnormal position, in doing which the North and South dip are\nsimultaneously affected and increased.\"\n\nThus it can readily be seen that every day as the earth turns round on\nits axis, and presents each side of the globe successively to the rays\nof the sun, there should be a gradual change in the intensity of the\nterrestrial magnetism. In Art. 2925, Faraday points out that the maximum\nof dip would be when the sun was at its zenith or directly overhead.\nWith reference to the Annual Variation, Faraday points out (2882) that\nif the axis of the earth were perpendicular to the plane of its orbit,\nthe intensity and direction of the magnetic forces might be considered\nconstant, but (2883) as the axis of the earth's rotation is inclined\n23 deg. to the plane of the ecliptic, the two hemispheres will become\nalternately warmer and colder than each other, and then a variation in\nthe magnetic condition may arise. The consideration of this annual\nvariation is further considered by Faraday in the subsequent paragraphs\nto those already quoted, and I must refer the reader to them for fuller\ndetails; I wish simply to indicate the possible explanation of the\nterrestrial magnetism, in so far as that explanation is in conformity\nwith the aspect of the Aether submitted in Chapter IV.\n\nWith regard to secular variations Faraday points out (2880) that the\ntemperature of the air at the equatorial parts of the earth is greater\nthan in latitudes north and south, and as an elevation of temperature\ndiminishes the conducting power of magnetism, so the proportion of force\npassing through those parts ought to be less, and that passing through\nthe cooler parts, greater, than if the temperature were at the same\ndegree over the whole surface of the globe.\n\nNow with our definite conception of the aetherial lines of force\ntraversing space, and existing on all sides of the earth, these\nsuggestions of Faraday's obtain an increased value in relation to the\nvarying intensity of terrestrial magnetism, and will account for the\nvariations in a satisfactory manner from the aetherial standpoint, if\ntaken in conjunction with the electro-magnetic character of the Aether.\nOf course, what applies to the earth equally applies to all the other\nplanets, as they also are magnets according to Art. 87, so that they\nwill also possess their magnetic fields, with their own lines of force,\nand their variations in intensity and magnetic dip.\n\nHitherto we have only considered the problem of the earth and all the\nother planets, as magnets, from the stationary standpoint, and the\nproblem faces us as to what effect the movement of the earth and all\nother planets through the Aether will have upon their magnetic fields,\nand their lines of force. Now from Clerk Maxwell's mathematical\ncalculations, we learn that the movement of any magnetic body through\nspace will practically have no effect upon the relation of the field,\nand the lines of force to the moving magnet; that is to say, the\nmagnetic field and the lines of force move with the earth and the\nplanets through space, as they journey round the sun with their varying\nvelocity. Maxwell has conclusively proved that the mathematical\nequations for moving bodies in relation to their magnetic lines of\nforce, and induction, are exactly the same as the equations for\nstationary bodies, and if this be true, then it follows that the\nphysical conditions for both stationary and moving bodies are the same.\n\nOn this point Maxwell writes: \"By its motions this (moving) matter\ncarries with it its lines of force, and electricity and magnetism may be\nregarded as free ends of these lines. Hence when both causes act\ntogether there can be no relative motion of true magnetism with\nreference to surrounding matter,\" etc.\n\n\"Under these circumstances electricity and magnetism move with the\nmatter in which they are present as if they were indestructible and\nadhered firmly to the parts thereof.\" So that from Maxwell's equations\nand statements we learn that the magnetic lines of force around every\nplanet, and every satellite in space, move with the planets in their\norbits round the sun. But as these magnetic lines of force are composed\nof aetherial atoms, as already indicated, it follows that the Aether\nwhich is associated with each planet and held bound to it by the\nso-called force of gravity moves with the planet also.\n\nThis result is entirely consistent with our experience and observation,\nas we shall see later on. We find that the atmosphere, which is also\ngravitative, moves with the earth, and therefore from experience we are\ncompelled to arrive at the conclusion that the Aether which is also\ngravitative moves with each planet, and this result is confirmed by\nmathematical calculations given by Clerk Maxwell, and is in perfect\nharmony with the same.\n\nHere then is the key to one of the problems that has been the subject of\ninvestigation and research for many years past, and one which is at the\npresent time occupying the attention of some of our most advanced\nscientists, viz. the relation of the Aether to moving matter.\n\nThat problem was solved by Maxwell from an electric and magnetic\nstandpoint, and his result was that the Aether, which we now know to be\nthe source of all electricity and magnetism, moves with the moving\nmatter. What is more, this result has been confirmed by actual\nexperiment made by Michelson and Morley in America, which experiment\nconclusively proves that Maxwell's result is physically correct, and\nthat the Aether does move through space with its associated planet, and\ntherefore its magnetic field and its lines of force move with it because\nof the electro-magnetic character of the Aether.\n\n[Footnote 37: Art. 2850, _Exp. Res._]\n\n[Footnote 38: Art. 2757, _Exp. Res._]\n\n\nART. 91. _Solar Magnets._--We have now to attack the problem as to the\ncause of all the satellites and planets, together with the sun, being\nelectro-magnets. What is the continuing and ever-acting cause which\nmakes all planetary bodies, including the sun, their centre, to be\npermanent magnets? According to the Rules of Philosophy there are two\ncauses which would be simple in conception, which are suggested by\nexperiment and observation, and both causes would satisfactorily account\nfor all the planets being magnets.\n\nThe first cause suggested to our minds is, that in view of the fact that\nthe sun is an electro-magnet, and therefore possesses a magnetic field\nwith its aetherial line of force, all the planets may become magnets by\nthe process of magnetic induction, which process has already been\nillustrated by the action of the iron filings placed over the magnet.\nSuch a hypothesis would fulfil all the Rules of Philosophy, as it would\nbe simple in conception, would not violate experience, and would\nsatisfactorily account for the fact sought to be explained.\n\nBut such a hypothesis would be based upon the assumption that the sun\nwas an electro-magnet, and then we should have to find out the cause of\nthat fact also. Hence the hypothesis that the planets are magnets,\nbecause they are situated in the magnetic field of the sun, is not a\nsatisfactory solution of the whole problem, as it fails to account for\nthe fact that the sun is also an electro-magnet. We must therefore seek\nfor another solution of the problem, which, while fulfilling all the\nRules of Philosophy as laid down in Art. 3, will also account for the\nsun being an electro-magnet, as well as every planet, satellite, meteor,\nor any other body that exists in space. If we can ascertain such a cause\nby philosophical reasoning, then we may say we have satisfactorily\nsolved the problem as to the cause of all planetary and stellar bodies\nbeing electro-magnets.\n\nIf, at the same time, we can solve other outstanding problems by the\nsolution thus offered, then such solution is more likely to be correct\nthan if it simply solved the problem of solar magnetism. The only other\nsolution that can possibly present itself to our minds, as to the cause\nof all magnetism in any planet, sun, or star, is the explanation which\nhas already been given in Art. 86 on electro-magnetism.\n\nIn that article we learned that magnetism was really due to the circular\nmotion of an electric current; and that, whenever and wherever we had an\nelectric current moving or revolving with a circular motion, there we\nshould always have those conditions which would give rise to an\nelectro-magnet. As long as the current continued to flow in its circular\ncourse, so long would there be those conditions which would give rise to\npermanent magnetism.\n\nNow in the solar system we find that there are these magnets, which have\nbeen in existence for millions of years. We also learn from the\nelectro-magnetic theory of light that Aether has an electro-magnetic\nbasis, which gives rise to electro-magnetic waves when disturbed, or set\nin motion by any heated or luminous body. It can readily be seen,\ntherefore, that we have only to set this electro-magnetic Aether in\ncircular motion around any planet or sun, and we have at once a circular\ncurrent of electricity flowing round that planet or sun, which would\ngive rise to those conditions by which any body within its influence may\nbe formed into a magnet.\n\nOur hypothesis, therefore, to explain the reason why all the planets and\nthe sun are magnets, is that the electro-magnetic Aether moves round the\nsun or planet or satellite as the case may be, thus giving rise to\ncurrents of electricity around the planet or sun, and so forming those\nconditions in the Aether by which the permanency of any planetary or\nstellar magnetism may be maintained and perpetuated.\n\nIn other words, to put it plainly and tersely, each aetherial atmosphere\nrevolves round the planet, subject to certain limitations, in the same\nway that the aerial atmosphere turns round with the earth, as that\nplanet revolves on its axis. At first sight, such an assumption may seem\nimpossible, but a little careful consideration will show not only the\npossibility of such a cause, but will establish it, as the only\nreasonable and philosophical explanation for the phenomena we are\nseeking to explain, viz. the electro-magnetism of all celestial bodies.\n\nThere is nothing extravagant in this assumption, as we already have a\nsimilar illustration in the case of the atmosphere which goes round with\nthe earth as it revolves on its axis. We have only to extend the same\nprinciple a little further, viz. to the aetherial atmosphere, and we at\nonce get the true physical conception of the hypothesis suggested to\nexplain the magnetism of all celestial bodies. We have already learned\nthat Maxwell has proved that the equations for moving magnetic bodies\nare the same as those for stationary bodies, from which we came to the\nconclusion that the electric and magnetic field of any planet goes with\nthat planet as it revolves on its axis in its journey round the sun.\n\nI would like to ask the reader to try to conceive of any electric or\nmagnetic field traversing space in association with any planet or sun\nwhich is revolving on its axis, while that electric or magnetic field\ndoes not revolve either partially or wholly with the revolving body. The\nfield can only be stationary relatively to the planet or sun, as it\nrevolves with the planet or sun on its axis.\n\nThere may be, as there doubtless are, conditions governing that\nrevolution, as is the case with the atmosphere moving and revolving with\nthe planet, but it is an absolute impossibility for Maxwell's equations\nrelating to moving magnetic bodies to be carried to their logical\nconclusion, without affirming some such hypothesis as we have affirmed\nin relation to the cause of all solar magnetism.\n\nLet me at once point out, this solution has already been offered by one\nwhose name has been referred to several times. I refer to Professor\nChallis. Let us see what he has to say as to the cause of the earth's\nmagnetism. In dealing with this subject, and writing in the _Phil.\nMag._, 1872, par. 42, he states: \"With respect to all magnetism which\nhas a cosmical origin, the view I now take is that it is due to\ngyrations of the Aether, produced by the impulses which it receives from\nthe motions of the constituent atoms of the bodies of the solar system.\nThe gyrations may either be immediately generated by the rotations of\nthe bodies about their axes, or directly result from disturbances of the\nAether caused by their motions of translation. This impressed motion\nwill be converted into circulatory or gyratory motion. Such circulatory\nmotion will necessarily partake of the motion of translation of the\nbodies which generate them, so as to have always the same geometrical\nrelation to these bodies provided their motion be uniform.\"\n\nIn paragraph 46 he continues: \"From what has been already argued (42),\nthe motions impressed on the Aether by the earth in consequence of its\nrotatory or orbital motions result in circulating motions which would be\nsteady motions, having always the same geometrical relation to the\nposition of the earth's centre.\"\n\nAgain, Ampere and Faraday were also of the opinion that the magnetism of\nthe earth was due to the circulation of electric currents round it, for\nin par. 446, _Exp. Res._, Faraday states: \"Assuming with Ampere that the\nmagnetism of the earth is due to electric currents circulating round it,\nparallel to the equator.\"\n\nI think it will be seen from these extracts that the hypothesis\nsuggested for all planetary and stellar magnetic bodies is thus\nconfirmed by Professor Challis, and by Faraday and Ampere. Professor\nChallis in these passages clearly and definitely points out that there\nare circulatory motions in the Aether, which motions are produced by the\nrotation of the earth or other body on its axis, and that these circular\nmotions of the aetherial medium always maintain the same geometrical\nshape relative to the earth's centre. So that we have only to combine\nwith his hypothesis the electro-magnetic basis of the Aether, and we at\nonce get the circulating currents of electricity constantly flowing\nround the heavenly bodies, which produce and give rise to the permanent\nmagnetism of those bodies.\n\nIf we desired still further confirmation as to the circulating motions of\nthe Aether caused by a rotating body, we find it in the writings of\nHerschel, who in relation to this matter asks:[39] \"What is the law of\ndensity of the resisting medium which surrounds the sun? Is it at rest or\nin motion? If the latter, in what direction does it move? Circularly round\nthe sun, or traversing space? If circularly, in what plane? Supposing the\nneighbourhood of the sun to be filled with material fluid, it is not\nconceivable that the circulation of the planets in it for ages should not\nhave impressed upon it some degree of rotation in their own direction, and\nthis may preserve them from the extreme effects of accumulated\nresistance!\" Words like these from one of the most searching intellects of\nthe last century are well worthy of our consideration, and the suggested\neffect on the Aether caused by the continued rotation of the earth gives\nus the key not only to the problem of celestial magnetism, but also to the\nother outstanding scientific problems.\n\nFor example, there is the problem of the relation of moving matter to\nthe Aether around it which still remains unsolved. The physical cause of\nthe rotation of the earth, and all other celestial bodies upon their\naxes, with unceasing regularity, still remains to be discovered. The\nphysical explanation as to the reason why the earth moves round the sun\nin its orbit according to Kepler's Laws, has yet to be determined, and,\nlastly, there is the relation of the magnetic vibration to the electric\nvibration in connection with the electro-magnetic theory of light still\nto be solved.\n\nNow, presuming that all these can be solved by the philosophical\nhypothesis, that the electro-magnetic Aether circulates round each\nplanet and sun and star, that revolves in space, then we are justified\nin our conclusion that such is the true cause of all electro-magnetism\nthat exists in connection with planetary and stellar bodies. I venture\nto premise that all these problems can be solved by the simple solution\nhere given, and will prove that this solution adequately accounts for\nall the other phenomena referred to.\n\nBefore proceeding to do this, we will endeavour to prove this hypothesis\nby an altogether different method of reasoning, in order to confirm the\nstatements made in this article. Let us therefore endeavour to form a\ncomplete view of the physical state of the solar system, and for the\nsake of simplicity we will suppose it to be at rest in space. We shall\ndeal with the effect of its motion upon its own planetary system, when\nwe explain Kepler's Laws.\n\nWe have, therefore, the Sun in the centre (see Fig. 14) of the system,\nwith Mercury, Venus, the Earth, Mars, Jupiter, Saturn, Uranus, and\nNeptune revolving round the sun at their respective distances, which are\nsubject to variations owing to certain causes which can be\nsatisfactorily explained. But circulating round the sun, in the same\ndirection as the rotation of the sun on its axis, we have the\nelectro-magnetic Aether, with its wide-spreading flow and extensive\nelectro-magnetic field. In like manner, we have each planet with its\naetherial electro-magnetic field, which also circulates round each\nplanet in the same direction as the planet revolves, that is, from west\nto east, and in the same direction as the sun's electro-magnetic field\nrevolves.\n\nThus we have to picture the whole of the solar system in a state of\nregular and harmonious rotation, while each planet adds to the harmony\nof the rotation by itself rotating in its own aetherial electro-magnetic\nfield, while all rotate in the same direction, viz. from west to east.\n\nOf course there are several objections that can be raised to such a\nhypothesis, and those objections will be briefly dealt with in a\nsubsequent article, but I venture to think that this hypothesis is the\ntrue philosophical explanation of a problem which has formed one of the\ngreatest outstanding difficulties in regard to the Aether medium for\nmany years, that problem being the relative motion of the Aether and\nMatter. Lord Kelvin, in an article in the _Phil. Mag._ for July 1901,\nentitled \"Clouds over the Dynamical Theory of Light,\" refers to this\nvery difficulty, and states there are two clouds over the present\nundulatory theory of light, one of which has reference to the difficulty\nof conceiving a body like the earth or any planet rushing through the\nAether without subjecting the Aether to enormous laceration, and\nconcludes by saying that \"we must still regard this cloud as very\ndense.\" Here, then, is the key to the solution of the problem.\n\nThe earth does not rush through the Aether, but the Aether being\ngravitative, it is associated with and bound to each planet, and\naccompanies that planet in its journey though space, rotating with it in\nthe same way that the atmosphere does, as we shall prove later on.\n\nThis conception is fully in accord with our hypothesis as to the\nphysical explanation of the cause of the electro-magnetic character of\nall the heavenly bodies, and indeed is the only physical solution that\ncan adequately account for all the varied phenomena hitherto unexplained\nin connection with the celestial mechanism.\n\nFrom the foregoing statements, we are now in a position to consider the\nterm Electro-Kinetic Energy, as used by Clerk Maxwell. What does he mean\nby Electro-Kinetic Energy? Let us see what he has to say about the term\nhimself.\n\nIn par. 636 of his _Magnetism and Electricity_ he writes: \"According to\nour hypothesis we assume kinetic energy to exist wherever there is\nmagnetic force, that is, in general, in every part of the field. This\nenergy exists, therefore, in some kind of motion of the matter in every\nportion of space;\" while again, in par. 569, he states: \"The electric\ncurrent cannot be conceived except as a kinetic phenomenon.\" Even\nFaraday speaks of the electric current as \"something progressive, and\nnot a mere arrangement\" (_Exp. Res._ 283).\n\nThen again in par. 552 he writes: \"It appears, therefore, that a system\ncontaining an electric current is a seat of energy of some kind, and,\nsince we can form no conception of an electric current except as a\nkinetic phenomenon, its energy must be kinetic energy, that is to say,\nthe energy which a moving body has in virtue of its motion.\"\n\nHere, therefore, according to Clerk Maxwell, the kinetic energy of an\nelectro-magnetic field is nothing more or less than the energy which a\nmoving body possesses in virtue of its motion. Any other explanation of\nkinetic energy would be opposed to all the Rules of Philosophy; for\nexperience in its widest form incontrovertibly proves that all kinetic\nenergy is associated, and alone associated, with a moving body;\ntherefore in all electro-magnetic fields there is this kinetic energy\never being manifested. We have, however, learned that the solar system\nforms a huge electro-magnetic field, traversed by lines of force, as\nMaxwell and Faraday suggested. Therefore, in the solar system, there\nmust be this kinetic energy due to the motion of a moving body, which is\nthe electro-magnetic Aether.\n\nWe have, however, just arrived at the conclusion that in the solar\nsystem there is ever going on a circulatory or rotatory movement of the\nelectro-magnetic Aether forming currents around each electro-magnet. On\nthe hypothesis of an atomic and gravitating Aether we have, therefore, a\nmedium or body continually circulating, which medium possesses inertia\nand momentum, and it is philosophically possible for such a rotating\nmedium to possess kinetic energy. So that our explanation of this term,\nas used by Clerk Maxwell, is, that this kinetic energy is indeed due to\nthe momentum of the moving Aether. Such a hypothesis is strictly\nphilosophical, and literally fulfils the statements made by Clerk\nMaxwell himself in the paragraphs already referred to.\n\nA remarkable feature about this hypothesis lies in the fact, that it is\nthe very hypothesis that Von Helmholtz suggested as the explanation of\nthe term. He came to the conclusion that the kinetic energy was due to\nthe momentum of the moving Aether. But with a frictionless Aether such a\nhypothesis, although correct, was philosophically untenable. In view of\nthe theory of the Aether presented in this work, however, both Clerk\nMaxwell's and Von Helmholtz's statements find their literal and perfect\nfulfilment. So that in an atomic Aether, which is gravitative because\natomic, and rotatory because it is gravitative, combined with its\nelectro-magnetic basis as proved by Hertz, we find for the first time a\ncorrect philosophical explanation of one of the most puzzling terms used\nby Maxwell in his greatest work on _Magnetism and Electricity_. This\nsolution alone ought to stamp the theory of an atomic and gravitating\nelectro-magnetic Aether with that authority that is always associated\nwith the names of two such great thinkers and experimentalists as those\njust mentioned.\n\nThe fact that the Aether is held bound to a planet has already been\nsuggested by Sir G. Stokes to account for the aberration of light\nalready referred to. In the _Phil. Mag._, July 1845, he writes: \"I shall\nsuppose that the earth and the planets carry a portion of Aether along\nwith them, so that the Aether close to the surface is at rest relatively\nto the earth, while its velocity alters as we recede from its surface,\ntill at no great distance it is at rest in space.\" Sir G. Stokes does\nnot, however, say how the Aether is held bound to the earth, and apart\nfrom an Aether which is gravitative, no satisfactory explanation can be\ngiven. Further, it is noticeable, that he suggests that the other\nplanets also carry part of the Aether associated with them along with\neach planet as it pursues its journey. It would be distinctly\nunphilosophical to assume that the earth was the only planet that\ncarried its aetherial field with it. So that by following Sir G. Stokes'\nsuggestion, we practically arrive at the same conclusion in relation to\nthe motions of the Aether that we have already arrived at from magnetic\nphenomena.\n\nWith this view of the case we are now in a position to answer a question\nasked by Professor Schuster at the British Association in 1892. He\nasked, \"Is not every large rotating mass a magnet?\" and added, \"If it\nis, the sun must be a powerful magnet. The comets' tails, which eclipse\nobservations show stretching out from the sun in all directions,\nprobably consist of electric discharges.\" Now, in relation to this\nquestion, the answer is that every rotating body in the Aether is\nundoubtedly an electro-magnet. Thus, not only is the sun an\nelectro-magnet, but every planet and satellite, and every meteor that\nrotates in the electro-magnetic Aether, is converted into a magnet,\npartly by that rotation, and partly by the currents induced in the\nAether by that rotation. We shall also find when we come to deal with\nthe phenomena of comets' tails, that Professor Schuster is also right as\nto their cause, and that they are due to electro-magnetic repulsions\noriginated in the Aether by the sun, which is an electro-magnet.\n\n[Footnote 39: _Outlines of Astronomy_, Herschel.]\n\n\nART. 92. _Cause of Rotation of the Earth on its Axis._--If there is one\nfact true in relation to the earth as a planet, it is that the earth\nrotates on its axis every 24 hours. Day in and day out, for centuries\npast, this revolution has taken place as the earth journeys in its\nannual path round the sun.\n\nNot only does the earth rotate on its axis, but every other planet\nrotates on its axis in varying times, as the following table shows--\n\n                  HRS.  MIN.  SEC.\n\n    Mercury        24     5     0\n    Venus          23    24     0\n    The Earth      23    56     4\n    Mars           24    37    23\n    Jupiter         9    55     0\n    Sarturn        10    14    23\n    Uranus          ?\n    Neptune         ?\n\nFurther, the sun also rotates on its axis in a period of 26 days. Here,\nthen, are certain phenomena in connection with the solar system, for\nwhich up to the present no explanation as to the physical cause of\nrotation has ever been offered. Surely there is some physical cause, to\naccount for such a rotation, and if there be a physical cause, then the\nproblem to be solved is--find the physical cause to account for the\ncontinuous and ever-recurring rotation of all the planets and the sun on\ntheir axes, which shall be so effective and continual that, year in and\nyear out, the rotation of all the planets may be continued as observed.\nIn solving this problem we have to revert to our reason why the earth is\na magnet. In Art. 91 we learned that the earth and all the other\nplanets, and indeed all stellar bodies, were electro-magnets, because\nthe electro-magnetic Aether was constantly circulating round them.\n\nIf, by accepting this explanation, we can at the same time solve the\nproblem of the rotation of the planets, and the sun, on their axes, then\nwe shall have further evidence that our hypothesis is the correct one.\nNow let me ask, What is the effect of an electric current continually\ncirculating round any magnet in the same way that the electro-magnetic\nAether continually circulates round the earth, which is a magnet?\n\nTo find out what the effect is, we must resort to experiment. Professor\nLodge, in his _Modern Views of Electricity_, shows us the effect of any\ncirculating current of electricity revolving round a magnet. In his\nchapter on Electro-Magnetism he writes as follows: \"How does a current\nact on a magnetic pole? Two currents attract or repel each other, two\npoles attract or repel each other, but a current and a pole exert a\nmutual force which is neither attraction nor repulsion. It is a rotatory\nforce. They tend neither to approach nor to recede, they tend to revolve\nround each other.\" \"A singular action this and at first sight unique\"\n(p. 135). \"The two things will revolve round each other for ever. This\naffords and has afforded a fine field for the perpetual motionist, and\nif only the current would maintain itself without a sustaining power,\nperpetual motion in fact would be attained.\"\n\nFaraday has shown by experiment the action of a current on the magnet,\nand _vice versa_. Faraday, in his description of an electro-magnetic\napparatus for the exhibition of rotatory motion, shows how the rotation\nof a current round a magnet, and a magnet round a current, may be\nexperimentally proved. With the apparatus used he shows that the current\nof electricity may be made to revolve round the pole of the magnet in\nthe direction dependent on the pole used, and further, illustrates how\nthe magnet may be made to revolve round the current. (Plate 4, Fig. 5,\n_Exp. Res._)\n\nThus we learn that wherever we have a current constantly circulating\nround a magnet, there we have the conditions by which, according to\nProfessor Lodge, perpetual motion may be obtained, that is to say, the\ntwo will revolve round each other as long as the current is maintained.\nHere then we find in space those very conditions by which perpetual\nmotion may be obtained.\n\nWe find the electro-magnetic Aether constantly circulating round the\nplanetary magnets, with the result that not only will the current\ncontinue to revolve around the planet, but the planet will continue to\nrevolve upon its axis as it revolves round the current. In fact we get\nin space an example of perpetual motion. We know that the rotation of\nthe earth on its axis has been in existence for several thousand years,\nand therefore we have a right to assume that it revolved on its axis\nthrough the untold ages of past geological times as revealed by the\nstrata, and rocks of pre-historic ages. Thus the motion must have\ncontinued, so far as the earth is concerned, at least 100,000,000 years,\naccepting that period as the age of the earth, but no physical reason so\nfar as I know has ever been assigned for such continued rotation.\n\nIf, therefore, it be true that the joint action of a current and a\nmagnet is a rotatory one, then, seeing that in all planetary and stellar\nspace we have both these conditions of matter, that is, the\nelectro-magnetic aetherial current, constantly circulating round an\nelectro-magnet, we have, in space, the conditions by which perpetual\nrotation may be maintained. We have therefore presented to us in that\njoint action, the true cause of the continued rotation of the earth on\nits axis, and therefore of all the planets on their axes, together with\nthe sun on its axis; and, if we carry the principle into the stellar\nworld, we can philosophically come to the conclusion that the same\nconditions prevail there that prevail in the solar system, with the\nresult that we have now a physical cause which fully satisfies all Rules\nof Philosophy to account for certain phenomena which up to the present\nhave never yet been accounted for from the physical standpoint. Thus in\nsolving the problem of the earth's rotation on its axis, we find greater\nconfirmation in the view presented in a previous article as to the\ncirculating motion of the electro-magnetic Aether around any and every\nbody in space. We shall deal again with the relation of a current and a\nmagnet, when we come to the physical explanation of Kepler's Laws.\n\n\nART. 93. _Vortex Motion._--From Art. 91 we have seen that the\nelectro-magnetic Aether possesses a circulating or rotatory motion\naround each central body, and because of this rotatory motion, the body\nis at once converted into a magnet. We have also seen that Professor\nChallis believed in the circulatory or rotatory motion of the Aether, as\nalso did Ampere.\n\nThus we are led back by scientific experiment and philosophical\nreasoning to the conception of vortex motion with which the world was\nfamiliar in the days of Kepler, Descartes, Huyghens and Bernoulli. There\nis this difference, however, that whereas the vortex motion of those\nphilosophers was to displace and do away with Gravitation, the\ncirculatory or rotatory Aether suggested by electro-magnetic phenomena\nis to supplement, confirm and establish more firmly than ever the true\npowers and laws of Gravitation Attraction.\n\nBefore passing, it will be as well to briefly glance at the conception\nof vortex motion as suggested by Kepler and Descartes and others.\nWhewell on this matter in his _Inductive Sciences_ states that \"Kepler\nassumed that a certain force or virtue resided in the sun by which all\nbodies within his influence were carried round him. He illustrated the\nnature of the force in various ways, comparing it to light, and to the\nmagnetic power which it resembles in the circumstances of operating at a\ndistance, and also of exercising a feebler influence as the distance\nincreases.\" \"Another image to which he referred suggested a much more\nconceivable kind of mechanical action by which the celestial motions\nmight be produced, viz. a current of fluid matter circulating round the\nsun, and carrying the planets with it like a boat in a stream.\" Whewell\nadds: \"A Vortex fluid constantly whirling round the sun, kept in this\nwhirling motion by the sun itself, and carrying the planets round the\nsun by its revolution, as a whirlpool carries straws, could be readily\nunderstood, and though it appears to have been held by Kepler that this\ncurrent and Vortex were immaterial, he ascribes to it the power of\novercoming the inertia of bodies, and of putting them and keeping them\nin motion.\"\n\nNow, as we have seen, the electro-magnetic Aether is not immaterial but\nmaterial, as it is matter possessing mass and inertia, the same as any\nother matter, as Tyndall and Lord Kelvin stated (Chap. IV.). Thus the\nobjection to Kepler's immaterial vortices is met and overcome by our\nconception of the Aether (Chap. IV.). Descartes, as Whewell points out,\nasserted, \"that a vacuum in any part of the universe is impossible. The\nwhole universe must be filled with matter, which must be divided into\nequal angular parts. This matter being in motion, the parts are\nnecessarily grounded into a spherical form, and the corners thus rubbed\noff, forming a second or subtle matter. There is besides a third kind of\nmatter, of parts more coarse and less fitted for motion. The first part\nmakes the luminous bodies as sun and stars, the second part is the\ntransparent substance of the skies, and the third part is the material\nof opaque bodies as the earth, planets and comets. We may suppose that\nthe motion of these parts takes the form of revolving circular currents\nor vortices. By this means the first matter will be collected to the\ncentre of each vortex, while the second or subtle matter surrounds it,\nand by its centrifugal effect constitutes light. The planets are carried\nround the sun by the motion of the vortex, each planet being at such\ndistance from the sun as to be in a part of the vortex suitable to its\nsolidity and mobility. The satellites are in like manner carried round\ntheir ordinary planets by subordinate vortices.\"\n\nIt would almost seem from this quotation that we had adopted purely and\nsimply Descartes' and Kepler's ideas _in toto_, whereas the truth is\nthat the hypothesis of a rotating electro-magnetic Aether has been\narrived at by following Newton's own Rules of Philosophy, and by\ndiscarding everything not in harmony with experience and experiment.\n\nFurther, Descartes was unable to give, or explain the ellipticity of the\norbits of planets, and had to assume that there were elliptic vortices.\nWhen we come to deal with Kepler's Laws, and their physical\ninterpretation, the correct solution of this problem will be given from\na purely experimental and philosophical standpoint, and in a way and\nmanner never suggested by Descartes or any other believer in the theory\nof vortices as then known and understood. Indeed there is no objection\nto the theory of vortices, which cannot be satisfactorily explained by a\nrotating electro-magnetic Aether, as we shall see when we deal with\nNewton's Laws of Motion and Kepler's Laws.\n\nBoth Liebnitz and Huyghens were believers in the theory of vortices, and\nthe fact that Huyghens' undulatory theory of light stands to-day as an\naccepted theory, is conclusive evidence that he was a philosopher of the\nhighest order, and his adhesion to the theory of vortices proves that he\nwas convinced that there was some truth in it.\n\nIt is a result greatly to be desired, therefore, if it can be\ndemonstrated, that in the Aether there is this rotatory motion\ncontinually going on around every planet, satellite, sun or star;\nbecause it will then join together, in perfect harmony, two great\ntheories in relation to celestial phenomena, that contended with each\nother for supremacy for very many years.\n\nIt will prove that, after all, men like Kepler, Descartes, Huyghens, and\nBernoulli had caught glimpses of the great truth which was partly\nrevealed by celestial phenomena, and that it was only for lack of data\nthat they were unable to successfully compete with Newton's mathematical\ngenius, by which he was able to bring his Law of Gravitation safely\nthrough the conflict with the simpler conception of aetherial vortex\nmotion. Of course certain objections will have to be met and answered\nbefore this aspect of aetherial dynamics can be expected to supplant the\nmore cumbrous and somewhat intricate mathematical laws of motion, but I\nshall prove later on, that all these objections can be answered from a\nsatisfactory standpoint.\n\nSo that if a modified form of aetherial vortex motion can be\nsuccessfully demonstrated to exist in the electro-magnetic Aether, then\nwe shall see the conflict that waged about two hundred years ago,\nbrought to a satisfactory issue, in the union of the two greatest\nphilosophic theories for the explanation of celestial phenomena that the\nworld has ever seen.\n\nFrom that union, therefore, there will then emerge a truer, simpler, and\nyet grander conception of the motions of the universe, which, when\nperfected by abler minds, will be as perfect a theory as human\nintelligence and philosophy can make it. So that, what an atomic and\ngravitative Aether has done for Newton's corpuscular theory of light, in\nshowing that it can be united and combined with the undulatory theory,\nand by such combination, for the first time, such phenomena as the\ntransverse action of light can be probably demonstrated and explained,\ntogether with other phenomena relating to reflection and refraction of\nlight, the enlarged conception of a rotating electro-magnetic Aether will\ndo for the two great theories that vied with each other for supremacy\nfor so many years. Thus it will be shown that the philosophers like\nKepler, Descartes, and Huyghens, the former of whom has stamped his name\non the three laws that bear his name to-day, and the latter who gave us\nthe inception of the very theory that overthrew Newton's theory of\nlight, had after all a more or less true philosophic conception of the\nphysical mechanism of the solar system and of the universe at large.\n\n\nART. 94. _Relative Motion of Aether and Matter._--There is hardly any\nsubject of greater importance which is engaging the attention of\nscientists at the present time, than the question as to what is the\nrelative motion of Matter to the Aether in which it moves.\n\nI venture to premise the successful solution of the problem will be\naccompanied with the greatest advance to science that has been known for\na long time. The problem to be solved may be stated thus: \"Does the\nAether surrounding a planet or sun or any body in space move with that\nbody, or does it allow the body to pass through it?\"\n\nUp to the present, opinions on the subject have been varied and\nconflicting. Some scientists hold that the planetary and other bodies in\nspace pass through the Aether without disturbing it, while others hold\nthat part of the Aether is carried along by the moving planet. Fresnel\nassumed that the surrounding Aether was carried along by the earth, so\nthat all relative phenomena would be the same as if the earth were at\nrest. Fizeau, from experiments which he conducted on running water, also\ncame to the same conclusion.\n\nWith the old idea of a frictionless medium, some of the present accepted\ntheories are altogether untenable, because, if Aether is frictionless,\nhow can it be carried along with the moving body, unless it is held\nbound to that body? and how can it be held bound to that body if it is\nfrictionless?\n\nThe whole view of the Aether is, however, changed by the conception of\nthe Aether put forward in Chapter IV. Aether is Matter, and being matter\nit is also gravitative, and therefore is just as much subject to the Law\nof Gravitation as any other kind of matter, as Young stated in his\nFourth Hypothesis (Art. 45).\n\nWe will therefore attack the problem of the relative motion of the earth\nand the Aether around it from this new standpoint. In order to be\nstrictly philosophical, we must base our hypothesis and conception on\nexperience and observation. Where in the whole of planetary phenomena do\nwe find similar conditions which exist between the Aether and the earth?\nSuch conditions are alone to be found between the atmosphere and the\nearth. The analogy between the atmosphere and the earth, and the Aether\nand the earth is very striking, as the following comparisons will prove.\n\nThe atmosphere (when pure) is invisible, so is the Aether. The\natmosphere is atomic, the Aether is also atomic. Both are subject to the\nsame laws of elasticity and density, and both are gravitative, according\nto our conception of the Aether. Now what is the effect of any large\nrevolving body on a liquid or gaseous medium surrounding that revolving\nbody?\n\nIf experience is any guide, we learn that the motion of the revolving\nbody is either partially or entirely transmitted to the liquid or\ngaseous medium surrounding such a body. So far as our experience teaches\nus anything, it teaches us that to that rule there is no exception, and\nno experiment can be devised of any body revolving in water or a gaseous\nmedium as air, without that body imparting its rotation to the water or\nthe air. The atmosphere in relation to the earth is no exception to this\nrule. We know that the earth has an equatorial circumference of about\n24,000 miles, and that it revolves on its axis once every day, so that\nat the equator the surface of the earth is whirling round in space at\nthe rate of 1000 miles per hour.\n\nTry to conceive what the result would be if the atmosphere were\nstationary at the earth's surface in the equatorial regions. It would\nmean that any body on its surface would be whirled round at that rate,\nwhile the atmosphere, being stationary, would exert a power equal to a\nwind travelling at the rate of 1000 miles per hour.\n\nUnder the influence of such a hurricane, nothing could exist on the\nsurface of the earth at the equator, if the earth revolved on its axis\nand the atmosphere did not participate in that motion. But the\natmosphere is gravitative, and being gravitative, it is not only held\nbound to the earth as it revolves on its axis in its onward rush through\nspace, but accepts the revolving motion of the earth, with the result\nthat as the earth revolves on its axis, the atmosphere revolves also.\n\nThus a balloon at the equator if allowed to rise several hundred feet\nabove the surface could remain comparatively stationary if held by a\nrope to overcome its tendency to rise, whereas such an event would be\nimpossible if the atmosphere failed to receive only half of the motion\nof the earth's surface, as it would still have a power equal to that of\na wind blowing at the rate of 500 miles an hour. If, however, we come\nfurther north, or go further south, then we find that the surface of the\nearth does not have the same velocity as at the equator, with the result\nthat the atmosphere has not the same velocity either; consequently it\nwould travel slower in the temperate regions than in the equatorial\nregions, and slower still at the poles than in the temperate regions.\n\nWe know by experiment what the effect of increased velocity has upon any\nwhirling body; it tends to enlarge the body at those parts where the\nvelocity is the greatest, the consequence being that the bulging out of\nthe atmosphere would be greatest at the equator. We find a similar\nresult in the shape of the earth, where the equatorial diameter is\ngreater than the polar diameter, because of the centrifugal force being\ngreatest in the equatorial regions.\n\nWe have, therefore, to apply these facts to the aetherial medium which\nsurrounds all planetary and stellar bodies in the same way as the\natmosphere does; and which, being also gravitative, is equally subject\nto the same laws of motion. We have seen, therefore, that not only does\nthe earth revolve on its axis, but that the atmosphere revolves on its\naxis also, and that the velocity of its revolution is greatest in the\nequatorial regions, the atmosphere spreading or bulging out in those\nparts more than in any other part of the earth's surface.\n\nLet us suppose that the atmosphere extends 200 miles above the earth,\nand that there we come to the pure Aether of universal space. In view of\nthe fact that Aether is Matter, and therefore gravitative, it is\nreasonable and logical to conclude that exactly the same result follows\nin relation to the atmosphere and the Aether at that height, as follows\nin relation to the earth and the atmosphere 200 miles beneath.\n\nUnless this view is accepted, we should then have our second Rule of\nPhilosophy violated, as we should have matter revolving in more rarefied\nmatter, and failing to impress upon that rarefied condition of matter\nthe motion either partially or wholly which it itself possesses; and\nsuch a result being contradictory to all experience cannot be admitted\nfrom a philosophical standpoint.\n\nTherefore, the only solution is, that the rotating atmosphere imparts\nsome of its motion to the aetherial atmosphere, which in its turn\nrotates, and that that rotation is governed by exactly the same\nconditions as govern the relation that exists between the earth and the\natmosphere. Therefore the Aether in space associated with each planet or\nsatellite or sun or star, rotates with the rotating body, and that\nrotation imparts to the Aether a greater bulging out in the equatorial\nregions of the aetherial atmosphere than in any other part thereof. It\nis interesting in relation to this point to note Herschel's view of the\neffect of the rotation of any body upon the Aether. In his _Outlines of\nAstronomy_, in a note, p. 358, he states: \"Supposing the neighbourhood\nof the sun to be filled with a material fluid; it is not conceivable\nthat the circulation of planets in it for ages should not have impressed\nupon it some degree of rotation in their own direction, and this may\npreserve them from the effects of accumulated resistance.\"\n\nIn this way we arrive at the conception of the motions of the Aether\nsuggested by Prof. Challis from the magnetic character of the earth,\nwhich he thought were due to aetherial currents circulating around it,\nand we learn that such physical conception of the Aether fully agrees\nwith the explanation of celestial bodies being electro-magnets; because,\nwe have only to add to our rotating Aether that which it has been proved\nto possess, viz. an electro-magnetic basis, and we have at once the\ncurrents of electricity circulating round the earth and other planetary\nor solar bodies, by which is obtained the true explanation of the\npermanent magnetism of all celestial bodies.\n\nNow to some minds unconversant with scientific research and knowledge,\nsuch a supposition may seem to be incredible, but that incredibility may\ndisappear, when I say that the fact that the Aether is bound to the\nearth, and goes along through space with it, has actually been proved by\nsome of the most delicate and successful experiments that have been made\nin recent times: experiments of which Lord Kelvin has stated that he can\nfind no error or flaw in them. I refer to the scientific experiments of\nMichelson and Morley of America. For full particulars of these\nexperiments I must refer the reader to the _American Journal of\nScience_, 1886, vol. 31, or to the _Phil. Mag._, vol. 44.\n\nThe conclusion which is arrived at from their experiments is, that the\nAether is carried along with the earth as it rushes on its journey\nthrough space. Of course such a result is altogether opposed to the\nordinary conception of a frictionless medium, and indeed to any\nconception of the Aether except to that submitted in this work, which is\nalso in harmony with Young's Fourth Hypothesis (Art. 45).\n\nSo that Michelson's and Morley's experiment is a direct experimental\ndemonstration of the fact that Aether is gravitative, and because it is\ngravitative, it is carried along with the earth, as that planet journeys\nthrough space. It further conclusively proves that not only is the\nAether carried along with the earth, but that the Aether circulates\nround the earth in the same way that the atmosphere circulates round the\nearth.\n\nThis result naturally follows from the experiment, because, if it were\ncarried along by the earth and yet did not rotate with the atmosphere,\nthen we should have a result opposed to all experience and experiment,\nas these teach us that when a body revolves in a medium which is held\nbound to that body by Gravitation, the medium so held bound participates\nin the rotation of the revolving body.\n\nSo that in Michelson's and Morley's experiment we have experimental\nevidence of the fact, already stated, that the Aether circulates round the\nearth, and therefore, in view of the electro-magnetic character of the\nAether, this circulation results in the production of magnetism in all the\nplanets, and other bodies around which it circulates.\n\nThus not only does the Aether circulate round the earth, but it also\ncirculates around every other planet, and not only round every other\nplanet, but equally so around every sun and star, as stated in Art. 91.\n\nThese results are perfectly consistent with philosophical reasoning, and\nany other result would be inconsistent with the analogies presented to\nus by the phenomena of the Aether in relation to our earth as\nascertained by experiments made by the scientists referred to. Thus for\nthe first time the experiment is brought into harmony with our\nPhilosophy, which up to the present has not been the case, a result\nwhich at once stamps the experiment with that validity of truth and fact\nwhich will ultimately win for it universal acceptance and favour.\n\nWe are now in a position to answer some queries regarding the motions of\nthe Aether asked by Herschel in his work on _Astronomy_, p. 345. These I\ngive with the answers opposite.\n\n\n              QUERIES.             |          ANSWERS.\n                                   |\n  1. What is the law of density    |  The Law of Gravitation\n     of the resisting medium which |  (Art. 45).\n     surrounds the sun?            |\n                                   |\n  2. Is it at rest or in motion?   |  In motion.\n                                   |\n  3. If the latter, in what        |  Rotates round the sun.\n     direction does it move?       |\n                                   |\n  4. Circularly round the sun      |  Both, as it circulates round\n     or traversing space?          |  the sun while that body\n                                   |  traverses space.\n                                   |\n  5. If circularly, in what        |  The plane of the ecliptic.\n     plane?                        |\n\n\nART. 95. _Physical Explanation of the Vibration in the Electro-Magnetic\nTheory of Light._--In Art. 78 we learned that light was an\nelectro-magnetic disturbance in the Aether which was propagated through\nthe Aether, with a finite velocity; and from this we gathered that light\nwaves were nothing more or less than electro-magnetic waves, which were\nradiated from the sun, out into the Aether on every side.\n\nWe were unable, however, at that time to give a definite physical\nconception of the aetherial vibrations, or of the relation of the\nvarious types of vibration to each other. Since, however, the\ndevelopment of the Aether from the electric and magnetic standpoint,\nwhich has led us up to the fact that the Aether possesses a circulating\nmotion round the sun (Art. 91), the solution of the problem appears\nprobable. I am of the opinion that the physical conception of the\nvarious vibrations to each other is now within the region of\npossibility, and in this article I wish to endeavour to give what seems\nto me to be a correct and philosophical explanation of this part of the\nelectro-magnetic theory of light, the physical conception of which up to\nthe present has not been generally understood.\n\nThe explanation may, or may not, be fully complete, but even if it be\nnot perfectly correct, I am convinced that it will ultimately lead to a\nsatisfactory physical explanation of this part of Maxwell's Theory of\nLight. In forming a conception as to the physical character of the\nvibrations in the electro-magnetic theory, we have to remember that\nthere are three distinct vibrations, or motions, concerned in this\ntheory.\n\n[Illustration: Fig: 22.]\n\n    1st. There is the direction of propagation.\n\n    2nd. There is the direction of the electric vibration which is\n         at right angles to the direction of propagation.\n\n    3rd. There is the direction of the magnetic vibration or\n         motion which is at right angles to both of the other two.\n\nNow we have seen that the direction of propagation of any aetherial\nlight ray, is that of a straight line from the sun corresponding to the\nradius vector (Art. 76). We have also seen that the front of a light\nwave is really that of a spherical shell (Art. 71).\n\nWe have also learned that the electric and the magnetic vibrations are\nin the wave front, so that these two vibrations, which are at right\nangles to each other, are to be found on the surface, so to speak, of\neach aetherial spherical shell, that surrounds the sun with\never-decreasing density, and ever-decreasing elasticity.\n\nLet us try to picture the actual fact by an illustration. Let _S_ be the\nsun, with concentric spherical aetherial shells surrounding it (Fig.\n22). Then _S_ _A_ and _S_ _C_ will be rays of light being radiated out\nfrom the sun, and the magnetic and electric vibrations have to be both\nat right angles to the line of propagation and in the wave front; the\nwave front being represented by the circular lines showing the section\nof the concentric shells running north and south.\n\nNow how can we picture these two motions at right angles to each other,\nand yet both at right angles to the line of propagation? First, let us\ntake three straight lines and see how this may be done (Fig. 23).\n\nLet _A_ _B_, _A_ _S_ be two straight lines at right angles to each\nother, and _A_ _C_ another straight line at right angles to both. This\ncan only be done by making _A_ _C_ perpendicular to the plane of the\npaper, and can be illustrated by supposing that it represents a pencil\nor pen placed upright on the paper, the point of the pencil being at\npoint _A_. If this be done, then not only will _A_ _B_ and _A_ _C_ be at\nright angles to each other, but both will be at right angles to _A_ _S_,\nwhich corresponds to the line of propagation.\n\n[Illustration: Fig: 23.]\n\nNow refer to Fig. 22, and we shall see that the line _A_ _B_ and the\nboundary of the shell will practically correspond. So that any section\nof a spherical wave front will always be at right angles to the ray of\nlight. But we have learned from Art. 89 that these sections of the\naetherial spherical shell are really identical with Faraday's Lines of\nForce, with the result that along any line which stretches from the\nNorth pole of the sun to the South pole, there will ever be an electric\nvibration, which is put into motion by the elasticity of the aetherial\nvortex atoms. So that on every side of the sun there is ever going on\nthis electric vibration, along the lines of force which correspond to a\nsection of the aetherial shell, the surface of which really constitutes\nthe wave front.\n\nTherefore it can readily be seen, that, as these lines are at right\nangles to the propagation of the ray of light, the electric vibration is\nat right angles to the lines of propagation, and is thus in accordance\nwith the result demanded by Maxwell's theory.\n\nWe have now to give a physical conception of the magnetic vibration or\nmotion of the Aether, and this has to be at right angles to both the\nelectric vibration and the line of propagation.\n\nIn Art. 91 we have learned that the Aether possesses a rotatory motion, by\nwhich it rotates round the central body of the solar system, the sun. So\nthat if we take any point, for example, in the path of the ray as _S_{1},\n_S_{2}, _S_{3}, and _S_{4}, situated upon some definite equipotential\nsurface or lines of force, and if we will imagine those lines to rotate\nround the sun, as the sun rotates on its axis, then in time the points\nwill have described half the circle, and will come to the position on the\nright of the sun indicated by the same Nos. _S_{1}, _S_{2}, _S_{3},\n_S_{4}. Thus there has been an aetherial motion at right angles to the\nelectric motion, as the Aether circulates round the sun, because this\nmotion may be represented as taking place from west to east of the sun,\nwhile the electric vibration takes place from north to south, or\ntransverse to the line of propagation.\n\nWe have, however, learned that the Aether has an electro-magnetic basis,\nand therefore the rotation of the Aether gives rise to electro-magnetic\ncurrents; hence the motion west to east is really the motion of\nelectro-magnetic currents which circulate round the sun. As these are at\nright angles to the line of propagation, and we have seen that they are\nat right angles to the electric vibration, it follows that all three are\nat right angles to each other, which is in accordance with the\nrequirements as laid down by Maxwell.\n\nWe have considered these vibrations, first, from the view of the solar\nsystem as a whole in its relation to the universal Aether; but the same\nprinciple holds good if considered from the aetherial atomic standpoint.\nFor if we take a line of force, composed as it is of aetherial vortex\natoms, and suppose them to be rotating, we know that by that rotation\nthere will be a tension due to that rotation, and Maxwell has shown this\ntension is due to magnetism, as in his standard work he says: \"This\nmagnetic force is the effect of the Centrifugal Force of the Vortices.\"\n\nSo that by postulating a rotatory movement for the Aether around the\nsun, as we have done in Art. 92, we have not only solved the problem of\nall planetary and solar magnetism, but we have also solved the problem\nof the relative motion of the Aether and the earth, and also given for\nthe first time (though it may be in an incomplete form) a physical\nexplanation of that part of the electro-magnetic theory of light, which\nhas hitherto been unexplained from the purely physical standpoint.\n\nSuch results, therefore, supported as they are by the direct experiment\nof Michelson and Morley of America, justify us in concluding that the\nconception of a rotating Aether is not only philosophically correct, but\nis in actual accord with experimental investigation and research, as\nindeed it ought to be.\n\n\n\n\n                               CHAPTER X\n\n                  AETHER AND NEWTON'S LAWS OF MOTION\n\n\nART. 96. _Centrifugal Force._--Before proceeding to apply some of the\nprinciples and laws which govern the electro-magnetic aetherial medium\nto solar and stellar phenomena, it will be as well just to review the\nconception of our new aetherial Centrifugal Force, so that we may form a\nright view of it in its completeness and entirety.\n\nIn Art. 11 we premised that there was in existence another force, which\nwas the exact opposite of the centripetal force, and that this force was\nthe complementary and counterpart of the centripetal force or\nGravitation Attraction; and further, that this force was due to the\nmotion of the universal Aether which filled all space.\n\nIn Art. 13 we saw that all force resolved itself into energy of some\nkind, the same being due either to potential energy, _i. e._ energy of\nposition, or to kinetic energy, which is the energy belonging to matter\nactually in motion. From Art. 56 we learned that all energy was energy\nof motion, so that all force resolves itself into motion of some kind.\n\nThus our term Centrifugal Force really implies, and demands, a motion of\nthe Aether which is ever directed away from the centre of gravity of any\nbody, whether that body be an atom or molecule, satellite or planet, sun\nor star. From the phenomena of heat we have seen that there exists a\nrepulsive motion, due to the aetherial medium, which is ever exerted\nfrom the central body of any atomic, planetary or stellar system, that\nrepulsive motion being due to the pressure of the universal Aether,\nwhich not only surrounds all atoms, but also surrounds all other bodies\nin the universe.\n\nFrom the phenomena of light we have also seen that the Aether possesses\na repulsive or centrifugal motion, which is also due to the pressure of\nthe same Aether as mathematically proved by Maxwell, and experimentally\nproved by Prof. Lebedew, and Nichols and Hull of America. Further, from\nthe phenomena of electricity, we have also seen that there exists this\ncentrifugal motion, due to the pressure of the same aetherial medium,\nwhich pressure is ever directed away from the electrified body, as the\nsun or planets.\n\nSo that from these three phases of the universal Aether, that is, from\nits thermal or heat manifestation, its luminiferous or light\nmanifestation, and its electro-magnetic manifestation, we get\nirrefutable evidence of the existence of a centrifugal motion, which\nmotion is ever directed away from the central body; and the result of\nthat motion takes the form of a pressure upon any body with which the\nmotion comes into contact.\n\nAgain, it was premised, that such a centrifugal force or motion must\nfulfil all the laws which governed the centripetal force or motion.\n\nFirst, it had to be universal (Art. 19). Second, it had to follow\nexactly the same path as the centripetal force or motion, which was that\nof a straight line joining the centre of gravity of two bodies, as for\nexample the earth and the sun (Art. 20). Third, the centrifugal force or\nmotion must be equal to the product of the masses, in the same way that\nthe centripetal force was governed by such a law (Art. 21). Fourth, its\nintensity was to be governed by the law of inverse squares, the same as\nthe centripetal force or Gravitation Attraction was governed (Art. 22).\n\nNow all these conditions are satisfactorily fulfilled, and have been\nshown to be satisfactorily fulfilled, from the phenomena of heat, light,\nand electricity in their relation to the universal Aether. For in Art.\n43 we saw that the Aether was universal, and therefore if the\ncentrifugal motion is produced and originated by the Aether, then such\nmotions must be as universal as that medium, which under qualifying\nconditions gives rise to these motions.\n\nFrom Arts. 65 and 76 we have learned that the path of this centrifugal\nmotion is that of a straight line, and follows exactly the same path\nthat the centripetal force of gravity takes. In Art. 85 we learned that\nthe centrifugal force between any two bodies was equal to the product of\ntheir masses, which is exactly the same as the centripetal force that\nexists between any two bodies; and, lastly, from the phenomena of heat,\nlight, and electricity we learned that the intensity of this centrifugal\nmotion due to aetherial pressure was inversely as the square of the\ndistance, which is the law governing the intensity of its counterpart,\nthe centripetal force. Thus we have learned that there is in existence\nthroughout universal space, a physical force or motion due to a physical\nmedium, the universal Aether, which force or motion is the exact\nopposite of the centripetal force or Gravitation Attraction, which may\nbe stated as follows--\n\nEvery particle in the universe repels every other particle with a force\nwhose direction is in the line joining the centres of gravity of the two\nbodies, and whose magnitude is directly as the product of their masses,\nand inversely as the square of the distance between them, at their mean\ndistances.\n\nWe shall see that it is by the conjoint working of these two forces, the\nCentripetal and Centrifugal, in combination with other motions of the\nAether, that the harmonious working of the whole celestial mechanism is\nmaintained and perpetuated. In confirmation of the existence of the\ncentrifugal force, I should like to draw the attention of the reader to\ncertain phenomena relative to the solar system, which phenomena violate\nthe centripetal force as at present recognized, and can alone be\naccounted for by the existence of another force or motion existing in\nspace, such as the centrifugal motion already proved and demonstrated.\n\nWe know that the law governing the centripetal force, or Gravitation\nAttraction, is regulated by the product of the masses of the two\nattracting bodies. So that if there were three bodies in space whose\nmasses are respectively represented by 2, 3 and 100, the proportion of\nthe attractive force of gravitation between the largest and the other\ntwo, would be 200 (100 x 2) and 300 (100 x 3) respectively. So that if\nthe centripetal force, or the Attraction of Gravitation, is the only\ngoverning force in the universe, then it naturally follows that the two\nbodies, between which the attractive force is greater, will be closer\ntogether than the two bodies between which the attractive force is less.\n\nThus the two bodies, whose product of their masses is represented by\n300, will, according to the Law of Gravitation, be closer together than\nthe two bodies, the product of whose masses is represented by only 200.\nUnless this is so, we should have a violation of the Law of Gravitation,\nand it would at once cease to be a law.\n\nLet us therefore apply the centripetal force, or Gravitation Attraction,\nto the solar system, and see how it works out. The law strictly defined\nis given in Art. 18, from which we learn that the attractive force\nbetween two bodies is as the product of their masses. Now what are the\nmasses of some of the bodies in the solar system?\n\nWe find that the sun, with its diameter of 865,000 miles, is about\n324,000 times greater in mass than our earth, so that it would take\nabout 324,000 bodies of the size and density of our earth to equal a\nbody of the size and density of the sun. It has been calculated,\nhowever, by Von Asten, from observations made on comets by the planet\nMercury, that the mass of Mercury is about 1/24 of the mass of the\nEarth. Therefore the mass of the sun must exceed the mass of Mercury\n324,000 x 24 = 7,776,000; the exact relation according to Von Asten is\n7,636,440. Again, the planet Jupiter, with its diameter of 85,000 miles\nand its density of 1.38, is only 1/1048 part of the mass of the sun, so\nthat it would take about 1048 Jupiters to equal the mass of the sun,\ntherefore Jupiter must weigh about 7400 times the mass of Mercury.\n\nIf the mass of Mercury, therefore, be represented by 1, the mass of the\nEarth would be represented by 24, the mass of Jupiter by 7400, and the\nmass of the sun by 7,636,400. So that the attractive forces between the\nplanets as regards their masses only will be represented numerically as\nfollows--\n\n    Sun and Mercury    7,636,400 x 1      =       7,636,400.\n\n    Sun and Earth      7,636,400 x 24     =     190,008,000.\n\n    Sun and Jupiter    7,636,400 x 7,400  =  56,435,360,000.\n\nThus we see that the attractive force between the sun and the earth\nexceeds 24 times the attractive force between the sun and Mercury, while\nthe attractive force of gravity between the sun and Jupiter is 7400\ntimes greater than the attractive force between the sun and Mercury,\nrelative to their masses.\n\nTherefore, according to the Law of Gravity, as regards the masses of\nbodies, Jupiter and the sun should be nearer together than Mercury and\nthe sun, because their attractive powers are greater, and the earth and\nthe sun should be nearer together than Mercury and the sun, because\ntheir joint attractive powers are also greater. In the same way it can\nbe proved that all the other planets whose masses are greater than\nMercury ought, according to the Law of Gravity in regard to masses only,\nto be nearer to the sun than what Mercury is, simply because the total\nattractive forces between any two are greater than the attractive force\nbetween Mercury and the sun.\n\nThe respective masses of the planets compared with the sun, taking the\nmass of the sun as unity, are as follows--\n\n    Jupiter  1/1,048  of mass of sun.\n\n    Saturn   1/3,529     \"  \"\n\n    Neptune  1/18,520    \"  \"\n\n    Uranus   1/22,020    \"  \"\n\n    Earth    1/324,439   \"  \"\n\n    Venus    1/397,000   \"  \"\n\n    Mars    1/2,994,790  \"  \"\n\n    Mercury 1/7,636,440  \"  \"\n\nTherefore, if the total attractive force of gravity is equal to the\nproduct of the masses of any two bodies, then the planets ought to be in\nthe following order in relation to their distance from the sun: Jupiter,\nfirst, followed by Saturn, Neptune, Uranus, Earth, Venus, Mars and\nMercury; that being the order in which the attractive power of gravity\nis regulated by their respective masses.\n\nYet the very opposite is nearly the case, as we find that some of the\nfurther planets, as Jupiter, Saturn, Uranus and Neptune, possess greater\nmasses than any of the nearer planets; so that here we have a distinct\nviolation of the Law of Gravitation Attraction, which states that the\nattraction between any two bodies is directly as the product of their\nmasses, because we find certain bodies with greater attracting powers\nfurther away from the sun, than other planets possessing less attracting\npowers, because of their smaller masses. I cannot recall having ever\nread of any explanation which has been given for such an anomaly, and\nindeed this apparent violation admits of no other explanation than the\nconception of the dual character of the so-called Law of Universal\nGravitation, which includes a repelling or repulsive force or motion,\nsuch motion being due to the pressure of the universal Aether.\n\nThus in the light of the centrifugal motion, combined with the fact that\nAether is gravitative, by which each body possesses an aetherial\natmosphere and electrical equivalent proportionate to its mass, it can\nbe demonstrated within a reasonable limit how it is that such planets as\nJupiter, Saturn, Uranus, Neptune, possessing aetherial atmospheres and\nelectrical equivalents proportionate to their masses, revolve in orbits\nround the sun at much greater distances than Mercury, Venus, the Earth,\nor Mars. This explanation will follow as we consider the Centrifugal\nForce and the Centripetal Force in their relation to Newton's Laws of\nMotion.\n\n\nART. 97. _Centripetal Force._--We have now to apply the Centripetal\nForce, together with the new Aetherial Centrifugal Force, to the solar\nsystem, and show that by their conjoint working taken in conjunction\nwith the motions of the Aether, all celestial phenomena may be\nsatisfactorily explained on a physical basis, in a similar way that\nNewton proved the same result from the mathematical standpoint.\n\nWe saw in Art. 10 that the centripetal force was really none other than\nthe Attraction of Gravitation, in that it always acted to a centre, and\nin no other way, and therefore by the centripetal force for the present\nwe must understand is meant the attractive power of Gravitation.\n\nAfterwards, when it has been demonstrated that the centripetal force and\nthe new aetherial centrifugal force can account for all celestial\nphenomena, then we shall be in a position to show what the physical\ncause of the centripetal force is.\n\nLet us again refer to the centripetal force, so that we may see exactly\nwhat its governing conditions are. In Art. 18 we learned that this force\nmight be thus expressed: \"Every particle of matter in the universe\nattracts every other particle with a force whose direction is that of a\nline joining their centres of gravity, and whose magnitude is directly\nas the product of their masses, and inversely as the square of the\ndistance between them.\" Now we have seen from the previous Art. that the\ncentrifugal force due to the pressure of the Aether medium is the exact\ncounterpart of this, in every way, so that if we combine the two, we get\nthe complete statement of the universal law which governs all matter,\nand which we may define as follows--\n\n\"Every particle in the universe attracts and repels every other\nparticle in the universe with a force whose direction is that of a line\njoining their centres of gravity, and whose magnitude is directly as the\nproduct of their masses, and inversely as the square of the distance\nbetween them.\" This complete law, however, only holds good when the two\nforces are in equilibrium.\n\nWith this conception of the universal law which governs all matter, the\nharmony and stability of the universe becomes possible from the physical\nstandpoint. Apart from this conjoint working of the two forces or\nmotions, a physical explanation of Universal Gravitation is impossible,\nas with one force operating only throughout the universe, ultimate\nstability is inconceivable, and the harmony of the spheres might at any\ntime be suddenly destroyed.\n\nWith this conception of the universal law which governs all matter, the\ngreat Law of Gravitation is brought into harmony with all experience and\nobservation. Look where we will, or at what we will, there we find\nforces possessing a dual character, as we have already seen proved.\nProfessor Tyndall, as we have already learned (Art. 63), definitely\nstates that the stability of atomic systems is preserved by the\nexistence and operation of _two forces, one attractive and the other\nrepulsive_, and what is true of the atomic world is equally true of\nsolar or stellar worlds. Thus for the first time in this respect, our\nphilosophy agrees with our experience, and the true relation of the\ncentrifugal force or motion to the centripetal force is made manifest.\nSo that, wherever in the solar system the centripetal force or\nGravitation Attraction operates, there, with exactly equal intensity and\npower, the aetherial centrifugal force operates, at the respective mean\ndistances of the planets and satellites, where the two forces are in\nequilibrium.\n\nIf it were possible to conceive of a stationary solar system, then, by\nthe conjoint working of the two forces, it would be equally possible to\nconceive of perfect stability and harmony existing between the\nrespective planets and satellites of that system while stationary.\n\nSuch a conception is altogether impossible in the present state of\nPhilosophy, as the stability of the system, with the old view of the\nCentrifugal Force, is entirely dependent upon the motions of the\nrespective bodies in that system; and if such orbital motions could be\nstayed, then the only physical conception possible would be, that every\nplanet and satellite, planetoid and meteor within the attractive force\nof the central body, the sun, would be slowly but surely drawn to a\nfiery death, as they would all ultimately be attracted and swallowed up\nby the sun.\n\nThus we learn, that while the sun is the centre of a centripetal force,\nwhich ever operates far and wide throughout space, it is equally the\ncentre of a repulsive or centrifugal force or motion which also operates\nco-extensively and co-equally with the former.\n\nNot only so, but every planet and satellite, nay every particle and\nevery atom, while it is the centre of a centripetal force, is also the\ncentre of a repulsive force, as pointed out by Professor Tyndall, which\nforce is due in each and every case to the pressure of the aetherial\natmosphere which surrounds the atom or molecule, satellite or planet.\nThus the physical conception of heat in its effect on molecules having a\nrepulsive force (Art. 63) is confirmed, and that that force is due to\nthe pressure of the Aether is also confirmed by subsequent\ninvestigations into the phenomena of light and electricity, by which we\nhave arrived at our physical conception of the Universal Centrifugal\nForce.\n\nSo that we have now a physical conception of the experiment performed by\nNichols and Hull of America, and by Professor Lebedew of Russia, in\nwhich they conclusively demonstrated the existence of the pressure of\naetherial light waves, which proves beyond the possibility of doubt the\nexistence of this physical centrifugal force. Every atom and molecule,\ntherefore, is the centre of two forces, which co-exist together, and\nevery meteor and satellite and every planet is also the centre of the\nsame two forces, and this we shall find in its application to planetary\nphenomena will have a most important bearing on the physical conception\nof those phenomena. Thus it is the Aether medium, by its energy of\nmotions, that constitutes the companion and complementary force to\nGravitation Attraction, and which, as we shall see later, is the medium\nwhich forms the physical basis of that attraction also. It is, then, by\nthe combined and harmonious working of these two co-equal, co-existent,\nand co-extensive forces that worlds roll and rush, sweep and swing, move\nand rotate about their respective centres; and, by these two forces\nworking in perfect harmony, that that order and stability are produced,\nwhich everywhere pervade the universe of worlds, and form them in their\nentirety into one grand, ultimate, and harmonious system.\n\nTo develop and prove this fact, by explaining their manner and mode of\nworking, we shall now proceed to consider Newton's Laws of Motion, and\ntheir relation to the aetherial medium, and by so doing shall be able to\nshow the unmistakable reality and complete efficiency of this physical\nconception of the Aether medium, which forms the physical basis of all\nuniversal motion and phenomena.\n\n\nART. 98. _Newton's First Law of Motion._--We will now apply the\ncentrifugal and centripetal forces to Newton's Laws of Motion, and\nendeavour to form a physical conception of the same from the aetherial\nstandpoint. Before doing so, we must recall some of the statements made\nin Art. 14 with reference to the First Law of Motion.\n\nIt will be remembered that we divided the First Law of Motion into two\nparts: 1st, \"Every body continues in a state of rest except in so far as\nit is compelled by impressed forces, _i. e._ impulses or motions, to\nchange that state.\" This we saw agreed with our experience, and\ntherefore was philosophically correct, and must hold good in its\napplication to the centrifugal and centripetal forces of the Aether in\ntheir effect upon any body in space.\n\nLet us proceed to apply the First Law of Motion to the planetary world.\nWe have seen in the previous Art. so far as the distances of the planets\nare concerned in their relation to the sun, that the Law of Gravity is\nviolated, and that planetary distance is not regulated by the law\ngoverning the centripetal force of Gravitation, otherwise the planets\npossessing the largest masses would be nearer to the sun than those\npossessing smaller masses.\n\nThe question arises, as to whether there is any law which governs\nplanetary distance, by which the distance of any planet was regulated at\nthe birth or creation of the solar system. It has been assumed by some\nscientists that planetary density is the regulating factor which\ndetermines the relative distance of the respective planets from their\ncentral body, the sun, but such an assumption is not consistent with\nscientific data. For we find that Venus, with a density of 4.81 compared\nwith water, occupies a nearer position than the Earth with a density of\n5.66, whereas the reverse should be the case if the density of a planet\nwere the deciding factor in regulating a planet's distance.\n\nAgain, we find Saturn, which possesses a density of .75, occupying a\nnearer position to the sun than Uranus, which possesses a density of\n1.28; so that here again, if density were the regulating factor which\ndecided planetary distance, such a law is violated. According to the\nvarious densities of the planets, the respective positions of the\nplanets in relation to the sun would be as follows: The nearest planet\nwould be Mercury, which possesses a density of 6.85. This would be\nfollowed by the Earth, with a density of 5.66. Then Venus would come\nnext, with a density of 4.81, followed by Mars, with a density of 4.01.\nAfter these we should have Jupiter, whose density is 1.38, with Uranus,\nwhose density is 1.28, followed by Neptune possessing a density of 1.15,\nand Saturn would take Neptune's place, as it possesses the least density\nof all, its density being only .75. So that it is manifest, that density\ncannot be the governing condition, as has been proved in the previous\narticle.\n\nNow, if all the planets ever formed part of the sun, and they were\nhurled off into space by the centrifugal motion of the Aether, then\nthere certainly would be some law which governs the relative distance of\nthe various planets; but as far as we can see, there is no such law, as\na law which is violated ceases to be a law, so that the law of masses or\ndensities of a planet, governing their distances, has no place in the\nsolar system.\n\nThis leads up to the question as to whether the planets ever did form\npart of the sun, as is generally supposed; and, in view of the fact that\nthere is no law by which planetary distances are regulated, we are\ncompelled to come to the conclusion that each planet and satellite once\nexisted in an aetherial condition in space, and that it was by the\ncondensation of that Aether, that each planet was formed; and that, at\nits birth, each planet occupied the relative distance from the sun which\nit occupies to-day.\n\nAt first sight this may appear startling, but I would ask the reader how\nhe can account otherwise for the great irregularity which exists in the\ndistances of the planets in their relation to the sun, as every known\nlaw which governs masses and density seems to be altogether set at\ndefiance.\n\nI hope to prove later on, that all matter has an aetherial origin, and\nif that be correct, then the origin of a planet briefly outlined can be\naccepted without violating the results of experience or experiment, and\nto that extent will be philosophically correct.\n\nDr. Larmor speaks of the aetherial constitution of matter, and refers to\nthe views of Faraday and Davy in support of such a theory, while Lord\nKelvin has referred to the same principle in an article on the\n\"Condensation of Gravitational Matter in any part of the Universe\"\n(_Phil. Mag._, July 1902). So that if it be possible for Aether to be\ncondensed, and so form the nucleus of a planet or satellite, then,\nseeing that the Aether is universal, any planet or satellite or meteor\nmay be formed in any part of the solar system; and the process has only\nto be continued, until we have planets of various sizes at various\ndistances from the central body, the sun.\n\nHere, therefore, at any rate, is a physical hypothesis which will\nsatisfactorily account for all the different distances of the various\nplanets. Apart from some such hypothesis, I fail to see how we can\naccount for the irregularity that exists between planetary distances,\nwhen viewed from the standpoint of their masses and their densities.\n\nFurther, such a conception is entirely in harmony with the view of the\ndual character of the motions or powers of the aetherial medium, that\nwould co-exist with the evolution and development of the planet. For, as\nthe planet was evolved and developed from the aetherial medium which\nsurrounded it on every side, two motions would be developed and grow\nwith it--the centrifugal force or motion, and the centripetal motion of\nthe Aether, or the attractive force known as Gravity. Thus, through all\nthe growth and development of a planet, these two powers, the\ncentripetal force and the centrifugal force, would be co-equal and\nco-existent.\n\nThe same truth applies to the sun or any other body in the universe; so\nthat, if a planet, as the Earth, was formed in the beginning at its mean\ndistance of 92,700,000 miles, then the joint centripetal motions\nproduced by the Earth and sun in the Aether, would always equal the\njoint centrifugal motions produced by the same two bodies, simply\nbecause the two laws are the exact opposite of each other both in regard\nto intensity, distance, and magnitude.\n\nThus the Earth would always occupy its relative position in relation to\nthe sun that it occupies to-day, as long as the two aetherial forces or\nmotions, the centripetal and the centrifugal, exist. With this brief\noutline of a planet's history, we are now in a position to form a\nphysical picture of the solar system when it first existed in the\nbeginning.\n\nWe find the sun then occupying its centre. At various distances, we find\nthe various planets situated without any regard to their relative masses\nor densities, as the following table shows. (The mass of sun is taken as\nunity.)\n\n                MEAN DISTANCE.    MASS.      DENSITY.\n\n    Mercury       35,900,000   1/7,636,440     6.85\n\n    Venus         67,000,000    1/397,000      4.81\n\n    Earth         92,700,000    1/324,439      5.66\n\n    Mars         141,000,000   1/2,994,790     4.01\n\n    Jupiter      482,000,000     1/1,048       1.38\n\n    Saturn       884,000,000     1/3,529        .75\n\n    Uranus     1,780,000,000     1/22,020      1.28\n\n    Neptune    2,780,000,000     1/18,520      1.15\n\nNow, in order for any of these planets to fulfil Newton's First Law of\nMotion, the sun, which occupies the centre of the solar system, must be\nassumed to have no rotatory or orbital motion of its own; because, so\nlong as it has a rotatory motion on its axis, or an orbital motion of\nits own through space, so long will even the first part of Newton's\nFirst Law of Motion be inapplicable to the solar system.\n\nBut if the sun can be assumed to possess at some point in its history no\norbital motion, or rotatory motion on its axis, then the physical\ninterpretation of the first law of motion can be physically conceived,\nand a planet at rest will remain at rest relatively to its central body,\nthe sun, for ever.\n\nLet us take the sun and Mercury as an example of the effect of the two\nmotions operating in the aetherial medium. We will consider first the\neffect of the centrifugal motion. The sun, with its huge form, occupies\nthe centre of the solar system, while Mercury has its mean distance\nabout 36,000,000 miles away.\n\nThe solar fires are intensely burning, and every atom and every particle\ncomposing them are excited thereby into the most intense activity, and\nby their energy of motion create myriads upon myriads of waves in the\nsurrounding Aether, which flow away on every side with the velocity of\nlight.\n\nWith such velocity are they generated, that they speed across the\ndistance of 36,000,000 miles which exist between Mercury and the sun in\nthe short time of about three minutes, and if it were not for the\naetherial and aerial atmosphere of the planet, would fall upon the\nsurface of Mercury with an intensity of heat that would scorch up all\nvegetable life, if any existed thereon.\n\nNow let us for a moment ignore the existence of the centripetal force,\nand then in that light view the influence of the electro-magnetic Aether\nwaves upon Mercury. We have seen that when aetherial light waves come\ninto contact with any body, they exert a pressure upon that body (Art.\n77), so that under the influence of the centrifugal force only, Mercury\nwould be borne away from its central body, the sun, with a power and\nenergy of motion entirely dependent upon the intensity of the\nelectro-magnetic Aether waves which give rise to the centrifugal force.\n\nThus Mercury would be carried away from the sun, far far away into the\ndepths of space, with ever-decreasing rapidity, the rapidity of its\nmotion through space being entirely dependent upon the intensity and\nenergy of the Aether waves; and, as that intensity varies inversely as\nthe square of the distance from the central body, the sun, so the\nimpelling and repelling energy of the Aetherial waves would vary\ninversely as the square of the distance from the central body.\n\nThus the motion of Mercury or any other planet through space would not\nbe uniform, but would gradually decrease, and such a result is perfectly\nin harmony with all experience and experiment in relation to moving\nbodies on this earth.\n\nThis effect of the Aetherial electro-magnetic light waves upon a planet\nis in harmony with Newton's nineteenth query in _Optics_, and is indeed\nthe physical illustration of that query in its corrected form which we\nhave already referred to in Art. 46, where Newton says: \"Doth it\n(Aether) not grow denser and denser, etc.; every body endeavouring to go\nfrom the denser parts of the medium towards the rarer?\"\n\nThat the Aether does grow denser and denser nearer to a body we have\nalready seen in Art. 46, and now we learn that a body, when under the\ninfluence of the centrifugal force only, would pass from the denser\nparts of a medium to the rarer parts, as suggested by Newton. We will\nnow suppose that Mercury has been repelled, by the pressure due to the\naetherial waves generated by the sun, to the distance of Neptune, a\ndistance of 2,780,000,000 miles; and that at this point the centrifugal\nforce is cancelled, and in its place is put the centripetal force of\nGravitation. What will be the effect upon Mercury then? At first sight\nthe effect will be exceedingly slight, but slowly, yet surely, the\nattractive power of the sun would begin to make itself manifest, and we\nshould find Mercury retracing its path along exactly the same straight\nline that it had taken in its outward journey.\n\nNot only so, but its motion would be accelerated just in the same\nproportion that it had decreased on its outward journey. On and on\nthrough the intervening space the planet would rush, and if there were\nno centrifugal force in existence, the planet would ultimately rush into\nthe central body, the sun, and being swallowed up by it, would maintain\nfor a time the heat thereof.\n\nLet us now view the case from the conjoint working of these forces, or\nmotions, the centripetal and centrifugal, and we shall see, that under\ncertain conditions it is possible to conceive physically of a planet\nbeing in a state of rest as stated in Newton's First Law of Motion, and\nalso remaining in that state of rest, until it is compelled by other\nforces or motions to change that state. Mercury is now situated at its\nmean distance of about 36,000,000 miles. At the same instant let both\nthe centrifugal and the centripetal forces or motions be applied to it,\nand to the sun. What is the result of such application? Will the planet\nmove nearer the sun, which we are supposing to be perfectly at rest, or\nwill it be urged further away? The effect is nil! for the simple reason,\nthat when we set in motion the centripetal force of Gravitation, at\nexactly the same time we set in motion an exactly opposite force which\nis the exact complement and counterpart of the other, so that they\nexactly counterbalance each other, and Mercury under the influence of\nboth forces still retains its mean position of 36,000,000 miles; and,\nuntil we either set the sun rotating, or give it a motion of its own\nthrough space, Mercury would remain at its distance of 36,000,000 miles\ncomparatively at rest. The same reasoning may be applied to all the\nother planets, in relation to their mean distances, with the result that\nthey too would remain in a comparative state of rest, so long as they\nwere only under the influence of the two forces or motions, viz. the\ncentrifugal and centripetal.\n\nEach of these, being the exact complement and counterpart of the other,\nwhen applied together to any planet of any size or mass or density, at\nany distance, fails to affect the distance of that planet in its\nrelation to the sun, but simply establishes it in that distance, subject\nto certain regulations dependent upon other motions of the sun, and the\naetherial medium in which they exist. Thus we learn, that if, in the\nbeginning, Mercury were formed at a distance of 36,000,000 miles, it\nwould for ever remain at that distance; and the same is true of the\nother planets at their mean distances, no matter what their mass or\ndensity may be; and that, according to the first law of motion, the\nplanet would remain in a state of rest until compelled by other forces\nor motions to change that state, when it would continue moving with\nuniform motion so long as the motive power applied was uniform.\n\nIf, however, the motive power applied was not uniform, then the result\nwould be an increase or decrease of the planet's motion, just in\nproportion to the increase or decrease of the motive power. This result\nis in perfect harmony with our statement in Art. 15, and is in\naccordance with observation and experience.\n\n\nART. 99. _Second Law of Motion._--According to Newton's Second Law of\nMotion, \"Change of motion is proportional to the impressed force, and\ntakes place in the direction in which the force is impressed.\"\n\nFrom a consideration of this Law (Art. 15) we saw that the impressed\nforce was a compound quantity, being regulated by the mass of the moving\nbody which exerted the impressed force, and that it was also\nproportionate to the velocity of the moving body; so that if either of\nthese quantities are changed, the total impressed force would be changed\nalso.\n\nWe have now to show that our aetherial medium agrees with this second\nlaw of motion in so far as the second law of motion agrees with\nexperience and experiments. To do this, we must review our conception of\nthe universal Aether, and remember that Aether is matter, and being\nmatter, it is atomic and gravitative, possessing density, elasticity,\ninertia, and kinetic energy, the same as any other moving matter.\n\nIn this Aether medium we have, according to this conception, something\nthat can both push and pull, or exert force upon any body with which it\ncomes into contact. Further, the inertia and kinetic energy of the\nAether at any part of space will be regulated by its mass in that\nparticular part, and if its mass is denser in some parts than others,\nthat part of the aetherial medium possessing the greatest mass will also\npossess the greatest capacity for impressing force upon any body that\nexists in the medium. Now we have learned from Art. 45 that Aether being\ngravitative, it is denser nearer to the sun, getting gradually less and\nless dense, the further it recedes from the central body, except where\nit is bound or associated to some other planet or satellite, and there\nit gradually gets denser, for the same reason that it is denser nearer\nto the sun. As, therefore, the Aether gets gradually less dense as it\nrecedes from the sun, the density of the Aether at the mean distance of\nMercury, 35,900,000 miles, would not be so great as near the sun's\nsurface; while the density of the aetherial medium at the distance of\nVenus, 67,000,000 miles, would be less than the density of the aetherial\nmedium at the distance of Mercury. This principle may be applied right\nthrough the sun's aetherial electro-magnetic field, until we come to the\nmean distance of Neptune, which is 2,780,000,000 miles, and there the\ndensity of the Aether would be less than at any other part of the\naetherial electro-magnetic field around the sun.\n\nSo that the mass of the Aether at Mercury, which is equal to the number\nof aetherial atoms per unit volume, is greater than the mass at Venus.\nThus the impressed force which the aetherial medium at the mean distance\nof Mercury can exert upon any body in its neighbourhood, is greater than\nthe impressed force which the Aether can exert upon any body at the\ndistance of Venus, because of its decreased mass at that distance. In\nthe same way it can be proved that the impressed force which the\nelectro-magnetic Aether exerts on any body at the distance of Venus, is\ngreater than the impressed force which the Aether exerts upon a body at\nthe mean distance of the Earth. So that at the respective mean distances\nof Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune, the\nelectro-magnetic Aether, if in motion, would exert less force at each\nof the mean distances of these planets exactly proportionate to the\ndecreased mass and decreased velocity of the Aether.\n\nNow what is the motion which the Aether possesses, so far as the sun is\nconcerned? because, upon the particular kind of motion which it\npossesses will depend the direction in which the impressed force will be\nexerted according to the second law of motion.\n\nIn Art. 98 we supposed the sun and planets to be stationary in the solar\nsystem, each planet being at its respective mean distance, from which it\ncannot move owing to the equality of the two forces. Now give to the\ncentral sun from whence the electro-magnetic Aether waves flow, a\nrotatory motion on its own axis, which it really possesses, as it\nrotates on its axis once in every twenty-six days nearly, and this will\ngive to the Aether medium a circular or rotatory motion. This circular\nor rotatory motion the Aether has already been proved to possess (Art.\n91, where we learned that all solar magnets were caused by\nelectro-magnetic aetherial currents constantly circulating round them).\nSo that the Aether will actually possess two motions: 1st, a radial\nmotion due to the Aether waves generated by the sun, which are radiated\nout into space with the velocity of light; and 2nd, a circular or\nrotatory motion. This result is in perfect harmony with our hypothesis\nas to the cause of the electro-magnetism of the sun (Art. 91, where we\nsaw that solar magnetism was due to electric currents circulating round\nthe various planets), and we have proved that the Aether has an\nelectro-magnetic basis; thus the rotatory Aether currents and the\nrotatory electro-magnetic currents are due to one and the same medium.\n\nNow what will be the effect of these circular or rotatory Aether\ncurrents on the bodies situated within their field? It must be\nremembered that we are no longer dealing with a frictionless medium, but\nwith a medium which possesses inertia and kinetic energy the same as any\nother moving matter. Therefore, as soon as it is set in motion, it will\nimpress its motions upon all planets that come under its control and\ninfluence, with the result that as the impressed force is ever directed\nin a circular form, the planet will be pushed along through space by the\nmoving Aether, and the path it describes will be circular also.\n\nThus the actual result of the rotatory electro-magnetic Aether currents\nwill be, that all dependent and associated planets under their influence\nwill be carried by them around the central body which generates the\nAether currents. So that they will literally and truly have an orbit,\nand the circle they describe will be, in its size and circumference,\nregulated by the mean distance of each planet, which mean distance will\nform the radius of the circular orbit.\n\nFurther, as we shall see later, if the sun were always stationary, and\nhad no orbital motion of its own, then the orbit of each planet would\nalways be circular, each planet always occupying its mean distance from\nthe sun, because at that mean distance the centripetal and centrifugal\nforces are equal.\n\nThat the actual path of any planet is a circle has been proved by Sir W.\nR. Hamilton. Tait, in his _Natural Philosophy_, on this point writes\n(Art. 38): \"The Hodograph for the motion of a planet or comet is always\na circle, whatever be the form and dimensions of the orbit.\" This path\nhas been termed the Hodograph. So that we have in the circling\nelectro-magnetic Aether currents a physical explanation for the\nHodograph of any planet.\n\nIn applying the rotatory Aether currents to the various planets, and in\nendeavouring to find out the quantity of the force impressed upon the\nvarious planets at their mean distances, by those currents, we have to\ntake into consideration, as we have already seen, two facts, viz. the\nmass of the Aether at any point in space, and the velocity of the Aether\nat the same point. We will first take the effect of the difference in\nmass. We have seen that at the distance of Mercury from the sun the\ndensity of the Aether is greater than at the distance of Venus, and that\nthe density at Mars is greater than the aetherial density at the Earth,\nthe aetherial density decreasing the further the Aether recedes from the\nsun.\n\nWhat, therefore, is the effect of the decreased density of the Aether on\neach planet? Even supposing the velocity of the moving Aether is the\nsame at the respective mean planetary distances, which it is not, the\ntotal impressed force at the respective mean planetary distances will\ngradually be decreased upon the various planets, proportionate to the\ndecrease in the mass and density of the Aether.\n\nSo that on Mercury, which is pushed along by a denser electro-magnetic\nAether than Venus, the impressed force, according to Newton's Second Law\nof Motion, will be greater than the impressed force exerted by the\nmoving electro-magnetic Aether on Venus; and, consequently, Mercury\nshould have a greater velocity through space than Venus, due partly to\nthe difference of the aetherial mass and density, by which the impressed\nforce or motive power that acts upon Mercury is produced.\n\nIn the same way, Venus should have a greater velocity through space than\nMars, and Mars a greater velocity than the Earth. The same principle, when\napplied to the outer planets, equally holds good; with the result, that\nthe greater the mean distance, the less the orbital velocity of each\nplanet, due partly to the decreased aetherial density at the increased\ndistance from the sun. But this is only part of the cause. Not only is\nthere a decrease in density of the Aether, as the distance from the sun\nis increased, but there is also a decrease in the velocity of the moving\nAether, with the result that the Aether at the distance of Mercury,\npossesses a greater angular velocity than at the distance of Venus.\n\nIt may be at once asked, How do we know that? Well, Philosophy alone can\ngive us the key, and Philosophy tells us to base our theories and\nhypotheses on experience and experiment. Now what does experiment and\nexperience teach us as to the effect of a body revolving in any medium\nupon that medium? If experience teaches us anything at all, it teaches\nus that the further away any medium is from the revolving body, the less\nis the angular velocity of that medium at that distance, while the\nnearer the medium is to the revolving body, the greater is the angular\nvelocity.\n\nThis applies in each and every case, whether the medium is either fluid\nor gaseous, and I will challenge the reader to perform any experiment on\nany solid body rotating in a fluid or gaseous medium, and prove by that\nexperiment that the angular velocity of the outermost part of the fluid\nor gaseous medium is equal to the angular velocity of the medium\ndirectly associated with the body, or even at a short distance from it.\n\nBut we have most conclusive evidence of the fact that a solid body does\nnot communicate all its rotational surface motion to the medium directly\nin contact with that body in the case of the earth revolving on its\naxis, surrounded by an atmosphere. If the principle held good anywhere\nin relation to a revolving body, viz. that the whole of the rotational\nvelocity is communicated to the medium surrounding the body, it should\ncertainly hold good at the surface of the body where the two media, the\nsolid and gaseous media, meet.\n\nIf a solid body fails to impart all its rotational velocity to the\nmedium there, then it will certainly fail to impart its full rotational\nvelocity to the enveloping medium 100 miles away, and fail still more at\na distance of 1000, and still more at a distance of 100,000,000, and so\non proportionate to the distance.\n\nWhat, then, is the effect of the rotational velocity of the surface of\nthe earth on the atmosphere near to it? We know that the velocity of the\nsurface of the earth is greatest at the equator, as at that place the\ncircumference of the earth is about 25,000 miles, but the further we get\naway from the equator, and the nearer we get to the North and South\npoles, the velocity of the surface decreases, simply because the\ncircumference of the earth decreases.\n\nOr, to reverse the statement, the velocity of the surface of the earth\nis least at the poles, but increases the nearer we get to the equator.\nIt is also familiar knowledge that there are currents of cold air ever\nmoving from the North and South poles to the equatorial regions near the\nsurface of the earth. Thus the cold air currents, in passing from the\nNorth and South poles, are ever passing over surfaces which are\nincreasing in velocity as they journey on their way to the equator. This\nof course occurs all round the earth, so that the earth is continually\nrevolving in these currents, and if the rotational velocity of the\nsurface of the earth were wholly imparted to the air directly over its\nsurface, then the currents would be always flowing due North and South.\n\nIf, however, the earth fails to impart all its rotational velocity to\nthe atmosphere, or the atmosphere fails to pick up the whole of the\nrotational velocity at once, then the result will be that the atmosphere\nas it passes over the surfaces of greatest velocity will lag behind,\nbecause its rotational velocity will be less than the velocity of the\nearth's surface.\n\nNow this is exactly what does happen in regard to the atmosphere, with\nthe result, that instead of getting winds blowing due north and south,\nwe get what are known as Trade Winds, which blow north-east in the\nnorthern hemisphere and south-east in the southern hemisphere. Here then\nwe have direct experimental proof on a large scale of the very principle\nI have stated, viz, that a medium surrounding any rotating body does not\nmove through the whole of its extent with the same velocity as its does\nat the surface. Thus it can be seen that the velocity of the rotating\nAether will be greatest at the surface of the sun, but its angular\nvelocity will decrease the further the medium recedes from the sun.\n\nThe same principle can easily be proved from an electrical standpoint;\nfor if we consider the Aether currents as electric currents, no one\nwould think of suggesting that the intensity of the currents was the\nsame at a distance of several million miles away, as it is near the\nsource of the currents, which in this case may be looked upon as the\nsun, because at its surface we have the greatest electric potential\n(Art. 80).\n\nSo that we see from this reasoning, that not only is there a decreased\nmass of the Aether at the distance of Venus, compared with Mercury, but\nthere is also a decreased velocity in the rotatory electro-magnetic\nAether currents, with the result that the impressed force exerted upon\nVenus is less than the impressed force exerted upon Mercury, and\ntherefore Venus should move slower through space than Mercury, which is\nexactly what happens, as Mercury has an orbital velocity of 29 miles per\nsecond, while Venus has an orbital velocity of 22 miles per second.\n\nAs the angular velocity decreases in proportion as the distance\nincreases, it follows that at the respective mean distances not only of\nVenus, but also of Mars, Jupiter, Saturn, Uranus and Neptune, the\ncapacity of the Aether to exert its impressed force upon the various\nplanets will decrease as the distance increases, with the result that\nthe farther a planet is from the sun, the less force will the Aether\ncurrents exert upon that planet, with the result that its orbital\nvelocity should decrease as the distance increases, and this is\nperfectly in accordance with planetary phenomena.\n\nHere, then, we have at once a physical basis for Newton's Second Law of\nMotion, the results of which are entirely in harmony with observation\nand experiment, and whose conception fully satisfies all the Rules of\nPhilosophy; as it is simple in conception, fully agrees with observation\nand experiment, and satisfactorily explains the Second Law of Motion\nsought to be explained.\n\nThus we find that from the physical standpoint, as well as from the\nmathematical standpoint, \"Change of motion is proportional to the\nimpressed force, and takes place in the direction in which the force is\nimpressed,\" that is, in a circular direction.\n\nWe have therefore arrived at exactly the same result that Newton arrived\nat, except that he had to introduce a third factor, viz. the\nParallelogram of Forces, while we have produced the result by a simpler\nmethod, which, according to his own rules, is more philosophical, as all\neffects are produced by the simplest causes, as Newton himself stated in\nRule 1. Thus it is the rotatory electro-magnetic Aether currents that\nurge the planets round the sun; and, as will be shown later, it is the\nsame Aether currents in combination with the other motions that give\nrise to the physical cause of Kepler's Laws. It is the electro-magnetic\nAether currents that produce the regular decrease in the velocity of the\nplanets in their orbits, because of the regular decrease of the mass and\nvelocity of the Aether currents themselves.\n\nWe have now a physical cause as well as a mathematical explanation of\nthe decrease of the velocity of a planet in its orbit, which physical\ncause is in perfect harmony with all philosophical rules. The following\ntable shows the gradual decrease in the velocity of each planet as the\nvarious planets recede from the sun--\n\n                   MEAN            PERIOD OF     VELOCITY IN\n                 DISTANCE.        REVOLUTION.    ORBIT PER HOUR.\n\n    Mercury      35,900,000         87.9 days\n\n    Venus        67,000,000        224.7             77.000\n\n    Earth        92,700,000        365.2             66.500\n\n    Mars        141,000,000        686.9             53.000\n\n    Jupiter     482,000,000      4,332.6             28.744\n\n    Saturn      884,000,000     10,759.              21.221\n\n    Uranus    1,780,000,000     30,687.              14.963\n\n    Neptune   2,780,000,000     60,127.              11.958\n\n\nART. 100. _Aether and Third Law of Motion._--We have seen (Art. 16) that\naction and reaction are equal and opposite, and that it is true of the\ncentripetal force in its application to all matter throughout the\nuniverse. If, therefore, the centrifugal force is the exact opposite of\nthe centripetal force, then the Third Law of Motion should equally hold\ngood in relation to that force also.\n\nWe have, therefore, to form a physical conception of the application of\nthe third law of motion, as it relates to the centrifugal force. As we\nhave already learned, this force is due to the universal\nelectro-magnetic Aether, which being gravitative, surrounds all atoms\nand molecules that may exist throughout the whole universe. It can\nreadily be seen, therefore, that if the Aether surrounds every atom and\nmolecule, then each atom repels another atom or molecule when the two\nforces are in equilibrium with exactly the same intensity with which the\natom and molecule attract each other.\n\nBut the centrifugal force in each case is due to the pressure of the\nAether, which presses always proportionately to the density of the\nAether surrounding the atom or molecules, as suggested by Professor\nChallis.\n\nThe mean density, however, of each atomic or molecular atmosphere is\nregulated solely by the mass of the atom or planet, therefore the\npressure exerted by one atom on another is proportionate to the mass of\neach atom, and to that extent is strictly in accordance with the law\nwhich governs the proportion of the forces between the two atoms or\nmolecules. If, therefore, we have two atoms, A and B, of different\nmasses, then it is true that while A exerts a pressure on B, which\npressure takes the form of a repulsion, at the same time B exerts a\npressure on A which is equal and opposite in its character and\nintensity, and in each case the pressure is due to the aetherial medium\nwhich surrounds each atom or molecule.\n\nWhen the atoms are equal in mass, then the resultant motion produced on\neach atom would be exactly equal, but when the masses vary, the\nresultant motion produced on each atom would vary also, though the\nmomentum in each case would be exactly equal and opposite, as momentum\nis a compound term dependent partly upon the mass of the body concerned.\n\nIn Art. 16 we saw that when this third law was applied to planetary\nphenomena, not only did the sun attract all the planets, but all the\nplanets attracted the sun with equal and opposite forces, and the\nplanets also attracted each other with equal and opposite forces. In the\nsame way it can be proved, that as the sun repels all the planets by the\npressure exerted by the aetherial centrifugal force on those planets,\nthe planets repel the sun with an exactly equal and opposite force at\ntheir mean distances. In Newton's conception, however, of the third law\nof motion, there was simply mathematical data to deal with, by which the\nlaw was shown to apply to the planetary and stellar world. In the case,\nhowever, of the centrifugal motion, we have a definite physical medium,\nwhich by its motions produces the pressure on the planets or suns that\nexist in space, which pressure forms the physical centrifugal force that\nforms the counterpart of Gravitation Attraction.\n\nLet us look at this phase of the case in detail, and by so doing help to\nestablish and confirm the physical existence of the force or motion\nreferred to. We have learned from Chapter IV. that as Aether is\ngravitative, it surrounds all satellites and planets, suns and stars\nthat exist in the universe.\n\nWe have also learned from Art. 86 that Aether has an electro-magnetic\nbasis, as mathematically proved by Maxwell and experimentally proved by\nHertz. Thus we came to the conclusion that each satellite and planet,\nsun and star, was an electrified body (Art. 81), or an electro-magnet\n(Art. 88), possessing its own electric or electro-magnetic field.\n\nWe also learned that in every electro-magnetic field there was a\npressure which was ever directed away from the body that generated the\nelectro-magnetic waves. Now, as every satellite and planet, sun and\nstar, is a generator of these waves according to our theory, it follows\nthat every satellite and planet, sun and star, is the centre of a\ncentrifugal force, which centrifugal force is regulated by the mass of\nthe satellite, planet, sun or star which gives rise to the centrifugal\nforce or motion.\n\nNow, in relation to all electro-magnetic action, it can be\nexperimentally demonstrated, that action and reaction are equal and\nopposite, so that if we have two electrified or magnetized bodies, then\nthe joint forces of attraction or repulsion between them are equal and\nopposite. This being so, when we apply the same law of action and\nreaction to the planets' influence on each other, it follows that the\nsame law must hold good in relation to them.\n\nSo that if we compare the repulsive powers of two planets on each other\nin the solar system, say the Earth and Jupiter, then, according to the\nthird law of motion, the repulsive action of Jupiter on the Earth is\nexactly equal and opposite to the repulsive action of the Earth on\nJupiter. If we compare the Earth and the sun, the repulsive action of\nthe sun on the Earth is exactly equal and opposite to the repulsive\naction of the Earth on the sun, that action or force being caused\ndirectly by the electro-magnetic Aether waves, which are generated by\neach electric, or electro-magnetic body.\n\nThus, as the third law of motion is true of the centripetal force,\nwhether in relation to the atomic world, or in relation to the solar\nsystem, or even to the universe at large, seeing that the centrifugal\nforce is the exact counterpart in every way of the centripetal force,\nexactly fulfilling all the laws which govern it, it follows as a matter\nof absolute necessity that the third law is also applicable to its\ncomplement or counterpart also, or else it would cease to be the\ncomplement and counterpart of the centripetal force.\n\n\nART. 101. _Why Planets revolve from West to East._--In Art. 99 we have\nseen that the revolution of the planets around the sun is produced and\nmaintained by the electro-magnetic Aether currents, which are generated\nby the axial motion of that electro-magnetic body. There is, however,\nanother effect produced, and another scientific fact which can be\naccounted for by the circulating motions of the Aether medium, viz. that\nthe orbital direction of each and all the planets would not only be in\nthe same direction, but they would also be in the same direction as the\nsun's rotation on its axis.\n\nSo that, whichever way the sun turns upon its axis, that way, and that\nalone, should be the orbital direction of all the planets in which they\nare circled round the sun by the circulating electro-magnetic Aether\ncurrents. It is the sun's axial motion that partly gives to the Aether\ncurrents their circling motion, and it is the circling motion of the\nAether currents that gives rise to the orbital motion of the planets,\nliterally carrying them round the sun by their kinetic energy and power.\n\nTherefore, if this be true, whichever way the sun turns upon its axis,\nthat will be the direction in which the Aether currents must circle\nround the sun, and in that direction the planets should travel in their\norbits. As must readily be seen, it is the inevitable result of the\nestablished working of the electro-magnetic Aether currents. If the sun\nrotated on its axis from east to west, then the electro-magnetic Aether\ncurrents would also travel in the same direction, from east to west, and\nthe planets would then revolve round the sun from east to west.\n\nIf the sun, however, rotates on its axis from west to east, then, if\nthere are such electro-magnetic Aether currents in existence, as those\nwe have already proved to exist, they, too, would travel from west to\neast, and as a natural result the planets, which are carried round the\nsun by the currents, would also possess the same orbital motion, that is\nfrom west to east.\n\nAs is well known, the sun rotates on its axis from west to east,\ntherefore the Aether currents also rotate from west to east, with the\nresult that the orbital directions of all the planets should also be in\nthe same direction, from west to east. Now, as is well known, all the\nplanets without exception, Mercury, Venus, the Earth, Mars, Jupiter,\nSaturn, Uranus, and Neptune, all travel round the sun from west to east.\n\nHere, then, we have indisputable evidence of the existence and mode of\nworking of the electro-magnetic aetherial currents, whose action alone\ncan produce the phenomena with which we are so familiar, and for which\nthere must be some physical cause. I am not aware that any reason or\nexplanation either mathematical or otherwise has ever been given, or\neven suggested, as to the cause of the phenomena which we have just\nendeavoured to explain.\n\nIndeed, there can be no other physical explanation of the fact, that all\nthe planets revolve round the sun in the same direction that the sun\nrotates on its axis, than the one here given, viz. that the cause is to\nbe found, and alone found, in the circulating electro-magnetic Aether\ncurrents which are generated in the Aether by the electro-magnetic body,\nthe sun. Again, in order to confirm the existence of these Aether\ncurrents that exist in space, not only those generated by the sun, but\nalso by all the other electro-magnetic bodies, as all the planets (Art.\n88), we will consider the working of the same upon the satellites of\nthose planets which possess them.\n\nThe Earth we know has one satellite, the moon, Mars has two satellites,\nPhobos and Deimos, Jupiter has five satellites, Saturn has eight\nsatellites, while up to the present Uranus has been found to possess\nfour, and Neptune one. There is, however, little doubt but that both\nUranus and Neptune possess more than those already discovered, as it is\ninconceivable that Jupiter and Saturn, which are nearer to the sun,\nshould possess a greater number of satellites by which the nights of the\nrespective planets are illuminated, while the further planets, which\nneed the increased lighting, because of the decreased intensity of the\naetherial light waves at the increased distance, possess apparently a\nless number of satellites, and therefore less illumination for their\nrespective nights.\n\nBut what have these satellites to teach us as to the existence of the\nelectro-magnetic aetherial currents that circulate round the planets? We\nhave to apply a similar course of reasoning to the planets, as we have\ndone in the case of the sun. If the sun is an electro-magnetic body, by\nits axial rotation it generates rotating Aether currents, and those\nAether currents partake of the same rotation as the revolving body, that\nis, from west to east. In a like manner each planet, being an\nelectro-magnet, generates electro-magnetic aetherial currents which also\npossess the same rotation as the planetary body which gives rise to\nthem.\n\nSo that if the planets rotate on their axes from east to west, the\nAether currents will also rotate from east to west, but if the rotation\nof each planet is from west to east, then the rotation of the Aether\ncurrents associated with each planet will also be from west to east,\nwith the result that each satellite will be carried round its primary\nplanet by the circulating Aether currents in exactly the same way as the\nplanet rotates on its axis.\n\nNow if this is the case, then we have further evidence of the existence\nof the circulating electro-magnetic Aether currents, not only those\nassociated with the sun, but those also associated with each of the\nplanets, as explained in Art. 91. It might have been urged in the case\nof the planet's revolution round the sun being in the same direction as\nthe sun's axial action, that such a fact was merely a coincidence, but\nsuch an objection loses its force if it is proved that the same\nprinciple or truth when applied to other bodies equally holds good. When\nwe come to analyze the direction of the satellites round their primary\nplanets, we find that each satellite has an orbital motion, or is\ncarried round its central and controlling planet by that planet's Aether\ncurrents in exactly the same direction that the planet rotates on its\naxis, viz. from west to east. So that we have in the orbital direction\nof the satellites, as we have also in the orbital direction of the\nplanets, conclusive evidence of the existence and mode of working of the\nAether and of the electro-magnetic currents generated in that aetherial\nmedium by the electro-magnetic bodies which rotate in it.\n\n\n\n\n                               CHAPTER XI\n\n                        AETHER AND KEPLER'S LAWS\n\n\nART. 102. _Aether and Kepler's First Law._--In Art. 26 we learned that\naccording to the First Law of Kepler, each planet revolves round the sun\nin an elliptic orbit, with the sun occupying one of the foci.\n\nWe also saw that that elliptic orbit was produced according to Newton by\nthe conjoint working of the centripetal and centrifugal forces in\nassociation with the three Laws of Motion, to which laws had to be added\na corollary, which is termed the Parallelogram of Forces, before the\nFirst Law of Kepler could be fulfilled.\n\nIn making any hypothesis as to the physical cause of Kepler's Laws, if\nit can be shown that the same aetherial medium that gives rise to the\ncentrifugal force, also gives rise to the centripetal force, and that\nthe same medium by its rotatory motions also fulfils the three laws of\nmotion, and gives a satisfactory physical explanation of all Kepler's\nLaws; then, according to our three Rules of Philosophy, we shall have\nfound a physical medium which, by its motions and pressures and\ntensions, can give rise to all the phenomena exhibited in the celestial\nmechanism. Such a physical explanation will be philosophically correct,\nin that it is simple in its conception, is entirely in harmony with\nobservation and experiment, and satisfactorily accounts for, and that on\na physical basis, all the phenomena associated with the whole of the\ncelestial mechanism.\n\nWe have therefore to apply the motions of the Aether medium to the solar\nsystem, and by so doing reveal the physical explanation of all Kepler's\nLaws, in the same way that Newton revealed their correctness from the\nmathematical standpoint. Let us review the conception of the solar\nsystem as given in Art. 99, so that we may be able to proceed from that\nphysical conception of a stationary solar system to a moving system.\n\nThus we see the sun in a stationary system occupying exactly the centre\nof that system. The solar energies are in full play, generating\nelectro-magnetic Aether waves which are radiated forth into space with\nthe velocity of light. Then, as there is given to the sun a rotatory\nmotion on its axis, that rotatory motion imparts to the gravitating\naetherial medium a circulatory or rotatory motion which spreads out\nthrough space with ever-increasing intensity.\n\nBy their radiating motion the Aether waves would repel all planets from\ntheir central body, the sun, if they were not counterbalanced by the\ncentripetal force; and the two forces, the centrifugal and the\ncentripetal forces, find their equilibrium at the mean distance of each\nplanet, thus fixing and regulating permanently the distance and orbit of\neach planetary world.\n\nAt the same time, the rotatory motion of the electro-magnetic Aether\ncurrents, according to the second law of motion, would act on the\nplanets by their kinetic or moving energy, and so circle them round the\nsun, their controlling centre. As long as the sun was quite stationary,\nwhile still possessing a rotation on its axis, if such a thing were\npossible, so long would the conception of the ancients be fulfilled, and\nthe rotation of all the planets would be strictly circular in form, and\ntheir orbits would be that of a circle only, as proved by Sir W. R.\nHamilton (Art. 99).\n\n[Illustration: Fig: 24.]\n\nBut, as is well known, the sun itself possesses an orbital motion of its\nown, so that, while all the associated planetary system is revolving\nround it, the sun with all that system is being carried along through\nspace in an orbit which is also elliptic in form, as we shall see later\non.\n\nAccording to Herschel, the sun is moving towards the constellation of\nHercules with a velocity of about 18,000 miles per hour, and the problem\nto be faced is, what is the effect of the sun's orbital velocity upon\nthe circular motion of the planets? By solving that problem, we shall\narrive at a physical conception for the first time of Kepler's Laws, and\nshall see that the first of Kepler's Laws is solved simply by giving an\norbital velocity to any central body, the result of which will be that\nthe circular form of any planet's orbit will be changed from the\ncircular into one of elliptic form.\n\nLet me ask the reader to perform a very simple experiment to confirm\nthis fact. Take a piece of string and a lead pencil, and start to draw a\ncircle on a piece of paper (Fig. 24). When, however, one quarter of the\ncircle has been drawn, viz. _D_ _F_, move the end of the piece of string\nrepresenting the centre of the circle along the paper, as represented in\nthe diagram, from _A_ to _B_. The result will be that the pencil will\nnow travel parallel with the moving centre for a time from _F_ to _G_,\nand then, when the centre is brought to rest again, the other part of\nthe half ellipse _G_ _H_ may be completed. In the same way, by reversing\nthe motion, the other half of the ellipse may be completed. So that it\nis possible for an ellipse to be formed simply by moving the central\npoint of a circle, and the motion of that central point will change the\nform of a circle into an ellipse. It is something like this that takes\nplace in the planetary world, with this difference, that the central\npoint which represents the sun does not return from one focus to\nanother, but continues to journey on through space, with the result that\nthe orbit of any planet is not strictly an ellipse, as we shall see\nlater on. We have, then, the sun occupying the centre of the solar\nsystem, with all the planets revolving round it. We will take the sun\nand the Earth as examples. Let _S_ in the diagram represent the sun, and\n_E_ the Earth at its mean distance of 92,000,000 miles away (Fig. 25).\n\n[Illustration: Fig: 25.]\n\nThe Earth we know is moving with a velocity of about 64,800 miles per\nhour around the sun, or an average velocity of 18 miles per second, so\nthat while the Earth is moving 64,800 miles through space to perform the\nhalf-circle, _E_ _D_ _C_, the sun is also travelling 18,000 miles\ntowards the point _D_.\n\nWhat, therefore, is the effect of this onward movement of the sun\ntowards the Earth as it tries to complete the half-circle _E_ _D_ _C_?\nWe have seen that the centrifugal force due to the pressure of the\nelectro-magnetic Aether waves is exactly equal to the centripetal force\nexerted by the sun on any planet, and if that be so, it can be readily\nseen that as the sun journeys towards the point _D_ of the Earth's\norbit, it tends to approach nearer and nearer the Earth. Thus the\nintensity of the aetherial pressure owing to the decreased distance will\nbe greatly increased, and the effect of the increased pressure of the\nAether upon the planet will be to push it away from the sun, so that the\ntwo forces may be equalized, and its mean distance, which is definitely\nfixed, be maintained as far as possible.\n\nThe result will be that, instead of the Earth describing the half-circle\n_E_ _D_ _C_, it actually describes the part of the ellipse _E_ _F_ _C_.\nThus it can be seen that while the sun is travelling through space, it is\nat the same time giving rise to the electro-magnetic Aether waves, which,\nby their repelling power, repel the Earth from the sun in the direction\nthat the sun is travelling, and hence the half-circle is elongated into\nthat part of the elliptic orbit known as the perihelion, which is that\npart of the orbit where the distance of any planet from the sun is the\nleast.\n\n[Illustration: Fig: 26.]\n\nThe repelling power of the Aether waves is not, however, sufficient to\novercome altogether the centripetal force in conjunction with the\nEarth's motion, with the result that when the Earth arrives at _F_, its\ndistance is only 91 million miles, that being the least distance between\nthe sun and the Earth. We shall see the result of this decreased\ndistance when we deal with Kepler's Second Law.\n\nWe will now proceed to notice the effect of the sun's orbital velocity\nupon that part of the Earth's orbit which includes the aphelion, or that\npart in which the Earth occupies a position of the greatest distance\nfrom the sun. Proceeding on the same method of reasoning, if the sun\nwere stationary, with the Earth being circled round it by the\nelectro-magnetic Aether currents, then the path described by the Earth\nwould be that of a circle, being represented by the half-circle _C_ _G_\n_E_ (Fig. 26).\n\nBut it has to be remembered that while the Earth is being circled round\nthe sun by the rotatory electro-magnetic Aether currents, the sun is\nstill travelling on towards _S_ _F_ at the rate of 18,000 miles per\nhour, while the Earth is travelling in almost an opposite direction\ntowards _C_ _G_, so that by the time the Earth has got to _G_, which we\nwill suppose is one quarter of its ellipse, the sun has travelled\nmillions of miles in that time.\n\nThus it can readily be seen, that by the time the Earth has got to its\naphelion, it is at its furthest distance from the sun, simply because\nthe sun has been travelling onwards through space all the time, while\nthe Earth has been receding from it; and as the motion of the Earth has\nbeen in an opposite direction, the mean distance has been exceeded, and\ninstead of the Earth being now at its mean distance from the sun, its\ndistance is now 94,500,000 miles. At that part of its orbit, its orbital\nvelocity is at a minimum, because the rotating Aether currents have\nthere a decreased flow and a decreased mass and density, and therefore\npossess a decreased kinetic energy or motive power.\n\nThus by the rotating Aether currents working in conjunction with the\ncentrifugal and centripetal forces, can be accounted on a physical basis\nthe first of Kepler's Laws in a manner which is strictly philosophical,\nas the explanation is simple in conception, does not violate experience\nor experiment, and satisfactorily accounts for, on a physical basis, the\nlaw which it is required to explain.\n\nIf we consider the rotating Aether currents as purely currents of\nelectricity, then exactly the same results follow. For, as we shall see\nlater, Professor Lodge in his _Modern Views of Electricity_ proves that\nelectricity possesses both inertia and momentum, and if electricity\npossesses these properties, then it also possesses the requisite\nproperties to enable the currents to propel or push any planet around\nits central body, or a satellite round its primary planet. Therefore the\nsame course of reasoning that applies to the rotating Aether currents,\nequally applies to the currents of electricity that circulate round each\nsatellite, planet, and sun and star, and by that circulation gives rise\nto the electro-magnetism associated with each body, while at the same\ntime they supply the kinetic energy which enables any dependent or\nassociated body to be propelled round their controlling centre.\n\n\nART. 103. _Second Law of Kepler._--According to Kepler's Second Law\n(Art. 27), we learn that the radius vector, which is the imaginary\nstraight line joining any planet to the sun, describes, or sweeps over,\nequal areas in equal times. So that, while Kelper's First Law describes\nthe path which a planet takes in revolving round the sun, the Second Law\nshows how the velocity of that planet varies in different parts of its\norbit.\n\nWhile, however, there is a difference in the velocity of any planet at\nvarious points in the orbit, there is still a proportion existing\nbetween its various velocities, in that equal areas are covered in equal\ntimes. We have now to apply the hypothesis of our rotatory Aether\ncurrents, in conjunction with the centripetal and centrifugal forces, in\norder to see whether the Second Law of Kepler can be explained on a\nphysical basis, in the same way that Newton explained it from the\nmathematical standpoint.\n\nWe have again to conceive the sun as the centre of two equal but exactly\nopposite forces, and also possessing a rotatory motion on its axis, with\nthe electro-magnetic Aether currents ever circulating round it. If the\nsun were stationary, it will be manifest at once that Kepler's Second\nLaw would be literally and strictly fulfilled, for in that case the\norbit of all the planets would be perfect circles, and the motion of\nplanets in their orbits would be perfectly uniform, and therefore equal\nareas would be covered by the radius vector in equal times. Thus any\nquarter of the orbit would be described in exactly a 1/4 of a year, 1/12\nin 1/12 of a year, 1/40 in 1/40 of a year, and so on, the time being\nexactly proportional to the proportion of the area covered by the radius\nvector.\n\nThe area covered would always be uniform, because the radius vector\nwould always be uniform in length. But, as we have seen in the previous\narticle, the distance of a planet from the sun, that is, the length of\nthe radius vector, is not uniform, as the Earth is nearer to the sun at\nperihelion, and further away at aphelion, its distance gradually\nchanging as it passes from each of these points to the other.\n\nNow what is the effect of the decreased distance upon the circulating or\nrotatory Aether currents? We have already seen (Art. 99) that the closer\nthese Aether currents are to the central body, the sun, the greater is\ntheir velocity and the greater their mass, so that the total impressed\nforce which they exert over any planet is greater the nearer that planet\nis to the sun. This is proved by the fact that Mercury has a greater\norbital velocity than Venus, Venus than the Earth, the Earth than Mars,\nand so on right through the whole of the planetary system. In view of\nthese facts, let us again consider the effect of the sun not being\nstationary, but having an orbital velocity of its own through space.\nThus let the sun be at _S_ and the Earth be at point _D_ of its orbit\n(Fig. 25).\n\nThe circulating Aether currents are ever acting upon the Earth, carrying\nit round the sun with them, while at the same time the centripetal force\nis pulling it towards the sun with a certain intensity, but the\ncentrifugal force is repelling the Earth with exactly the same\nintensity, and if the sun remained motionless the two forces would\nexactly balance each other, while the Earth would describe the\nhalf-circle _E_ _D_ _C_. But while the Earth is moving towards the\npoint _D_ with a velocity of 64,000 miles per hour, the sun is also\nmoving at the velocity of about 18,000 miles per hour towards that\npoint.\n\nThus the repelling power of the radiating electro-magnetic Aether waves\nhas to overcome, not only its exact counterpart, the centripetal force,\nbut also the onward motion of the sun as it rushes on its course through\nspace. This the centrifugal force is unable to do, with the result that\nthe distance is gradually lessened, and instead of the Earth describing\nthe arc _E_ _D_, it describes the arc _E_ _F_, at which point its\ndistance is at the minimum, or about 91 millions of miles.\n\nOr, to put the same fact in another way. When the Earth is at _E_, the\ncentripetal force and the orbital velocity of the Earth and the sun are\nacting conjointly, with the result that they overcome the centrifugal\nforce, and the distance is gradually decreased. This decreased distance\nmeans an increased aetherial density and an increased velocity of the\naetherial currents, with the result, that as the distance is decreased,\nthe orbital velocity of the Earth is gradually increased, so that by the\ntime the Earth gets to _F_, at its perihelion, it has now acquired its\ngreatest orbital velocity, and is carried round the sun by the\nelectro-magnetic Aether currents at its maximum velocity.\n\nNow let us look at the Earth being circled round the sun by the\nelectro-magnetic Aether currents as it goes on to perform the other half\nof the orbit. In this case we have the orbital motion of the sun and the\ncentrifugal force working conjointly, with the result that together they\novercome the centripetal force, and the Earth is repelled and carried\nbeyond its mean distance. Let _S_ represent the sun, the Earth being at\npoint _C_ of its orbit, after passing round its perihelion, and at this\ndecreased distance it is carried along by the circulating and denser\nAether with its maximum velocity (Fig. 26).\n\nNow while the Earth is going on to describe the half-circle _C_ _G_ _E_,\nthe sun is still pursuing its journey at the rate of about 18,000 miles\nper hour, only this time in a direction away from the Earth. As, however,\nthe Earth has not yet regained its mean distance of 92,000,000 miles,\nthe centrifugal force is still greater than the centripetal force, so\nthat the centrifugal force is urging the planet away from the sun with\ngreater intensity than the centripetal force is attracting it, as the\ntwo forces are only in equilibrium at the mean distance of the Earth.\n\nThus, as stated, the orbital motion of the sun and the centrifugal\nforces are now working conjointly together, with the result that the\nEarth is repelled gradually further and further from its central body,\nuntil it reaches its maximum distance of 94,500,000 miles. While,\nhowever, the distance is gradually being increased, it is passing into a\npart of the Aether possessing not only a decreased mass, but also a\ndecreased velocity, with the result that the motive power or kinetic\nenergy of the aetherial currents at the increased distance is gradually\nlessened, and as a natural result the velocity of the Earth is also\ndecreased; so that by the time the Earth has got to its furthest\ndistance from the sun, its orbital velocity is slowest, because of the\ndecreased momentum of the aetherial currents.\n\nThus we can account for the difference of velocity of a planet in its\norbit by the same electro-magnetic Aether currents working in\nconjunction with the sun's orbital motion, and that upon a strictly\nphysical basis. This result is in perfect harmony with Kepler's Second\nLaw, which states that equal areas are described by the radius vector in\nequal times. Newton proved that by the Law of Gravitation Attraction he\ncould account for this second law, as well as all the others, and as we\nhave not destroyed that law, but perfected it by giving it its exact\ncomplement and counterpart, the same mathematical reasoning that applies\nto the centripetal force must equally apply to the centrifugal force,\nand if it is true that the centripetal force works harmoniously with the\nsecond of Kepler's Laws, then it is equally true that the centrifugal\nforce does also, as the two are inseparably and indisputably united\ntogether in the atomic Aether. We have, however, a physical basis for\nthis centrifugal force, and we have an equal physical basis for the\ncentripetal force, as we shall see later, and therefore, by the conjoint\nworking of these two forces taken in conjunction with the orbital motion\nof the sun, we have now a physical conception for the first time of\nKepler's Laws, as well as a mathematical conception, that physical\nconception being derived from the pressure and motions of the universal\nAether.\n\n\nART. 104. _Aether and Kepler's Third Law._--In Art. 28 we saw that\naccording to the Third Law of Kepler, the square of the periodic time\nwas proportionate to the cube of the mean distance of that planet from\nits controlling centre. Newton proved that this Third Law was\nmathematically correct, and that it could be mathematically accounted\nfor by the existence and operation of the universal Law of Gravitation.\nAs the centrifugal force is the exact opposite of that force in\nintensity, proportion and mode of operation, it follows that\nmathematically the centrifugal force also bears the same relation to the\nThird Law that the centripetal force does.\n\nWe have, however, a physical basis for the centrifugal force, and it is\nwith the physical conception of this Third Law rather than with its\nmathematical character that we are now dealing. Kepler by his Third Law\nshowed that the chief regulating factor in the orbital velocity of a\nplanet was its mean distance from the sun.\n\nThe great regulator of the velocity of any planet in its orbit is\nsimply planetary distance, and planetary distance alone. If there were\nno other law which operated in the solar system than the centripetal\nforce, or the attractive force due to gravity, then such factors as mass\nand density of a planet ought to play a most important part in the\norbital velocity of a planet, as the centripetal force directly\nrecognizes the influence of mass, that is, volume and density, but says\nnothing about mean distances. This fact unmistakably points to the\nexistence, and demands the operation, of another force, which shall\nexplain, and that on a physical as well as a mathematical basis, how it\nis that the mean distance of a planet from any centre regulates the\norbital velocity of that planet.\n\nThe only real and true conception of such a force is to be found in the\nradiating waves and circulating motions of the aetherial medium, which\nwaves, like water waves, increase in their radial outflow and extent\nwith a regular decreasing intensity, and at the same time decrease in\ntheir angular velocity as they recede from the sun. With such a regular\ndecrease of kinetic energy, there must necessarily be imparted to the\nplanets, as their mean distance is increased, a decreased velocity of\nmotion, with the natural result, that the further a planet is from the\nsun, the less will be its orbital velocity, and that in a regular and\nuniform proportion as the distance is increased.\n\nNow let us view the matter for a moment in its application to the solar\nsystem, and by so doing show the simplicity of the explanation, and at\nthe same time give added proof to the existence and operation of the\ncirculating aetherial currents that exist in space. Let us again picture\nthe solar fires burning in all their fierceness and intensity, every\natom and particle of the sun being thrown thereby into the most intense\nstate of activity, and by their energy of motion creating\nelectro-magnetic Aether waves in their myriads, which speed away from\nthe sun on every side.\n\nUnder their influence, all subordinate worlds would be carried away into\nspace, were it not for the complementary Law of Gravitation Attraction,\nthat is, the centripetal force. But to every planet, by the operation of\nsome governing and determining principle, a mean distance has been\ngiven, and at that mean distance the two forces find their equilibrium;\nand by their conjoint and co-equal working hold each planet at that mean\ndistance with a power that cannot be broken. Each power or force may be\nmodified under certain conditions, as shown in the two preceding\narticles; but, whether the planet be repelled further away, or attracted\nnearer to the sun, through the onward motion of the sun, the two forces\never seek to maintain their equilibrium, and to place the planet at its\nmean position assigned to it in the solar system.\n\nThe nearer that mean position is to the sun, the greater is the velocity\nof the aetherial currents which circulate round the sun; and the greater\ntheir mass, volume for volume, on account of the increasing density of the\nAether, the nearer it is to the sun. The effect of this increased\nvelocity, and the increased mass of the circulating Aether currents, is to\nimpart to planets nearest to the sun the greatest orbital velocity; while,\nthe greater the distance, the less will be the orbital velocity of the\nplanet. That this is exactly in accordance with observation and\nexperience may be proved by considering the respective mean distances\nand orbital velocities of the various planets.\n\nMercury, with a mean distance of 35,900,000 miles, is circled round the\nsun at the enormous rate of about 108,000 miles per hour, accomplishing\nits entire journey in the short period of 88 days. Venus, whose mean\ndistance is about 67,000,000 miles, is carried round the sun at the\nreduced rate of 78,000 miles per hour, completing her orbit in the\nincreased time of 224 days. Our own Earth, at the still further\nincreased mean distance of 92,000,000 miles, performs her journey at the\nreduced velocity of 64,000 miles per hour, accomplishing the journey\nround the sun in a period of 365 days.\n\nThus, the further we get from the sun, the slower becomes the movement\nof a planet in its orbit, and the longer it takes to complete its\nrevolution round its controlling centre. Mars, at the increased distance\nof 141,000,000 miles, possesses a reduced velocity of 54,000 miles per\nhour, and completes its orbit in the increased duration of 686 days. So\nthe decrease of velocity goes on, as the planets increase their mean\ndistance from the sun, as the following figures show--\n\n                 MEAN DISTANCE.   PERIOD OF   ORBITAL VELOCITY\n                                  REVOLUTION.     PER HOUR.\n\n    Jupiter       482 millions    4,332 days    28,000 miles\n    Saturn        884    \"       10,759  \"      21,600   \"\n    Uranus      1,780    \"       30,687  \"       1,800   \"\n    Neptune     2,780    \"       60.127  \"         900   \"\n\nThe relation of this decrease of velocity to the mean distance is\nexactly determined by Kepler's Third Law, in which he states that the\nsquare of the periodic time is proportionate to the cube of the mean\ndistance. That this is true has already been proved in Art. 28.\n\nIn conclusion on this point, let me ask the reader to try to conceive\nany other physical explanation for this decrease of orbital velocity as\nthe mean distance is increased, than the one given here, namely, the\ndecrease in the velocity and mass of the radiating and circulating\nAether currents, and if such attempt is made, I premise that its only\nresult will be utter failure. No other physical conception to account on\na physical basis for all Kepler's Laws can be given or conceived, than\nthat which finds its origin in the universal electro-magnetic Aether,\nwhich by its pressures, tensions and motions gives rise to all the\nphenomena incidental to, and associated with, planetary and stellar\nphenomena.\n\nTherefore, inasmuch as all the laws of motion, and all Kepler's Laws can\nbe accounted for by a gravitating and rotatory Aether medium, those\nfacts alone, apart from the explanation of other phenomena associated\nwith light and heat, would stamp the circulating Aether medium as the\nphysical cause of all the motions and phenomena associated with the\nwhole of the celestial mechanism.\n\n\nART. 105. _Orbital Motions of Satellites and Planets._--According to\nKepler's First Law, the Earth and all the other planets move round the\nsun in orbits which are in the shape of an ellipse. Not only, however,\nis the first law true of planetary motion, it is equally true of the\nmotions of all satellites moving round their primary planets. I wish,\nhowever, to point out, and prove in an indisputable manner, that\nKepler's First Law does not sufficiently explain and determine the exact\norbit of any satellite as it revolves around its primary planet, or even\nof any planet as it revolves around the sun.\n\nSimply because, if any satellite or planet is to perform a perfect\nellipse as it revolves around its central body, that central body must\nonly move for a time and must then come to rest, or partly return in its\njourney in order for a perfect ellipse to be formed, as shown in a\nprevious figure. Now we know from observation that such a thing as rest\nin space by any planet, or by the sun, is absolutely unknown in the\ncelestial mechanism.\n\nFrom Art. 92 we learned that the electro-magnetic Aether currents not\nonly circulate round the sun, but they also circulate round each planet.\nThus we found there were electro-magnetic Aether currents circulating\nround each planet, while those planets themselves were circled round the\nsun by the Aether currents generated by the sun; the planetary Aether\ncurrents in their turn propel the satellites round their primary\nplanets. It can easily be seen, therefore, that such phenomena as rest\nand return of a planet in its journey are physical impossibilities, for\neither the circulating Aether currents would have to cease circulating,\nor would have to return upon themselves in some inconceivable manner.\n\nThus there is ever going on this conjoint motion, so to speak, of the\nsun's aetherial currents which circle all the planets round that body,\nand the planetary aetherial currents which circle all the satellites\nround their central body, and it is the effect of the conjoint working\nof these currents on the planets and satellites to which I wish to call\nthe reader's attention.\n\nLet us in starting represent the earth's orbit by a perfect ellipse _A_\n_B_ _C_ _D_, with the sun occupying one of the foci _S_ (Fig. 27). We\nwill suppose that the earth is at point _A_ of its orbit and is being\ncircled round the sun with uniform velocity. As it is circled round the\nsun by the sun's aetherial currents, at the same time its satellite the\nmoon is being circled round the earth by the electro-magnetic Aether\ncurrents which circulate round that planet. We will represent the orbit of\nthe moon by part of a smaller circle _D_ _E_ _F_, and suppose the moon to\nbe at point _D_ of that orbit. The mean distance of the moon from the\nearth is about 240,000 miles, so that the diameter of the orbit is 480,000\nmiles, therefore the circumference of the orbit is 480,000 x 3.1416, which\ngives us about 1,500,000 miles.\n\n[Illustration: Fig: 27.]\n\nThat distance is traversed in about 28 days, so that the moon's average\nvelocity in its orbit, as it is circled or pushed round the earth, is\nabout 2200 miles per hour. While, therefore, the moon is travelling 2200\nmiles, the earth in its journey round the sun has travelled about 64,800\nmiles in the same time. So that by the time the moon has travelled half\nits orbit, that is, from _D_ to _F_, which would take about 14 days, the\nearth has also travelled in its orbit 64,800 x 24 x 14 = 21,772,800\nmiles, with the result, that instead of the moon arriving at point _F_,\nwhich it would do if the earth were stationary, it really arrives at a\npoint about 21,772,800 miles in front of that point.\n\nIn a similar way, while the moon goes on to describe the other half of\nthe orbit, the earth still proceeds on its journey, so that at the end\nof 14 days it is again 21,772,800 miles further on, with the result,\nthat the centripetal force (by which the moon is attracted to the earth)\nkeeps it at the distance of 240,000 miles according to Kepler's Second\nLaw as explained in Art. 103.\n\nThe moon, therefore, completes its orbit about 21,772,800 miles further\non than it would do if the earth were stationary. The effect of this\ncontinual progress of the earth on the moon's orbit as it describes its\norbit round the sun is seen in the diagram. As the moon revolves round\nthe earth thirteen times in one year, it performs thirteen revolutions\nround that planet; but it cannot be said that these orbits are perfect\nellipses, as the earth is ever being circled round its central body, the\nsun. Even this diagram does not accurately represent the orbital motion\nof the moon through space, as it assumes that the earth returns to the\nsame point in space from whence it started. This, however, is incorrect,\nas we have to remember that the sun has also an orbital velocity of\n18,000 miles per hour, so that while the earth has performed one\nrevolution in its orbit, the sun has actually progressed through space\nto the extent of 18,000 x 24 x 365 = 157,680,000 miles.\n\nWhen we come to deal with the sun's motion through space, we shall see\nthat this distance only represents a fraction of the sun's orbit, as it\ncan be philosophically proved, that if the sun moves at all, it, too,\nobeys Kepler's Laws; and therefore, according to his First Law, it also\ndescribes and possesses an orbit of its own. So that by the time the\nearth has made its annual revolution round the sun, the whole system has\nbeen carried 157,680,000 miles through space, and therefore the earth\ndoes not complete a perfect ellipse, but its orbital motion round the\nsun will be represented by a similar kind of diagram to the one which\nrepresents the orbital motions of the moon, or any other satellite round\nits central body.\n\n\nART. 106. _Eccentricity of Orbit of Moon._--From astronomical\nobservation we learn, that all the satellites and planets do not possess\nuniformity of motion, as they are carried round their controlling\ncentres by the circulating aetherial currents, because the respective\ncontrolling centres themselves move through space. The result is, that\nthe orbit of any satellite or planet is not always of the same size, but\nconstantly varies, sometimes having a larger circumference than at other\ntimes, and sometimes a smaller circumference.\n\nThis change in the size of the orbit of a satellite or planet is known\nas the eccentricity of the orbit, which eccentricity is constantly\nchanging, being sometimes greater and sometimes less. We will look at\nthis truth in its relation to the moon first, and then consider the same\nprinciple in its relation to the earth and other planets later on. For\nthe purpose of illustration, we will consider the earth as being circled\nround the sun by the electro-magnetic Aether currents in a closed orbit,\n_A_ _B_ _C_ _D_, which forms a perfect ellipse, the sun occupying one of\nthe foci _S_ (Fig. 28), the earth occupying a position in the orbit\nrepresented by point _C_, with the moon being circled round the earth by\nthat planet's aetherial currents. As we have already seen in Art. 103,\naccording to Kepler's Second Law, at this point the earth is furthest\nfrom the sun, being now at a distance of 94-1/2 millions of miles, and\ntherefore its orbital velocity will be slowest at that part of its\norbit.\n\nIf it were absolutely at rest in space, and simply revolving on its own\naxis, then the result would be that the moon would be circled round the\nearth in an orbit _M_ _C_ _F_ which is perfectly circular in form; but, as\nthe earth is being carried along slowly through space by the circulating\nAether currents, this onward movement changes the circular orbit into an\norbit of elliptic form.\n\n[Illustration: Fig: 28.]\n\nThe eccentricity of the moon's orbit when the earth is at its aphelion,\nor furthest from the sun, is now at a minimum, for the simple reason\nthat the earth is proceeding slowly through space, owing to the\ndecreased kinetic energy of the aetherial currents at the increased\ndistance.\n\nSo that, at this point of the earth's orbit, the difference between the\ntwo axes of the moon's orbit will be the least, and its orbit at that\npoint will be the nearest approach to that of a circle. But, as we have\nalready seen, as soon as the earth leaves this part of its orbit, and\nbegins to get nearer to the sun, it passes into a part of the aetherial\nmedium possessing greater kinetic energy, with the result that its own\nvelocity is accelerated. Now what is the effect of this increased\nacceleration of the earth on the eccentricity of the orbit of the moon?\n\nThe earth's rotation on its axis remains unaltered during this\nincreasing orbital velocity, consequently the aetherial currents\ngenerated by the earth will remain uniform, and the moon will still be\ncircled round the earth in the same period of about 28 days. But while\nthe time of the moon's revolution remains unaltered, the orbit that she\nhas to describe is now increased owing to the increased orbital\nvelocity of its central body, with the result, that by the time the\nearth gets to that part of its orbit represented by point _D_, it is\nthen two millions of miles nearer to the sun than at point _C_, and will\nbe circled round the sun by the aetherial currents at a much greater\nrate. Therefore, the eccentricity of the moon's orbit is increased just\nin proportion to the increased velocity of the earth in its orbit round\nthe sun. By the time the earth has arrived at point _A_, when it is only\na distance of about 91 millions of miles from the sun, it reaches the\nminimum distance, and is circled round at the decreased distance with\nits maximum velocity.\n\nAt this point, therefore, the eccentricity of the orbit of the moon will\nbe at its greatest, and, if one revolution could be represented by an\nellipse _E_ _G_ _H_, then that ellipse would be more elongated, and the\ndifference between the two axes of the moon's orbit would be greater\nthan at any other point of the earth's orbit.\n\nThus it can readily be seen that the eccentricity of the moon's orbit is\nprimarily due to the different velocities of the central body, in this\ncase the earth, as that body is carried round its central body, the sun.\nWhere the earth's motion is slowest, there the eccentricity of the\nmoon's orbit will be at a minimum; but where the earth's velocity is\ngreatest, there the eccentricity of the moon's orbit will be at a\nmaximum.\n\nBetween this minimum and maximum velocity of the earth in its orbit\nthere is the constant increase or decrease in the eccentricity of the\norbit of the moon; the eccentricity increasing as the orbital velocity\nof the central body increases, and decreasing as the orbital velocity of\nthe earth decreases. A further fact has, however, to be taken into\nconsideration, which is that the primary body about which the moon\nrevolves is itself subject to the same eccentricity of its orbit, and\nfor similar reasons, as we shall see later on. So that when the\neccentricity of the earth's orbit is at its greatest, then the moon's\norbit will possess its greatest possible eccentricity, and as the\neccentricity of the earth's orbit is dependent upon the orbital velocity\nof the sun, so the greatest possible eccentricity of the moon's orbit is\nindirectly connected and associated with the sun's motion through space,\nwhich motion will now be considered.\n\n\nART. 107. _The Sun and Kepler's First Law._--We have learned in the\nprevious articles that Kepler's Laws not only apply to planetary motion,\nbut are equally applicable to the motion of all satellites as they\nrevolve round their respective planets.\n\nThe question now confronts us, as to whether Kepler's Laws are equally\ntrue in their application to the sun? Now the sun is one of the host of\nstars that move in the vast infinity of space, and if it can be proved\nthat Kepler's Laws hold good in relation to one star, as they do in\nrelation to all planets and satellites, then such a result will have a\nmost important bearing upon the motions of other stars, and we shall be\nable to determine with some degree of exactness what are the motions and\norbits by which all the stars in the universe are governed.\n\nSir Wm. Herschel first attacked the question as to whether the sun, like\nall the other stars, was in motion, and if in motion, what was the shape\nof its orbit, and the laws which governed its orbital velocity.\n\nWe know that the sun is the centre of the solar system, and the question\nto be considered is, whether that system is circled round a controlling\ncentre while the sun is at rest in space, simply possessing its one\naxial rotation, or whether, like every planet and satellite, it is\nsubject to two motions, an axial rotation and an orbital velocity\nthrough space. Further, if it possesses an orbital velocity through\nspace, what is the cause of that orbital velocity?\n\nIt was due to the genius of Sir Wm. Herschel to first solve this\nproblem, and by careful research he was able to determine that the sun,\nwith all its attendant planets, was indeed moving through space.\n\nNot only did he discover this fact, but he also found out the direction\nin which the whole of our solar system was moving, as well as the\nvelocity with which the general movement was performed. Herschel proved\nthat the onward march of the solar system was in the direction of the\nconstellation of Hercules, and that the velocity of the march of this\nsystem exceeds five miles per second, or 500,000 miles per day.\n\nThus we learn that the whole of our solar system, comprising the sun,\nwith all its planets with their attendant satellites which circle round\neach planet, and the asteroids or minor planets, are bound together by\nthe two forces, the centripetal and the centrifugal, while the system as\na whole is urged on its way by some force or power through the realms of\nspace.\n\nWhat that power is we shall try to find out as we consider the\napplication of Kepler's Laws to this onward movement of the sun. If,\nthen, the sun is moving through space with this enormous velocity, the\nquestion arises as to what is the shape of the path or orbit which it\ndescribes? Sir Wm. Herschel attacked this question from a mathematical\nstandpoint, and came to a certain conclusion, as we shall see. We will,\nhowever, attack the problem solely from the philosophical standpoint, by\napplying to it the Rules of Philosophy given in our first chapter, and\nwe will then see whether our result is in harmony with the conclusions\narrived at by Sir Wm. Herschel.\n\nNow what has experience and observation to tell us regarding the orbit\nwhich any body moving in space assumes? Take, for example, our moon as\nillustrating the movement of all satellites, and our earth as\nillustrating all planetary motion.\n\nWhat does observation teach us as to the orbits which these bodies\ndescribe? If it teaches us anything at all, it teaches us that every\nsatellite and planet moves with varying velocity in a varying orbit\naround some central body. So far as our observation goes, then, in\nrelation to planetary motion, or the motion of satellites, we learn that\nevery body which moves in space fulfils Kepler's First Law, and\ndescribes an orbit round a central body, that body occupying one of the\nfoci.\n\nThus, wherever we get any body moving in space, if there be any truth in\nphilosophy which is based on experiment and observation, that body ought\nalso to move in similar elliptic orbits, and be subject to exactly\nsimilar conditions governing those orbits. But we have learned that the\nsun moves through space with a velocity of about five miles per second,\ntherefore it follows, philosophically, that the sun must also move\naround some other central body, and the path of such movement is that of\nan elliptic orbit, with the central body around which it moves occupying\none of the foci.\n\nIn other words, the sun obeys the first of Kepler's Laws, the same as\nall the planets and satellites do. Suppose, for a moment, that it is\ndenied that the sun moves in an elliptic orbit! What path would it\npursue in place of that? Would the path be that of a straight line\ntowards the constellation of Hercules? Such an assumption would be\naltogether unphilosophical, as it is contrary to all experience and\nobservation, and is therefore untenable.\n\nBefore such an assumption can be made, it must be proved that every\nplanet and satellite moves in a straight line, and not till that has\nbeen done can it be assumed that the sun moves in a straight line, or\nindeed in any other path than that stated in the first of Kepler's Laws.\n\nThis conclusion is in perfect harmony with the conclusion arrived at by\nHerschel, for in his work on _Astronomy_, in Arts. 292, 295 and 297, he\npoints out that the sun's path is elliptic in form, and that Kepler also\nshowed the sun fulfilled the first of his laws, and described an orbit\nwhich was in the shape of an ellipse. We have therefore philosophically\narrived at the conclusion that the sun moves in an elliptic orbit, and\nto do so it must move round some central body, which is to the sun what\nthe sun is to the planets, and what the planets are to the satellites.\n\nIt is impossible to conceive of the sun moving in an elliptic orbit,\nand yet not moving around some central body, as we should have a\ncelestial phenomenon altogether opposed to all experience and\nobservation. For we have already seen that the central body is just as\nimportant a factor to the elliptic orbit as the planet itself, because,\nwithout the central body there cannot possibly be any elliptic orbit.\nWhere then in the universe is the central body around which the sun\nrevolves? What is its distance away from the sun? What is its size?\nThese are questions that philosophy alone cannot answer, as there is no\nlaw, so far as I can see, that regulates the size and distance of the\ncentral body in proportion to the size and distance of the planets or\nsatellites.\n\nIf there were, then it would be possible for philosophy to apply such a\nlaw or rule. That there is a central body around which the sun revolves\nis as true as the fact that there is a central body about which each\nplanet revolves, or each satellite revolves, and it remains for the\npractical astronomer, or the mathematician, to endeavour to discover the\nexact part of the heavens in which it is situated, and ascertain its\ndistance and possibly its size. What will be the effect of the existence\nof this central body of the sun upon the solar system? One effect will\nbe to do away with that isolation that up to the present has apparently\nexisted with regard to our solar system and stellar space.\n\nInstead of the solar system being a solitary system that moves through\nspace subject to apparently no law, and moved by apparently no physical\npower, that system, through the influence and effect of the aetherial\ncurrents originated by that central body, will be linked to other parts\nof the universe, and will become a part of one harmonious whole, its\nphysical connection being made manifest and plain in the self-same\nelectro-magnetic Aether medium that forms the connecting medium between\nthe satellites and planets, or the planets and the sun.\n\nAnother result will be, that as the sun is a star, we shall be able to\napply the self-same principles and laws of Kepler to the stellar world\nin exactly the same way that we have done to the solar system. Thus, by\nbringing all stellar phenomena under the influence of Kepler's Laws, we\nshall be able to philosophically give an unity to the universe, and\nshow, within rational limits, how such unity may be physically\nconceived, which result will be an advance upon any physical conception\nof the universe hitherto manifested or revealed. Further, by accepting\nthe first of Kepler's Laws in relation to the sun, and admitting the\nexistence of a central body, we shall be able then to apply the second\nof Kepler's Laws, and by so doing shall be able to give a physical\nexplanation of two scientific facts which up to the present have never\nbeen physically explained, viz. the physical conception of the plane of\nthe ecliptic, and a physical explanation of the eccentricity of the\nearth's orbit, which is but the result of the application of Kepler's\nSecond Law to the sun's orbital motion around its central body.\n\n\nART. 108. _The Sun and Kepler's Second Law._--We will now proceed to\napply the second of Kepler's Laws to the orbital motion of the sun, and,\nin so doing, shall find we are able to give at the same time a physical\nexplanation of the eccentricity of the earth's orbit.\n\nIn order to obtain a physical conception of the sun's orbital motion\naccording to Kepler's First Law, it is essential that we should consider\nthe effect of the existence of a central body around which the sun\nrevolves; or, to put the matter into another form, we will ask the\nquestion as to what is the physical cause of the sun revolving round\nthat central body?\n\nLet us look at the case for a moment. Here, according to astronomical\nobservation, we find a certain phenomenon which takes the form of a huge\nbody 865,000 miles in diameter moving through space with a velocity of\nnearly 500,000 miles per day. What then is the physical cause of the\nmovement of this large sphere?\n\nCertainly there must be some physical cause, or else we have a violation\nof all experience, which indisputably teaches us that no body moves\nunless it is either pushed or pulled. We have, however, done away with a\npulling power so far as the cause of the actual revolution of bodies\naround a central body is concerned, and in its place have substituted a\nmedium that pushes or carries them round each central body. For over 200\nyears the scientific world has accepted a pulling power, that is, an\nattractive power, solely as the cause of the movements of celestial\nbodies, with the result that the physical cause of all the motions of\nplanets and satellites has been outstanding and undiscovered.\n\nIt would, therefore, be unphilosophical to revert to the old conception\nof a gravitating attractive power as the sole cause of the sun's orbital\nmotion through space. If we desire to know what is the cause of its\nrevolution round that central body, then we must seek to find the same\nfrom the result of observation and experience in other directions.\n\nWe have learned from Art. 102 that the orbital motion of the moon is\ncaused by the electro-magnetic Aether currents that circulate round its\ncentral body, the earth. By the same means every satellite is circled\nround its central body also. We have also learned from Art. 99 that the\nearth is carried round the sun by the circulating and rotating\nelectro-magnetic Aether currents, and that these same currents also form\nthe physical cause of the revolution of all the other planets round\ntheir central body, the sun.\n\nThus we arrive at the fact that wherever there is a body moving in\nspace, it is moving solely because it is pushed along, or carried round\nits controlling centre by the rotating Aether currents. But we have just\nlearned that the sun is moving through space, and that it describes an\nelliptic orbit around some central body in accordance with Kepler's\nFirst Law. So that the only philosophical conclusion that we can\npossibly arrive at in relation to the orbital motion of the sun is, that\nsuch motion is caused by similar electro-magnetic Aether currents whose\ncirculating motion is partly caused by the rotation of that central\nbody.\n\nThus we are led up to the philosophical conclusion, that it is the\naetherial currents of the central body around which the sun revolves,\nthat produce, and alone produce, the onward motion of the sun through\nspace. Any other conclusion must be unphilosophical, and therefore\nuntenable. We have, therefore, to conceive of the sun's central body\ngenerating and giving rise to electro-magnetic aetherial currents that\nextend through space to the limits at least of the solar system, and\nthese aetherial currents, acting upon the sun's huge form by their\nkinetic energy, carry it with all its associated worlds through infinite\nspace.\n\nThere is nothing extravagant in this conception, when we remember that\nthe solar system has been moving on and on through infinite space year\nafter year, and yet it never seems to get appreciably nearer to the\nother stars, but I hope to show the reason of this by strictly\nphilosophical reasoning later on. With this conception of the sun in its\nrelation to its central body we are now in a position to consider the\napplication of Kepler's Second Law upon the sun's orbital motion, and\nits resultant effect upon the orbit of our earth and all the other\nplanets.\n\nFrom Kepler's Second Law we know that equal areas are described by the\nradius vector in equal times, and if the first law of Kepler is at all\napplicable to the sun, then it must follow that if the sun has an orbit,\nand moreover an elliptic orbit as stated by Kepler himself, then, as a\nnatural result, the radius vector of the sun must move over equal areas\nin equal times.\n\nThe physical explanation of Kepler's Second Law was given in Art. 103,\nand there is no need to traverse the same ground again. It is,\ntherefore, true that the sun moves faster in certain parts of its orbit\nthan in others, being urged through space at its greatest velocity when\nit is nearest its controlling centre, and slowest when farthest away\nfrom that controlling centre.\n\nHerschel, in his work on _Astronomy_, states: \"The motion of the sun will\nbe such that equal areas are thus swept over by the revolving radius\nvector in equal times in whatever part of the circumference of the ellipse\nthe sun may be moving.\" He, however, suggested that the earth forms a\nfocus of the sun's ellipse, a suggestion which is unphilosophical, it\nseems to me, as we might equally suggest that the earth revolves round the\nmoon, which is contrary to all observation. Thus the sun is not carried\nuniformly through space by the aetherial currents of its central body,\nbecause it is nearer to that central body at certain times; its velocity\nbeing regulated by its distance from that body, the same being increased\nas the distance is decreased, and decreased as the distance increases.\n\nNow if this reasoning be correct, and if the sun really moves round a\ncentral body and is subject to Kepler's Second Law, then that increase\nand decrease of distance will be made manifest in the increase and\ndecrease of the eccentricity of the earth's orbit.\n\nSo that if the eccentricity of the earth's orbit should vary from\ncentury to century, then we have conclusive evidence that the sun obeys\nthe first and second of Kepler's Laws, and therefore that it revolves\naround a controlling centre of its own. From observation we find that\nthis is exactly what is happening, and that at the present time the\neccentricity of the earth's orbit is gradually diminishing, and in about\n24,000 years the orbit will be very nearly a circle.\n\nNow, from what was stated in Art. 106, we know that the moon's orbit\nwill be nearly a circular orbit when the earth is farthest from the sun,\nand that then its orbital velocity is at a minimum.\n\nIn order for this result to be produced, the earth must reach that part\nof its orbit known as aphelion, where the distance from its controlling\ncentre is greatest, so that the eccentricity of the moon's orbit is\nalways an indication of the position of the earth in its relation to the\nsun. When the eccentricity of the moon's orbit is decreasing, the\nearth's distance from the sun is increasing, but when the eccentricity\nof the moon's orbit is increasing, then the earth's distance from the\nsun is decreasing.\n\nNow if we apply this analogy to the eccentricity of the earth's orbit,\nwe shall be able to obtain some idea of the relation of the sun to its\ncentral body. We find then that the eccentricity of the earth's orbit is\ndecreasing, therefore, arguing from analogy, we arrive at the conclusion\nthat the sun's distance from its controlling centre is increasing, and\nthat its orbital velocity is decreasing.\n\nIf it be true that in 24,000 years the earth's orbit will be nearly\ncircular, then it follows that in 24,000 years the sun will be at that\npart of its orbit corresponding to the aphelion of the orbit of the\nearth, that is, its distance from its controlling centre will then be at\na maximum. After that the eccentricity of the earth's orbit will begin\nto increase, and will continue to increase for about 40,000 years,\naccording to some scientists, which implies that the sun will then have\nstarted from its aphelion point, so to speak, and will begin its return\njourney towards its central body, gradually getting nearer and nearer.\nAs it gets nearer its orbital velocity will be proportionately\nincreased, with the result that the eccentricity of the earth's orbit\nwill increase also. From a consideration of the movement of the major\naxis of the earth's orbit, which is moving forward at the rate of\n11 deg. per year, we are told that a whole revolution will be made in\n108,000 years.\n\nWe have here, then, an indication of the time that the sun takes to\nrevolve round its central body, because the time of the whole revolution\nof the eccentricity of the orbit should correspond with one complete\nrevolution of the sun around its central body. So that from a\nconsideration of the eccentricity of the earth's orbit, we are not only\nable to demonstrate that the sun satisfactorily fulfils the first and\nsecond of Kepler's Laws, but, conversely, we are able to give a\nsatisfactory physical explanation of the cause of the eccentricity of\nthe earth's orbit, which explanation is again primarily to be found in\nthe universal Aether medium.\n\n\nART. 109. _Plane of the Ecliptic and Zodiacal Light._--As already\npointed out, another phenomenon which can be physically accounted for by\nthe sun's orbital motion through space around its central body, is that\ncelestial plane known as the Plane of the Ecliptic.\n\nWhat then is the Plane of the Ecliptic whose physical explanation we are\nto attempt? We know that the moon revolves round the earth as the earth\nrevolves round the sun, while the sun is pursuing its way through space.\nIt has been found also, that all these motions of these different bodies\ntake place on one level, so to speak; that is to say, they do not go up\nor down in space, but straight on.\n\nSo straight do they move, that their path has been likened to the level\nof the ocean, on which a ship may sail for thousands of miles, always\nkeeping the same level and even course. On some such ocean as this in\nspace all the planetary systems and solar systems seem to move, ever\nmoving on and on with the same uniformity of level through infinite\nspace. Further, this plane of the ecliptic is to the celestial sphere\nwhat the sea-level is to the earth. The height of a mountain on the\nearth is stated to be so much above the sea-level.\n\nIn a similar way astronomers say that a star is a certain height above\nthe plane of the ecliptic. What then is the physical explanation of this\nscientific term? We will lead up to it by first considering the effect\nthat rotation has upon a liquid body.\n\nIt has been demonstrated that if a mass of oil is placed in a\ntransparent liquid of the same density, so long as the oil is perfectly\nat rest, its shape will be that of a sphere which will float about in\nthe liquid, but as soon as the oil is made to rotate by means of a piece\nof wire, then the spherical shape is changed into that of an oblate\nspheroid.\n\nFurther, the faster it is made to rotate, the more it will bulge out, so\nthat its equatorial diameter will greatly exceed its polar diameter. The\nsame principle may be illustrated by making a hoop to revolve rapidly on\nits axis, when a similar effect of bulging out will be produced.\n\nNow let us apply this principle to the earth with its electro-magnetic\nAether currents circulating round it, and ask what is the effect of the\nrotation first upon the earth, and then upon the rotating Aether\ncurrents?\n\nIt is a matter of common knowledge that the effect of rotation upon the\nearth when it was in a fluid state was to make its equatorial parts\nbulge out as it rotated, with the result that as it solidified the\nequatorial diameter exceeded the polar diameter by 26 miles.\n\nIf, therefore, the result of rotation upon the earth when in its fluid\nstate was to make it spread out greater in the equatorial regions than\nin any other part of its surface, what must be the effect of a similar\nrotation upon the rotatory Aether currents? It can easily be seen that\nthe rotation of these currents will be to make them spread out into\nspace in a region which corresponds to the equatorial regions of the\nearth, so that the rotating Aether currents will be congregated more in\nthe equatorial regions of the earth than in any other part of the\nearth's surface. The further also they extend into space the less depth\nthey will have, gradually tapering off, as shown in the illustration,\nwhere _E_ represents the earth and _B_ _C_ the Aether currents (Fig. 29).\n\nAny body, therefore, situated within the sphere of their influence would\nbe carried round the earth by the currents, and the currents would be to\nthem their governing and controlling level.\n\nSo that the moon, which is held bound to the earth by the two opposite\nand equal forces, would always be carried around the earth by those\nelectro-magnetic Aether currents, and outside of those currents it could\nnot pass. But the earth is only 8000 miles in diameter, therefore if the\ncurrents gradually tapered off as suggested, by the time the aetherial\ncurrents reached the distance of the moon, their depth would not exceed\n2000 or 3000 miles.\n\nThe diameter of the moon is, however, only 2160 miles, so that the\nrotating Aether currents would practically form an ocean in which the\nmoon would swim, and one constant level on which it revolves in space.\nWherever the earth was carried by the aetherial currents of the sun,\nthere the aetherial currents of the earth would carry the moon, its mean\ndistance by the conjoint working of the two co-equal forces having been\npermanently fixed.\n\n[Illustration: Fig: 29.]\n\nSo that it can be readily seen, as regards the moon, that the earth's\naetherial currents form the plane on which it revolves around the earth.\nNow in exactly the same way it can be proved that it is the sun's\naetherial currents which form the plane or level on which all the\nplanets revolve or are carried around their central body. We have only\nto enlarge our conception and the same result follows. Instead of\ndealing with a body 8000 miles in diameter, we are now dealing with a\nbody 865,000 miles in diameter, and as this huge body is more or less in\nan incandescent state, the aetherial currents will therefore be\nproportionate in intensity and flow to its size and atomic activity.\n\nInstead, therefore, of the aetherial currents which circulate round the\nsun only extending a quarter of a million of miles, their energy and\nflow extend far away into space, even beyond the greatest distance of\nNeptune, a distance of 2,800,000,000 miles. The same truths apply here,\nhowever, as in the case of the earth and the moon. The aetherial\ncurrents which circulate round the sun congregate together, and possess\ntheir greatest depth nearest to the equator, while the further away they\nrecede, the less and less depth they possess, with a decreased intensity\nand decreased kinetic energy. These Aether currents will be to all the\nplanets, therefore, what the earth's aetherial currents will be to the\nmoon, being to them the ocean level on which they alone can move, and by\nwhich they are carried round their central body.\n\nThus these currents will form for all the planets the level in infinite\nspace upon which they float, and from which they cannot pass. Let us\nfurther consider the movements of these currents in space, and we shall\nfind further confirmation of this fact by so doing. Astronomers tell us\nthat it takes light about three and a half years to reach us from the\nnearest star. By calculation, therefore, we find that the nearest star\nto our system is about 205,000,000,000,000 miles away, that being about\nthe distance that light travels in three and a half years.\n\nThe diameter of the sun is about 865,000 miles, so that the distance of\nthe nearest star is 240,000,000 times the diameter of the sun. We could\ntherefore put 240,000,000 of our solar systems in the space that exists\nbetween us and the nearest star. How is it, then, that all the planets\nas they revolve round the sun do not float up and down in the space that\nextends between us and the nearest star?\n\nI can give no other answer, and can see no other possible physical\nexplanation than the one already given, which is, that they are bound to\nthe sun by the two co-equal forces, the centrifugal and centripetal\nforces, and while so bound are carried round the sun by the\nelectro-magnetic aetherial currents which extend out into space. It has\nto be remembered that the aetherial electro-magnetic currents\ncirculating round the earth are situated within the aetherial currents\nwhich circulate round the sun, therefore the plane of the moon's orbit\nwill coincide more or less with the plane of the earth's orbit. We have\nnow only to go one step further to get our complete conception of the\nplane of the ecliptic.\n\nIn Arts. 107 and 108 we learned that the sun was subject to Kepler's 1st\nand 2nd laws, and as a natural result we came to the conclusion that it,\ntoo, was circled round some central body. We have only to apply a\nsimilar course of reasoning to the sun and its central body as we have\nto the moon and the earth, and the earth and the sun, and then we arrive\nat our physical conception of the plane of the ecliptic, which is due to\nthe aetherial currents that circle round the sun, while that body is\ncarried round some other central body.\n\nThus by the circulating Aether currents, originated and outflowing from\ntheir respective sources, each source being immutably fixed and bound to\neach other by the two equal and complementary forces, can be accounted\nfor, the uniformity of position and plane of the various orbits of the\nvarious satellites, planets, and the sun, as they move in one great\nplane, termed the Plane of the Ecliptic.\n\nIt could not be otherwise than it is, and thus another celestial\nphenomenon can be accounted for on a real tangible basis by accepting\nthe existence of those aetherial currents which form the physical basis\nof all the celestial mechanism.\n\nIf further evidence were required of the existence of these rotating\nAether currents round the sun, such evidence is found in that phenomenon\nof the solar system known as the Zodiacal Light, of which up to the\npresent no physical explanation has been forthcoming. In the conception\nof the atomic and gravitating Aether which rotates round the sun, I\nventure to premise will be found the physical solution of this\nphenomenon also.\n\nI will refer the reader to an extract taken out of _Outlines of\nAstronomy_, by Herschel (Art. 894), so that we may see what his\nconception of the zodiacal light was, and we will see how far his\nexplanation is in conformity with our hypothesis of an atomic,\ngravitating and rotatory Aether medium.\n\nHe writes: \"We shall conclude this chapter by the mention of two\nphenomena, which to me indicate the existence of some slight degree of\nnebulosity about the sun itself, and even to place it in the list of\nnebulous stars. The first is that called the Zodiacal Light, which may\nbe seen any very clear evening soon after sunset, about the months of\nMarch, April and May, as a cone or lenticularly-shaped light extending\nfrom the horizon obliquely upwards, and following generally the course\nof the ecliptic, or rather that of the sun's equator. The apparent\nangular distance of its vertex from the sun varies, according to\ncircumstances, from 40 deg. to 90 deg., and the breadth of its base\nperpendicular to its axis from 8 deg. to 30 deg. It is extremely faint\nand ill-defined, at least in this climate, though better seen in\ntropical regions, but cannot be mistaken for any atmospheric\nmeteor or aurora borealis. It is manifestly in the nature of a\n_lenticularly-formed envelope surrounding the sun_, and extending\nbeyond the orbits of Mercury and Venus, and nearly, perhaps quite,\nattaining that of the earth, since its vertex has been seen fully 90\ndeg. from the sun's place in a great circle. It may be conjectured to\nbe no other than the _denser part_ of that medium which we have some\nreason to believe resists the motions of comets; loaded perhaps with\nthe actual materials of the tails of millions of those bodies of which\nthey have been stripped in their successive perihelion passage. If its\nparticles have inertia, they must necessarily stand with respect to\nthe sun in the relation of separate and independent minute planets,\neach having its own orbit, plane of motion, and periodic time.\"\n\nLet me call the reader's special attention to one or two statements of\nHerschel's given in this extract, in order to see how these statements\nharmonize with the view of the Aether submitted in this work. In the\nfirst place he states its shape is that of a lenticularly-formed\nenvelope surrounding the sun, and extending beyond the orbits of Mercury\nand Venus, and probably to our earth. This harmonizes with the shape of\nthe aetherial envelope as given in Art. 70. Then Herschel states it may\nbe the denser part of that medium which we have reason to believe\nresists the motions of comets. That is exactly what it is, though\nHerschel failed to show why it should be the denser part of the Aether,\nas we have seen is the case, on account of its being gravitative. I will\nalso prove later on, that Herschel was right with regard to the\nresistance of the motion of comets through it. Then he refers to its\nparticles probably possessing inertia, as though he had anticipated the\natomicity of the Aether, and assuming that atomicity, he was compelled\nto postulate inertia also as we have done in Art. 48.\n\nLastly, he points out that each separate particle must have its own\nplane of motion, its own orbit, and its periodic time. Now this view\nfully coincides with that laid down in this article, where we have\nlearned that the rotating Aether has its own plane of motion, that plane\nbeing the Plane of the Ecliptic, and as every particle or atom has its\nallotted place in the rotating Aether, then, as Herschel points out, the\nparticle must have its own orbit, and plane of motion, and also its own\nperiodic time. If, therefore, we had desired fuller confirmation of this\natomic gravitating Aether, we could not have wished for more conclusive\nproof than that given by one of the greatest philosophical astronomers\nof the last century. We shall see later that Herschel also had a clearer\nview of cometary phenomena, and of the forces which played a part in\nthose phenomena, than any of his contemporaries, when we deal with the\norigin and motions of all comets. Thus from Herschel we learn that the\nzodiacal light is caused by the atomic, gravitating, and rotatory Aether\nas that aetherial medium revolves round the sun, while at the same time\nevery atom of the medium is itself in a state of rotation on its axis,\nas it performs its journey in its own orbit and in its own plane of\nmotion.\n\n\nART. 110. _Centripetal Force._--We have now to consider what is the\nphysical cause of that part of the compound Law of Gravitation known as\nthe Centripetal Force. As we have already learned (Art. 10), this force\nis really none other than the Attractive Force of Gravitation, in that\nits mode of operation always acts towards the centre of the attracting\nbody, and hence was called by Newton the Centripetal Force.\n\nThe centripetal force is, however, the exact counterpart and complement\nof the centrifugal force, in the same way that the latter is the exact\ncounterpart of the former, as we have already learned that the\ncentrifugal force operates along the same path, and that it is subject\nto the same law of proportion, being equal to the product of the masses\nof a body (Art. 85), and further, that its intensity is inversely as the\nsquare of the distance (Arts. 66, 74 and 84).\n\nWe have, however, discovered that the physical cause of the centrifugal\nforce is due to the pressure of the electro-magnetic Aether (Art. 96).\nIf, therefore, the physical cause of that law which is the complement\nand counterpart of Gravitation Attraction is to be found, and alone\nfound, in the pressure and motions of the electro-magnetic Aether, then\nit is only logical and reasonable to infer that the physical cause of\nthe Attraction of Gravitation is to be found in the same\nelectro-magnetic Aether. That the Attraction of Gravitation is to be\nfound in this medium is now an accepted hypothesis among scientists.\nBecause, unless the physical cause of Gravitation Attraction is to be\nfound in this electro-magnetic Aether, then, in order to account for\nthat attraction, we should have to postulate the existence of another\nmedium in space, in lieu of the Aether, which would be to the\ncentripetal force what the Aether is to the centrifugal force. This\nwould be distinctly unphilosophical, as it would be a violation of the\nfirst two rules of our philosophy, in that it would not be simple in its\nconception, and that such a hypothesis would imply the existence of two\nmedia which would occupy the same planetary and interstellar space at\none and the same time, and this is a violation of all experience in its\nwidest form.\n\nTherefore the physical cause of Gravitation must be sought for in the\nsame medium which gives the physical cause of the companion force, and\nthat medium is the electro-magnetic Aether. Professor Preston in his\n_Theory of Light_ is of this opinion. In Art. 327 he writes: \"To account\nfor the propagation of heat and light, that is, of radiant energy, we\nhave postulated the existence of a medium filling all space. But the\ntransference of the energy of radiant heat and light is not the only\nevidence we have in favour of the existence of an Aether. Electric,\nmagnetic and electro-magnetic phenomena and Gravitation itself point in\nthe same direction.\"\n\nProfessor Lodge, in his _Modern Views of Electricity_, is even more\nexplicit in his statement of the case. On page 338 he states:\n\"Gravitation is explainable by differences of pressure in the medium\n(_i. e._ the Aether) caused by some action between it and matter not\nyet understood.\" Further, Newton himself suggested that the physical\ncause of Gravitation Attraction was to be found in that aetherial medium\nwhich pervaded all space.\n\nIf, therefore, we attempt to explain the physical cause of Gravitation\nAttraction by the tensions of the universal Aether, we shall not only be\ndealing with the subject from a philosophical standpoint, but we shall\nsolve the problem in that direction in which Professors Preston and\nLodge and other scientists have suggested we are to seek for the\nsolution. Professor Curry, in his _Theory of Electricity and Magnetism_,\npage 406, states: \"If we regard the luminiferous Aether, as defined by\nVon Helmholtz's equations, as the given medium or transmitter of\nso-called gravitating action, we are then able on the one hand to\ninterpret its longitudinal oscillations as gravitational waves\npropagated through space with the given enormous velocity, and on the\nother hand, to form some conception of the mysterious force of\nGravitation itself, for we can then conceive it as a medium stress\narising from a certain type of Aether oscillations, its longitudinal\nones, that pervade entire space.\"\n\nNow in order for us to lead up to the physical cause of the centripetal\nforce, we must recall some of the facts already given with regard to\nplanetary and solar space. Thus we have learned that the sun is an\nelectro-magnet possessing its own magnetic field, with its lines of\nforce (Art. 88). We have also learned that all the planets are\nelectro-magnets, each possessing its own field with its lines of force\n(Art. 91).\n\nWe have further seen that the cause of all this electro-magnetism is due\nto the fact that electric currents are continually circulating round\neach body, and by their conjoint action with the magnets there are\nproduced the electro-magnetic fields that are associated with each body\nin the solar system. From this hypothesis we arrived at the conclusion,\nthat wherever there was Aether, there we found electricity, because of\nthe electro-magnetic basis which Aether possesses. This result is fully\nconfirmed by Maxwell's electro-magnetic theory of light (Art. 78), which\nhas been so fully experimentally demonstrated by Hertz. Indeed, in the\nminds of several scientists there is a growing conviction that Aether\nand Electricity are possibly one and the same substance.\n\nProfessor Lodge, in the work already referred to, in relation to this\nhypothesis, writes in the preface to that book: \"Crudely, one may say\nthat as heat is a form of energy, so electricity is a form of Aether, or\na mode of aetherial manifestation.\" And again: \"A rough and crude\nstatement adapted for popular use is that _Electricity and Aether are\nidentical_. But that is not all that has to be said, for there are two\nopposite kinds of electricities, and there are not two Aethers. But\nthere may be two aspects of one Aether, just as there are two sides to a\nsheet of paper.\"\n\nAs, therefore, we learn that Aether has an electro-magnetic basis, and\nthat electricity is a mode of aetherial manifestation, we have therefore\nto consider one of the most fundamental laws of electricity, and note\nits application to solar and planetary space.\n\nIt is one of the fundamental laws of electricity, that equal and\nopposite quantities of electricity are always generated at one and the\nsame time. Faraday's well-known ice-pail experiment proved this. It is\nan absolute impossibility for one kind of electricity to be generated\nwithout an equal quantity of the opposite kind being produced, although\nit is not strictly correct to use the term generated or produced in\nrelation to electricity, as electricity cannot really be produced by any\nprocess whatever.\n\nAnother way of stating this law is, that the total induced charge on any\nbody is always equal and opposite to the inducing charge. So that if we\nlook upon the sun as an electrified body (Art. 80) surrounded by the\naetherial envelopes or shells, then we can conceive of the inductive\naction of the sun upon any planet as taking place along the tubes of\nforce in the Aether, which tubes are sections of the spherical envelopes\nthat surround it. But this inductive action implies the existence of the\nvery law already enunciated, viz. that equal and opposite quantities are\nalways generated at one and the same time, and before that law can\nbecome operative in relation to the Aether, it must be postulated that\nthe Aether possesses a dual character, that is, it possesses a positive\nand negative electrical basis.\n\nThis view of the Aether has already been developed by Dr. Larmor in his\nElectron Basis of the Aether, as in that hypothesis he postulates both\npositive and negative electrons. In his _Aether and Matter_ he writes,\npage 3: \"It assumes that the mass of each sub-atom is proportional to\nthe absolute number of electrons, positive and negative, that it\ncarries, and that the effective interatomic forces are entirely or\nmainly electric.\" Further, Professor Lodge on this point writes:[40] \"We\nnow proceed a step further and analyze the Aether into two constituents,\ntwo equal opposite constituents, each endowed with inertia and each\nconnected to the Aether by elastic ties. The two constituents are called\npositive and negative electricity respectively, and of these two\nelectricities we imagine the Aether to be composed.\" Again, later on, p.\n349 of the same work, he adds: \"Is Aether electricity then? I do not say\nso, but that they are connected there can be no doubt. What I have to\nsuggest is, _that positive, and negative electricity together may make\nup the Aether_.\"\n\nNow, accepting this as correct, and I will prove that it is correct later\non, from experiments performed by Faraday, we can see how the inductive\naction of the sun may be transmitted through space, and how that inductive\naction will effect any body in its electrical field, such inductive action\nalways taking place through the polarization of the atomic Aether, and\ntaking the form of an attractive power which is exerted towards the\ncentre of the attracting body.\n\nFurther, this inductive action will be subject to the same laws of\nelectricity as the centrifugal force is, which is the repulsive power\ndue to the pressure of the Aether. Therefore the inductive action of the\nsun upon any body will, according to the laws of electricity, act\ninversely as the square of the distance (Art. 84), and will be directly\nas the product of the charges on the two attracting bodies, which we\nhave seen according to Art. 85 is equal to the product of their masses.\nNot only will this inductive action apply to the sun, but it will\nequally apply to all planets, satellites and stars that exist in the\nheavens, each of these bodies according to Art. 80 being an electrified\nbody possessing its electric field and lines of force radiating out into\nspace.\n\nThus we arrive at the conclusion, that each body in the solar system is\nnot only the centre of a centrifugal force due to the pressure of the\nelectro-magnetic Aether, but that it is also the centre of an attractive\nforce due to the existence of the positive and negative elements of the\nAether, and of their attractive power for each other.\n\nThis attractive power is also subject to exactly the same laws that the\ncentrifugal force is subject to in regard to intensity, proportion, and\nthe direction which it takes. So that we have now two centripetal forces\nexisting in space, which exactly correspond with each other, viz.\nGravitation Attraction and the attraction due to Electrical Induction.\nThe cause of one, however, is known, being due to the inductive\ninfluence of the various electrified bodies that exist in space, which\ninductive influence can be traced through the whole of the atomic Aether\nthat exists between the two bodies, whereas the cause of the centripetal\nforce or Gravitation Attraction is unknown. According to the Rules of\nPhilosophy, therefore, it will be much simpler if we replace our\nGravitation Attraction, whose cause is unknown, by the inductive power\nof the various bodies, the physical cause of which lies in the\nelectro-magnetic Aether, or the dielectric as Faraday called it. In\nother words, we are compelled to come to the conclusion that the\ncentripetal force, or Gravitation Attraction so called, is an electrical\nphenomenon, which finds its physical cause in the same universal Aether\nthat the centrifugal force does.\n\nUnless this view of the attraction of Gravitation is accepted, we should\nhave two forces operating between all bodies, both operating at exactly\nthe same time, in exactly the same direction, and with exactly the same\nintensity, and this phenomenon according to Newton would be\nunphilosophical. In Art. 4 we learn that Newton in the first rule states\nthat \"Nature is simple, and does not abound in superfluous causes of\nthings.\" And again: \"In the nature of Philosophy nothing is done in vain;\nand by means of many things, it is done in vain when it can be done by\nfewer.\" Here then we have apparently two forces which act in the same\nmolecular or planetary or interstellar space, at one and the same time.\nTherefore if this be true, Nature does abound in a superfluous cause,\nbecause we have two forces in existence where one will suffice, and one\nof them therefore exists in vain. So that it will be philosophical if we\ndo away with one of the causes, and replace the two causes by only one.\nNow which shall be done away with--the electrical attraction which is due\nto a physical medium, the electro-magnetic Aether, or the Gravitation\nAttraction, that is caused by some virtue of a body of which we have no\nknowledge, which is transmitted through space in a way that we cannot\nunderstand, and acts upon distant bodies in a manner altogether outside\nour usual experience and observation? There can only be one answer. If\neither of the two forces has to be done away with, it must be the\nmysterious, intangible, unphilosophical attraction of Gravitation, which\nmust be replaced by the philosophical and known attraction of electricity,\nwhich can be traced to a physical medium, the electro-magnetic Aether that\njoins atom to atom, molecule to molecule, satellite to planet, planet to\nsun, and sun to star, and so gives unity to the universe of worlds. From\nphilosophical considerations, therefore, we are compelled to come to the\nconclusion that the attraction of gravity and electrical attraction are\none and the same.\n\nFaraday arrived at this conclusion and performed certain experiments to\nconfirm that conclusion, but he was unable to experimentally prove the\ntruth. It does not follow, however, that because he failed to\nexperimentally establish the connection, therefore the conclusion is\nwrong. In his _Experimental Researches_ he writes, par. 2705, \"On the\npossible relation of gravity to electricity\":--\"First of all, a body\nwhich was to be allowed to fall, was surrounded by a helix, and then its\neffect in falling sought for.\" This experiment Faraday states produced\nnegative results (par. 2706). \"A solid cylinder of copper was introduced\ninto the helix, and carefully fastened to it, and this compound\narrangement was allowed to fall.\" \"The result of this experiment may be\nclassified as doubtful. It gave very minute, but remarkable indications\nof a current in the galvanometer, and the probability of these being\nrelated to gravity appeared the greater, when it was found, in raising\nthe helix or core, similar indications of contrary currents appeared.\"\nIn par. 2717 Faraday thus sums up: \"Here end my trials for the present.\nThe results are negative. They do not shake my strong feeling of the\nexistence of a relation between gravity and electricity, though they\ngive no proof that such a relation exists.\" Here then we have expressed\nthe strong conviction of the relation that undoubtedly exists between\ngravity and electricity by one of the greatest scientists that has ever\nlived, and I believe that it is a fact that he was engaged upon\nexperiments to prove his conviction about the time of his death.\n\nWe will now endeavour to trace the action of the Law of Gravitation in\nits compound working, in its application to the atomic Aether that fills\nall space, and by its gravitating property surrounds all bodies situated\nin that space. We are dealing no longer with a frictionless medium,\nwhich is incapable of accepting and transmitting motion of any kind or\nsort, but we are now dealing with a medium composed of atoms, which can\ngive rise to pressures and tensions, or repulsions and attractions from\nany one part of space to another.\n\nIf we can prove that an atomic Aether can give rise to these pressures\nand tensions from one body to another, and those pressures and tensions\nharmonize with, and satisfactorily account for, the phenomena sought to\nbe explained, then we shall have succeeded in making our philosophy\nagree with our experience, and such a result as action at a distance\nwill for ever disappear from the mental conception of all men, as it has\nlong disappeared from the pages of philosophical and scientific works,\nthough that disappearance was not accompanied with a satisfactory\nsolution of the problem.\n\nLet us, therefore, consider these pressures and tensions, or so-called\nrepulsions and attractions that exist in this electro-magnetic Aether\nfrom the atomic standpoint, and by so doing try to realize how it is\nthat one body, as the sun, acts upon another body, as the earth, through\nthe intervening medium, the Aether. We can either consider it from the\nmaterial standpoint, that is, by considering the Aether as matter, pure\nand simple, or by viewing it from the electrical standpoint, which may\nbe considered from Clerk Maxwell's physical conception of an electric\nfield. We will briefly consider it from the latter standpoint. Our\nconception of an aetherial atom was that of a spherical vortex atom\npossessing polarity and rotation on an axis. We must, however, make the\ndistinction between the two kinds of aetherial atoms that Clerk Maxwell\nfirst indicated in his paper on Physical Lines of Force, _Phil. Mag._,\n1861, and that Dr. Larmor has worked out in his _Aether and Matter_ from\nthe electron standpoint, viz. that the Aether is composed of positive\nand negative electrons. Or we can accept Professor Lodge's theory, that\nAether is made up of positive and negative electricity. We are compelled\nto accept the hypothesis of two kinds of aetherial or electrical atoms,\nwhatever they may be called, in view of the teaching of electricity,\nthat positive and negative electricity are always to be found in\nassociation, and in combination, wherever electricity exists. We have\nproved that electricity is to be found throughout the realm of space\n(Art. 78); therefore in all planetary and stellar regions electricity is\npresent. Thus it exists in the so-called space between the sun and\nplanets, and between the planets and satellites, forming around them all\nspherical shells, that become less and less dense as they recede from\nthe central body. Now it is by the action of these positive and negative\nelectrical atoms, that the attraction of one body is transmitted across\nspace from the sun to the earth, or from the earth to the sun, or from\nthe earth to Jupiter, or from Jupiter to any of the planets, the action\nalways taking place along the line joining the centres of gravity of the\nbodies, _i. e._ the radius vector, and with a force equal to the\nquantities of electricity in association with those bodies (Art. 85),\nand with an intensity that always acts inversely as the square of the\ndistance. Thus the inductive action of any sun, planet or satellite, or\nany other planet or satellite, can be mentally traced from atom to\natom, across the intervening space, that is filled with the atomic\nAether, between any two attracting bodies. So that, if the sun attracts\nthe earth, it attracts it by and through the motions and properties of\nthe electro-magnetic Aether that is made up of positive and negative\nelectricity, and that attraction, being produced by a physical medium\nwhich is as real and tangible as air or water, is brought into harmony\nwith our experience and observation, as no body pushes or pulls another\nbody, be it what it may, unless both bodies are joined together by some\nmedium which transmits the push or the pull. Professor Lodge, in his\n_Modern Views of Electricity_, has illustrated from an electrical\nstandpoint how the pressure and tension in any electrical field may be\ntransmitted from particle to particle, or atom to atom. He supposes that\na positive atom of electricity rotates in one direction while a negative\natom rotates in the opposite direction. In any electric field these\natoms are so associated with each other, that when one atom revolves, it\nmakes the other to revolve in the opposite direction, with the result,\nthat the spin or rotation is transmitted through the medium at a speed\ndependent upon the density of the medium.\n\nFor fuller details of the description I must refer the reader to the\nwork already referred to. What I wish to call the reader's attention to\nis, that the tension and pressure in this field is not transmitted\nacross a vacuum, in some unknown way, but is transmitted solely by a\nphysical medium. The action is direct, and is produced, and alone\nproduced, continued, and perpetuated by a physical medium which is\ncomposed of atoms of negative and positive electricity. So that if one\nbody _A_ acts upon another body _B_, it acts upon _B_ solely and\nentirely by the action of the atoms which form the magnetic lines of\nforce, and the equipotential surfaces around the electrified body, and\nthat action can be traced mentally step by step across the intervening\nspace that may exist between the two bodies. It is in an exactly similar\nmanner, that the Attraction of Gravitation, which we conceive to be the\nsame as electrical attraction, is transmitted from body to body in the\natomic, molecular, planetary or stellar world. In each and every case,\nthe pressure and tensions, which are inseparably connected, are\ntransmitted by the atoms of the electro-magnetic Aether, that is, by the\npositive and negative atoms of electricity of which, according to\nProfessor Lodge and Dr. Larmor, the Aether is composed. So that, if the\nsun acts on the earth, by the centrifugal force, it acts on it solely\nthrough and by the pressures which are originated in the atomic Aether\nby the central body. If the sun attracts the earth, by the centripetal\nforce, that action can also be traced to the tensions that are\noriginated among the atoms of the electro-magnetic Aether. There is\nnothing mysterious about the phenomenon in either case, as by accepting\nthis view of an atomic Aether with its dual character of positive and\nnegative electricity, the action may be traced mentally from point to\npoint across the so-called intervening space that exists between any two\nbodies. In each and every case, wherever the centripetal or centrifugal\nforce acts, the action is direct, because it is caused by a physical\nmedium, which physical medium is in direct contact with each body acted\nupon, and also fills the space between those bodies. With this view of\nthe centripetal force of Gravitation, our Philosophy is made to agree\ndefinitely with our experience, which teaches us beyond contradiction,\nthat no body moves, unless it is either pushed or pulled by a physical\nmedium. Unless this view of the centripetal force is accepted, we shall\nhave to stumble on in darkness as to the physical cause of the\ncentripetal force, and mentally accept the unphilosophical proposition,\nthat a body can act on another in a way that we cannot understand, and\nby means which lie outside our experience and observation, and this\nhypothesis, as Newton and Herschel pointed out, is distinctly an\nunphilosophical proposition.\n\n[Footnote 40: _Modern Views of Electricity_, p. 221.]\n\n\n\n\n                              CHAPTER XII\n\n                           AETHER AND COMETS\n\n\nART. 111. _Comets. What are Comets?_--In addition to the planets and\nasteroids which revolve around the sun, there are also other bodies\ntermed Comets, which revolve round the solar orb.\n\nUnlike the planets, however, they do not all keep to the plane of the\necliptic, but approach to, and recede from the sun at all angles to that\nplane, as well as in that plane itself. Comets are supposed to be huge\nmasses of gaseous matter, in a more or less condensed condition. That\nthey are not composed of absolutely solid matter is proved by the fact\nthat it is possible to see the stars through the gaseous matter of which\nthey are composed.\n\nHow the gaseous matter of which these comets are formed is originated,\nor how it is formed in solar or stellar space, has, I believe, up to the\npresent never been explained, and indeed, with the idea of a\nfrictionless Aether, I fail to see how any physical explanation of the\norigin and development of a comet can be satisfactorily given. With the\nconception of the Aether, however, that is put forward in this work,\nviz. that Aether is matter in its most rarefied and attenuated form,\nwhich can be condensed into a gaseous condition, with such a conception\nof the universal aetherial medium, the origin and development of gaseous\nmatter from this Aether becomes a physical possibility.\n\nLord Kelvin, in the _Philosophical Magazine_, July 1902, on the\n\"Clustering of Gravitational Matter in any part of the Universe,\" has\nalready suggested the possibility of the condensation of the Aether, but\nwith the old idea of a frictionless Aether, that is, an Aether which\ndoes not possess mass, such a hypothesis is improbable. Because, if the\nAether becomes condensed at all, it must be condensed into gaseous and\nsolid matter, and all experiments and observation teach us that both\nthese forms of matter possess mass and weight.\n\nTherefore, if the frictionless Aether, which possesses no mass and\nweight, is to be condensed into gaseous or solid matter, there must come\na period in the process of condensation when it must pass out of the\ncondition of possessing no mass and no weight, into the condition of\npossessing mass and weight, which assumption is altogether opposed to\nthose Rules of Philosophy based upon experiment and observation.\n\nAether can only pass into a gaseous or solid condition, in which\ncondition it will possess mass and weight, on the assumption that in the\naetherial condition it possesses the same properties, only in a modified\nform, which it possesses after the process of condensation has taken\nplace. In a similar way that air can pass out of its gaseous condition\ninto a liquid condition, or any gas can pass out of its gaseous into a\nliquid condition, so Aether, on the conception as given in Chapter IV.,\ncan pass out of its aetherial and rarefied condition into that form of\nmatter which is known as gaseous. We shall deal with this aspect of\nAether more fully when we come to deal with the Nebular Hypothesis, as\nthe same principle underlies that hypothesis as underlies the origin and\ndevelopment of comets.\n\nThus, comets may be formed at any time in interstellar space out of the\nAether that exists there, provided the conditions of its formation are\nto be found there. Then, as they are gradually formed, they would, like\nany other bodies, come more directly under the influence of any large\nbodies, as the sun, and be attracted by them.\n\nThis conception of the origin and development of a comet will also\naccount, and that on a logical and philosophical basis, for another fact\nwhich is associated with cometary phenomena. I refer to the fact of the\nexpulsion of gaseous matter out of the head of a comet as it nears the\nsun, which expulsion will be dealt with in the article on \"Parts of a\nComet.\"\n\nAnother problem that might be solved by this conception of a comet lies\nin the question, as to whether comets shine by their own light?\n\nIf comets are really formed of condensed Aether, as I believe them to\nbe, then, as light is due to a periodic wave motion of the Aether, as\nsoon as the Aether (of which the comets' tails, for example, were\nformed) was made to vibrate with that rapidity sufficient to produce\nlight waves in the surrounding Aether, the tails would then shine by\ntheir own light, in exactly the same way that any other body emits light\nwaves, as soon as its aetherial vibrations reach the rapidity necessary\nto produce the waves of light, which vibrations would lie between 2000\nto 8000 billions per second.\n\nThe number of the comets that exist in the solar system cannot be\nascertained with any degree of accuracy, but the total probably extends\ninto millions. They are of all sizes, from those which possess diameters\nof several miles, to those extending over thousands of miles. They also\npossess orbits, with which we will now deal.\n\n\nART. 112. _Orbits of Comets._--As has already been pointed out, comets\nperform their journey round the sun, not only in the plane of the\necliptic, but also at all angles relatively to that plane. In this\nrespect they differ from the orbits of planets and satellites, which\nperform their journey in orbits situated wholly in the plane of the\necliptic (Art. 109).\n\nThere is another important difference between the orbits of the comets\nand those of the planets. In the case of the latter the orbit is that of\nan ellipse, while in the case of the comet the orbit may be either that\nof a parabola or a hyperbola, which may be looked upon as elongated\nellipses open at one end. There are, however, some comets whose orbits\nare perfectly elliptical, and whose return may be calculated with a fair\namount of accuracy.\n\nThese are known either as Short Period Comets, as represented by Faye's\nComet, Encke's and De Vico's; or Long Period Comets, as represented by\nthe comets of 1811, 1844, and 1858. In the case of all these, as their\nreturn to our solar system can be determined, it follows that they must\nrevolve around the sun in some sort of a closed orbit, probably that of\nan exceedingly elongated ellipse.\n\nThere are, however, other comets which appear once, or it may be several\ntimes only, and then disappear out of the solar system for ever. Now the\nquestion arises, as to whether the orbits of the comets which are so\nvariable can be explained by the motions of the Aether which we have\nalready ascribed to it? We have seen (Art. 109) how it is possible to\naccount physically for the plane of the ecliptic from the motions of the\nAether, and how it is that all the planets move within that plane, but\nhere we have a phenomenon of a different kind, as observation distinctly\nteaches us that the comets do not move in, or keep within the plane of\nthe ecliptic, but gravitate round the sun at all angles to that plane.\n\nIn order for us, therefore, to be able to account, and that on a\nphilosophical basis, for this fact, we must revert to our conception of\nthe sun in its relation to the solar system. In Art. 88 we learned that\nthe sun was an electro-magnet possessing its electro-magnetic field, and\ngenerating electro-magnetic waves which were radiated forth from it on\nevery side. From Art. 89 we learn that an electro-magnetic body\npossesses lines of force, and that these lines of force take various\ndirections as they are generated by the body, as proved by Faraday's\nillustrations. Further, a moving electro-magnet, as the sun for example,\ncarries its lines of force with it, as proved by Maxwell.\n\nNow these lines of force extend not only east and west, but also north\nand south, as depicted in Fig. 29.\n\nHitherto we have only dealt with the lines of force proceeding from the\nsun equatorially, which lines form the plane of the ecliptic. We have,\nnow, to take into consideration those lines which extend out into space,\nnorth and south of that plane. These are not so curved as the others, but\nare more inclined to be straight, or less curved, as they are really\nparts of large curves which extend much further outwards into space.\n\nThe orbits of the Short or Long Period Comets can be explained by the\nfact that they perform their journey more or less in the plane of the\necliptic, though in some cases at a much greater angle than that of any\nof the planets. Provided, however, they remain within the influence of\nthe electro-magnetic field of the sun, there is then a physical\nexplanation as to their orbital motion round the sun, in a similar way\nto the orbital motion of the planets, though at greater angles to the\nplane of the ecliptic.\n\nFor we have to remember, that wherever the electro-magnetic waves of the\nsun's electro-magnetic field extend, there we have also the rotation of\nthat field round its central body, though with a continually decreasing\nintensity, as already pointed out. Wherever, therefore, we get rotatory\nAether currents, due to the rotation of the electro-magnetic field,\nthere we get the conditions which would enable any kind of gaseous or\nmaterial body to be circulated round the sun. The case, however, of\ncomets which do not return has to be viewed from a different standpoint.\nHere it seems to me we are dealing with masses of condensed Aether that\ncome within the inductive influence of the electro-magnetic waves of the\nsun, as that body moves through space with its velocity of about 500,000\nmiles per day. We have to conceive of this condensed Aether situated\nnorth and south of the plane of the ecliptic, and situated probably\nmillions of miles away. As the sun moves onward in its journey through\nspace, carrying its electro-magnetic field with it, then, by the\ninductive action of the sun, the comet would be attracted by that body,\nand so would be gradually drawn towards it.\n\nUnder this inductive influence it would rush towards the sun, until,\napproaching very close to it, it would be repelled by the\nelectro-magnetic waves or centrifugal force of that body, and be hurled\nagain by their repulsive energy far far away into space to the north or\nsouth of the plane of the ecliptic. As it was moving away from the syn,\nnorth or south of the ecliptic, the sun would be moving onwards through\nspace in the plane of the ecliptic, which would practically be at right\nangles to the motion of the comet, so that by the time the comet had\nreceded far into the depths of space, the sun with its electro-magnetic\nfield would have moved on also in a direction at right angles to the\ncomet's motion.\n\nThe effect of the sun's orbital motion would be, that it would be unable\nto again exert sufficient inductive power upon the comet to bring it\nwithin its inductive influence once more. For example, suppose there is\na mass of Aether condensing at point _A_ in interstellar space situated\nsome millions of miles north of the plane of the ecliptic, which is\nrepresented by the straight lines _B_ _C_. The sun is moving in the\ndirection towards the part of space represented by point _B_. We will\nsuppose that when the sun is near point _C_ the mass of Aether at point\n_A_ is too far away to be appreciably influenced by the inductive action\nof the sun. But as the sun moves towards point _F_, then the condensed\nAether, which practically forms the body of the comet, will come within\nits influence and be drawn towards the sun, at an angle to the plane of\nthe ecliptic.\n\n[Illustration: Fig: 30.]\n\nBy the time the body of the comet has reached the sun, it will have\nacquired a momentum which enables it to rush past the sun, and then it\nwill be repelled by the electro-magnetic waves in the direction of _F_\n_G_, which is still at an angle to the plane of the ecliptic; but its\nmotion, combined with the repulsive power of the electro-magnetic waves,\nis carrying it outside the sphere and influence of the sun's\nelectro-magnetic field. At the same time the sun is proceeding onwards\nthrough space, leaving the comet far behind, so that by the time the\ncomet has reached the confines of the solar system, it has either passed\nunder the influence of another star, or has become further condensed to\nform a meteor, which begins to circle around the largest and nearest\nbody. I do not assert that this hypothesis is strictly correct, but it\nseems to me that only on some such hypothesis can the appearance and\napparent loss of irregular comets be explained.\n\n\nART. 113. _Short Period Comets and Long Period Comets._--We have seen in\nthe previous article, that some Comets revolve round the sun in closed\norbits of exceeding great eccentricity, and the return of these may be\ncalculated with certainty. There are about two dozen comets which revolve\naround the sun, and which return at intervals lying between three years\nand 76 years.\n\nThis class of comets may be divided into two kinds, which are known as\nShort Period Comets and Long Period Comets respectively. The following\ntable gives a list of the chief of the Short Period Comets, together\nwith some particulars relating to time of revolution, etc.:--\n\n    COMETS.          PERIOD OF         PERIHELION         APHELION\n                    REVOLUTION.         DISTANCE.         DISTANCE.\n\n    Encke's    ...  3-1/4 years.    32,000,000 miles.   387,000,000 miles.\n    De Vico's  ...  5-1/2   \"      110,000,000   \"      475,000,000   \"\n    Biela's    ...  6-1/2   \"       82,000,000   \"      585,000,000   \"\n    D'Arrest's ...  6-1/2   \"\n    Faye's     ...  7-1/2   \"      192,000,000   \"      603,000,000   \"\n    Halley's   ... 76-3/4   \"       56,000,000   \"    3,200,000,000   \"\n\nEncke's Comet was discovered by Professor Encke of Berlin, and named\nafter him. It revolves in an ellipse of great eccentricity, as proved by\nthe fact that when nearest to the sun, it is inside Mercury's orbit, but\nwhen furthest away from the sun, it passes beyond the orbit of Mars,\nreaching almost to the orbit of Jupiter. One of the most remarkable\nfacts about this comet is, that it has done more to establish the\nexistence of that resisting medium around the sun, whose existence we\nhave demonstrated, than any other comet. Encke found on its periodical\nreturn that its mean distance was gradually getting less, and in order\nto account for this, he supposed that it was due to the existence of a\nresisting medium which enveloped the sun, and extended some distance\ninto space.\n\nThis conclusion has been supported in recent years by Von Asten, a\nGerman mathematician, who has supported the theory of a resisting\nmedium. On this point Herschel writes in his _Outlines of Astronomy_,\nArt. 577: \"This is evidently the effect which would be produced by a\nresistance experienced by the comet from a very rare aetherial medium\npervading the regions in which it moves; for such resistance, by\ndiminishing its actual velocity, would diminish its centrifugal force.\nAccordingly, this is the solution proposed by Encke, and at present\ngenerally received.\"\n\nSo that we have in Encke's Comet another proof of the existence of that\naetherial medium, which is not frictionless, but has the power to oppose\nany body which moves through it, when that body moves in an opposite\ndirection to its own motions.\n\nAnother Short Period Comet worthy of notice is that of Biela, named\nafter M. Biela, its discoverer. This comet had a period of six and a half\nyears, and reappeared at several successive intervals until about the\nyear 1845, when it seems to have been broken or split up into two parts.\nIn December 1845 the comet divided into two parts, which travelled\nparallel to each other for a long distance. During this separation, very\nsingular changes were observed to be taking place in both the original\ncomet and its offshoot.\n\nBoth had a nucleus, and both had tails, which were parallel to each\nother. The comets continued to travel together until the 15th March\n1846, when the new comet began to fade away, until, on the 24th March,\nthe old comet only was visible, while in April both had disappeared\nentirely. A similar phenomenon was again observed at its next passage in\n1852, but since then Biela's Comet has entirely disappeared. It is\nsuggested by astronomers, that the comet has become condensed, and\nbroken up, forming a shoal of meteors.\n\nSupport is lent to this theory by the fact that in November 1872, when\nthe earth was passing through space and had arrived at that part of its\norbit which intercepted the orbit of Biela's Comet, instead of the comet\nbeing seen, the earth came into contact with a swarm of meteors, and\nthis is accepted as evidence that Biela's Comet was condensed far away\nin the colder regions of interplanetary space into a more solid form of\nmatter, known as meteors. One of the more famous of the short period\nclass of comets is that known as Halley's Comet, which has a period of\nabout 76 years. This comet has been seen in its return journey to the\nsun about 25 times. It was named after its discoverer, Edmund Halley. He\nwas led to identify this comet with that of 1531 and 1607, and thus to\nconclude that it had a period of 75 or 76 years. He therefore predicted\nits reappearance in 1759. As the year approached, its arrival was\neagerly looked for, to see if the prediction would be verified.\n\nIt was thought, however, by a certain astronomer named Clairaut, that\nthe larger planets, as Saturn and Jupiter, might interfere with its\norbital motions, and after careful calculations a difference of 618 days\nwas allowed, which brought its anticipated reappearance down to April\n1759. It actually reappeared in March of that year. Its next\nreappearance was fixed to take place about November 1835. The comet\nbecame visible on 5th August 1835, and continued to be seen till April\n1836, when it again disappeared.\n\nAs the reappearance of the comet was calculated by the application of\nthe Newtonian Law of Gravitation, such a result only gave added\nconfirmation to the application of that law to cometary bodies.\n\nOf the Long Period Comets there are several known. That of 1858 has a\nperiod, it is thought, of 2000 years. The 1811 comet has a period of\n3000 years, while that of 1844 has a period of over 10,000 years. All\nthese comets move in orbits of such great size that their return is\nimprobable. One of the characteristic features about Long Period Comets\nis their great brilliancy and size.\n\nThe 1858 comet, known as Donati's Comet, was first seen by that\nastronomer at Florence in June. It was invisible, however, to the naked\neye, as it only appeared through the telescope like a faint cloud of\nlight, gradually getting brighter and brighter. Toward the end of August\nit began to show signs of developing a tail, and became visible to the\neye on August 29th. During September and October it greatly increased in\nsize and brilliancy, and was plainly visible in the western heavens.\nAfter October 10th it was only visible in the southern hemisphere,\ngradually decreasing in brightness. It was seen till March 1859, when it\ndisappeared, and will probably not return till the year 3858, as its\nperiod of revolution is about 2000 years.\n\nDonati's Comet passed between the earth and many stars, which could be\nseen very distinctly through its tail. One of the stars was Arcturus,\nand, though some of the densest parts of the comet passed over it, yet\nthe star could be seen all the time, thus conclusively proving that the\nhead and tail of a comet are only composed of gaseous matter, probably\ncondensed Aether, as suggested in Art. 111.\n\n\nART. 114. _Parts of a Comet._--A comet may be divided into three parts:\n1st, Nucleus; 2nd, Head or Coma; and 3rd, Tail.\n\nThe nucleus is the central part of the head or coma, and is generally\nthe brightest part of the whole comet. On the theory that a comet is due\nto the condensation of Aether, the nucleus would represent the first act\nin the process of condensation, as there would have to be some centre of\ncondensation, and that centre would be represented by the nucleus.\nFurther, the process of condensation would assume a spherical form, as\nthe conception of our aetherial atom is that of a sphere or an oblate\nspheroid. As the process of condensation went on, the layers that would\nbe produced would form a kind of envelope around the point of\ncondensation, with the result that the nucleus would ultimately consist\nof a large mass of gaseous matter, made up of layer upon layer of\ncondensed Aether around some central point, which formed the nucleus.\n\nThis hypothesis agrees with observed phenomena, because, when we deal\nwith the tails of comets, we shall see that the tail is simply formed by\nthe reverse process to that of condensation, as in the case of cometary\ntails the gaseous envelopes so formed will be thrown off (either through\nheat generated by friction, or by the increased heat as the comet nears\nthe sun), which are then repelled away from the sun by the centrifugal\nforce. Herschel,[41] referring to the nucleus, states, paragraph 559:\n\"An atmosphere free to expand in all directions would envelop the\nnucleus spherically,\" while in his Reflection on Halley's Comet, he\nstates, Art. 570, \"1st, That the matter of the nucleus of a comet is\npowerfully excited and dilated into a vaporous state by the action of\nthe sun's rays, escaping in streams and jets at those points of its\nsurface which oppose the least resistance. 2nd, That the process chiefly\ntakes place in that portion of the nucleus which is turned towards the\nsun, the vapour escaping in that direction. 3rd, That when so emitted,\nit is prevented from proceeding in the direction originally impressed\nupon it, by some force directed _from_ the sun, drifting it back and\ncarrying it out to vast distances behind the nucleus forming the tail.\"\n\nWhen we come to deal with the question of the formation of the tail, we\nshall find that every reflection made by Herschel is satisfactorily\nfulfilled by the conception of a gravitating and condensing Aether.\nBefore considering the tail, however, we will deal with the head or\ncoma.\n\nThe head or coma is that part of the comet which exists round the\nnucleus. It is less bright than the nucleus, and oftentimes appears as a\nshadowy mass of light. Herschel, in his 4th Reflection, states that \"a\nconsiderable part of the vapour actually produced remains in the\nneighbourhood of the nucleus forming the head or coma.\" So that the head\nof a comet is simply the vaporised part of the nucleus which is produced\nby the increased heat of the sun, in the same way that water would be\nvaporised by the addition of heat, the vapour in that case being thrown\noff in the form of steam.\n\nThis formation of the head is but a continuation of the reversal of the\nprocess of condensation, which originally gave existence to the mass of\nmatter termed the comet. The diameter of this head or coma often extends\nto thousands of miles. The head of the 1811 comet was 540,000 miles in\ndiameter, while that of the 1843 was 112,000 miles. As the nucleus is\nformed of a series of envelopes, so the head also consists of a series\nof envelopes.\n\nThe comet of 1858 constantly threw off these envelopes, which were first\nexpelled _towards_ the sun, and then repelled away _from_ the sun,\nforming the tail. The matter forming the head and the nucleus is\nperfectly transparent, as stars have been seen through the matter which\nforms those parts. Herschel,[42] paragraph 558, states \"that whenever\npowerful telescopes have been turned on these bodies, they have not\nfailed to dispel the illusion which attributes solidity to that more\ncondensed part of the head which appears to the naked eye, though it is\ntrue that in some a very minute stellar point has been seen indicating\nthe existence of a stellar body.\"\n\n_Tails._--The tail of a comet is that part which flows from the head,\nand is afterwards repelled by the repulsive power of the sun into space.\nWe shall deal with this repulsive power, whose existence we have already\ndemonstrated, and the part which it plays in the formation of a comet's\ntail, in the next article. The tail of a comet is oftentimes considered\nto be the comet itself, rather than a part of the same, but as the tail\nis the most distinctive feature of a comet, and is the part most visible\nto the naked eye, there has arisen the popular but mistaken idea of\nidentity between the tail and the comet itself.\n\nTails are of all kinds. There are some which are short, while others are\nlong. Then we have comets with single tails, or double, and in some\ncases even multiple tails. Occasionally comets appear which have no\ntails at all. The comet of 1744 had six tails, which spread out in the\nshape of a large fan.\n\nOne of the most remarkable features of tails is their abnormal length,\nwhich oftentimes reaches into millions of miles. The comet of 1843 had a\ntail 112,000,000 miles long. Another feature about the tails of comets\nis that they are always directed _away_ from the sun. Up to the present\nI believe no satisfactory explanation has been given of this fact, but\nwith the conception of the rotating Aether as given in Art. 94, we shall\nfor the first time be able to give a satisfactory physical explanation\nof that phenomenon. In addition to this, the formation of cometary tails\nof all shapes receives a physical explanation, when taken into account\nwith the fact that the sun is an electro-magnet, possessing its\nelectro-magnetic field, and its lines of force, as described in Art. 88.\n\n[Footnote 41: _Outlines of Astronomy._]\n\n[Footnote 42: _Outlines of Astronomy._]\n\n\nART. 115. _Centrifugal Force and Comets' Tails._--In order to account\nfor the existence of the tails of comets, various repulsive forces have\nbeen introduced from time to time into the solar system, so that the\nphenomena of cometary tails might be satisfactorily accounted for.\n\nIt has been felt by every astronomer that some repulsive force, which\nhad its origin in the sun, was absolutely necessary to explain the\nexistence of the tails, and as no real force could be demonstrated to\nexist, recourse had to be made to repulsive forces of a more or less\nhypothetical nature. The necessity of this repulsive force is nowhere\nmore plainly indicated than by Sir J. Herschel in his _Lectures on\nScientific Subjects_, where, dealing with the phenomena of comets'\ntails, he writes: \"They have furnished us with a proof, amounting to\ndemonstration, of the existence of a repulsive force directed from the\nsun, as well as that great and general attractive force which keeps\nplanets in their orbits.\"\n\nIn the same work, referring to the comet of 1680, he writes: \"This comet\nwas perhaps the most magnificent ever seen. It appeared from November\n1680 to March 1681. In its approach to the sun it was not very bright,\nbut began to throw out its tail when about as far from the sun as the\nearth. It passed its perihelion on December 8th, and when nearest to the\nsun was only about 1/10 part of the sun's diameter from the surface. No\nwonder it gave evidence of violent excitement, coming from the cold\nregion outside planetary space. Already, when arrived even in our\ntemperate regions, it began to show signs of internal activity. The head\nhad begun to develop and the tail to elongate, till the comet was for a\ntime lost sight of. No human eye beheld the wondrous spectacle which it\nmust have offered on December 8th. Only _four days_ afterwards, however,\nit was seen again, and the tail, whose direction was reversed, and which\nobserve could not possibly be the same tail, its tail had already\nlengthened out to the extent of about 90 millions of miles, so that it\nmust have been shot out with immense force in a direction _from_ the\nsun.\"\n\nThe reader will have observed it took from November 10th to December\n8th, or 28 days, to fall to the sun for the same distance, and that with\nall the velocity it had on November 10th to start with. Herschel sums up\nthe matter thus: \"Beyond a doubt, the widest and most interesting\nprospect of future discovery which their study (comets' tails) holds to\nus, is, that distinction between gravitating and levitating matter, that\npositive and unrefutable demonstration of the existence in nature of a\nrepulsive force co-extensive with, but enormously more powerful than the\nattractive force we call gravity, which the phenomena of their tails\nafford.\"\n\nThus the philosophic mind of Herschel saw in the existence of cometary\ntails, the irrefutable evidence of the existence of a repulsive force,\nnot of a hypothetical character, but as real as the existence of gravity\nitself. Various attempts have been made to define that repulsive force\nwhich was thus demanded, and the same force has been ascribed by\nscientists to the repulsion due to heat, to light, and also to\nelectricity.\n\nSeveral French scientists have suggested that the repulsive force was\ndue to the heat of the sun. M. Roche was one of those who stated that\nthe phenomena of cometary tails was due to the repulsive power of heat,\nwhich found its origin in the heat of the sun. M. Faye, another French\nscientist, states that the repulsive force had its origin in the heat of\nthe sun. By a series of experiments he demonstrated that there was a\nrepulsive power in all heat waves, which gave his theory that\nexperimental support that any theory must possess to make it permanent.\n\nNow in Art. 63 it was shown that heat does possess a repulsive power,\nbut that that power is rather due to the electro-magnetic Aether whose\nvibrations produce the heat waves, than to the repulsion of heat; so\nthat, indirectly, the assumption of both these French scientists, that\nthe repulsive power of heat gave rise to the tails of comets, is\ncorrect. Then again it has been suggested that the repulsive power is\nproduced by the pressure of the light waves. Professor Lebedew suggested\nthis after he had experimentally proved that light waves did possess a\nrepulsive power (_Annalen der Physik_, November 1901). It can easily be\nseen, as pointed out in Art. 70, that, inasmuch as light is due to the\nvibrations of the Aether, they too possess this repulsive power, and\ntherefore Professor Lebedew's suggestion as to the nature of the\nrepulsive power is correct, as the real centrifugal force is really due\nto an aetherial pressure.\n\nWhether, therefore, we consider it from the standpoint of heat, or light\nor electricity, it ultimately resolves itself into the same aetherial\nmedium which is at once the common source of all these forces. Again, it\nhas been suggested that the repulsive power is electrical or\nelectro-magnetic, and this view is receiving more support than either of\nthe others from modern scientists.\n\nHerschel suggested that the repulsive power was electrical, while\nBredichin has worked out a very careful theory as to the effect of\nelectrical repulsion upon different elements that are found in the\ncomets' tails, with a view to explain the different shapes of the tails.\nBut whether the force is looked at from the standpoint of heat, light or\nelectricity, it ultimately resolves itself into the motions of the\nAether, which gives rise by its different vibrations and motions to all\nthe three forms of energy referred to.\n\nWhen we also take into account the fact that Aether is gravitative, and\ntherefore denser nearer to the sun than further away, and that it is\nalso rotating round the central body the sun (Art. 91), then we have at\nonce every condition necessary to explain all the various kinds of\ncometary tails, and also for the remarkable fact that the tail is always\nturned away from the sun, which is simply due to the effect of the\nrotating Aether with its outflowing electro-magnetic waves upon the\ngaseous matter of the comet. Thus from the phenomena of comets' tails,\nwe have again arrived at the conclusion of the existence of that\ncentrifugal force, whose origin and continuity are to be found in the\nelectro-magnetic Aether which surrounds the sun, and which by its\nelectro-magnetic waves gives rise to pressure on all bodies upon which\nthey fall.\n\n\nART. 116. _Formation of Tails._--With the conception of the formation of\nthe comet advanced in Art. 111, viz. that it is nothing more or less\nthan Aether in a state of condensation, and remembering the explanation\ngiven of the parts of the comet, as the nucleus, and head or coma, we\nare now in a position to give a philosophical account of the formation\nof the tails of comets, which will satisfactorily fulfil all the Rules\nof Philosophy. In addition to the facts already referred to in the\nprevious articles of this chapter, we must also recall our conception of\nthe Aether as given in Chapter IV., remembering that it gets denser\nnearer the sun, and that it is not frictionless; therefore, when a body\nis urged through it, friction is produced, and heat is generated.\n\nWe must also remember that the Aether is rotating round the sun as that\nbody proceeds through space. We have, therefore, to picture the\ncondensed mass of Aether situated out in the cold interstellar space,\ngradually coming under the influence of the sun, as that body rushes on\nits journey through space with a velocity of 500,000 miles per hour.\n\nSlowly, but surely, the mass of condensed Aether begins to respond to\nthe attractive power of the sun, and to move through space towards the\nsun. So long as it is moving towards the sun, it is encountering and\nhaving to overcome the resistance of the Aether.\n\nAt first this resistance is very feeble, owing to the decreased density\nof the Aether, but as it proceeds on its journey it is constantly\npassing into denser parts of the aetherial electro-magnetic field around\nthe sun. The result is, that as the resistance is increased, so there is\ngreater friction between the matter of the comet and the atomic Aether\nin space, and, in consequence, heat is generated.\n\nIn addition to the generated heat, the comet is all the while passing\ninto regions of greater intensity of heat. In both cases, the effect is\nonly manifested on that side of the comet which is approaching the sun;\nfor, if there be any friction at all, it will only be on that half of\nthe comet which encounters the Aether, so to speak, while the same part\nwill receive the added heat, as the distance between the comet and the\nsun is decreased. As can readily be seen therefore, this added heat acts\nonly upon the half of the comet which is advancing, and which faces the\nsun, and as the effect of heat is always to vaporise, so the effect on\nthe nucleus of the comet is to vaporise the condensed aetherial matter,\nand this vaporised aetherial matter is thrown off in layers which are\npartly spherical in form, the layers always being expelled in the first\ninstance _towards_ the sun, on account of that centrifugal motion which\nhas its birth in the nucleus of the comet.\n\nThis explanation fully establishes and confirms the first and second\nReflections of Herschel as given in Art. 114, and, moreover, is itself\nestablished by the very phenomena which comets present in their approach\nto the sun. As soon, however, as the vaporised matter is expelled from\nthe nucleus towards the sun, it is met by the centrifugal motion of the\nelectro-magnetic Aether which proceeds _from the sun_, and this pressure\nof the aetherial waves on the advancing comet acts as a repelling power,\nliterally repelling the vaporised matter from the sun, and thus giving\nrise to the existence of its tail.\n\nThis explanation fully confirms the third Reflection of Herschel\nreferred to in Art. 114, and is itself also confirmed by actual\nobservation. During all this time, however, the comet has been\napproaching the sun with a decreased velocity, for its velocity has been\nminimised by the resistance it has had to overcome in its approach to\nthe sun. As soon, however, as it reaches the sun, it is whirled round\nthat body by the rotating Aether medium, as the intensity of its\nrotation is greatest nearest the sun, with a velocity which often\nexceeds thousands of miles per hour.\n\nHaving passed its perihelion, in view of the physical existence of our\ncentrifugal motion, let us now ask ourselves what ought to happen to the\ncomet? Previous to its perihelion, the comet's motion and the\ncentrifugal motion due to the pressure of the Aether were in opposition,\nbut after passing the perihelion, the comet's motion and the centrifugal\nmotion will be acting conjointly, with the result that the motion of the\ncomet would be accelerated. Now this is exactly what observation teaches\nus does happen in regard to comets, when they have passed their\nperihelion passage.\n\nAs Herschel pointed out with reference to the comet of 1680 (Art. 114),\nit took 28 days to fall to the sun, but only took four days to cover the\n_same_ distance, after it had passed the sun and rounded the perihelion.\nSo that we have here, as Herschel stated, an irrefutable evidence of the\nexistence of the repulsive power whose existence we have demonstrated.\n\nAgain, there is another fact which has to be taken into consideration in\nregard to the tails of comets. Observation teaches us that their tails\nare invariably turned _from_ the sun, though why they always are so\nturned away is an unsolved problem, apart from some real or hypothetical\nrepulsive power. We have, however, to further remember that the\nelectro-magnetic Aether around the sun is ever rotating with that body,\nand carrying with it in its rotation all associated planets and meteors.\n\nThis rotation of the Aether plays a most important part in the phenomena\nstated. Whether the comet is approaching the sun, or receding from the\nsun, it is still subject to the influence of this rotatory Aether\nmedium. The result will be that the lighter particles of the vaporised\nmatter will be acted upon more powerfully than the heavier parts, so\nthat even when the comet is receding from the sun, after it has passed\nthe perihelion, the lighter parts which go to form the tail will be more\nunder the influence of the repelling Aether waves than the heavier\nparts, as the nucleus, as suggested by Bredichin.\n\nThus the natural result will be that the tail will still be directed\naway from the sun even when it is receding from that body. Gradually,\nhowever, as the comet recedes, it passes out of the denser Aether, where\nthe intensity of motion and vibration are greatest, to those slower\nparts of the sun's aetherial field where they are less intense.\n\nThe effect of this is soon made manifest on the tail and head of the\ncomet. The process which took place as it approached the sun is now\nexactly reversed, as it is now passing out of a denser into a more\nrarefied medium, where its motions and vibrations are less intense. The\ntail, therefore, appears to be drawn back to the head, while the head\nwill itself gradually contract into the nucleus, as it recedes further\nand further into space. If the comet be situated within the plane, or\nnearly the plane of the ecliptic, then it is possible for it to return\nagain, and go through the same process, unless it is captured on its\noutward journey by some of the large outer planets, as Jupiter. If,\nhowever, their planes do not coincide with the plane of the ecliptic,\nthen it is very possible that they will not reappear again, but pass on\nto some other stellar system. Thus we can explain on a strictly\nphilosophical basis one of the most interesting, and yet one of the most\nmysterious phenomena associated with our solar system, from the simple\nyet truly philosophical assumption that Aether is matter, in conjunction\nwith all that that assumption logically involves.\n\n\n\n\n                              CHAPTER XIII\n\n                      AETHER AND STARS AND NEBULAE\n\n\nART. 117. _The Starry World._--In addition to the planets and comets\nthat are found in the heavens, there are other bodies, countless in\ntheir number, which we know as stars. Who has not looked up into the\nheavens on some clear night, and noticed how the vault of heaven was\nspangled over with points of light, each point representing a huge sun\nthat exists in far-off space? For it must be remembered that every star\nis a sun, which, reasoning by analogy, is the centre of a stellar\nsystem, just in the same way that our sun is the centre of our solar\nsystem. Like our sun, all stars shine by their own light, and the\nquality of that brilliancy decides the magnitude of the star, the\nmagnitude being indicative of the relative brilliancy of a star rather\nthan its size. So that stars are divided into groups according to their\nmagnitude, the magnitudes ranging from the first to the sixteenth, and\neven beyond. Those of the first magnitude are more brilliant than those\nof the second, those of the second more brilliant than those of the\nthird, each magnitude decreasing in relative brilliancy as the number\nwhich indicates the magnitude increases. There are about sixteen\ndifferent degrees of magnitude, in which are classified the millions of\nstars that exist in infinite space, but only stars up to the sixth\nmagnitude are visible to the naked eye, the telescope revealing those\nwhich lie beyond. The total number of stars visible to the naked eye are\nabout 6000, half of which are visible in each hemisphere.\n\nAbout 20 stars comprise the group of the first magnitude, which include\nall the brightest stars visible, as Sirius, Canopus, Alpha, Arcturus,\nRigel, and Capella.\n\nThose of the second magnitude number about 65, and include the brighter\nstars to be found in the constellation known as the Great Bear. Stars of\nthe third magnitude number about 200, of the fourth magnitude about 400,\nof the fifth magnitude 1100, and of the sixth magnitude about 3200.\n\nWith the aid of the telescope about 13,000 stars of the seventh\nmagnitude are revealed to us, and 40,000 of the eighth magnitude, while\nof the ninth magnitude over 140,000 are revealed by the telescope. As\nthe power of the telescope is increased, so the number revealed is\nincreased also, until by the time we have reached stars of the\nfourteenth magnitude, at least 20,000,000 are revealed to us.\n\nIf we look into the heavens on a clear moonlight night, we shall further\nsee that here and there are groups of stars clustered together. These\nclusters are termed constellations, and are named after some object\nwhich the arrangement of the stars seemed to suggest. Thus every one is\nfamiliar with that constellation known as the Great Bear, or the\n\"Plough,\" so called because of its resemblance to a plough.\n\nThe brightest stars of each constellation are named after the letters of\nthe Greek alphabet, the brightest being called Alpha, the next in\nbrilliancy Beta, and so on, right through the Greek alphabet. For\nexample, the seven stars in the Great Bear are known as Alpha, Beta,\nGamma, Delta, Epsilon, Zeta, and Eta.\n\nThe constellations are grouped into two divisions, known as the Northern\nand Southern constellations respectively.\n\nThe visible Northern constellations are 25 in number, and include the\nfollowing well-known groups--\n\n    Ursa Major          The Great Bear.\n    Ursa Minor          The Little Bear.\n    Draco               The Dragon.\n    Hercules            Hercules.\n    Cygnus              The Swan.\n    Lyra                The Lyre.\n\nThe visible Southern constellations are 18 in number, and include such\ngroups as--\n\n    Cetus               The Whale.\n    Orion               Orion.\n    Canis Major         The Great Dog.\n    Canis Minor         The Little Dog.\n    Corona Australis    The Southern Crown.\n    Crux Australis      The Southern Cross.\n\n_Variable Stars._--Not only are the stars of different magnitudes, but\nthe brilliancy of some of them changes from time to time. This class of\nstars is known as variable stars, and has received the attention of\nmodern astronomers for many years, in order that the cause of their\nvariation might, if possible, be ascertained. The periods of variation\ndiffer in length, ranging from a number of days to 60 or 70 years.\n\nOne of the most interesting of variable stars is that known as Omicron\nCeti, whose period of change is about 331 days. Its brilliancy varies\nfrom one of the second magnitude to one of the tenth.\n\nBeta Persei is another well-known variable star. This star shines as one\nof the second magnitude for 2 days and 13 hours, and then suddenly loses\nits light, and in less than 4 hours becomes a star of the fourth\nmagnitude. Its brilliancy then increases again, and in a similar time it\nregains its former brilliancy.\n\nThe conclusion that has been arrived at in regard to the cause of the\nvariation of these stars is, that in each case the diminution of light\nis due to the existence of dark bodies, probably planets, which revolve\nround the central star.\n\nThis hypothesis was confirmed by Professor Vogel about 1889 by means of\nspectroscopic results.\n\nAnother interesting fact about stars is that they shine with various\ncolours. The colours of stars are as various as the colours of the\nrainbow, and range through the whole spectrum, of red, orange, yellow,\ngreen, blue, indigo, violet, and white. What is more remarkable is the\nfact that the colours of the stars seem to change through great periods\nof time. If we turn to ancient records we learn that Sirius was red\nthen, but is now green, while Capella was also red, but is now pale\nblue.\n\n_Double and Multiple Stars._--Many stars when looked at through powerful\ntelescopes are found to be double, triple, quadruple, and even multiple,\nalthough when looked at by the naked eye, they seem to be single in\nappearance.\n\nAn example of a double star is to be found in the constellation of Lyra.\nA moderate telescope reveals this as a double star, while a still more\npowerful telescope reveals the strange fact that each apparently single\nstar which forms the double is itself double, so that we have in this\nconstellation a system of four stars, in which each pair revolves round\na point situated between them.\n\nSeveral thousand double stars are known altogether, while the motions of\nseveral hundreds of them have been detected with powerful telescopes.\nSome of the double stars are as follows--Zeta Hercules, Eta Coronae\nBorealis, Gamma Coronae Borealis, Beta Cygni, Alpha Centauri.\n\nThe colours of some of the double stars are very beautiful. Some are\nyellow and blue; others, yellow and purple, while others are orange and\ngreen. Some of the double stars are only optical doubles, that is to\nsay, they apparently seem close together, while as a matter of fact they\nare immense distances from each other, the apparent doubleness being due\nto the fact that they are more or less in the same line of vision. Real\ndouble stars, where the component stars are situated close together, are\nknown as physical doubles, to distinguish them from the optical doubles.\n\n_Binary Stars._--Another class of double stars are known as Binary\nStars. This class of stars is composed of two stars which revolve around\neach other in regular orbits, and are among some of the most interesting\nobjects in the heavens. About 1000 Binary stars are known altogether.\nTheir motions, however, are very slow, and only in a comparatively few\ncases have the dimensions of their orbits been ascertained. Some of the\nBinary stars are Zeta Hercules, which has a period of about 36 years;\nEta Coronae Borealis, which has a period of 43 years; while the\nbrightest star, Sirius, is also a Binary star, with a period of about 50\nyears.\n\n_The Milky Way._--The Milky Way is the name given to that band of light\nwhich stretches across the sky at night-time, and forms a zone or belt\nthat completely circles the celestial sphere.\n\nThis belt of light has maintained from the earliest ages the same\nrelative position among the stars, and, when resolved by powerful\ntelescopes, is found to consist entirely of stars scattered by millions\nacross the expanse of the heavens.\n\nThe whole zone or belt is composed of nothing but stars, whose average\nmagnitude, according to Herschel, is about the tenth.\n\nStars of all magnitudes are, however, found in this zone.\n\nOf the brightest stars, about twelve are found in this region, while the\nmajority of stars of the second, third, and fourth magnitudes are also\nfound in or near it.\n\nThe great majority of star clusters are also found along the course of\nthe Milky Way, while many of the irresolvable nebulae seem to congregate\nnear the poles of this starry region.\n\nThe Milky Way is divided in one part of its course by a stream of stars,\nwhich seems to branch off as a separate stream, thus dividing it into\ntwo parts.\n\nAll these facts seem to point to the conclusion that the stars of the\nuniverse, instead of being scattered about haphazard in the space, form\na ring or layer, of which the thickness is very small compared with its\nlength and breadth.\n\nOur own solar system, according to Herschel, occupies a place somewhere\nabout the middle of the thickness of the zone, and near the point where\nit divides into two parts.\n\nRecent observations go to show that there is a tendency of the sun's\napex to drift along the edge of the Milky Way, and this drift seems to\npoint to a plane of motion of the sun, nearly coinciding with the plane\nof the Milky Way.\n\n\nART. 118. _Stars and Kepler's Laws._--We have learned in a previous\nchapter that the sun is the centre of a system which comprises a retinue\nof planets, with their attendant satellites, together with a number of\nasteroids or minor planets, with the addition of meteors and comets to\ncomplete the system.\n\nNow if the sun is a star, then, according to our First and Second Rules\nof Philosophy, every star ought also to be the centre of a stellar\nsystem and the centre of two aetherial motions, that is, the Centrifugal\nand Centripetal forces, due to the pressures and tensions of the Aether\nmedium. Further, every stellar system would be composed of exactly\nsimilar bodies to those which compose our solar system, as planets with\ntheir attendant satellites, together with meteors and comets; the whole\nof the stellar planets being bound to the central body by the\ncombination of the two aetherial motions, and kept revolving round the\ncentral star by the rotating electro-magnetic Aether currents.\n\nSuch a hypothesis is entirely philosophical, as it is simple in\nconception, and fully agrees with our experience in relation to the only\nstar of which we have any complete knowledge.\n\nIt is unthinkable to conceive of a star existing in so-called space, and\nconstantly radiating out its light and heat for no purpose at all. All\nNature teaches us that there is not a single thing in existence but what\nhas a definite purpose, and a definite place to fill in the universe.\nEven the aetherial atoms, which form the foundation stones of the\nuniverse, have their own purpose to fulfil in the glorious scheme of the\nUniverse conceived by the Eternal Infinite; and to suppose that a star\nhas no purpose to fulfil, no task to perform, is to suppose something\naltogether opposed to the teaching of all Philosophy. Why even man, with\nhis finite wisdom, would not be so foolish, so unwise, as to make a\nstar, and set it in the firmament of heaven for no purpose at all! Are\nwe therefore to suppose that the Divine Creator of all things possesses\nless wisdom than the creatures which He Himself hath made? Such an\nassumption would be a reflection not only on the wisdom of an All Wise\nBeing, but would also be a reflection on our own ideas of philosophical\nreasoning.\n\nTherefore the conclusion that we are compelled to come to, in relation\nto the millions of stars that exist in interstellar space, is that every\nstar is the centre of a stellar system, and the centre of two aetherial\nmotions due to the pressures and tensions of the electro-magnetic\nAether; while rotating round each star are the ever-circulating\nelectro-magnetic Aether currents, which form the medium by which all the\nstellar planets with their attendant satellites are ever made to revolve\naround that central body which supplies them with their light and heat.\nSome such conclusion as this Sir John Herschel arrived at, for in his\n_Treatise of Astronomy_, Art. 592, he writes: \"Now for what purpose are\nwe to suppose such magnificent bodies scattered through the abyss of\nspace? Surely not to illuminate our nights, which an additional moon of\nthe 1/1000 part of our own moon would do much better. He must have\nstudied astronomy to little purpose who can suppose man to be the only\nobject of the Creator's care, or who does not see in the vast and\nwonderful apparatus around us, provisions for other races of animated\nbeings. The stars, doubtless, are themselves suns, and may perhaps each\nin its sphere be the presiding centre around which other planets or\nbodies may be circulating.\"\n\nFurther, with reference to the stability of each of these stellar\nsystems, it is essential that the existence of a physical centrifugal\nforce should be recognized, in order that the unity and harmony of the\nspheres should be maintained.\n\nProfessor Challis points this out very conclusively in the _Phil. Mag._\nof 1859, where, writing on this point, he states: \"It may also be\nremarked, that if the Law of Gravity be absolute, there is no security\nfor the stability of a system of stars, whether the system be a Milky\nWay or a nebulous cluster. For, however small the mutual attraction\nbetween the constituent bodies may be, in the course of ages it must\nproduce a general movement towards the centre or densest region. But the\nform of the Milky Way and of certain nebulae seems to present an utter\ncontradiction to any such tendency.\" With the conception, however, of a\nphysical centrifugal force or motion due to the pressure of a physical\nmedium, the stability of even the Milky Way may be physically conceived\nand understood.\n\nAgain, when we consider the sun as a star, we find that it has two\nmotions of its own, one of rotation on an axis, and the other of\ntranslation in an orbit, such rotation being due to the fact that it is\na magnet and has ever circulating round it electro-magnetic Aether\ncurrents (Art. 91). By inference, therefore, we arrive at the fact that\nevery star is a magnet, as suggested by Professor Schuster, and\npossesses rotation on an axis, such rotation being due to exactly the\nsame cause as produces the rotation of any other planetary or solar body\n(Art. 92). Not only has each star a rotation on its axis, but it must\nalso possess translational motion in an orbit, and that orbital motion\nmust be due to exactly a similar cause as that which produces the\norbital motion of the sun. Are there any indications given by\nastronomical observations which lead us to the conclusion that stars do\npossess such orbital motions? The answer is unanimously in the\naffirmative; for, although all the stars and the constellations retain\napparently the same relative position to each other, yet they are all in\nmotion. The actual translational motion of the stars is termed proper\nmotion, and has been calculated with more or less success in relation to\nmany of the stars nearest to us. There are other motions of the stars\nknown as apparent motions, which are easily noted by any observer. These\napparent motions are due to the rotation of the earth on its axis, and\nits orbital motion round the sun.\n\nNothing is more certain, however, than that careful astronomical\nobservations have revealed the fact that stars have actual orbital\nmotions of their own through space. In many cases the orbital velocity\nhas been approximately ascertained.\n\nHalley discovered proper motions of certain stars as far back as 1715,\nwhen he found out, by comparing different observations, that Sirius,\nArcturus, and Aldebaran had moved during the period which had elapsed\nsince the respective observations were taken.\n\nMore recent observations tend to confirm the fact that stars have indeed\nproper motions, due to their actual translation through space. It has\nbeen ascertained, for example, that Arcturus is travelling at least 54\nmiles per second.\n\nThe proper motion of the stars, however, only gives us an indication of\ntheir relative motion through so-called space. It does not tell us\nwhether the star is apparently receding from the earth, or approaching\nit.\n\nDr. Vogel has ascertained by a special system of photography in relation\nto the spectra of stars, that Rigel has a velocity away from the earth\nof nearly 39 miles per sec., Aldebaran of 30 miles per sec., and Capella\nof 15 miles per sec., while the Pole star is apparently approaching the\nearth at a rate of nearly 16 miles per sec.\n\nNow if all the stars move through space with varying velocities, as\nspectroscopic and telescopic observations seem to suggest, the question\nnaturally confronts us as to what is the particular kind of orbit which\neach star completes? Is the orbit that of an ellipse, or a circle, or a\nparabola?\n\nThat it must have some kind of orbit is obvious from the proper motions\nexhibited by the several stars. We have already learned from Arts. 107\nand 108 that the sun possesses an orbit, which orbit fulfils the first\nand second of Kepler's Laws.\n\nIf therefore the sun, as representing all stars, is subject to Kepler's\nLaws, then, according to our Second Rule of Philosophy by which we base\nour hypotheses on our experience, we are compelled to come to the\nconclusion that every star which possesses any motion at all through\nspace must also be subject to Kepler's Laws, and therefore must each\npossess a controlling centre around which they severally revolve. Kepler\nhimself was of the opinion that the stars were subject to the laws which\ngo by his name, and this view of the subject was also accepted by Sir\nWilliam Herschel.\n\nThus from philosophical considerations we affirm that each star, while it\nis itself the centre of a starry system, is also dependent upon and\nassociated with some other body, to which it is held bound by the\nelectro-magnetic Aether, and around which it is made to revolve by the\ncirculating electro-magnetic currents associated with that central body.\nSo that by philosophical reasoning we are led to view the whole of the\ninnumerable stars that flood interstellar space, not as so many individual\nand isolated units, that have no relation to each other, but rather as\nparts of one great system, which in its entirety may form in its ultimate\nunity one harmonious whole, a universe.\n\nAs we come to consider star clusters and nebulae, we shall see how this\nidea of unity seems to be manifested throughout all celestial phenomena.\n\n\nART. 119. _Aether and Nebulae._--In addition to the host of stars that\nflood the infinite space, there are other celestial bodies that meet the\ngaze of the astronomer as the telescope is turned upon the heavens.\n\nThese bodies, which are glowing masses of gaseous matter, are termed\nNebulae. The word Nebulae signifies a cloud, but they are not clouds in\nthe same sense as we apply that term to masses of vapour that exist in\nour own atmosphere. Sir Wm. Herschel did more towards the discovery of\nnebulae than perhaps any other astronomer, either before his time or\nsince. His labours in the direction were completed and enlarged by his\nson, Sir John Herschel, who surveyed the Southern heavens in a way that\nhad never been accomplished before.\n\nThe result of the combined labours of the two Herschels has placed\ninformation of the nebulae at our disposal which is invaluable. Several\nthousands of different nebulae are now known to us, and as the telescope\nis improved and its powers increased, fresh nebulae are being added to\nthe number. Like stars, nebulae vary not only in size, but also in\ncolour, shape, and even in the materials of which they are composed.\nThey also vary in brightness, the light from some being much fainter\nthan the light from others.\n\nIt has been estimated by Huggins that the light received from a nebula\nwill not exceed the light of a sperm candle looked at from a distance of\na quarter of a mile. It is thought by some astronomers that the light\nreceived from a nebula is indicative of the stage of development to\nwhich it has arrived. Where the light is faint, the nebulae are in their\nfirst stages of formation, and where it is brighter it is indicative of\na more advanced stage of development. Thus nebulae may consist of\nnebulous matter in various stages of condensation, but they are not yet\nin that condition which corresponds to the condition supposed to exist\nin our sun.\n\nNearly all the nebulae lie outside the Milky Way, so that it would seem\nas if in ages past all the nebulae that had ever existed in this starry\nzone had passed out of their nebulous condition and been further\ncondensed into suns or stars, as they are called. Astronomical\nobservations teach us that there are very few nebulae indeed to be seen\nin this starry highway, the part of the heavens which are richest in\nthem lying far beyond the confines of this zone. For many years certain\naggregations of luminous points in the heavens were supposed to be\nnebulae, but by the aid of more powerful telescopes they have now been\nresolved into clusters of stars. One of these clusters is the cluster in\nHercules, while another is the great nebula of Orion. In the case of the\nformer, situated in the constellation of Hercules, we find a great\nnumber of very small points of light grouped together in a more or less\nglobular form. When looked at through a small telescope, this object\nlooks like a nebula, but looked at through Lord Rosse's, or some other\ngreat telescope, it becomes at once resolved into an immense number of\nseparate points of light, each one representing a star, there being\nbetween one and two thousand altogether in this constellation.\n\nClusters of stars are usually globular in form, though some are\nirregular in outline. The latter are generally rich in stars, with a\nless condensation of stars towards the centre. Sir Wm. Herschel\nconsidered the irregular clusters as being in a less advanced stage of\ncondensation, as he was of the opinion that all groups ultimately tended\nto clusters which were globular in form. Before dealing with the\ndifferent kinds of true nebulae we will now consider the question as to\n\"What are Nebulae?\"\n\n\nART. 120. _What are Nebulae?_--The question which presents itself to the\nmind of all astronomers when they have viewed the wondrous nebulae that\nexist in far-off space is, \"What are Nebulae?\" This question is so\nclosely identified with the question as to \"What is Matter?\" that the\nsolution of the one will give us the key to the solution of the other.\nIt is now generally admitted, that nebulae are composed of a glowing\nmass of gaseous matter, that gaseous matter being partly composed of the\ngas Hydrogen. Dr. Huggins in 1864 first made the discovery of the\nexistence of Hydrogen in certain nebulae by means of the spectroscope,\nwhich distinctly revealed certain lines that proved the existence of\nHydrogen in the nebulae.\n\nIn the spectra of some of the nebulae, that of 31 Andromeda, for\nexample, there are no dark lines shown, but only a continuous band of\nbright light, which would seem to indicate that there was no glowing\ngaseous matter in that nebula at all. But accepting the fact that the\nnebulae are composed of glowing gaseous matter, the problem confronts us\nas to where this gaseous matter comes from.\n\nIf, as spectrum analysis seems to teach us, there are nebulae in various\nstages of formation, there must be a period in their history of\ndevelopment when they had an origin. What, then, is the origin of a\nnebula, and what the physical explanation of that origin? From optical\nphenomena we learn that all space is not empty, but filled with the\nAether which is universal (Art. 42). What is the relation, then, of this\nglowing nebulous matter to this universal Aether? If it be suggested\nthat there is no relation, then we are in the unphilosophical position\nof having to admit, either that the nebulous matter of which the nebulae\nare composed never had any origin, or that it had its origin in some\nunknown and still undiscovered medium which exists in space. But both of\nthese hypotheses are unphilosophical, as the former is contrary to all\nexperience, while the latter is opposed to that simplicity of conception\nby which we only postulate one medium, the Aether, to fill all space.\n\nThus we are led to the conclusion, that the gaseous matter, be it\nhydrogen or nitrogen, must have some relation to the electro-magnetic\nAether that is so universal in its extent. Already this relationship has\nbeen dealt with by one who has done more for the development of\naetherial physics than any other scientist. Lord Kelvin, in his paper\n\"On the Clustering of Gravitational Matter in any part of the\nUniverse,\"[43] has solved this relationship, though in so doing he has\nhad to depart somewhat from the idea of an incompressible Aether. In\nthat paper he writes as follows: \"If we consider Aether to be matter, we\npostulate that it has rigidity enough for the vibrations of light, but\nwe have no right to say that it is absolutely incompressible. We must\nadmit that sufficiently great pressure could condense the Aether in a\ngiven space, allowing the Aether in the surrounding space to come in\ntowards the ideal shrinking surface.\" In another part of the paper,\ndealing with the same question, he writes: \"In regions where the density\nwas greater than in neighbouring regions, the density would become\ngreater still; in places of less density, the density would become less,\nand large regions would quickly become void or nearly void of atoms.\nThese large void regions would extend so as to completely surround\nregions of greater density.\" He then points out, that as soon as this\ndensity becomes something like the density of the atmosphere, then\ncollisions would take place between the particles, and continues: \"Each\ncollision would give rise to a train of waves in the Aether. These waves\nwould carry away energy, spreading it out through the void Aether of\ninfinite space. The loss of energy thus taken away from the atoms would\nreduce large condensing clusters to the conditions of a gas in\nequilibrium under the influence of its own gravity, rotating like our\nsun or moving at moderate speed as in spiral nebulae. Gravitational\ncondensation would at first produce rise of temperature, followed later\nby cooling, ultimately freezing, giving solid bodies, collision between\nwhich would produce meteoric stones such as we see them.\"\n\nHere then we have a definitive relationship between Aether and nebulae\ngiven to us from one of the keenest intellects of the present time, but\nin order for that relationship to become strictly philosophical, the\nconception of the Aether as advanced in this work must be accepted. For\nwith the present conception of a frictionless Aether, such a hypothesis\nis altogether untenable, because it supposes something that is contrary\nto all experience and observation.\n\nOn the basis of a condensing frictionless Aether into any kind of solid\nbody, be it nebula, meteor, sun or star, we have to suppose that it is\npossible for a medium (the Aether, which is outside the Law of\nGravitation according to the present theory) to be condensed into a\nbody, that is, a nebula or meteor which is subject to the Law of\nGravitation; and the question arises, at what point in the history of\nits condensation does this frictionless Aether pass out of the condition\nof having no weight, to the condition when it has weight; or, in other\nwords, from the condition when it is outside the Law of Gravitation, to\nthe condition when it comes under the Law of Gravitation?\n\nNo satisfactory solution can possibly be offered to such a problem.\nTherefore one of two results must follow, either that the Aether is not\nfrictionless, but possesses weight; or, that the condensation of the\nAether is not possible. With the theory of Aether presented in this\nwork, the whole question receives a simple and philosophical solution.\nAs Aether is matter, it is therefore atomic; and being atomic, it is\nsubject to the Law of Gravitation; and therefore, possessing mass and\nweight, it can readily pass into other forms of matter, and with such a\nconception Lord Kelvin's hypothesis becomes not only possible but\nprobable. So that it is exceedingly probable that nebulae are nothing\nmore nor less than condensed Aether, the same as comets were suggested\nto be condensed Aether. It may be asserted that such a hypothesis lacks\nthat experimental evidence which is so necessary for its establishment,\nbut I hope to show in the last chapter that Faraday has given the world\nthat very experimental evidence which will place this hypothesis upon a\nfirm and solid foundation, and enable it to pass out of the region of\nthe hypothetical into the region of fact and experiment.\n\nAccording to our hypothesis, therefore, nebulae are simply condensations\nof the electro-magnetic Aether that exists in interstellar space, and\nthe various spectra of the different nebulae indicate the stage of\ndevelopment to which the process has arrived. Where the spectra are\nbright, and continuous, and free from any dark lines, there we have\nsimply the Aether in its very first stage of condensation; and where we\nhave the dark lines appearing, such lines indicate a more advanced stage\nto which the process has arrived.\n\n[Footnote 43: _Philosophical Magazine_, July 1902.]\n\n\nART. 121. _Nebular Hypothesis._--The Nebular Hypothesis was first\nintroduced by Kant in his work on the _History of the Earth and Theory\nof the Heavens_.\n\nIn that work he attempted to explain the origin of the universe on\npurely mechanical lines. Laplace, a French mathematician, about the same\ntime came to similar conclusions as Kant had done, and published his\nviews in his work on _Exposition du Systeme du Monde_, and later on in\nhis more famous work the _Mecanique Celeste_.\n\nA feature common to both these theories rested in the fact, that they\nsupposed that all material bodies which exist in the universe once\nexisted in a nebulous condition, and that they were formed out of this\nnebulous matter. Further, that this nebulous matter gradually condensed,\nand as it condensed, a rotational motion was imparted to them, which\nrotation quickened as the condensation was continued.\n\nThen, as the rotation was accelerated, portions were flung off by the\ncentrifugal force, and these portions of nebulous matter gradually\ncondensed, forming the various planets of the system. As these\ncondensed, they, in their turn, parted with some of their nebulous\nmatter through the repulsive energy of the centrifugal force, and these\nsecondary parts gave origin to the various satellites that exist round\nthe planets.\n\nNow, while the general principle involved in the nebular hypothesis is\ntrue, yet the conception according to Laplace is not verified by fact,\nas we learn that Uranus and Neptune are still in a state of\nself-luminosity, while their density is the smallest of all the planets.\nFrom this we should infer that the two outermost planets are the\nyoungest planets of our solar system, but according to Laplace's theory,\nthey ought to be the oldest, as they would have been flung off first by\nthe parent body as it rotated; and therefore, being flung off first,\nshould be in a more advanced stage of development than any of the inner\nplanets. M. Faye has suggested a remedy for this defect in the theory.\nHe supposes that the nebulous matter out of which the planets were\nformed, was not flung off by the central body the sun, but that each\nplanet was formed at different centres of condensation within the\nnebular mass that existed in space. This would, undoubtedly, meet the\ndifficulty already referred to, and solves the problem as to how the\nvarious planets were formed at different distances in space.\n\nFurther, such a solution is in perfect harmony with all the Rules of\nPhilosophy. It is much more simple to conceive of Aether condensing at\nvarious points in what originally was the solar nebula, than it is to\nconceive of Aether condensing and shrinking towards one central point,\nand yet while condensing and shrinking, portions were flung off into\nspace which would form the planet. A greater objection has to be met,\nwhen we come to deal with the origin of all the meteors and minor\nplanets that exist in their numbers in the solar system. In relation to\ntheir origin, it is much easier to conceive of portions of the Aether\ncondensing at different centres of condensation, than to suppose that\neach portion of aetherial matter that originally formed the meteor, or\nasteroid, was flung off as a separate portion from the central body.\n\nWith the conception of an atomic and gravitating Aether, the Nebular\nHypothesis, therefore, for the first time is placed upon a sound and\nphilosophical basis, because the condensation of Aether, which is matter\nand possesses mass, admits of the origin of other matter from it which\nalso possesses mass, together with other properties, as elasticity,\ndensity, compressibility and inertia.\n\nWhen there is added to the atomic Aether the conception of a rotatory\naetherial atom, as was indicated in Art. 44, we have at once a source\nfrom whence the rotation of the whole mass may be derived. Thus, as the\ncondensation continued, and the nucleus or central part of the body was\ngradually formed, the rotation would be accelerated, because of the\ninherent energy which would exist in the condensed part. Further, as the\ncondensation continued, the body so formed would be more or less\nspherical in form, as the conception of our aetherial atom was\nspherical, and when we conceive of the primary point of condensation, we\nhave to think of a large number of spherical atoms coming together; and,\nas all the motions of the Aether which give rise to light, heat,\nelectricity and magnetism, and which now include gravitation, are\nspherical in their operations, so their effect upon any condensing\nAether would take a spherical form. Thus such bodies as nebulae, comets,\nasteroids, satellites, planets and suns should possess bodies more or\nless of a spherical form, subject to certain qualifying conditions, as\nrotation and orbital velocity, and this is in harmony with observation\nand experience. For we shall find that even in the case of nebulae, we\nhave globular, ring or annular nebulae, and elliptic nebulae, while in\nthe case of comets, the nuclei and coma are more or less spherical.\nFurther, it is a familiar fact that the shape of all asteroids,\nsatellites, planets, and even the sun is spherical or that of an oblate\nspheroid, which latter is simply due to its rotational velocity on its\naxis.\n\nThus the principle involved in the nebular hypothesis receives its\nconfirmation in the atomic and gravitating Aether, and with certain\nmodifications of the different hypotheses advanced, is capable of\nuniting all those hypotheses that have ever been put forth in this\ndirection into one perfect and harmonious whole.\n\nAgain, the condensation of the Aether, composed as it is of its atoms,\never in a state of rotation, does away with the Primitive impulse which\nwas objected to in Art. 9. For in that article it was shown that the\nconception of a primitive impulse as conceived by Newton was\nunphilosophical, in that its conception was not simple, and failed to\nsatisfactorily account for observed phenomena. With the hypothesis,\nhowever, of a rotatory aetherial atom, we have at once those conditions\nwhich at any time, in the history of the universe, may give rise to\nthose conditions by which a body may be set rotating not only on its\naxis, but also revolving around some central body, as the process of\ncondensation is continued.\n\nSo that in the primordial and universal electro-magnetic Aether that\nexists in all space, we get those conditions which will not only give\nrise to the phenomena of light, heat, magnetism and electricity, but\nalso those properties, qualities and motions by which are produced,\nmaintained and perpetuated, the various bodies that exist in the Aether,\nwhich is at once the physical source and cause of the bodies.\n\n\nART. 122. _Kinds of Nebulae._--Nebulae may be classified into the\nfollowing groups--\n\n    1. Irregular Nebulae.\n    2. Ring and Elliptical Nebulae.\n    3. Spiral or Whirlpool Nebulae.\n    4. Planetary Nebulae.\n\n_Irregular Nebulae._--Of this class the most conspicuous are those in\nthe constellations of Orion and Andromeda. So clearly defined are they,\nthat they are oftentimes seen by the naked eye on a clear night, and are\noften mistaken for comets.\n\nThe great nebula in Orion is one of the most noticeable objects in the\nheavens. It is noted for its size and brilliancy, and also for the\nsuccessful observation which it has been subjected to from time to time.\nThis large nebula is situated in that part of Orion which is occupied by\nseveral stars known as the Sword Handle. These multiple stars are known\nby the name of Theta. Around these multiple stars is to be seen the\nnebula, as though the multiple stars really were enveloped by the nebula\nextending for a great distance out into space. It is of a faint bluish\ncolour, with the central parts possessing the greatest brilliancy. The\nsuggestion arises in our mind as to whether the nebulae are in any ways\nindicative of the presence of the electro-magnetic aetherial field that\neach star undoubtedly possesses. We learned in Art. 88 that the sun is\nan electro-magnet, and that it possesses its electro-magnetic field. We\nhave also seen in Art. 109 that the zodiacal light, which is to be\nobserved in connection with our solar system, is really indicative of\nthe presence of that electro-magnetic field, as it rotates round the\ncentral body. Now, if an observer were situated out in space, where the\nnebula of Orion is situated, and could look at our system with\ntelescopes equally as powerful as those we possess, would not our sun\npresent an equally nebulous light to them because of the presence of its\nelectro-magnetic field?\n\nConversely, if every star possesses an electro-magnetic aetherial field,\nas they undoubtedly do, then it seems only reasonable to infer that that\nelectro-magnetic field possesses a nebulosity which corresponds with our\nzodiacal light. The fact that the spectra of the nebulae are continuous,\nrevealing no dark lines, seems to indicate the purity of some of the\nnebulae, and that therefore they are free from all known elements.\n\nSo that spectroscopic results seem to confirm this hypothesis, as the\npure Aether that would surround every star, or multiples of stars, would\ncertainly not reveal any dark lines by means of the spectroscope. Such a\nhypothesis, as to the real nature of a nebula, is entirely in harmony\nwith the theory of the Aether presented in Chapter IV., because being\ngravitative it will surround each star or multiples of stars, and\ntherefore be denser nearest to those stars, and being atomic, there will\nbe a certain amount of nebulosity manifested by the denser parts of the\nmedium, as is the case in our own solar system.\n\n_Ring or Elliptical Nebulae._--These forms of nebulae are so named from\ntheir ring-shaped appearance, sometimes being known as Annular Nebulae.\nThe elliptical nebulae are usually classed with them, as they are\nsupposed to be similar kinds of nebulae looked at edgeways. The best\nknown of this class is that found in the constellation of Lyra, and\nknown as 57M, which is the number of the star in Messier's catalogue of\nstars. It is small but well-defined, so that it looks more like a flat\noval solid ring than a nebula.\n\nThe central part is not entirely dark, but is filled up with a hazy\nlight. Another annular nebula is that situated to the south-west of\nLambda Scorpii. Sir J. Herschel[44] writes of it thus: \"It is a delicate\nbut well-defined annulus. The field is crowded with stars, two of which\nare nebulae. A beautiful delicate ring of a faint ghost-like appearance,\nabout 40\" in diameter, in a field of about 150 stars, of 11 and 12\nmagnitude and under.\"\n\nOf the elliptical nebulae the best known is the one in the constellation\nof Andromeda, which goes by the name of 31M. It is visible on a clear\nnight, and can be seen by the naked eye as a hazy light. There are\nseveral other elliptical nebulae, lying to the north-west of this great\nnebula.\n\n_Planetary Nebulae._--The planetary nebulae represent a number of minute\nobjects visible in the heavens. They look like globes of a\nbluish-coloured gas and are sometimes mistaken for small stars. Sir J.\nHerschel writes about them as follows: \"Planetary nebulae are very\nextraordinary objects. They have, as their name implies, a resemblance\nto planets, presenting discs, round or slightly oval, some being quite\nsharply defined, terminating in others a little hazy or softened at the\nborder. They are comparatively rare objects, not more than 25 having\nbeen observed, and of these nearly three-quarters are in the southern\nhemisphere. Their disc is circular or slightly elliptic, with sharp,\nclear, and well-defined outline, having exactly the appearance of a\nplanet with the exception only of its colour, which is full blue,\nvarying somewhat upon green. M. Arago has surmised that they may\npossibly be envelopes shining by reflected light from a solar body\nplaced in their centre, invisible to us because of its excessive\ndistance.\"\n\nThe suggestion which arises to our mind in view of the atomic and\ngravitating Aether is, that the planetary nebulae are exactly what their\nnames imply, that is, nebulous matter around planets. We have already\nlearned that each satellite and planet possesses an electro-magnetic\nfield, which field takes more or less the shape of a spherical form, so\nthat if there are planets existing in the far-off systems in space, as\nwe are compelled to believe that there are, then they too would possess\nan electro-magnetic field, which would be composed of spherical\nenvelopes surrounding the several planets. These planets would shine by\nreflected light, as suggested by M. Arago.\n\nThe possession by the planet of the nebulous matter, which we have\nalready suggested is composed of the denser parts of the Aether around\nthe planet, would give to the planet a nebulous appearance which would\nsatisfactorily account for the term already given. They would indeed be\nwhat Sir John Herschel suggested they were, viz, planetary nebulae.\n\n_Spiral Nebulae._--The Spiral, or Whirlpool Nebulae, are remarkable\nobjects, and were first discovered by Lord Rosse with his six-foot\ntelescope. One of the best examples of the spiral nebulae is that known\nas 51M. Small telescopes show this as two clusters, one of them being\nsurrounded by a ring, at a distance, which is divided into two parts.\nLord Rosse, however, found it to be really a spiral nebula, the ring\nrunning into a series of spiral coils of nebulous matter, the outlying\nparts being connected with the main part by curved bands.\n\nHuggins has found that the spectrum of this nebula is not gaseous. Other\nexamples of this class are 99M and 33M. What these spiral or whirlpool\nnebulae are, is unknown, but, on the hypothesis of a condensing and\ngravitating Aether which is in a state of rotation, the spiral nebulae\ncan be easily pictured. For, as the condensation goes on, rotation will\nset in, and if we can picture such a phenomenon taking place in a plane\nwhich is at right angles to the line of vision, then we should have a\nfull view of a nebula which would present a spiral form. Indeed, there\nis no phenomenon in connection with nebulae that cannot be physically\nexplained by a condensing, gravitating and rotatory Aether; and as\nAether is universal, the same properties will apply to it in distant\nspace as they do in the solar system; and apart from a gravitating and\nrotatory electro-magnetic Aether, the phenomena of our own solar system\ncannot be physically conceived or explained.\n\nTherefore, if such an Aether can explain the phenomena associated with\nour own system, it ought also to explain, and that to the fullest\nextent, all phenomena incidental to and associated with the innumerable\nsystems that flood the universe at large.\n\n[Footnote 44: _Outlines of Astronomy._]\n\n\n\n\n                              CHAPTER XIV\n\n                           UNITY OF UNIVERSE\n\n\nART. 123. _The Universe._--In the preceding chapters we have endeavoured\nto deal with some of the principal phenomena that help to give a\nmechanical conception to the entire Universe.\n\nIt now remains for us to show, in this last chapter, how, underlying all\nthe physical structure of the Universe, there is one fundamental and\nprimordial medium, in which all the forms of matter and motion find\ntheir ultimate unity.\n\nThe Universe literally means one ultimate whole, though that whole may\nbe compounded of many parts, the very essence of the term embodying the\nidea of a complete unity which runs throughout its whole physical\nstructure.\n\nApart from some such hypothesis as will be suggested in this chapter,\nthat ultimate unity is incapable of a physical or mechanical conception.\nIn Art. 29 we learned that the Universe was composed of two classes of\nthings, matter and motion, while in Art. 30 we learned that the sum\ntotal of matter according to the law of the conservation of matter ever\nremains the same; while further, in Art. 53, according to the law of the\nconservation of energy, the sum total of energy ever remains the same.\nWe have also learned that the two are indissolubly united, so that\nwherever we found matter, whether that matter was in its atomic,\nmolecular, planetary or stellar form, there, as its necessary complement\nand counterpart, was the ever-present and unceasing motion, in one or\nother of its many forms. Thus, throughout the entire Universe, we find\nthe same two essentials ever working in unison and harmony.\n\nNowhere in the realm of infinite space is there such a phenomenon as\nrest or absolute death. The ideal that seems to be the key of the\nUniverse, is that continuity of motion which science teaches us is so\ninseparably connected with all matter. Grouped, however, here and there\nthroughout the Universe are modifications of this aetherial matter,\ntermed molecules, satellites, planets, suns, or stars, which\nmodifications are, however, not so real and abiding as the\nelectro-magnetic Aether from which they receive their physical origin.\n\nThe physical character of the universe is progressive. Even in its\nultimate unity there is no such thing as stagnation or standing still;\nfor, while in some parts of the Universe new stars and suns and planets,\nyea, even new systems are being evolved out of the primordial Aether, in\nother parts of the Universe old stars and suns, with all their attendant\nplanets and satellites, are passing on towards that final end, when they\nthemselves will be again resolved into the original form of matter from\nwhich they were first made. This assertion is in perfect harmony not\nonly with science, but also with revelation. For even revelation teaches\nus that all the stars shall grow old as doth a garment, and as a vesture\nshall they be folded up (Heb. i. 11), and that (out of their ruins) a\nnew heaven and a new earth shall be created and the former shall not be\nremembered (Isaiah lxv. 17).\n\nThus amid all the modifications of that which is the real physical basis\nof all matter, we find indissolubly associated with each and all of the\nvaried forms and modifications certain motions which are analogous to\neach other. In the aetherial atom itself, so infinitesimal in its\nproportions that even our imagination is almost strained in our attempt\nto conceive it, yet even here we have rotation and translation in an\norbit, such rotation and translation being due to the motions of the\nelectro-magnetic Aether. Then in the gaseous forms of matter into which\nthese atoms may be condensed, we find the same two essentials, of matter\nand motion, of rotation and translation in an orbit, always working\nharmoniously together, through the motions of the selfsame Aether, which\ngives rise to the attraction and repulsions of the atoms.\n\nThen following the principle into the planetary world, and taking the\nplanet Saturn with its ring of satellites as an example, we find again\nthe same two factors ever working in unison and in harmony, with their\nincessant rotation and translation in an orbit, forming a complete and\nperfect unity in themselves, such unity being due to the pressures and\ntensions of the Aether combined with its rotatory character. Then going\na step further, we find a number of planets, with or without satellites,\nall rotating around one central body, that rotation and translation\nagain being due to the motions of the rotating electro-magnetic Aether,\ncombined with its pressures and tensions.\n\nFor millions of years, so far as we can tell, this solar system of ours\nhas been moving through space as one complete unit.\n\nThen out in stellar space there are millions of such systems, each\ndistinct and perfect in themselves, each of which is made up of exactly\nsimilar parts to our solar system, these innumerable systems being\ndoubtless joined together by the same electro-magnetic Aether, forming\none larger and grander unity, known as a constellation. Then these\nconstellations, increasing in their number, are again joined together,\nand form a still larger unity called a Galaxy; and galaxy being joined\nto galaxy, constellations to constellations, we get such an ocean of\nsuns and stars like that known as the Milky Way, the ultimate whole\nrevealing in all its beauty and harmony the unison of the two\nessentials of matter and motion. It may even be that all the oceans of\nsuns and stars, that exist in far-off space, are joined together by one\ncommon bond, the universal electro-magnetic Aether by its two\ncomplementary motions, the centripetal and the centrifugal, the whole\nforming one ultimate unity which we call the Universe, having for its\ncentre one common point or central orb, which indeed forms the centre of\ngravity of the entire Universe.\n\nThus the key to the physical conception of the Universe is to be found,\nand alone found, in that beauty of order, and harmony of motion, which\nare so inseparably associated with the varied forms of matter,\ngraduating through a series of units or atoms, each with its dual nature\ncomplete in itself, through a series of minor entities termed elements,\nwhich in their aggregations form meteorites, satellites, planets, suns\nand stars, and systems of stars and oceans of suns and stars, until all\nare united into one ultimate unity where all are blended into one\ncomplete and perfect whole; the whole of the universal fabric being held\ntogether in its mechanical order and beauty by the electro-magnetic\nAether. Then in the very centre of the Universe there dwells that\nSupreme Being whom we call God, who is at once the one real fountain and\nsource of all the light and life of the Universe itself. For it is His\nuniversal Spirit that moulds and fashions the plastic matter into the\nmany forms which it assumes, and uses the various modes of motion, as\nheat, light, electricity and magnetism, as instruments to build up and\nerect in all their beauty and harmony the innumerable systems that flood\nimmensity and space.\n\nFor if there be a centre of gravity to an atomic system, and a centre of\ngravity to a planetary system, and a centre of gravity to a solar\nsystem, then there is also a centre of gravity to a group of systems,\neven to a constellation, or a galaxy; otherwise our philosophy relative\nto the centres of gravity of masses fails in its application to wider\nphenomena of an exactly similar kind.\n\nThus, if there is a centre of gravity to a galaxy, even to the Milky Way\nitself, then, going one step further, with a faith that laughs at\nscientific data and leaps beyond the narrow bounds of pure reasoning, we\naffirm that there must even be a centre of gravity to the entire\nUniverse. Now let me ask the reader, What can be more fitting, more\nappropriate, more reasonable than to infer that the centre of gravity of\nthe Universe is to be found in that celestial orb or orbs where the\nthrone of God exists and endures, and where ultimately there will be\ncongregated together in perfect felicity the spirits of just men made\nperfect, not only from our insignificant planet, but all the spirits of\nall beings from all the planets which in their almost infinite number\nare circled round their central suns by the electro-magnetic Aether? It\nis there, in these bright orbs, with their vision and powers\nspiritualized, quickened and intensified, that all perfected spirits\nshall look out into space, with increasing wonder, upon the birth and\ndecay of worlds, the evolution and devolution of planets and systems and\nconstellations, and shall watch the continuation and working out of that\ngrand and glorious plan, which alone finds its perfection and its\nultimate fulfilment in the wisdom, and power, and glory of the Eternal\nSpirit of the Living God.\n\nTo see if this conception of the Universe is borne out by scientific\ndata, we will now address ourselves more particularly to those\nfundamental truths which underlie the unity of the Universe.\n\n\nART. 124. _The Unity of the Universe._--The Unity of the Universe is a\ndream which has passed before the imagination of many philosophers in\nby-gone times, and has been a fruitful source of speculation to\nold-world, as well as more modern philosophers. The researches of such\nliving scientists as Sir William Crookes, Professor J. J. Thomson and\nothers, have, however, made this dream come within the range of\npractical research and direct experiment. Professor J. J. Thomson\nbelieves that it is possible to break off from an atom, a part which is\nonly 1/1000 part of the whole, and these infinitesimal parts he has\ncalled corpuscles, which he considers are the carriers of the electric\ncurrent.\n\nIf, therefore, it can be philosophically proved that the hypothesis of\nan atomic, gravitating, and condensing Aether can satisfactorily account\nfor the physical existence of all atoms, and therefore of all matter,\nthe dream of old-world philosophers will be helped on its way to a\nsuccessful realization.\n\nWe have already suggested, that nebulae are formed out of the\ncondensation of the electro-magnetic Aether that fills the Universe; and\nas that nebula, according to the Nebular Hypothesis, ultimately resolves\nitself into a sun, or planet, or satellite, as the case may be, it\nfollows that the condensation of this electro-magnetic Aether forms the\nbasis of all the various elements, as Hydrogen, Nitrogen, Oxygen and the\nother seventy elements of which those bodies are composed. Thus the\nconclusion that we are compelled to come to in regard to the ultimate\nnature of matter, in its primordial condition, is, that all matter which\nexists in its varied forms throughout the entire Universe finds its\nphysical origin and source in the universal electro-magnetic Aether,\nwhich is itself atomic, and possesses all the essential properties of\nmatter.\n\nWith the conception of the Aether as advanced in this work, this\nhypothesis is perfectly philosophical and logical. For the conception is\nsimple, in that it supposes one form of matter to spring out of another\nform, that is, from an aetherial form to gaseous, in a similar manner to\nthat in which a gaseous form changes into a liquid form, that is, by\ncondensation, or a closer drawing together of the aetherial elastic\nenvelopes that surround each atom; each particular gas, as Hydrogen,\nNitrogen, or Oxygen, representing different quantities of aetherial\ncondensations, as will be seen in the next article.\n\nThe aetherial constitution of matter has received recognition from the\nhands of such scientists as Lord Kelvin and Dr. Larmor. The latter, in\nhis _Aether and Matter_, writes on the subject as follows (page 7):\n\"Matter must be constituted of isolated portions, each of which is of\nnecessity a permanent nucleus or singularity in and belonging to the\nAether, of some such type as is represented for example by a minute\nvortex ring in a perfect fluid, or a centre of permanent strain in a\nrotational elastic medium.\" And again on the same page he adds: \"It is\nincumbent on us to recognize an aetherial substratum of matter, in so\nfar as this proves conducive to simplicity and logical consistency in\nour scheme of physical relations, and helpful towards the discovery of\nhitherto unnoticed ones.\"\n\nDr. Larmor, as has already been pointed out in Art. 44, speaks of his\naetherial atoms as electrons, which are of two kinds, negative and\npositive, and of these he states (page 97): \"Each electron has an\neffective mass of aetherial origin, which forms part, and may be the\nwhole of the mass of the matter to which it is attached.\"\n\nHere, then, we have definite statements as to the hypothesis of all\nmatter having a definite aetherial origin. If, therefore, it can be\nproved experimentally that matter does possess this aetherial basis,\nthen the hypothesis will pass out of the region of speculation into the\nregion of fact and science.\n\nThe question, therefore, suggests itself to our mind, as to whether\namong all the experiments that have ever been performed by any\nscientist, there are any which will conclusively confirm and establish\nthe hypothesis as to the aetherial origin of all matter. In my opinion\nthere are such experiments, which have been given to the world by such\neminent scientists as Faraday and Sir Humphry Davy. Before, however, the\nvalue of their experiments can be rightly understood and valued, we\nshall have to ask ourselves another question, and that is, \"What is the\nrelation of Aether to electricity?\" Upon the correct answer to this\nquestion depends the application of Faraday's experiments to the\nhypothesis of the aetherial constitution of all matter, and therefore of\nthe great underlying principle of the unity of the Universe.\n\nIs there any relation therefore between Aether and electricity? If so,\nwhat is that relation, and to what extent does it hold good? Professor\nLodge, in his preface to _Modern Views of Electricity_, asks a similar\nquestion. \"Electricity,\" he states, \"has been thought to be a form of\nenergy, it has been shown to be a form of Aether. There remains the\nquestion, What is Aether?\"\n\nWhile again he writes: \"A rough and crude statement adopted for popular\nuse is that electricity and Aether are identical. But that is not all\nthat has to be said, for there are two opposite kinds of electricities,\nand there are not two Aethers. But there may be two aspects of one\nAether, just as there are two sides to a sheet of paper.\"\n\nThat there is a definite relation between Aether and electricity is as\ncertain as there is a definite relation between electricity and light.\nIn order to find out how far the relationship and identity between\nAether and electricity extend we will review our conception of the\nAether as given in Chapter IV. According to the conception advanced in\nthat chapter, on the hypothesis that Aether was matter, we\nphilosophically came to the conclusion that Aether was atomic, and\ntherefore gravitative. Because it was gravitative, it possessed density,\nand varying degrees of density; and having mass, it possesses the\nproperty of inertia the same as any other matter; and was also elastic.\n\nWe have now to add to these properties that of compressibility, which\nproperty we have ascribed to it from philosophical considerations when\ndealing with comets, and nebulae, and the origin of planets and\nsatellites. Now, if there is any identity between Aether and\nelectricity, then it follows that that identity will be more or less\nmanifested, as we find electricity possessing more or less of the\nproperties which have been ascribed to the electro-magnetic Aether. For,\nif we find two apparently different substances, or entities, possessing\nexactly the same properties, and occupying the same space at one and the\nsame time, then the only logical conclusion that we can come to is, that\nthese two apparently different substances are not two substances, but\none.\n\nWe have already proved that they both occupy exactly the same space,\nthat is, they occupy the planetary and interstellar regions of space,\nand fill indeed the entire Universe. The electro-magnetic theory of\nLight (Art. 78) indisputably proves this. We will therefore find out if\nelectricity possesses the properties which have already been ascribed to\nthe Aether. The first property, and indeed the fundamental property, of\nAether is that it is atomic, and upon the atomicity of the medium\ndepends the whole of the theory as worked out in relation to heat,\nlight, electricity and so-called gravitational phenomena. Is there\nanything about electricity that can suggest the hypothesis that\nelectricity is atomic? The answer is unquestionably in the affirmative.\nMany of the greatest scientists of the past and present century have\nbelieved and worked at the hypothesis of the atomic character of\nelectricity, and none more so than Dr. Larmor in his _Aether and Matter_\nand Professor J. J. Thomson.\n\nNow what is Dr. Larmor's opinion as to the atomicity of electricity?\nThese are some of his statements quoted in the work. In the very first\nwords of his preface he writes:[45] \"The following essay was originally\nundertaken mainly as a contribution towards the development of the\nstandpoint which considers electricity, as well as the matter, to be\nconstituted on an atomic basis.\" He continues: \"Since Faraday's work on\nElectrolysis, the notion of the atomic constitution of electrification\nin its electro-chemical aspect has never been entirely absent.\" While\nlater on he adds: \"Thus, for example, the present view of the atomic\ncharacter of electricity, which is at length coming within the scope of\ndirect experiment, has been in evidence with gradually increasing\nprecision ever since theoretical formulations were attempted on the\nsubject.\"\n\nWe are, however, possibly indebted to Professor J. J. Thomson for the\nmost direct experimental evidence as to the atomic nature of\nelectricity, for, as is well known to scientists, he has discovered what\nhe termed corpuscles, in association with electricity, which he makes\nthe carriers of the charges involved in electrical phenomena.\n\nHere, then, we have one proof of the identity that exists between Aether\nand electricity, in that while they both fill the same space, they are\nboth equally atomic; Dr. Larmor's ultimate atom, as we have already\nseen, being known as positive and negative electrons. Aether, we also\nlearned, was gravitative (Art. 45), but we have since learned that\ngravitation is itself an electrical phenomenon, in that both the\ncentripetal and centrifugal forces are due to the repulsions and\nattractions or pressure and tension of this electro-magnetic Aether.\n\nSo that when we affirm that Aether is gravitative, we do but affirm it\nis subject to the laws of electricity, which govern all electrical\nphenomena, and therefore we might just as truly affirm that electricity\nis gravitative, because such an affirmation is simply another way of\nsaying that electricity gives rise to the attractions and repulsions\nincidental to, and associated with, all electrical phenomena. Here,\nagain, we have further evidence of the identity that exists between\nAether and electricity.\n\nThen we learned that Aether possessed density, and also different\ndegrees of density, and the question arises as to whether there is\nanything corresponding to this property in electricity. As a matter of\nfact, this very property of density is itself recognized and known to\nall scientists by the term Electric Density, the electric density being\nalways proportionate to the charge of electricity on a given area.\n\nWe learned also in Art. 79 that aetherial density and electrical density\nwere identical in relation to solar and planetary space; so that,\nwherever there was the denser Aether, there was also the denser\nelectricity, the density of the one increasing or decreasing exactly in\nthe same ratio as the other increased or decreased. From aetherial and\nelectrical density, therefore, we have another proof of the close\nidentity that exists between Aether and electricity.\n\nAgain, we learned (Art. 48) that Aether possessed inertia. Here at\nleast, it may be thought, we shall find the first point of difference\nbetween the two entities. Surely such an intangible, aetherial\nmanifestation as electricity cannot possess inertia. Let us see what\nProfessor Lodge has to say on the subject. In the chapter on electrical\ninertia he writes (p. 89, par. 365 of _Modern Views of Electricity_): \"A\ncurrent does not start instantaneously: it takes a certain time, often\nvery short, to rise to its full strength; and when started it tends to\npersist, so that if its circuit be suddenly broken, it refuses to stop\nquite suddenly, and bursts through the introduced insulating partition\nwith violence and heat. It is this ram or impetus of the electric\ncurrent which causes the spark seen on breaking a circuit; and the more\nsudden the breakage, the more violent is the spark apt to be. We shall\nunderstand them better directly; meanwhile they appear to be direct\nconsequences of the inertia of electricity; and certainly if electricity\nwere a fluid possessing inertia it would behave to a superficial\nobserver just in this way.\"\n\nFrom these statements we learn then that electricity does possess\ninertia, although there are other phenomena of electricity that would\ndestroy the hypothesis. But undoubtedly an electric current possesses\nmomentum, and it is philosophically impossible to associate momentum\nwith any body that does not possess inertia, as one of the factors of\nmomentum implies mass, even though it be a mass of an infinitesimal\nform, and mass is the very essence of the property of inertia (Art. 40).\n\nDr. Larmor, in the work already referred to, dealing with the subject\nof electric inertia, explains that it is concentrated at the nucleus of\nthe electron (p. 230), while on p. 202 he states: \"Each electron as it\nis moved by the aetherial displacement belonging to the radiation,\nresists with its own definite inertia.\"\n\nApart from this evidence, the philosophical evidence already adduced in\nChapter X. is altogether in favour of the fact that electricity\npossesses inertia. So that we may say that, though the evidence as to\nthe identity of electrical and aetherial inertia is not fully complete,\nthe balance of opinion lies in favour of the identity rather than\notherwise. See _Appendix A_.\n\nIt can further be demonstrated that electricity possesses elasticity the\nsame as the Aether does. The charge and discharge of a Leyden jar are\nconclusive evidence of the elasticity associated with electrical\nphenomena, while further proof is to be found in the fact that Dr.\nLarmor attributes elasticity to his electrons, such elasticity being of\na rotational type.\n\nThe identity, therefore, that exists between Aether is now almost\ncomplete. We have now only to prove that both are compressible, and the\nidentity is fully established. This will be done by reference to certain\nof Faraday's experiments before the conclusion of this article. As we\nhave established, logically, the identity that exists between Aether and\nelectricity, the question arises now as to whether they are not one and\nthe same medium. If they are not one and the same medium, then we are in\nthe distinctly unphilosophical position of having to admit that all\ninterplanetary and interstellar space are filled at one and the same\ntime by two different media, and such an assumption is directly opposed\nto all observation and experience.\n\nTherefore, to be strictly philosophical, one of these media must be done\naway with, and we may either assert that interplanetary and interstellar\nspace is filled with electricity, or else it is filled with Aether, as\nit is much simpler to conceive of space being filled with one medium,\nthan it is to suppose it to be filled with two media, which are\nabsolutely identical in all their characteristic properties and\nfunctions. Both can give rise to exactly the same kind of phenomena,\nwhether they are the phenomena of heat, light, electricity, or\nmagnetism, and even gravitation itself. So that, if Science wishes to be\ndistinctly philosophical in her statements in future, it will be\nnecessary, it seems to me, to do away either with the Aether, or with\nthe electricity, and as the latter is the better known entity, I am of\nthe opinion that Science will retain the electric conception of space\nand matter, and do away with the aetherial, as being altogether\nunnecessary. See _Appendix B_.\n\nThus are we led to the conclusion that electricity is itself a form of\nmatter, as indeed it must be if it is atomic, as suggested by Dr. Larmor\nand Professor Thomson.\n\nProfessor Lodge, on p. 9 of the work already referred to, states:\n\"Electricity in this respect behaves just like a substance;\" and again,\np. 313, he writes: \"We cannot assert that it is a form of matter,\nneither can we deny it; on the other hand, we certainly cannot assert\nthat it is a form of energy, and I should be disposed to deny it. It may\nbe that electricity is an _entity per se, just as matter is an entity\nper se_.\"\n\nWhether electricity be a form of matter or not, as I believe it\nundoubtedly is, we have arrived at the fact, in view of the identity\nbetween Aether and electricity, that, wherever the one is present, the\nother is present also. So that if it can be demonstrated by direct\nexperiment that matter can be changed into its equivalent quantities of\nelectricities, or that equivalent quantities of electricities could\nproduce their equivalent forms of matter, then the electrical basis of\nmatter, and consequently the aetherial basis of matter, are proved\nbeyond contradiction, and we are thus led one step nearer to the\nultimate unity of the Universe, which unity is to be found in the\nuniversal electro-magnetic Aether, which is identical with universal\nelectricity. For if Aether be the basis of all modes of motion, as heat,\nlight, and gravitation, and it is identical with electricity, it follows\nthat electricity is equally the basis of all the varied phenomena, and\nif to that we add the constitution of matter itself, then we are within\nsight of the medium in which the ultimate unity of the Universe is to be\nfound.\n\nThis view of the subject has already been dealt with by a German\nscientist, Professor Vogt, in his book on _The Nature of Electricity and\nMagnetism_, a book, however, which is not translated into English. In\nthat work I believe he shows the possibility of all matter having its\norigin in electricity; and if that be so, then that theory is really\nidentical with an aetherial basis of matter, seeing that Aether and\nelectricity philosophically seem to be one and the same medium. Let us\ntherefore turn to Faraday's experiments, and see what they teach us on\nthe subject of the electrical basis of matter, and therefore the\naetherial basis at the same time.\n\nIn paragraph 852 of his _Experimental Researches_ Faraday writes: \"The\ntheory of definite electro-chemical action appears to me to touch upon\nthe absolute quantity of electricity, or electrical power, belonging to\ndifferent bodies. Although we know nothing of what an atom is, yet we\ncannot resist forming some idea of a small particle which represents it\nto our mind, and though we cannot say what electricity is, so as to be\nable to say whether it is a particular _matter or matters_, or mere\nmotion of ordinary matter, yet there is immensity of facts which justify\nus in believing that the atoms of matter are in some way endowed or\nassociated with electrical powers to which they owe their most striking\nqualities, and amongst them their chemical affinity. As soon as we\nperceive, through the teaching of Dalton, that chemical powers are\n(however varied the circumstances in which they are exerted) definite\nfor each body, we learn to estimate the relative degree of Force which\nresides in such bodies; and when upon that knowledge comes the fact that\nelectricity, which we appear to be capable of loosening from its\nhabitation for a while, or conveying from place to place, whilst it\nretains its chemical Force, can be measured out, and being so measured,\nis found to be as definite in its action as any of those portions which,\nremaining associated with the particles of matter, give them their\nchemical relation, we seem to have found a link which connects the\nproportion of that belonging to the particles in their natural state.\"\n\nThen in paragraph 855 he writes as follows: \"It seems a probable and\nalmost a natural consequence, that the quantity which passes is the\nequivalent of, and therefore equal to, that of the particles separated,\n_i. e._ that if the electrical power which holds the elements of a grain\nof water in combination (or which makes a grain of oxygen and hydrogen,\nin the right proportions, unite into water when they are made to\ncombine) could be thrown into the condition of a current, it would\nexactly equal the current required for the separation of that grain of\nwater into its elements again.\"\n\nFurther, in Art. 857, he states, \"I can have no doubt that, assuming\nhydrogen as 1, and dismissing small fractions for the simplicity of\nexpression, the equivalent number or atomic weight of oxygen is 8, of\nchlorine 36, of bromine 78.4, of lead 103.5, of tin 59, etc.,\nnotwithstanding that a very high authority doubles several of these\nnumbers.\" Then, writing upon the definite relationship of\nelectro-chemical equivalents, he states, Art. 835: \"Electro-chemical\nequivalents are always consistent; _i. e._ the same number which\nrepresents the equivalent of a substance _A_, when it is separating from\na substance _B_, will also represent _A_ when separating from a third\nsubstance _C_. Thus 8 is the electro-chemical equivalent of oxygen,\nwhether separating from hydrogen or tin or lead; and 103.5 is the\nelectro-chemical equivalent of lead, whether separating from oxygen or\nchlorine or iodine.\"\n\nSo that from Faraday's experiments we learn definitely that the\nelectro-chemical equivalents coincide with and agree with the ordinary\nchemical equivalents according to Dalton's theory. From these\nexperimental results of Faraday's we therefore learn that Faraday was of\nthe opinion that each atom had a definite and certain quantity of\nelectricity associated with it; and if this be true, then, in view of\nthe identity of Aether with electricity, it follows that each atom must\nhave definite and certain quantities of Aether associated with each\natom. So that through Faraday's experimental researches we are again led\nto the hypothesis enunciated by Lord Kelvin in his paper \"On the\nClustering of Gravitational Matter in any part of the Universe,\" viz.\nthat all matter has an aetherial, that is, an electrical basis, and that\nit is by the condensation of this electricity, and combinations of the\ncondensational particles, that all the various elements are formed which\ncompose the infinite variety of forms that constitute the entire\nUniverse. Here, then, it seems to me, we have the evidence which gives\nto the aetherial Nebular Hypothesis (Art. 121) that experimental\nevidence which places that hypothesis upon a firm and philosophical\nfoundation, and conclusively proves that it is possible for Aether out\nin the colder regions of interstellar space to be condensed into masses\nof gaseous matter, which form nebulae, and other masses in the cold\nregions of interplanetary space to condense and form comets and meteors.\n\n[Footnote 45: _Aether and Matter._]\n\n\nART. 125. _Physical Constitution of Matter._--In Art. 31 we learned that\nall matter was made up of minute parts called atoms. When these atoms\nenter into combination with each other, they form the smallest particles\nof elementary substances as well as compound bodies, these particles or\nbodies being termed molecules.\n\nA molecule, therefore, may consist of any number of atoms of the same\nelement, or may be formed of the union of the atoms of two different\nelements. In the preceding article we have learned that the atom of\nhydrogen or carbon, however, is divisible, at least theoretically if not\nexperimentally, as we came to the conclusion that all atoms are composed\nof infinitesimal aetherial atoms, which are synonymous with atoms of\nelectricity.\n\nWhether we shall ever be able to experimentally prove the existence of\nsuch an atom remains to be seen, though Dr. Larmor states that the\natomicity of electricity is coming within the scope of direct\nexperiment; while the researches of Professors Crookes and J. J. Thomson\nhave undoubtedly given direct evidence of the existence of corpuscles,\nwhich are part of the atoms of the various elements.\n\nWhen we try to conceive, however, of the manner in which the various\nelements can be formed from one primary medium, that is, the Aether or\nelectricity, we find it difficult to arrive at a simple physical\nconception of the process involved.\n\nWe are indebted to Professor J. J. Thomson for what is practically the\nonly simple physical conception of the method in which various elements\nmay be formed from that medium, which gives unity to the whole of the\nuniverse. In the Adams Prize Essay of 1883 Professor Thomson indicated a\ntheory based on the vortex atom (Art. 43) which satisfactorily accounted\nfor the various laws which governed gaseous matter, and also showed how\nthe varied chemical combinations might be physically conceived as being\nproduced from one primary medium.\n\nIn this theory we have to conceive of the vortex atom as possessing a\nhollow core, while in our conception of an aetherial atom (Art. 43) we\nconceived it as being more of a spherical or globular form than\nring-shaped. We have, then, to consider the atom of any element as being\ncomposed of a vortex ring of various thickness, the thickness of the\nring being an indication of its atomic weight.\n\nEach vortex ring must also be conceived as itself being composed of a\nnumber of aetherial atoms, or atoms of electricity, the number of such\natoms being proportionate to the respective atomic weights of the\nvarious elements. Dr. Larmor suggests that a vortex ring may have this\nconstitution in his work on _Aether and Matter_.\n\nAccording to Professor J. J. Thomson, then, any vortex ring, which we\nhave supposed to be constituted of aetherial atoms, or atoms of\nelectricity, may unite with any other vortex ring, thus producing a\nvortex ring of double density, which would possess double the\nelectricity of the unit vortex ring. If we united three vortex rings,\nthen the result would be an atom of threefold the density and strength\nof the unit vortex ring.\n\nWe might conceive of four or any number of these rings uniting together\nto form a separate element, and then each element would simply be a\nmultiple of the unit vortex ring, and so possess regular multiples of\nthe atoms of electricity, each multiple representing a distinct element.\n\nWe will now let Professor Thomson speak for himself on the matter, and\nwill describe the theory in his own words, always keeping in mind the\nhypothesis that the unit vortex ring is itself composed of a definite\nnumber of atoms of electricity or electrons, as proved by Faraday. See\n_Appendix C_.\n\nIn the work already referred to, Professor Thomson states: \"We may\nsuppose that the union or pairing in this way of two vortex rings of\ndifferent kinds is what takes place, when two elements of which these\nvortex rings are atoms combine chemically; while, if the vortex rings\nare of the same kind, this process is what occurs when atoms combine to\nform molecules. Now let us suppose that the atoms of different chemical\nelements are made up of vortex rings, all of the same strength, but that\nsome of these elements consist of only one ring, others of two rings\nlinked together, others of three loops, and so on. Then if any of these\nrings combine to form a permanent combination, the strength of all the\nprimaries in the system so formed by the combination must be equal.\"\n\n\"Thus an atom of one element may combine with another atom of the same\nkind, to form a molecule of that substance consisting of two atoms.\nAgain, three of these atoms may combine, and form a system consisting of\nthree primary elements, but the chance of their doing so is small\ncompared with the chance of two pairing; so that the number of systems\nof this kind will be small compared with the number of the systems\nconsisting only of two atoms. We might have systems of four atoms, but\nthe number would be small compared with the number of systems that\nconsist of three atoms.\"\n\n\"Now, suppose that an atom of one element is to combine with an atom of\nanother. Suppose, to fix our ideas, that the atom consisting of two\nvortex rings linked together, is to combine with an atom consisting of\none vortex ring; then, since, for the stability of connection, the\nstrength of all the primaries which form the components of the compound\nmust be equal, the atom consisting of two links must unite with\nmolecules containing two atoms of the one with one link. Thus the\ncompound formed will be the simplest combination, consisting of one of\nthe atoms which consist of two vortex rings linked together with two of\nthe atoms consisting of only one vortex ring. Similarly, if an atom\nconsisting of three vortex rings linked together were to combine\ndirectly with atoms consisting of only one vortex ring, the compound\nformed would consist of the three linked atoms with three of the others,\nand so on for all the combinations of atoms formed by any number of\nvortex rings linked together. This suggests that the elements, called by\nthe chemists monads, dyads, triads and so on, consist of one, two, etc.\nvortex rings linked together, for then we should know that a dyad could\nnot combine with less than two atoms of a monad to form a stable\ncompound, or a triad with less than three, and so on, which is just the\ndefinition of the terms monad, dyad, triad.\"\n\n\"On looking at chemical combination from this point, we expect to find\nthat such compounds as Hydrochloric acid, where one atom of Hydrogen has\nonly to meet one atom of Chlorine; or water, where one atom of Oxygen\nhas only to meet two atoms or a molecule of Hydrogen, would be much more\neasily and quickly formed than a compound such as ammonia gas, to form\nwhich an atom of Nitrogen has to find itself close to three atoms of\nHydrogen at once.\"\n\n\"It is the case, I believe, in direct combination, that simple compounds\nare formed more quickly than compound ones. We might call the ratio of\nthe number of links in the atom of any element, to the number in the\natom of Hydrogen, the Valency of the element. Thus the compounds H-CL,\nH-I, H-F, show that the atoms of Chlorine, Iodine, Fluorine have the\nsame number of links as the atom of Hydrogen, so that the valency of\neach of these elements is unity. From the compound H_{2}O we infer that\nthe atom of Oxygen consists of twice as many links as the atom of\nHydrogen. The compound H_{2}S indicates that the atoms of Sulphur have\ntwice as many links as the atom of Hydrogen.\"\n\n\"The molecules CO_{2} and Marsh Gas have each three primaries\nrepresented by C-O-O and C-H-H respectively. According to the view we\nhave taken, atomicity corresponds to complexity of atomic arrangement,\nand the elements of high atomicity consist of more vortex rings than\nthose whose atomicity is low.\"\n\n\"Thus high atomicity corresponds to complicated atomic arrangement, and\nwe should expect to find the spectra of bodies of low atomicity much\nsimpler than those of high. This seems to be the case, for we find that\nthe spectra of Sodium, Potassium, Lithium, Hydrogen, Chlorine, which are\nall monad elements, consist of comparatively few lines.\"\n\nHere then, on the vortex theory of matter, especially when that vortex\ntheory is given an electric basis, as is the case in Dr. Larmor's\nelectron theory, we have a thinkable and logical explanation of the\nphysical and chemical properties of matter, by which all elements and\ncompounds may be formed from the primordial aetherial or electric atom.\nAs all Nature is composed of about seventy elements, and it has been\nconclusively demonstrated that an atom of Hydrogen is the same all over\nthe universe, no matter whether it exists on this planet, or in some\ndistant star or nebula, we arrive at the conclusion that all the other\nelements are exactly the same in their properties and qualities wherever\nthey are found. If, therefore, we couple Faraday's experiments and\nresults as to the electro-chemical equivalents of all atoms, with this\ntheory of Professor J. J. Thomson's, then we are again compelled to come\nto the conclusion that the unity of the universe in all its\nuniversality, and infinite variety of forms and modes of matter, is to\nbe found, and alone found, in the universal Aether, which is co-existent\nand coextensive with electricity.\n\n\nART. 126. _Quod Erat Faciendum._--Before concluding this work let us\nbriefly review the whole of the theory submitted herein to the reader.\n\nThat which was to be done consisted primarily in ascertaining the\nphysical cause of Gravitation, by which would be accounted for on a\nphilosophical basis all the phenomena incidental to and associated with\nthe Law of Gravitation. Such phenomena included the physical cause of\nthe Centripetal and Centrifugal Forces, the physical cause of Kepler's\nLaws, together with a physical conception of the application of Newton's\nLaws of Motion to all solar and stellar bodies. In addition to this,\nthere were other outstanding problems in physics that it was premised\nwould receive either a partial or an entire physical explanation. It was\npremised, for example, that the problem of the relative motion of Aether\nand matter would be solved, that the cause of the permanent magnetism of\nthe earth would be revealed, and the great problem of the constitution\nof matter attacked, together with the unity of the universe which arose\nfrom that conception.\n\nIn order, however, for any theory to be philosophical in its initial\nstages, the rules of some of the greatest philosophers which govern the\nmaking of any hypotheses were briefly outlined, and were found to\nresolve themselves into three divisions.\n\nThe first rule dealt with the general simplicity of Nature's mode of\nworking, and therefore the general simplicity which must govern our\nhypotheses in perfecting any theory as to the cause of all phenomena,\ngravitational or otherwise.\n\nThe second rule showed that the only sound basis from whence we could\nderive all our data upon which to speculate and reason, lay in our\nexperience of all natural phenomena. Whatever else we might do, or not\ndo, it was absolutely necessary, if we wished to be perfectly\nphilosophical in our conclusions, that we should not traverse the direct\nresults of observations and experiments.\n\nThe third rule laid down was the obvious axiom, that the theory so\nperfected by logical reasoning must satisfactorily account for and\nexplain all the phenomena sought to be explained.\n\nNow I wish to submit the whole theory as propounded in this work in its\ncompletion and in its entirety to the reader, and to ask him if the\nRules of Philosophy have not been adhered to throughout the whole work?\nCan any theory be more simple than the one submitted in this work, by\nwhich we have endeavoured to account for all, and even more, than was\npremised in the opening chapters?\n\nThe very simplicity of the fundamental hypothesis that Aether is matter,\nin all its properties and qualities, has been the chief obstacle to the\nretardation of its earlier discovery.\n\nAny proposition more simple, more easy of comprehension, is, to my mind,\ndifficult of conception. Why, children in our homes and schools may be\ntaught the truth, and grasp it in its concrete form, and that is the\nhighest test of the simplicity of any hypothesis.\n\nThus the first Rule of Philosophy is satisfied and fulfilled in the\ninitial hypothesis, and I venture to affirm that the same simplicity has\ncharacterized the development of the theory throughout its entire\nprogress. Step by step, simple facts and simple truths which are known\nto any ordinary student have been shown to have a wider and more\nuniversal application than even the writer dreamed of, when he started\nout on his voyage of discovery in philosophical research.\n\nWhen we consider the second Rule of Philosophy in its application to our\ntheory, we find that experience, as revealed by observation and\nexperiment, is fulfilled to the minutest detail. The simple hypothesis\nthat Aether is matter, fulfils to the very fullest extent all\nrequirements demanded by the experience of all the scientists and\nexperimentalists that the world has ever known. To assert that Aether is\nnot matter is to assert a proposition contrary to all the accumulated\nexperience of the past generations. Therefore, if Aether is matter, then\nits fundamental qualities must be those which belong to and are\nassociated with all matter, those qualities being atomicity, gravity,\ndensity, elasticity, inertia, and compressibility.\n\nThe objector to this statement is himself violating the chief rule of\nall philosophy, in that he is going contrary to the tenor and teaching\nof his own experience. Then, following out the second rule step by step\nwe arrive at the one grand central truth, that electricity is also a\nform of matter, and that all the forces of the entire universe are but\ndifferent modes of motion, different vibrations of the universal\nelectro-magnetic Aether; while all the varied bodies that exist are\nthemselves but different manifestations in a gaseous, liquid, or solid\nform of the same electro-magnetic substance.\n\nThus, step by step, we have tried to build up a theory of the physical\ncause of all phenomena, which will satisfactorily account for those\nphenomena, and even for the structure of the universe itself, from the\nmechanical standpoint, and by so doing have fulfilled the third Rule of\nour Philosophy as enunciated by Newton and others.\n\nSo that by the conception that Aether is matter, in its primordial\nstate, we have more than fulfilled all that was premised should be done.\n\nThus the long-sought-for and long-expected cause of Gravitation,\ntogether with the cause of the two complementary forces, is found in the\nsimple statement that Aether is matter, with all that is logically\nincluded therein. Kepler's Laws and Newton's Laws of Motion also receive\na physical explanation in the same universal electro-magnetic Aether.\n\nIn addition to the solution of these problems, the transverse vibrations\nof light has received for the first time a physical conception, and a\nphysical explanation, even admitting that that explanation may not be\nperfect in detail.\n\nThe origin of the permanent magnetism of the earth has also received a\nphysical explanation through the motions of this same electro-magnetic\nAether, while certain theories in relation to electricity given to the\nworld by Ampere, Weber, Faraday, and Clerk Maxwell have found their\nconsummation in this atomic electro-magnetic medium.\n\nFurther, astronomical hypotheses in relation to comets and nebulae are\nnot untouched by the theory of a compressible and condensing atomic\nAether. Indeed, there is not a phase of natural phenomena which is not\naffected in some way or other by the philosophical result arrived at\nthat Aether is matter in its original state. Therefore, we claim,\nhowever imperfectly it may have been done, that not only have the Rules\nof Philosophy been fulfilled, but that the theory so advanced has\naccomplished more than even we in our wildest imagination hoped and\ndreamed for it.\n\nLook at the problem of the Aether how we may, the advantages of the\ntheory of an atomic electro-magnetic Aether far surpass and outweigh the\nadvantages of a frictionless medium, which in some unknown way possesses\nmass and inertia, although the conception of such properties themselves\ndisproves the existence of such a frictionless medium.\n\nAfter all, how much of this theory is there which is entirely new or\nabsolutely original? Age after age, men have had exactly similar dreams,\nand seen similar visions. In the old Grecian days similar views were\nexpressed by their philosophers; and, even in the philosophy of less\ncivilized countries, many of the suggested hypotheses found their place\nin a more or less perfect form.\n\nAnalyze the whole theory from its initial stages to the last chapter,\nand we shall find, with the exception of one or two features, that every\nhypothesis first had its origin in the mind of some of the greatest\nthinkers and philosophers that the world has ever known.\n\nTake several hypotheses as examples. The hypothesis that Aether is\natomic was suggested by such men as Newton, Huyghens, Descartes,\nChallis, Clerk Maxwell, and others.\n\nThat Aether is gravitative has been suggested by Young, Grove, Faraday,\nand Lord Kelvin. Huyghens, Fresnel, and Young postulated different\ndegrees of density for the Aether, while Stokes and McCullagh have\naffirmed and proved different degrees of elasticity of the medium.\n\nThe inertia of the medium has received experimental evidence from\nTyndall, Maxwell, Faraday, Lodge, and others, and its compressibility\nhas received the adherence of men like Faraday, Maxwell, and Lord\nKelvin.\n\nThen, when we come to deal with the causes of the forces involved in\ngravitational phenomena, we find that exactly similar hypotheses in\nregard to the Centrifugal Force have been postulated by Herschel,\nBredichin, M. Faye, and Lebedew; while Faraday, Gauss and others have\nsuggested the close relationship that exists between electrical and\ngravitational phenomena.\n\nThe physical explanation of Kepler's Laws was suggested by Kepler\nhimself, while Huyghens, Bernoulli, Descartes, and many of their\ncontemporaries believed in the existence of some kind of vortices.\n\nThe unity of the universe has been a dream of philosophers for\ngenerations past, and that dream is now crystallized in the definite\nconception of an atomic universal electro-magnetic medium, while the\nelectrical basis of matter receives the support of such men as Crookes,\nJ. J. Thomson, Larmor and Vogt.\n\nThus we learn that all the dreams and thoughts, all the hypotheses and\npostulates of old-world as well as present-day philosophers find their\nconsummation and ultimate realization in one universal, atomic,\nelectro-magnetic medium.\n\nIf this fact does not stamp the theory with that authority which is\nundeniably associated with the names of some of the scientists quoted,\nthen all the greatest men in the scientific world have lived and toiled,\nthought and dreamed in vain, while the priceless gems of their\nimagination and research are treated as worthless and valueless.\n\nAgain, what shall we say of the discoveries of to-day?\n\nWhat is the key to the greatest scientific discovery of modern times,\nviz. wireless or aetherial telegraphy, which is girdling the earth with\nits mysterious communications? Is not the key to that discovery to be\nfound in this universal electro-magnetic medium?\n\nWhence come the X-rays, Rontgen rays, and other light rays with their\nadaptability to human suffering, if they come not from this same\nelectro-magnetic medium? their adaptability to human suffering being\ndependent upon the intimate and close relationship that exists between\nthe physical body and the electro-magnetic medium.\n\nWhere is the key to the principle underlying the gramophone, the\nphonograph and the telephone, if it be not in this self-same atomic and\neasily impressible medium?\n\nNay! let us go further, and ask ourselves where is the key to be found\nfor the many marvellous effects of so-called spirit phenomena? Who can\nread F. W. Myer's _Human Personality and its Survival of Bodily Death_,\nand not feel that we are standing on the threshold of the unseen world?\n\nAlready men are asking themselves the meaning of the strange sensations\nwhich they receive from unseen sources; already men's spirits are\nvibrating in unison with vibrations that come from the unseen world; and\nto-day we see spiritual phenomena as through a glass darkly, and the\nquestion arises, what is the medium of all this communication, of all\nthese vibrations?\n\nIs there no medium at all which forms the medium of communication? To\nassert that would be to assert something opposed to all experience and\ntherefore would be unphilosophical.\n\nMay not then the theory of an atomic universal electro-magnetic medium\nhelp us on in our groping and searching after light in this direction?\nWho will uplift the veil? Already we peer almost into the spirit world.\nA little more light, a little more truth, and then there will burst\nforth upon the hearts and minds of men the grandest and most glorious\ntruth that Nature can reveal of her Creator, and then men shall come to\nknow and understand the place that God holds in the Universe, such truth\nbeing advanced on its way by an atomic, universal electro-magnetic\nAether which is as truly matter as our own bodies.\n\n\nART. 127. _God and the Universe._--To the superficial reader it may\nappear at first sight, that the theory of the Aether suggested in this\nwork leaves no place in the Universe for the operations and existence of\nan Infinite and living Spirit, a God. It may be objected, that if all\nmatter and all modes of motion find their physical origin in one common\nand primordial medium, the electro-magnetic Aether, where is the\nnecessity for the existence of an Eternal and Infinite Spirit?\n\nAt first sight there appears some force in the objection, but it loses\nits point when we come to view the Universe from the standpoint of\nspirit phenomena. The purpose of the writer in this work has been to\ndeal with natural phenomena only, purely from the philosophical and\nscientific standpoint. Spirit phenomena (which is equally as real and\nobvious as natural phenomena) have no part or place in a work which\ndeals with scientific facts and data, but demand and will receive in a\nfuture work equal consideration and philosophic treatment. A man must\nindeed be lacking in vision who cannot see behind all things the\nevidence of a richer and fuller truth than that which merely lies on the\nsurface, or who fails to read and learn the greatest truth that circles\nthe Universe in its ultimate unity, which indisputably points to the\nexistence of an Eternal and ever-living Spirit, a God. I affirm that\nthere is no scientific truth, even including the law of the conservation\nof matter and motion, which has been enunciated in this work, but what\nis reconcilable with the existence of an Eternal and Infinite Spirit;\nand although such a statement may seem a paradox, yet I am convinced\nthat before many more years have passed, the reconciliation of natural\nwith spiritual phenomena will be an accomplished fact. The fool to-day\nmay say in his heart, there is no God, but ere long not only religion,\nbut Science herself, shall expose his lack of wisdom and his folly.\n\nFor all things derive their existence primarily, with all the energies\nand powers they possess, from God. Look where we will, or at what we\nwill, from the smallest atom or molecule up to the most stupendous\nworld, or myriads of worlds that roll and sparkle in the blue infinity,\nin each and all we see the indisputable evidence of the existence of a\nmysterious spirit, or power, that controls and governs them. A spirit or\npower that we cannot see, but which is so indisputably evidenced that\nits existence cannot be denied. For example, we see forms of many kinds,\nsome of which are simple entities of themselves, while others are\ncomplex and made up of many parts, but while each part is inseparably\nconnected with the other, yet each part is itself distinct from the\nothers in nature and substance. The whole combined forms a complete\nmechanism or organism, and, like all mechanisms of human make, not only\nneeds a controlling and governing power, but also evidences a maker.\nEven the laws of Nature and modes of motion, whether it be heat, light,\nelectricity, or magnetism, are, however, unable of themselves to control\nthe mechanism, and therefore prove themselves to be but the servants of\nan infinite Intelligence, a GOD.\n\nThus, behind and beyond all we see, in every living form, there is the\nevidence of a hidden spirit, which is the governing and controlling and\nsustaining power, and without which the organism ceases to be an\norganism. A spirit which animates the mechanism, and uses its activities\nand powers as it wills for its own purposes and ends. This spirit or\npower we call its life, which gives to the form its existence, together\nwith all that it possesses, as its powers, activities, energies and\nproductions, for all are but the effects of the hidden life. If this\nmysterious something, termed its life, becomes in any way separated from\nthe mechanism or organism, then as a distinct and separate organism it\nceases to be; and though the mechanism may still exist for a time, yet\nall its powers are gone, while the organism, robbed of its very life,\nbegins slowly to decay.\n\nWe cannot see this power; we cannot find it We may search for it, rend\nand tear part from part, only to find that it baffles all our skill, and\nlaughs at our endeavours to discover the secret of its existence. We\nknow that it is there, just as truly as we know that in these forms of\nours, these living stoves, these perfect mechanisms called our bodies,\nthere exists and dwells a spirit, a living, conscious, self-acting and\ncontrolling power. A spirit which we know is not the mechanism itself,\nand which by experience and observation we know to be distinct from the\norganism. It is this mysterious spirit which controls and governs all\nour acts, that rules and reigns as king of our bodies, and makes the\nphysical mechanism, with all its wondrous parts, obey and do its\nbidding. That this is so, that the spirit is distinct from the body, and\nis the controlling and governing principle within us, is evident in a\nthousand ways. If, however, that spirit departs from the mechanism of\nour bodies, then the controlling and governing influence is gone; and\nthe mechanism, robbed of its life, ceases to work, ceases to fulfil its\nfunctions, and ceases to exist in that particular form.\n\nJust as it is with ourselves, so it is with the Universe. For look where\nwe will, from the smallest atom to the great aggregation of atoms, as\nour earth, or even to the more stupendous orbs of heaven, the working of\na secret and mysterious power or spirit meets our gaze. A spirit or\npower that is not the form or the mechanism, but is separate and\ndistinct from the mechanism, while at the same time it is inseparably\nconnected with each and all. For everything that we see, from an atom to\nthe Universe itself, is a perfect mechanism, or complexity of\nmechanisms. The entire Universe is one vast, intricate, and elaborate\npiece of mechanism, beginning with the simple aetherial atom, ranging\nthrough all the atomic systems, graduating by successive steps through\ncompound substances, which, in their aggregations, form meteors,\nsatellites, planets, suns, and stars; until the ultimate whole is\nreached, where everything is blended into one vast whole; a perfect,\ninfinite, complex mechanism, a Universe.\n\nNow if philosophy teaches anything at all regarding mechanisms of human\ninvention, it indisputably teaches that every machine or mechanism that\nhas ever been made, implies the existence of a maker, and that the maker\npossessed intelligent attributes, as reason, judgment, perception, and\nimagination. For example, stand before some elaborate machine of human\ninvention, as a lace machine, and watch the working of that machine in\nall its details. It is composed of many parts, each of which is perfect\nin itself. Each part may be distinct in nature and purpose, yet each and\nall are inseparably and unitedly connected with each other, and all work\nharmoniously together for the accomplishment of a definite and specific\nend, that is, the production of a lace curtain of exquisite design and\npattern. As we watch the machine and its workings, we see therein the\nevidence of the existence of a spirit or power that gave it its birth. A\nspirit or mind that made and formed the machine, that constituted,\narranged, and gave it its governing and controlling power; fitted and\nordered every part, gave to each part its allotted task, and moulded all\nto the harmonious fulfilment of the definite end and purpose he had in\nview.\n\nThus in the machine we see evidence of contrivance and design, of method\nand arrangement, of conception, perception and judgment, which are all\nthe effects and outflowings of intelligence which belong, and alone\nbelong, to mind; and therefore we say, \"The machine was made, and there\nwas and must have been a maker.\" So universally is this fact accepted,\nthat any one who seriously challenged the statement, or dared to deny\nit, would be at once pitied as insane or laughed at as a fool. Thus all\nexperience proves, and philosophy testifies, that wherever we get a\nmachine or mechanism of any kind or sort, there must have been a living,\nconscious being or person, who is distinct from and outside of the\nmachine. He made it, and therefore must have existed before it, in order\nto make it. Wherever, therefore, we find a mechanism that bears the\nmarks of intelligence and design, of judgment, perception and\nconception, it is only logical and philosophical to infer, that such a\nmechanism equally evidences the existence of an intelligent being. The\nmore intricate and elaborate the mechanism, the greater the ingenuity\ndisplayed, the more complex and perfect the design, the more harmonious\nthe working, the greater will be the wisdom, the more profound the\njudgment, the keener the perception, the more perfect the understanding,\nand the vaster, nobler, and more sublime the order of Being who\noriginated and made it. This being so, according to philosophical\nreasoning, let us glance at the Universe in all its fulness and oneness,\nand we shall see the indisputable evidence of the existence of an\nInfinite Being, who made, controls and governs the infinite Universe.\n\nIn the atomic world we get an illustration of the perfect mechanism that\nunderlies all atomic systems. Our conception of an aetherial atom was\nbased upon the analogy of our own planet, and there is every reason to\nbelieve that the little world in which all atoms live and move and have\ntheir being, is analogous to a planetary or solar system, in which we\nfind the two essentials of matter and motion ever associated together,\nto form a larger and more complete mechanism. For atoms are not simply\nmere points; they possess real dimensions, with a determinate and fixed\nform, differing in their relative weights, and in the amount of motion\nor force with which each is endowed. The very fact that they possess\natomic weights which are unalterable throughout the long periods of time\nthat mark the history of the Universe, and that they combine in definite\nand fixed proportions, indisputably evidence the fact that they but do\nthe bidding of an Eternal and Infinite Spirit, a God. Thus each\nmolecule, or atomic system forms a perfect mechanism in itself, with its\nown centre of gravity, and subject to the same laws of repulsion and\nattraction, or pressures and tensions--due to the vibrations and motions\nof the universal electro-magnetic Aether.\n\nIn each of the planetary systems we get an illustration of the same\nperfect mechanism, which is indicative of all systems whether large or\nsmall; each system being characterised by the same beauty of order and\nharmony of motion which are equally characteristic of atomic systems.\n\nOur own solar system, composed as it is of many parts, of thousands of\nmeteors and comets, of numbers of satellites and planets, all revolving\naround one common centre, also forms a complete and perfect mechanism in\nitself. For millions and millions of years this perfect mechanism has\nbeen harmoniously working together in all its parts, as it moves in all\nits unity through the realms of infinite space. Yet through all the\nunknown ages of the past, such a phenomenon as disorder in the working\nof any part of the system is inconceivable and unknown. Out in stellar\nspace there are, however, innumerable systems, similar to our own solar\nsystem, each distinct and perfect in itself; each being made up of\nsimilar parts, as meteors, comets, satellites, planets, and central sun.\nThese systems are, however, united together into one vast aggregation of\nworlds, having one common controlling centre of their own, and by their\nunity form a constellation, a larger and grander mechanism. Throughout\nthe whole constellation there is the same order, and harmonious working\nof part with part, that characterise the solar system. Then these\nconstellations increasing in their aggregations form a still larger\ncomplexity of systems, called a Galaxy; and galaxy being added to\ngalaxy, constellation to constellation, there is formed by such union,\nan ocean of suns and stars like our own Milky Way, the ultimate whole\nbeing characterised by the same mechanical order and harmonious working\nthat characterise the solar system. It may even be, that there are\nnumbers of these oceans of suns and stars existing in infinite space,\nall bound together by one common bond, the universal electro-magnetic\nAether, and forming one vast ultimate whole, a Universe; with all its\noceans of suns moving around one central Orb or mass of Orbs called the\nThrone of GOD.\n\nThus the whole Universe is a mechanism, complete and perfect in every\ndetail, and forming a system, so great, so grand, so sublime, so\nmagnificent that it puts all mechanisms of human origin to shame and\nscorn. Now, if a mechanism of human invention evidences the existence of\nintelligence and mind, and proves itself to be the production of a\nliving, sentient, conscious, and intelligent being, how much more,\nincomparably more, does the Universe with its infinite complexity\nevidence a Maker also; and that Maker must be as infinitely greater in\nwisdom, knowledge, perception and judgment as the Universe is infinitely\ngreater in mechanical perfection than any mechanism of human origin.\n\nThe Universe is God's teaching in symbol and in type. It is His great\npicture-book, where in living form He has portrayed Himself, and all\nthat belongs to Him--His nature, character, wisdom; His greatness,\nglory, and His power. The Universe is a temple, where He sits enshrined\nin the things His own hands have made, and where those who have eyes to\nsee, and hearts to learn and understand, may adore and worship Him.\n\nThus is it true that \"the heavens declare the glory of God,\" _i. e._ the\ncharacter of God, His infinite wisdom, His infinite knowledge, His\nprofound judgment, and His eternal righteousness; while the firmament\nshoweth His handiwork. \"Day unto day uttereth speech, and night unto\nnight showeth (His) knowledge.\"\n\n\"The Lord by wisdom hath founded the earth, by understanding hath He\nestablished the heavens.\"\n\n\"He hath made the earth by His power. He hath established the world by\nHis wisdom, and hath stretched out the heavens by His discretion.\"\n\n\"Thou, Lord, in the beginning hast laid the foundations of the earth,\nand the heavens are the work of Thy hands; they shall perish, but Thou\nremainest; and they all shall wax old, as doth a garment; and as a\nvesture shalt Thou fold them up, and they shall be changed; but Thou art\nthe same, and Thy years shall not fail.\"\n\nTo prove the validity of these statements from a scientific and\nphilosophic standpoint, and to show the harmony that exists between the\nnatural and the Divine revelation as given in the Word of God, will form\nthe subject of a future work.\n\n\n\n\n                              APPENDIX A\n\n\nAccording to Sir Oliver Lodge the fact that electricity possesses mass\nor inertia has now passed out of the hypothetical stage into the realm\nof fact and experiment. In his Romanes Lecture recently published, he\nstates, page 4: \"My first thesis is that an electric charge possesses\nthe most fundamental and characteristic property of matter, viz. mass or\ninertia; so that if any one were to speak of a milligramme or an ounce\nor a ton of electricity, though he would certainly be speaking\ninconveniently, he might not necessarily be speaking erroneously.\"\n\nNow in view of the identity that exists between Aether and electricity,\nas proved by Hertz' experiments, the only logical conclusion that can be\narrived at is, that Aether must also possess mass and inertia. So that\nthe most recent experiments in relation to electricity confirm the\ntheory of the Aether presented in this work, viz. that it also possesses\nmass and inertia, otherwise we should have a massless medium being\ncomposed of electrons which possess mass, and that would be a violation\nof all experience, and therefore an unphilosophical statement.\n\n\n\n\n                              APPENDIX B\n\n\nThe hypothesis of electricity being the fundamental basis of all matter\nmade in the last chapter on the \"Unity of the Universe,\" receives\nconfirmation from Sir Oliver Lodge in his _Modern Views of Matter_,\nwhere he writes, page 13: \"The fundamental ingredient of which, in this\nview, the whole of matter is made up, is nothing more or less than\nelectricity, in the form of an aggregate of an equal number of positive\nand negative electric charges. This, when established, will be a\nunification of matter such as has through all the ages been sought; it\ngoes further than had been hoped, for the substratum is not an unknown\nand hypothetical protile, but the familiar electric charge.\"\n\n\n\n\n                              APPENDIX C\n\n\nThe hypothesis that all elements have definite quantities of electricity\nin them, or a definite number of electrons, as suggested on page 335,\nreceives added weight by the testimony of Sir Oliver Lodge in the work\nalready referred to. Writing on the subject, he says: \"It is a\nfascinating guess that the electrons constitute the fundamental\nsubstratum of which all matter is composed. That a grouping of say 700\nelectrons, 350 positive and 350 negative, interleaved or interlocked in\na state of violent motion so as to produce a stable configuration under\nthe influence of their centrifugal inertia and their electric forces,\nconstitutes an atom of hydrogen. That sixteen times as many, in another\nstable grouping, constitute an atom of oxygen. That some 16,000 of them\ngo to form an atom of sodium; about 100,000 an atom of barium; and\n160,000 an atom of radium.\"\n\nFrom these extracts, taken from _Modern Views of Matter_, the author\nclaims that the theory of the Aether presented to the reader in _Aether\nand Gravitation_ receives added confirmation and support.\n\n\n                        *    *    *    *    *\n\n\n\n\n                                ERRATA\n\n\nThe author regrets that Professor J. J. Thomson's name has been\nincorrectly spelled in several places.\n\n\n\n\n                                INDEX\n\n\nAberration of light, 69, 149, 218\n\nAbsorption, 104-6\n\nAcceleration, 239\n\nActinic rays, 141\n\nAction at a distance, 96, 174, 176\n  and re-action, 20, 251\n\nAdams' discovery of Neptune, 25\n\nAether is matter, 54-8\n  is atomic, 59-67\n  is gravitative, 64-9\n  density of, 69, 71, 136, 243\n  elasticity of, 74-7\n  inertia of, 76, 330\n  its motions, 80\n  compressibility of, 291, 315\n  waves, 79-80\n\nAetherial basis of matter, 326\n\nAffinity, chemical, 43\n\nAldebaran, 312\n\nAluminium, 79\n\nAmpere, 192\n\nAmpere's theory of magnetism, 193\n\nAndromeda, 314\n\nAnnual magnetic variation, 208\n\nAnnular nebulae, 320\n\nAphelion of earth, 36\n\nArago, M., 321\n\nArcturus, 312\n\nAreas, Kepler's law of, 36\n\nAsten, Von, 234, 296\n\nAsteroids, 31\n\nAtmosphere, 68, 73, 102, 225\n\nAtom, vortex, 45, 46, 61\n  what it is, 43\n  electron, 63\n  Boscovitch, 61\n  hard, 61\n  size of, 43\n\nAttraction, electrical, 2, 286\n  of gravitation, 13, 24, 31\n  magnetic, 195\n\n\nBalance, Torsion, 187\n\nBernoulli, 221, 341\n\nBeta Persei, 308\n\nBiela's comet, 296-7\n\nBinary compound, 143\n  stars, 25, 309\n\nBiot, 138\n\nBoscovitch atoms, 44, 138\n\nBoyle and Marriotte's law, 76, 103\n\nBradley's discovery of aberration, 149\n\nBredichin on comets' tails, 302\n\nBrilliancy of stars, 307, 309\n\nBritish Association Report, 57, 59\n\n\nCalcium, 79\n\nCanis major, 307\n  minor, 307\n\nCapella, 312\n\nCarbon, 48\n\nCarboniferous period, 115\n\nCarnot on heat, 116-18\n\nCassini, 307\n\nCause and effect, 14\n  of gravitation, 1, 282-9\n\nCavendish experiment, 24\n\nCentauri, 79\n\nCentre of gravity, 325\n\nCentrifugal force, 9, 13, 15, 30, 236-8\n\nCentripetal force, 9, 12, 282\n\nCetus, 307\n\nChalk, 6\n\nChallis, Prof., 74, 96, 100, 107, 151, 155,\n214, 227, 311\n\nChemistry, 47, 336\n\nCoal, 86, 88\n\nClairaut, 297\n\nClusters of stars, 314\n\nCohesion, 48\n\nColour, 138\n\nColours of stars, 308\n  seven primary, 139\n\nComets, 291\n  attracted by planets, 298\n  condensation of, 292\n\nComets and meteors, 297\n  short period, 293-4\n  long period, 293-4\n  tails of, 298-9\n  orbits of, 293\n  nucleus of, 298-9\n  coma, 298-9\n\nCompressibility of aether, 291, 315\n\nCondensation of gases, 47\n\nConservation of matter, 42\n  of energy, 84\n  of motion, 92\n\nConstellations, 307\n\nCorollary, 15\n\nCorona Borealis, 309\n\nCorpuscles, 42, 64, 136\n\nCorpuscular theory of light, 122\n\nCorrelation of forces, 83\n\nCoulomb Torsion balance, 185, 187\n\nCrookes, Sir William, 42, 136, 326, 341\n\nCurrent, electric, 163\n  magnetic, 192\n\nCurrents, 90\n\nCurry, Prof., 284\n\nCycle of operations, 114, 116\n\nCygnus, 307\n\n\nDalton's atomic theory, 42\n\nDavy, 99, 107\n\nDay and night, 4\n\nD'Arrest's comet, 296\n\nDeimos, 38\n\nDemocritus, 44\n\nDensity of matter, 51\n  of aether, 69\n  electric, 170\n  of earth, 242\n  of sun, 27\n  of planets, 242\n\nDescartes, 221-2, 341\n\nDewar, Prof., 47\n\nDiameter of earth, 29\n  polar, 29\n  equatorial, 29\n  of sun, 280\n  of planets, 29\n\nDielectric, 168, 175\n\nDiffusion, 49\n\nDip, magnetic, 199\n\nDistances of stars, 280\n\nDiurnal variations, magnetic, 209\n\nDog star (Sirius), 306\n\nDonati's comet, 298\n\nDouble stars, 308\n\nDraco, 307\n\nDynamical equivalent of heat, 114\n  value of light, 150\n\nDynamics, laws of thermo-, 114-18\n\nDynamo, 87, 90\n\n\nEar, 120\n\nEarth, mass of, 235, 242\n  a magnet, 196-8\n  size of, 29\n  rotation of, 219\n  orbit of, 276\n  periodic time of, 251\n  gravity of, 29\n  shape of, 29\n  distance from sun, 242, 251\n  velocity in orbit, 251\n\nEccentricity of orbits, 268, 276\n\nEclipse, 145, 148\n\nEcliptic, plane of, 277-9\n\nElasticity, 46\n  of matter, 51\n  of aether, 74\n\nElectric current, 154\n  potential, 170\n  induction, 175\n  radiation, 182\n  density, 170\n  energy, 179\n  field, 166, 179\n  lines of force, 173\n\nElectricity, 64, 162\n  two kinds of, 175\n  positive, 175\n  negative, 175\n  laws of, 184\n  theories of, 162\n\nElectrons, 136, 163\n\nElectro-static, 158, 164\n  kinetic, 158, 164\n  kinetic energy, 217\n  magnetism, 192-5\n  magnets, 199\n  magnetic theory of light, 229\n  chemical equivalents, 189, 333\n\nElements of matter, 47\n\nEllipse, 34\n  Kepler's discovery of, 34\n\nElliptical nebulae, 320\n\nEmission theory of light, 122\n\nEncke's comet, 293, 296\n  resisting medium, 228\n\nEnergy, 83, 84\n  what it is, 83\n  conservation of, 84\n  transformation of, 86\n  potential, 87\n  kinetic, 89, 164\n  radiant, 109\n  electrical, 179\n  and motion, 91\n\nEngine, Carnot's heat, 116\n\nEnvelopes of comets, 298\n\nEpicureans, 44\n\nEqual areas, 36\n  times, 36\n\nEquator, N. and S. Poles, 29\n  magnetic, 202\n  terrestrial, 29\n\nEquipotential surfaces, 171\n\nEquivalents, electro-chemical, 189, 333\n\nEuler, 123\n\nExchanges, theory of, 105\n\nExperience, 4\n\nExperiments of Rumford, 98\n  of Michelson and Morley, 67, 227\n  of Lebedew, 302\n  of Nichols and Hull, 153\n  of Hertz, 165\n  of Faraday, 65, 285\n  of M. Faye, 302\n  of Joule, 114\n\n\nFalling stone, 21, 29\n\nFaraday, 45, 175, 220\n  on matter, 56\n  on Lines of Force, 168, 200, 203-5\n  on magnetic space, 208\n  on gravitation, 287\n  on electricity, 332\n  on induction, 176\n\nFaye, M., 111, 302, 319\n\nFaye's comet, 293, 296\n\nField, electric, 179\n  magnetic, 199\n\nFizeau, 149, 224\n\nFluids, 48\n\nFood, 89\n\nForbes, 121\n\nForce, 16, 19, 90\n  centrifugal, 9, 13, 236\n  centripetal, 9, 12, 282\n  lines of, 200\n\nForces, direction of the, 26\n  proportion of the, 26\n\nFoucault, 149\n\nFranklin, 106\n\nFresnel, 75, 131\n\nFrictionless medium, 17, 131, 136, 224\n\nFundamental medium, 54\n\n\nGalaxy, 325, 346\n\nGaseous nebulae, 313\n\nGases, condensation of, 47\n  liquefaction of, 47\n  kinetic theory of, 49\n\nGlazebrook, Prof., on aether and gravitation, 22\n\nGlobular clusters of stars, 314\n\nGravitation, law of, 61, 65\n  universal, 24\n  intensity of, 27\n  law of proportion, 26\n  cause of, 1, 282\n  and binary stars, 25\n\nGravity, centre of, 325\n\nGreat Bear, 307\n\nGrove, 83\n\n\nHalley's comet, 296-7\n\nHamilton, Sir W. R., 247\n\nHead of comets, 298\n\nHeat is motion, 98\n  a mode of motion, 107\n  radiant, 109\n  dynamical equivalent of, 116\n  effects of, 107\n  nature of, 98\n  radiation of, 109\n  transformation of, 87\n\nHeat engine, Carnot's, 116\n  of sun, 109\n  and matter, 100\n  and work, 114\n  refraction of, 121\n\nHelmholtz, Von, 45, 86\n\nHercules, 257, 271, 307\n\nHerschel, Sir J., 3, 4, 7, 226, 228, 281, 299, 301, 310, 321\n  Sir W., 109, 271-2, 313\n\nHertz, 138, 159, 182\n\nHicks, Prof., 13\n\nHodograph of planets, 247\n\nHot springs, 90\n\nHuggins, 313-14\n\nHuyghens, 54, 123, 125, 128\n\nHydrogen, 40, 42, 44, 60, 93, 314, 333\n\nHypotheses, 3, 338\n\n\nIce, 42\n\nIdentity of heat and light, 119\n  light and electricity, 156, 160, 165\n  aether and electricity, 331\n\nImponderable, 71\n\nImpressed force, 20\n\nImpressible aether, 78\n\nInduction, electric, 174-5\n  magnetic, 199\n  Faraday's theory of, 175\n\nInertia of matter, 52\n  of aether, 330\n\nIntensity of light, 28, 146\n  of heat, 28, 113\n  of electricity, 184\n  of gravity, 28\n\nIron, 42\n  expansion by heat, 101\n  contraction by cold, 102\n\n\nJoule, 85, 114\n\nJupiter, 26, 68\n  mass of, 235\n  satellites of, 149, 178\n  rotation of, 219\n  orbital velocity of, 251, 265\n  size of, 235\n  distance from sun, 242, 251\n  density of, 242\n  and comets, 305\n\n\nKant, 317\n\nKelvin, Lord, 43, 71, 77, 80, 95, 216, 227\n  on aether, 56-7\n  on vortex atom, 63\n  on compressible aether, 291, 315\n  on light, 151\n\nKepler's laws, 32\n  first, 33, 256-9\n  second, 36, 260-2\n  third, 37, 263-5\n  on vortex motion, 221-2\n\nKinetic energy, 89\n  electro, 217\n\nKirchhoff, 43\n\n\nLaplace, 317\n  nebular hypothesis, 317\n\nLarmor, Dr., 22, 44, 56, 63, 93, 163\n  on electrons, 284\n  on aetherial physics, 22, 327-9\n\nLavoisier, 42\n\nLaw of gravitation, 24\n  of inverse squares, 27\n\nLaws of electricity, 184\n  of light, 145\n  of heat, 113\n  of motion, 9, 15, 233\n\nLead, 88, 333\n\nLebedew, 32, 76, 153\n\nLe Verrier, 25\n  discovery of Neptune, 25\n\nLeyden jar, 157\n\nLiebnitz, 223\n\nLight, 75\n  a mode of motion, 122\n  corpuscular theory of, 123\n  undulatory theory of, 123, 136\n  electro-magnetic theory of, 156\n  path of a ray of, 144\n  intensity of, 145\n  reflection of, 136\n  refraction of, 135\n  aberration of, 149\n  composition of, 139\n  velocity of, 148\n  zodiacal, 277\n  transverse vibration of, 130\n\nLines of force, electric, 173\n  magnetic, 201-3\n\nLiquefaction of gases, 47\n\nLiquid air, 47\n\nLiquids, 48\n\nLittle Bear, 307\n  Dog, 307\n\nLockyer, 109\n\nLodge, Dr., 219\n  on aether density, 69\n  on aether, 284, 289, 328, 332\n  on electric inertia, 330\n  on electricity, 64, 69, 284, 285\n  on force, 17\n  on gravitation, 283\n\nLorentz on light, 154\n\nLyra, 307\n\n\nMacLaurin, 2, 10, 17\n\nMagnesium, 79\n\nMagnet, 21\n\nMagnets, bar, 199\n  moving, 211\n\nMagnetic axis, 202\n  field, 199\n  lines of force, 200\n  shells, 205\n  equator, 202\n  induction, 199\n  variation, 208\n  molecules of, 193\n  polarity, 194\n\nMagnetism of earth, 207-12\n  of planets, 211\n  cause of solar, 211\n  Ampere's theory of, 193\n\nMars, 68, 79\n  a magnet, 196\n  rotation of, 219\n  size of, 236\n  orbital velocity of, 251\n  satellites of, 178\n  orbit of, 33\n\nMass, 27, 53, 187\n  of earth, 235, 242\n  of planets, 235, 242\n  of sun, 190\n\nMatter, elements of, 40\n  properties of, 42, 50\n  and motion, 41, 322\n  conservation of, 42\n  divisibility of, 44\n  four states of, 48\n  aetherial basis of, 48, 333\n  physical constitution of, 334\n\nMaxwell, J. C., 43, 73, 85, 151, 211\n  on physical lines of force, 168, 203-5, 288\n  on aether, 59, 206\n  on magnetism, 205\n  on electro-kinetic energy, 180, 217\n  on aether, 58\n\nMayer, 84, 86, 114, 118\n\nMcCullagh, 75\n\nMechanical energy, 87\n\nMedium, Descartes on a, 221\n  Kepler on a, 222\n\nMercury, 68, 79\n  a magnet, 196\n  rotation of, 219\n  eccentricity of orbit, 33\n  mass of, 242\n  orbital velocity of, 251\n\nMeteorites, 95, 118\n\nMeteors, 31, 85, 118\n\nMichelson and Morley, 7, 67\n\nMilky way, 79, 309, 314\n\nMolecules, 44\n\nMomentum, 20\n\nMoon, 61\n\nMotion of stars, 310\n  planetary, 253\n  of sun, 274\n  of aether, 80\n  and work, 95\n  modes of, 92, 122, 163\n  first law of, 15, 16, 239\n  second law of, 19, 244\n  third law of, 20, 251\n\nMultiple stars, 308\n\n\nNatural philosophy, 4\n\nNebulae and aether, 313\n  structure of, 314\n  spiral, 322\n  annular, 320\n  elliptical, 320\n  planetary, 321\n  spectrum of, 314\n  irregular, 319\n\nNebular hypothesis, 317\n\nNebulous stars, 311\n\nNeptune, 68\n  discovery of, 25\n  mass of, 235\n  orbital velocity of, 251, 265\n  distance from sun, 242\n  a magnet, 196\n\nNewton's coloured rings, 107\n  _Optics_,72, 98, 122\n  letter to Bentley, 2, 96\n  Rules of Philosophy, 3\n  _Principia_, 3, 7, 38\n  emission theory, 123\n  law of gravitation, 24\n  atoms, 44\n  on aether, 98\n\nNichols and Hull, 32, 153\n\n\nOcean, 81, 90\n\nOperations, cycle of, 114\n\n_Optics_, Newton's, 2, 122\n\nOrbital motions of planets, 266\n\nOrbit of earth, 33\n  of Venus, 33\n\nOrbits of satellites, 34\n  of planets, 33-4, 266\n  moon, 267\n  stars, 310\n  sun, 270\n\nOrigin of sun's heat, 95\n\nOrion, 79, 307, 314, 319\n\nOxygen, 40, 44, 60, 93\n\n\nParallelogram of forces, 15\n\nPendulum, 88\n\nPeriodic times, 37\n\nPerpetual motion, 93, 220\n\n_Phil. Mag._, 58, 67, 71, 73, 74, 80\n\n_Phil. Trans._, 58, 62, 64, 75\n\nPhilosophy, Rules of, 3\n\nPhobos, 38\n\nPhysical lines of force, 203-6\n\nPitch of Sound, 105, 120, 139\n\nPlane of ecliptic, 277-9\n\nPlanetoids, 31\n\nPlanets, minor, 31\n  origin of, 240\n  orbits of, 33, 266\n  electrified bodies, 177\n  masses of, 242\n  relative distances of, 242\n  orbital velocities of, 251\n  periodic times of, 251\n\nPlatinum, 48\n\nPleiades, 79\n\nPolarization, 176\n\nPotential energy, 87\n\nPotential, electric, 170\n  magnetic, 194\n\nPouillet, M., 109\n\nPoynting, 91\n\nPressure, aetherial, 181\n\nPreston, Prof., 283\n\nPrevost, theory of exchanges, 105\n\nPrimitive impulse, 9, 10, 12, 319\n\n_Principia_, Newton's, 3, 7, 38-9, 122\n\nProperties of matter, 42\n\n\nQuantity of sun's heat, 109\n\nQuery, 18-19\n  _Optics_, 72, 122\n\n\nRadiant heat, 109\n  energy, 115\n\nRadiation, 104\n\nRadius Vector, 26\n\nRankine, 103\n\nRays, actinic, 141\n  dark heat, 140\n  infra-red, 141\n  ultra-violet, 140\n  Rontgen, 341\n  X, 341\n\nRectilinear propagation of light, 144\n  of heat, 111\n\nReflection, 160\n\nRefraction, 160\n\nRelative motion of aether and matter, 224-6\n\nResistance to motion, 17\n\nResisting medium, 228\n\nReversible cycle, 116, 118\n\nRings, vortex, 45\n\nRival theories, 8\n\nRivers, 89-90\n\nRoemer, and velocity of light, 148\n\nRotation of earth, 219\n  of planets, 219\n  of sun, 246\n\nRotatory motion, 93\n\nRucker, Prof., 59\n\nRules of Philosophy, 3\n  first, 3\n  second, 4\n  third, 3, 7\n\nRumford, 98\n\nRunning water, 95\n\n\nSatellites of Mars, 38, 178\n  Jupiter, 149, 178\n  Uranus, 254\n  Neptune, 254\n\nSaturn, 26-7, 68\n  mass of, 235, 242\n  orbital velocity of, 251, 265\n  rotation of, 219\n  density of, 242\n  a magnet, 196\n  satellites of, 178\n\nSchuster, Prof., 8, 218, 311\n\nSirius, 306, 308-9\n\nSodium, 43\n\nSolar system, motion of, 257, 271\n  spectrum, 79, 139\n  magnetism, 211\n\nSound, 75\n  waves, 104, 120\n\nSpace, interstellar, 310, 313\n\nSpectroscope, 47, 79\n\nSpectrum analysis, 50, 139\n\nSpiral nebulae, 322\n\nStars, fixed, 58\n  number of, 11, 306\n  binary, 309\n  distances of, 280\n  magnitude of, 306, 309\n  colour of, 79, 308\n  motion of, 310-11\n  nebulous, 320\n  proper motions of, 312\n  variable, 307\n  double, 308\n  clusters of, 314\n  orbits of, 310\n  are magnets, 307\n\nStokes, Sir G., 69, 152, 218\n\nString, 21\n\nSun, diameter of, 280\n  constitution of, 79\n  a magnet, 164, 198-9\n  mass of, 190\n  heat of, 109\n  motions of, 270\n  orbital velocity of, 35\n  rotation of, 246\n  centre of two forces, 186\n\n\nTails of comets, 300, 304\n  straight, 300\n  curved, 301\n  multiple, 300\n\nTait, Prof., 18, 40-1, 88, 247\n\nTelescope, 79\n\nTemperature, 104-5\n\nTerrestrial magnetism, 207-12\n  gravity, 29\n\nTheory, atomic, 44\n  rules for making, 3\n  undulatory, 123\n  of exchanges, 105\n\nThermodynamics, first law of, 87, 114\n  second law of, 116\n\nThomson, J. J., Prof., 43, 326, 335\n\nTidal water-power, 88\n\nTides, 89, 96\n\nTorsion balance, 185\n\nTrade winds, 96, 249\n\nTransformation of energy, 86\n  of motion, 93\n\nTransverse vibration of light, 130\n\nTuning-fork, 104\n\nTympanum, 120\n\nTyndall on radiation, 104, 106\n  on light, 71\n  on Lines of Force, 174\n  on aether, 77\n  on atoms, 106\n  on aether waves, 112\n\n\nUltra-violet rays, 140\n  red rays, 140\n\nUnity of universe, 322-9\n\nUniversal gravitation, 24\n  aether, 58\n\nUniverse, 313, 322, 347\n\nUranus, 68\n  mass of, 235\n  density of, 242\n  orbital velocity of, 265\n  a magnet, 196\n\nUrsa Major, 307\n  Minor, 307\n\n\nVapour, 49\n\nVariation, magnetic, 209-11\n\nVelocity of light, 148\n  of electric waves, 182\n  of heat waves, 148\n  of falling bodies, 21\n  of wave motion, 76\n\nVelocity, angular, 250\n\nVenus, 33, 68, 79\n  a magnet, 197\n  mass of, 235\n  rotation of, 219\n  orbital velocity of, 251\n  periodic time of, 251\n\nVibration, atomic, 75\n\nVibrations, transverse, 130\n  longitudinal, 130\n  of sound, 123\n\nVibratory motion, 91\n\nVogel, Prof., 308, 312\n\nVogt, Prof., 332\n\nVolume of sun, 27\n\nVon Asten, 234, 296\n\nVortex theory, 92, 337\n  motion, 221-4\n  atom, 93, 126, 337\n  rings, 125, 337\n\nVortices, molecular, 103\n\n\nWater waves, 124\n  currents, power of, 95\n  composition of, 141\n  power, 88\n\nWave front, 128\n  motion, 124, 160\n\nWave lengths, 120\n  envelope, 112\n\nWaves, chemical, 141\n  sound, 104, 120, 124\n  light, 126\n  heat, 141\n  electric, 159\n  spherical, 112\n  electro-magnetic, 165\n\nWeight, 29, 69, 84\n  variation of, 29\n  pound, 30\n\nWhewell, 3, 221\n\nWinds, 81, 90\n  energy of, 90\n  trade, 225\n\nWork, 96\n  and energy, 84\n  from heat, 116\n\n\nYoung, Thomas, 54, 64, 67, 123\n  on aether, 58\n  fourth hypothesis, 70\n  Prof., of America, on electric space, 166\n\n\nZinc, 88\n\nZodiacal light, 277-9\n\n\n              _Richard Clay & Sous, Limited, London & Bungay._\n\n\n\n\n                        Some New Publications\n\n                                 OF\n\n                     Messrs. Chapman & Hall, Ltd.\n\n                               1903-4\n\n                              * * * * *\n\n                      MR. H. G. WELLS'S NEW WORK.\n\nMANKIND IN THE MAKING. By H. G. WELLS, author of \"Anticipations,\" etc.\nCrown 8vo, _7s. 6d._\n\nIn this new and important work Mr. Wells attempts to deal with social\nand political questions in a new way and from a new starting-point,\nviewing the whole social and political world as aspects of one universal\nevolving scheme, and placing all social and political activities in a\ndefined relation to that; and it is to this general method and trend\nthat the attention of the reader is especially directed.\n\n\n                   DR. ALFRED RUSSEL WALLACE'S NEW BOOK.\n\nMAN'S PLACE IN THE UNIVERSE. A study of the results of scientific\nresearch in relation to the unity or plurality of worlds. By ALFRED\nRUSSEL WALLACE, LL.D., D.C.I., F.R.S., author of \"Natural Selection,\"\n\"Darwinism,\" etc., etc. With Diagrams. Demy 8vo, _12s. 6d. net_.\n\nThis volume is an amplification and extension of the much-discussed\narticle contributed by Dr. Wallace to the _Fortnightly Review_ for March\n1903, and presents the whole subject in a more complete and systematic\nmanner, besides containing many new and forcible arguments which a more\ncareful consideration of the whole problem has suggested.\n\nIn the course of the work the various astronomical and other criticisms\nof the article are considered and replied to.\n\n\n                       A NEW THEORY OF GRAVITATION.\n\nAETHER AND GRAVITATION. By W. G. HOOPER, F.S.S. With Diagrams. Demy 8vo,\n_12s. 6d. net_.\n\nThis work seeks to offer an acceptable solution of the greatest\nscientific problem that has puzzled scientists for the past 200 years.\nEver since the discovery of universal gravitation by Sir Isaac Newton,\nthe question has arisen, over and over again, as to what is the physical\ncause of the attraction of gravitation. Is it due, as Newton himself\nsuggested, to the properties and qualities of the universal aether, or\nis it due to some still unknown and undiscovered medium?\n\nBy the theory propounded in this work, the author has for the first time\nbrought aetherial physics into harmony with all observation and\nexperiments; so that the inertia, the density, and the elasticity of the\naether are brought into harmony with all experience by philosophical\nreasoning based on Newton's Rules of Philosophy.\n\n\n                    LIFE AND TOPOGRAPHY OF DICKENS.\n\nTHE REAL DICKENS LAND. With an outline of Charles Dickens's life. By H.\nSNOWDEN WARD and CATHARINE WARD, authors of \"Shakespeare's Town and\nTimes.\" With a Steel Plate Portrait of Dickens, Three Photogravures, and\nnearly 300 full-page and other Illustrations. Crown 4to, _10s. 6d. net_.\n\nCharles Dickens's understanding of the human character is apparent to\nevery good reader of his works; but his intimate knowledge of the\n\"character\" of places, and of the important effect of place upon the\nhuman being, is not so apparent, because the reader has not the\nnecessary knowledge of the places upon which to base an estimate.\n\nIn \"The Real Dickens Land\" the authors have attempted to supply this\nnecessary knowledge, not only by literary identification, but by\npresenting one of the fullest collections of photographic views thus\nidentified ever got together.\n\n\n                     LONDON: CHAPMAN & HALL, LTD.\n\n\n\n\n                     CARLYLE'S LIFE AND TOPOGRAPHY.\n\nTHE CARLYLE COUNTRY. With a study of Carlyle's life. By J. M. SLOAN.\nWith a Foreword by SIR JAMES CRICHTON-BROWN, M.D., LL.D., F.R.S. With a\nPhotogravure of the Whistler Portrait of Carlyle, Two other\nPhotogravures, and about 100 Portraits, full-page and other\nIllustrations. Crown 4to, _10s. 6d. net_.\n\nThis new Carlyle Book deals with the Carlyles in all their multiform\nrelations to the Carlyle Country, and casts much valuable light upon the\ncomplex problems raised by Carlyle's earlier and later life.\n\nIt forms a most useful and instructive Guide to the Carlyle Country, and\nwill appeal to old Carlylean Readers by its careful grouping of\nbiographical events around the places with which they are inextricably\nidentified.\n\nA valuable Carlyle Chronology is appended, together with an Index and\nMap.\n\n\n                            HISTORY OF CHINA.\n\nCHINA, PAST AND PRESENT. By E. H. PARKER, Professor of Chinese at the\nOwens College, Manchester; formerly H.B.M. Consul at Kiungchow; Author\nof \"China,\" \"John Chinaman,\" etc., etc. With a Map of China. Demy 8vo,\n_10s. 6d. net_.\n\nMr. Parker is one of the great authorities on all that concerns China\nand the Chinese, and has been writing upon every phase of the subject\nfor many years past. In this work he deals with the whole history of the\nnation from the earliest times to the present day. His volume is divided\ninto nine books: I. Historical and Statistical; II. The \"Boxer\" Wars;\nIII. Religious; IV. The Imperial Power; V. The Foreigner in China; VI.\nMandarin or Official; VII. Celestial Peculiarities; VIII. Political; IX.\nThe Seamy Side.\n\nEach of these books is divided into chapters dealing comprehensively\nwith the whole subject.\n\n\n                       NEW WORK ON PAGAN IDOLATRY.\n\nTHE WORSHIP OF THE DEAD. The Origin, Nature, and History of Pagan\nIdolatry. By COLONEL J. GARNIER, R.E. With Four full-page Illustrations\nand numerous Pictures in the text. Demy 8vo, _16s. net_.\n\nThe intimate relation of the ancient Paganism to the early history of\nmankind and its influence on the fate and fortunes of the human race\ngives no little interest and importance to any inquiry into its origin\nand nature, and the facts collected and compared in the present work\nwill be found, not only to throw a remarkable light on the early history\nof Egypt and Babylonia but to have an especial bearing on important\nquestions of the present day.\n\n\n                       EVERYDAY LIFE IN CHINA.\n\nLIFE AND SPORT IN CHINA. By OLIVER G. READY, B.A. With Thirteen\nIllustrations and a Map. Demy 8vo, _10s. 6d. net_.\n\nIn this work the author, who has resided in various parts of the country\nfor upwards of twelve years, has endeavoured to place before readers an\naccount of things and events as he saw them, and to convey to their\nminds an idea of how Europeans live there, of their amusements, of their\nwork, and of those things which are matters of daily interest to them,\nso that the work may serve as a kind of preface to that enthralling\nvolume, the current history of China, as it is daily revealed in the\nPress, in Magazines, and in learned works.\n\n\n                            IZAAK WALTON.\n\nIZAAK WALTON AND HIS FRIENDS. By STAPLETON MARTIN, M.A., Christ's\nCollege, Cambridge, Barrister-at-Law. With Portraits and Illustrations.\nDemy 8vo, _10s. 6d. net_.\n\nMr. Stapleton Martin has written this book with the primary object of\nbringing out the spiritual side of Walton's character. He traces\ncarefully the inner workings of Walton's mind, and aims at setting forth\nthe man as he was best known to the circle of intimates with whom he\nshared his confidences.\n\nThe better to indicate this aspect, the volume also contains brief\nbiographical sketches of Walton's: poet and ecclesiastic friends,\ntogether with a fine collection of portraits and illustrations of places\nconnected with Walton's life. There is also a selection from the\npoetical works of Walton, Cotton, Donne, Herbert, Wotton, Duport.\n\n\n                    LONDON: CHAPMAN & HALL, LTD.\n\n\n\n                        *    *    *    *    *\n\n\n\nTranscriber's note:\n\n   ART. 41 is missing from the book.\n\n   In several instances changed S, W, E into italics to be\n   consistent with the rest of the book.\n\n   Page 194: Fixed typographical error for demonstated\n\n   Changed Figure captions so that all are of the form\n   \"Fig: number.\"\n\n   Left unknown/misspelled word protile in appendix b\n\n   Page 148: ... and the Index, The surname of Ole Christensen\n   Romer [with o-slash] is spelled multiple times Roemer and\n   once as Roemer [with o-umlaut] in the index. These have been\n   changed to the English spelling \"Roemer.\"","title":"Aether and Gravitation","tradition":"philosophy-ethics","translated_text":null,"word_count":164118}