{"collection":"scripture-revelation","full_text_available":true,"graph_url":"https://unchartedknowledge.5gfusion.net/v2/api/page/gutenberg_64489/graph","html_url":"https://unchartedknowledge.5gfusion.net/v2/page/gutenberg_64489","id":"gutenberg_64489","license":"Public Domain (US)","rights_basis":"gutenberg_metadata_copyright_false","source":"gutenberg","source_url":"https://www.gutenberg.org/ebooks/64489","summary":null,"tags":["Astronomy, Ancient","Astronomy, Medieval","Category: History - Early Modern (c. 1450-1750)","Category: Philosophy & Ethics","Category: Religion/Spirituality","Dante Alighieri, 1265-1321 -- Knowledge -- Astronomy","Early maps"],"text":"Transcriber\u2019s Notes:\n\n Underscores \u201c_\u201d before and after a word or phrase indicate _italics_\n in the original text.\n Small capitals have been converted to SOLID capitals.\n Illustrations have been moved so they do not break up paragraphs.\n Old or antiquated spellings have been preserved.\n Typographical errors have been silently corrected.\n The table \u201cTIME REFERENCES IN THE DIVINE COMEDY\u201d on pages 358-366\n has been reformatted from horizontal to vertical in order to\n better fit the 72-column format.\n Footnotes have been separated out from the main text by the use of\n lines above and below, made of hyphens.\n\n\n\n\n[Illustration: DANTE STUDYING. _Frontispiece_\n\n_From a fresco by Luca Signorelli at Orvieto._\n\n Or vedi insieme l\u2019uno e l\u2019altro polo,\n Le stelle vaghe e lor viaggio torto;\n E vedi \u2019l veder nostro quanto \u00e8 corte.\n _Petrarch._]\n\n\n\n\n DANTE AND THE\n\n EARLY ASTRONOMERS\n\n BY\n M. A. ORR\n (MRS. JOHN EVERSHED).\n\n Plainness and clearness without shadow of stain,\n Clearness divine!\n Ye heavens, whose pure dark regions have no sign\n Of languor, though so calm, and though so great\n Are yet untroubled and unpassionate;\n Who, though so noble, share in the world\u2019s toil,\n And though so tasked keep free from dust and soil!\n\n * * * * *\n\n You remain\n A world above man\u2019s head, to let him see\n How boundless might his soul\u2019s horizons be,\n How vast, yet of what clear transparency.\n MATTHEW ARNOLD.\n\n London\n GALL AND INGLIS, 31 HENRIETTA ST., W.C.\n _And Edinburgh._\n\n PRINTED AND BOUND BY\n GALL AND INGLIS,\n NEWINGTON PRINTING AND BOOKBINDING WORKS,\n EDINBURGH.\n\n\n\n\nPREFACE.\n\n\nAn observatory on a mountain top is an ideal place in which to write\non astronomy and poetry, but it has one drawback: the difficulty of\nobtaining books on special subjects. My husband\u2019s criticisms and help\nhave been invaluable, and of books on modern astronomy there is no\nlack; but many others which I have wished to consult I have been unable\nto procure, and doubtless there are many more which I ought to have\nread, but of whose existence I am ignorant.\n\nThis defect has been partly remedied, however, by Mr. Wicksteed\u2019s great\nkindness in lending me a number of books on Dante subjects.\n\nI am much indebted to my sister, Miss Orr, who has helped me in\npreparing these sheets for the press. The index is mainly her work.\n\nThanks are also due to several members of the staff of this\nobservatory: Mr. Sitarama Aiyar made some calculations, Mr. Nagarajan\nAiyar projected the map facing page 295, Mr. Krishna Aiyar prepared\nphotographs of several illustrations, and Mr. Krishnasawmy typed the\ngreater part of the copy for press. Mr. Raymond Beazley, the Trustees\nof the British Museum, and Messrs Macmillan, have kindly allowed me to\nreproduce illustrations from their publications.\n\nTo all these I offer grateful thanks.\n\n M. A. EVERSHED.\n\n KODAIKANAL OBSERVATORY,\n SOUTH INDIA.\n _October 1913._\n\n THIS BOOK\n IS DEDICATED TO\n LUCY.\n\n\n\n\nLIST OF PRINCIPAL AUTHORITIES.\n\n\n Alfraganus, Elementa Astronomica. Arabic\u00e8 et Latin\u00e8,\n opera Jacobi Golii (Amsterdam, 1669).\n Angelitti, Sulla Data del Viaggio Dantesco.\n \u201d Sull\u2019 Anno della Visione Dantesca.\n Antonelli, Sulle Dottrine Astronomiche della Divina Commedia (1865).\n Aratus, The Phainomena. Translation by R. Brown.\n Aristotle, Four Books on the Heavens. Greek and German, with notes,\n by C. Prantl.\n Beazley, Dawn of Modern Geography.\n Berry, History of Astronomy.\n Blake, Astronomical Myths, based on Flammarion\u2019s History of the\n Heavens.\n Boffito et Melzi Eril, Almanach Dantis Aligherii (1908).\n Brunetto Latini, Li Livres dou Tr\u00e9sor. (Chabaille, Paris, 1863).\n Budge, Wallis, Guide to the Babylonian and Assyrian Antiquities,\n British Museum, 1900.\n Cantelli, La Conoscenza dei Tempi nel Viaggio Dantesco.\n Cicero, De Senectute.\n \u201d Somnium Scipionis.\n Cornewall Lewis, Historical Survey of the Astronomy of the Ancients.\n Coulton, From St. Francis to Dante.\n Delambre, Histoire de l\u2019Astronomie Ancienne.\n \u201d Histoire de l\u2019Astronomie du Moyen Age.\n Della Valle, Il Senso Geografico-Astronomico della Divina Commedia\n (1869).\n Dreyer, Planetary Systems from Thales to Kepler.\n Epping and Strassmeier, Astronomisches aus Babylon.\n Gardner, Dante\u2019s Ten Heavens.\n Gruppe, Die Kosmischen Systeme der Griechen.\n Ideler, Ursprung und Bedeutung der Sternnamen.\n Imbriani, Studi Danteschi.\n King, History of Sumer and Accad.\n Lockyer, Dawn of Astronomy.\n Lubin, Dante e gli Astronomi Italiani.\n Maunder, The Oldest Astronomy. (_Journal of the British\n Astronomical Association_).\n Moore, Dante and his Biographers.\n \u201d Studies in Dante. 3 vols.\n \u201d Time references in the Divina Commedia.\n Parker, Mrs. Langloh, Australian Fairy Tales.\n Plato, The Republic. Translation by Jowett.\n \u201d The Timaeus. \u201d \u201d\n Plutarch, On the Face in the Moon. Translation by Prickard.\n Pradeau, Key to the Time-Allusions of Dante.\n Rashdall, Universities of Europe in the Middle Ages.\n Ristoro d\u2019Arezzo, Della Composizione del Mondo colle sue Cagioni.\n (Narducci, Milan, 1864).\n Scartazzini, A Companion to Dante, translated by Butler.\n \u201d La Divina Commedia (edizione minore, with notes).\n Schaubach, Geschichte der Griechischen Astronomie bis auf\n Eratosthenes.\n Schiaparelli, I precursori di Copernico nell\u2019 Antichit\u00e0.\n \u201d I Primord\u00ec dell\u2019 Astronomia Babilonese.\n \u201d I Progressi dell\u2019 Astronomia Babilonese.\n \u201d L\u2019Astronomia nell\u2019 antico Testamento.\n \u201d Le Sfere Omocentriche di Eudosso, di Callipo,\n e di Aristotile.\n \u201d Origine del Sistema Planetario Eliocentrico presso\n i Greci.\n Temple Classics, Dante, (Divine Comedy, Convivio, Latin Works, with\n translations and notes).\n The Panchasiddh\u00e2ntik\u00e2 of Var\u00e2ha Mihira. Translated from the\n Sanscrit, and edited by Thibaut and M. S. Dvivedi.\n Toynbee, Paget, Articles on Dante\u2019s Obligations to Alfraganus,\n Albertus Magnus, Orosius, and Dante\u2019s theories regarding\n the markings on the Moon (in _Romania_ and _Giornale\n Storico della Letteratura Italiana_).\n \u201d Dante Dictionary.\n \u201d The Life of Dante (Oxford Biographies).\n Tozer, An English Commentary on Dante\u2019s Divina Commedia.\n Wicksteed, The Early Lives of Dante.\n Wicksteed and Selfe, Villani\u2019s Chronicle.\n Witte, Dante-Forschungen.\n\n * * * * *\n\nAll quotations from Dante\u2019s works are taken from Moore\u2019s _Tutte le\nOpere di Dante Alighieri_, 3rd edition, Oxford 1894.\n\nAstronomical data are chiefly taken from Young\u2019s _Manual of Astronomy_,\nand the _Nautical Almanac_.\n\n\n\n\nCONTENTS.\n\n\n PAGE\n INTRODUCTION 1\n\n PART I.\n\n ASTRONOMY FROM PRIMITIVE TIMES UNTIL THE AGE OF DANTE.\n\n I. APPARENT MOVEMENTS OF THE HEAVENLY BODIES AS SEEN\n FROM EARTH 9\n\n II. THE BEGINNINGS OF ASTRONOMY. Gnomons and\n clepsydras; the constellations and the calendar;\n astrology and star-worship; early cosmogonies 25\n\n III. GREEK ASTRONOMY: FIRST PERIOD.\n B.C. 900 to B.C. 350\n 1. Homeric Greece; First Notions of Astronomy 51\n 2. Thales and Anaximander: Earth flat, heaven a\n series of hemispheres 55\n 3. Later Flat Earth Systems: the Universe a sphere 60\n 4. Pythagoras and his Followers: Earth round,\n Earth in Motion 66\n\n IV. GREEK ASTRONOMY: SECOND PERIOD,\n B.C. 400 to A.D. 150\n 1. Plato: the World-Soul 79\n 2. Eudoxus: the Spheres 88\n 3. Calippus: the Spheres of Eudoxus improved 93\n 4. Aristotle: the Philosophy of the Spheres; the\n three kinds of motion; Earth immoveable at the\n centre of the Universe; the elements; the\n celestial movers, and the First Mover 95\n 5. Aristarchus: Earth turning on her axis, and\n revolving round the sun 107\n 6. The School of Alexandria: instruments and\n methods; Earth\u2019s diameter measured; the theory\n of Moveable Eccentrics 112\n 7. Hipparchus: \u201cthe Father of Astronomy;\u201d his\n star catalogue; his inventions and discoveries;\n the precession of the equinoxes 122\n 8. Ptolemy: the Almagest; the system of Epicycles\n and Eccentrics; distance and size of the moon\n discovered; the stars; astrology; geography, the\n seven climates 134\n V. RETROSPECT: Greek Cosmogonies; Greek calendar 159\n VI. ASTRONOMY UNDER IMPERIAL AND CHRISTIAN ROME.\n B.C. 46 to A.D. 1000. Amateur\n Astronomers; the Julian Calendar; passion for\n Astrology; the Fathers; the ecclesiastical Calendar;\n the Schools; the Monasteries 167\n VII. ARAB ASTRONOMY. A.D. 750 to 1250.\n Schools of Baghdad, Egypt, Spain. Improvements in\n Mathematics and Instruments; Ptolemy\u2019s values more\n correctly determined; supposed discoveries of\n planetary distances and trepidation; a ninth sphere\n added to Ptolemy\u2019s eight 181\n VIII. THE RETURN OF GREEK ASTRONOMY TO EUROPE.\n A.D. 1000 to 1300. The Universities;\n Arab influence; Greek books; new European books;\n the course in Astrology in Bologna; Aristotle and\n the Church 199\n\n PART II.\n\n THE ASTRONOMY OF DANTE.\n\n I. POPULAR ASTRONOMY IN ITALY IN DANTE\u2019S\n TIME. The astronomy of Dante contrasted with\n Homer and Milton. General feeling for astronomy\n in his day; some famous astrologers: astronomy\n considered an ennobling study; Ptolemy\u2019s system\n final. Knowledge of average educated man. 209\n\n II. DANTE\u2019S STUDIES. Dante a representative of\n contemporary beliefs: his erudition; his\n education; Brunetto Latini\u2019s influence;\n possible visits to universities of Bologna,\n Padua, Paris. 223\n\n III. BOOKS ON ASTRONOMY USED BY DANTE.\n Dante\u2019s wide reading; his diligence and memory.\n Ptolemy his supreme authority on astronomy; his\n principal text-books Alfraganus and Aristotle;\n versions used. Classical Latin authors; Greek;\n Arab; Christian 231\n\n IV. ASTRONOMY IN DANTE\u2019S WRITINGS. References\n to heavenly bodies in Vita Nuova, the Canzoniere,\n Convivio, Latin works and letters, Divine Comedy.\n Artistic use of the facts and theories of astronomy. 253\n\n V. OBSERVATIONAL ASTRONOMY\n 1. Movements of the Moon 261\n 2. Movements of the Sun 270\n 3. The Stars 283\n 4. The Galaxy 303\n 5. The Planets 307\n 6. Eclipses 316\n 7. Comets and Meteors 318\n 8. The Sun\u2019s Path in the Sky seen from\n different Parts of the Earth 322\n 9. Celestial Phenomena and Time 338\n VI. DANTE\u2019S JOURNEY THROUGH THE THREE REALMS:\n INDICATIONS OF TIME AND DIRECTION BY\n MEANS OF THE SKIES\n 1. Time references in the Divine Comedy 353\n 2. The Inferno 367\n 3. Purgatory 373\n 4. Paradise 391\n 5. Positions of Sun, Moon, and Planets among\n the Stars during Dante\u2019s Vision 402\n 6. The Assumed Date of the Vision 409\n VII. THEORETICAL AND SPECULATIVE ASTRONOMY\n 1. The Spheres 429\n 2. The Spheres and the four Elements 441\n 3. Dimensions and Physical Nature of the Universe 457\n 4. Influence of the Spheres on Human Affairs 471\n 5. The Motive Power 480\n VIII. MEDI\u00c6VAL AND MODERN VIEWS OF THE UNIVERSE 487\n\n\n\n\nILLUSTRATIONS.\n\n\n PART I.\n FIG. PAGE\n DANTE STUDYING. _From a fresco by\n Luca Signorelli at Orvieto_ _Frontispiece_\n 1. The Sun\u2019s Path in the Sky at different Seasons 11\n 2. The Moon at Sunset, soon after New, and three days old 14\n 3. Path of Mars among the Stars, 1909 16\n 4. The Star Sphere 19\n 5. Synodic and Sidereal Periods 21\n STAR MAP 34\n THE MOON-GOD OF UR. _From a Cylinder-seal in the British\n Museum, date about_ B.C. 2400.\n _By permission of the Trustees of the British Museum_ 36\n 6. The triple Star-sign of the Babylonians 37\n 7, 8, 9. The young Moon and the Pleiades after\n sunset, as seen in Babylon, B.C. 1000 42\n 10. The Scorpion. _From a Babylonian boundary stone\n of about_ B.C. 1120, _set up in the reign\n of Nebuchadnezzar I. Now in the British Museum_ 43\n 11. The Goat with Fishes\u2019 Scales. _From a Babylonian\n boundary stone_ 43\n THE BOAT OF THE SUN TRAVELLING OVER THE SKY.\n _From an ancient Egyptian papyrus. Reproduced\n from Flammarion\u2019s Astronomical Myths_ 46\n 12. The Universe according to Anaximander 59\n 13. The Universe of Leucippus 63\n 14. The Universe of Democritus 64\n 15. The Universe of Pythagoras 71\n 16. The System of Philolaus: night on Earth 73\n 17. do. twelve hours later: day on Earth 73\n 18. Earth and Sun according to Heraclides 74\n 19. The Spheres of the Sun in the system of Eudoxus 90\n 20. Method of Aristarchus for finding the Distance of the Sun 108\n 21. Pekin Observatory 114\n 22. A Pekin Astrolabe of the thirteenth century A.D.\n _From photographs taken in 1888 and published\n in the Bulletin de la Soci\u00e9t\u00e9 belge d\u2019Astronomie_ 116\n 23. The Moveable Eccentric 119\n 24. The Movement of Spica 124\n 25. The Sun and the Equinox 128\n 26. The Movement of the Earth\u2019s Axis which is the true cause\n of Precession. _From Young\u2019s Manual of Astronomy_,\n 1902 131\n 27. Precession of the Equinoxes 133\n 28. Path of Mars, 1909 139\n 29. The Epicycle 139\n 30. A Planet \u201cretrograding\u201d and \u201cin opposition\u201d 140\n 31. Venus, Mercury, and the Sun 142\n 32. The Sun\u2019s Deferent 145\n 33. Apparent Variation in the size of the Sun.\n _Photographs taken at Kodaikanal Observatory,\n with the spectroheliograph, July 1, 1911, and\n Jan. 3, 1912. Actual size of the negative_ 146\n 34. The Moon\u2019s Epicycle and Deferent 148\n 35. The Ptolemaic System 151\n 36. Method (erroneous) of estimating Planetary Distances,\n described by Alfraganus 188\n 37. Earth\u2019s Shadow 192\n\n PART II.\n FIG. PAGE\n\n A MEDI\u00c6VAL ASTRONOMER. _From a painting by Gerard Dow_ 200\n ASTRONOMY. _From a fresco in the Spanish Chapel\n of Santa Maria Novella, Florence_ 217\n 38. The Half-Moon shape of the Habitable Earth (Ristoro) 247\n CLIMATE MAP OF ABOUT A.D. 1110. _Reproduced from\n Beazley\u2019s Dawn of Modern Geography_ 248\n 39. Sun, Moon, and zenith. To illustrate _Par._ xxix 1-6 267\n 40. The Zodiac and the Months 276\n 41. The Ram on the Ecliptic. _From the Cosmi Historia\n of Robert Flud_, A.D. 1612.\n _Reproduced from Brown\u2019s Aratos._ 279\n MAP OF STARS VISIBLE BEFORE DAWN IN PURGATORY 295\n 42. Ursa Minor as a Horn. _Par._ xiii. 10 299\n 43. The Sun at the Equinox, seen from the poles and\n the equator. _Conv._ III. v. 327\n 44. Lunar and Solar Eclipses 339\n MAP OF THE WORLD BY HEINRICH OF MAINZ,\n about A.D. 1110. _Reproduced from Beazley\u2019s\n Dawn of Modern Geography_ 344\n 45. The Universe of Dante 355\n 46. The Signs of the Zodiac at sunrise from the Mountain\n of Purgatory 375\n 47. Northern Slope of the Mountain of Purgatory 377\n 48. Dante\u2019s View of Earth from the stars. _Par._ xxii. 395\n 49. do. Six hours later. _Par._ xxvii. 396\n 50. An impossible interpretation of _Par._ xxvii. 399\n 51. The Rising Sun at the spring equinox. _Par._ i. 39 403\n 52. The Moon\u2019s Epicycle and Deferent 449\n 53. Comparative sizes of the Sun and his satellites 490\n\n\n\n\nABBREVIATED TITLES OF BOOKS USED IN THE TEXT.\n\n\n Dante\u2019s Works:\u2014\n _Inf._ Inferno.\n _Purg._ Purgatorio.\n _Par._ Paradiso.\n _Canz._ Canzone.\n _Son._ Sonetto.\n _Ball._ Ballata.\n _Ecl._ Eclogue.\n _V. N._ Vita Nuova.\n _Conv._ Convivio.\n _De Mon._ De Monarchia.\n _V. E._ De Vulgari Eloquentia.\n _Ep._ Epistola.\n _Qu._ Qu\u00e6stio de Aqua et Terra.\n\n _El. Ast._ Elementa Astronomica (Alfraganus).\n _Comp. del Mond._ Della Composizione del Mondo (Ristoro).\n\n\n\n\nDANTE AND THE EARLY ASTRONOMERS.\n\n\n\n\nINTRODUCTION.\n\n\nIn a beautiful passage of the _Convivio_ Dante describes how he first\nbegan to devote himself diligently to science and philosophy. When\nthe gentle soul of Beatrice had passed to heaven, a great darkness\nfell upon him: the streets of Florence were to him as a deserted city,\nand his life empty and purposeless. It was long before he could find\nany comfort, but at last he bethought himself of studying a book by\nBo\u00ebthius, who when exiled, imprisoned, and unjustly condemned to death,\nhad strengthened his soul with the \u201cConsolations of Philosophy.\u201d This\nled him on to Cicero\u2019s book \u201cOn Friendship,\u201d in which L\u00e6lius explains\nhow he is consoled for the death of Scipio.\n\nBooks in those days could only be had in manuscript, full of\nabbreviations, and often also of errors, and at first the young\nstudent found the Latin hard to master; but as he struggled on,\nhalf deciphering and half divining the meaning, the mists cleared a\nlittle, and the weight was lifted from brain and heart. With elation\nhe discovered that obscure passages were becoming luminous, and to\nthe exhilarating sense of conquest was added the joy of finding,\nbeautifully expressed, thoughts which had already floated in his own\nmind, but dimly, as in a dream. He compares himself to one who, seeking\nsilver, should light (not without Divine guidance) on a treasure of\ngold; for he found not only relief from his tears, but a door into a\nnew world of literature, philosophy, and science. Henceforth, he tells\nus, he eagerly frequented the schools of the religious orders and the\ndiscussions of the philosophers; and how extensive and thorough was his\nlearning we can see in his writings. In them we find a reflection of\nthirteenth-century thought in every field of intellectual research.\n\nAmong all his studies was one which evidently had a great attraction\nfor him, even in the early days of the _Vita Nuova_, before learning\nhad become a passion. Astronomy appealed to many sides of his nature.\nThe beauty of the skies stirred his imagination; their suggestive\nsymbolism touched his religious sense; the harmony of the celestial\nmovements and the accuracy with which they can be foretold delighted\nhis instinct for order and precision. He must have read, and perhaps\npossessed, some of the best text-books then available, and he grasped\nwith singular clearness the phenomena observed and the theories taught\nin his day. His works are full of allusions to astronomy. In the _Vita\nNuova_ he finds pleasure in connecting the story of his lady with the\nrevolutions of the spheres; in the _Convivio_ he teaches the elements\nof the science; in the Vision of the _Divine Comedy_ he journeys\nthrough the universe as it was depicted by medi\u00e6val astronomers;\nand throughout his works are scattered similes drawn from celestial\nphenomena and descriptions of \u201cle belle cose che porta il ciel.\u201d[1]\n\n------------------------------------------------------------------------\n[1] \u201cThe fair things that Heaven holds.\u201d Inferno XXXIV. 137, 138.\n------------------------------------------------------------------------\n\nTherefore, for full enjoyment and understanding of Dante\u2019s works it is\nnecessary to have a rudimentary knowledge of astronomy.\n\nMany of his readers think that Dante\u2019s astronomy is very complicated\nand difficult to understand. What makes it seem difficult is that in\nthis age we are generally unfamiliar with the skies. We do not eat our\nbreakfast or go to our office by the sun, nor do we watch the stars\nto see when grouse-shooting begins or the summer holidays end. If it\nis important for us to know at what hour the sun sets and lamps must\nbe lighted, or if we wish to see a view by moonlight, we consult an\nalmanac. When we think at all of the movements of the heavenly bodies,\nour notions are usually taken from diagrams and tables, not from what\nis actually seen in the skies. We only think, for instance, of the\nseasons as caused by the earth\u2019s journey round the sun, and the tilt\nof her axis: therefore, when Dante speaks of Venus as a Morning Star\nveiling the Fishes with her rays, or the horn of the Celestial Goat\ntouching the sun, it conveys little, although the seasons of spring\nand of winter are as clearly indicated as if he had spoken of the\nblossoming of primroses or the fall of snow. When Cacciaguida, in the\nheaven of Mars, tells the date of his birth by counting how many times\nthe planet had since then returned to his Lion, those who only think of\nMars as circling round the Sun, and have never traced his path among\nthe stars, are at a loss, and think the method very far-fetched. A\nshort description, and especially a little individual watching, of the\napparent movements of the heavenly bodies, would put us in a position\nto realize the meaning of a large number of Dante\u2019s astronomical\ndescriptions and allusions, without any knowledge of any theory.\n\nOthers complain that the subject is dull. Dante\u2019s astronomy, when\ninterpreted only by means of notes on single passages, is undoubtedly\ndull\u2014as dull as the history of his own times learned in the same way.\nBut when either subject is studied as a whole these passages acquire a\nspecial interest; and they in their turn give new life to the subject\nthey illustrate.\n\nOther readers say that Dante\u2019s astronomy is so entirely false and\nobsolete that it is not worth study. This is hardly true. Where Dante\nspeaks of appearances he is remarkably accurate, far more so than\nmost modern artists and writers of fiction. Where he speaks of the\nheavens as he supposes them actually to exist, he is interpreting the\nappearances according to the astronomical theories of his day, with\nwhich he was very well acquainted. This interpretation was not correct,\nbut it was an ingenious and beautiful system, and very successful in so\nfar as it enabled astronomers to calculate the positions of sun, moon,\nstars, and planets for any date. Its main outlines can be explained in\na few pages, with the help of a couple of diagrams, but when presented\nthus, especially to those unfamiliar with the skies, it seems very\nstrange and artificial. To appreciate it at its true worth, we must\nknow just what are the phenomena it was intended to explain, and trace\nits gradual development out of man\u2019s first clear perception that the\nmovements of sun, moon, and stars follow unchanging laws.\n\nThe story of this development is of enthralling interest, and after\nthe system had been completed by one of the greatest mathematicians\nthe world has seen, its later history reads like a romance. Though of\nclassical Greek origin, it was almost wholly lost to Europe for many\ncenturies, it returned at last in Oriental dress, and its final form\nwas given by a devout and learned Dominican friar.\n\nIt was at this time that Dante was born, and the scholar-poet\nimmortalized the Ptolemaic system of astronomy in his verse, adding\nto its popularity in his own day, and making it known to thousands of\nreaders since, who might otherwise scarcely have heard of it.\n\nDante\u2019s astronomy, therefore, is of wide and deep significance. To\nstudy its history is to learn a chapter in the development of the\nhuman intellect; to see the universe with his eyes is to know how it\nappeared, not only to his contemporaries but to men in many lands and\nmany centuries. The system of Ptolemy was already a thousand years\nold when Dante studied it, and it continued to be taught long after\nCopernicus had introduced a truer one; nor has it ever been completely\nswept away, for much that it taught was accurate. The new astronomy\nhas developed from the old, and bears traces to this day, in its\nphraseology, its written symbols, and its methods, of the many races\nand ages which have contributed to its progress.\n\nThis book, therefore, is divided into two parts. In the first, I put\nbefore my readers the elementary facts which form the foundations upon\nwhich all astronomy is based, the movements of sun, moon, stars, and\nplanets, so far as they can be easily observed by the naked eye; then\nfollows a sketch of the attempts which were made to interpret these\nobservations from very early days until Dante\u2019s time. Unnecessary\ntechnicalities are avoided, but we shall try to enter into the thoughts\nof past generations concerning the stars, to see why they were\ninterested, how they worked, what hindered and what helped them in\ntheir search for truth.\n\nIn the second part, we shall examine Dante\u2019s works, and see how\nfamiliar he was with the movements of the skies, and how well he\nunderstood the theories which in his time were held to explain them.\nWe shall see how astronomy was generally regarded in his day, what\nbooks he read, and which authors influenced him most. We shall see how\nfalse is the assertion often made that in the Middle Ages men studied\nastronomy only for the sake of astrology, and how closely the science\nof the stars was connected with religion and the loftiest speculations\nof philosophy.\n\nWe shall also examine in particular some difficult passages connected\nwith astronomy which occur in Dante\u2019s works, but my aim is not so much\nto explain all the astronomical references as to put the reader in a\nposition to attempt an explanation himself.\n\nMy greatest ambition is to share with others the pleasure I have had in\nlearning what Dante knew and thought about the stars, and who were the\nmaster builders who had erected through the ages the system so vividly\npictured in his immortal poem.\n\n\n\n\n_FIRST PART._\n\n THE STORY OF ASTRONOMY FROM PRIMITIVE TIMES\n UNTIL THE AGE OF DANTE.\n\n\n\n\nI. APPARENT MOVEMENTS OF THE HEAVENLY BODIES AS SEEN FROM EARTH.\n\n\nThe stars appear to us like points of light, differing greatly in\nbrightness, and scattered very irregularly over the dome above us. All\nare moving, some much more quickly than others, yet a little attention\nshows that they do not change their relative positions, and therefore\nthat all must share in one connected movement. If, for instance, any\none group be singled out, and looked for again some hours later, it\nwill be evident that it has moved considerably as a whole, yet the\nstars composing it have kept the same places with regard to one another.\n\nCareful and prolonged observations prove that to observers in the\nnorthern hemisphere one star has hardly any perceptible movement, that\nthose nearest to it sweep round it in small circles, and those further\naway in larger and larger circles, parts of which are hidden below\nthe horizon. All these circlings are performed in the same time, and\ntherefore the stars near the stationary point move more slowly in their\nsmall circles than those further away.\n\nAll this is precisely what we should see if the sky were a great hollow\nsphere, turning about the earth on an axis which runs close to the\nalmost stationary star\u2014known therefore as the Pole Star. The direction\nis from east to west, and a complete revolution is made in a day and\nnight.\n\nWe can plot the stars on a globe, and draw an equator on it, which will\neverywhere be at an equal distance from the poles, and we may add other\ncircles, as on a terrestrial globe: then the position of each star can\nbe referred to these circles as towns on earth are found by latitude\nand longitude, and the path of any moving body, such as a comet, may be\ntraced.\n\nThe stars fade out when the sun rises, but he too sweeps across the\nsky as though carried round by the same sphere, and he sets like them,\nin the west. Has he a fixed place on the sphere, keeping always the\nsame position relatively to the stars? No, for in the place where he\nhas just set we do not always see the same stars. Night after night\nthose which were clear in the western sky as soon as it was dark enough\nto see them, grow closer to him, till at last they are lost in his\ntwilight beams. Thus the sun, though sharing in the daily east to west\nmovement, has a slow movement of his own on the sky-sphere, slipping\nback from west to east, until in a year he has accomplished the whole\nround, and sets again among the same stars.\n\nMoreover, this peculiar movement of the sun is not a mere lagging\nbehind the stars, for his west to east motion is combined with a north\nand south motion. If we note the star-groups which are just behind him\nwhen he sets (or just before him when he rises), we shall find that\nthey form a great circle round the globe, half of which lies north\nand half south of the celestial equator. The Greeks named this circle\nthe Zodiac, or \u201cPath of the Animals,\u201d because the star-groups forming\nit were mostly called by the names of animals (the Ram, Lion, Fishes,\netc.). When the sun is in the most northerly part of the zodiac it is\nsummer in the northern hemisphere; when he is in the most southerly, it\nis summer in the south. (See Map).\n\n[Illustration: Fig. 1. The Sun\u2019s path in the sky at different seasons.]\n\nThis north and south motion of the sun may be noted more directly in\nanother way. Seen from any given place on the earth, each star rises\nand sets at the same points of the horizon always, and has the same\ncourse in the sky; but the rising and setting points of the sun,\nwhich on about the 21st of March are due east and west, travel daily\nfurther north, and the sun mounts daily higher in northern skies until\nabout the 20th of June; then he returns towards the south, passing\nthe east and west points again about September 23, and reaches his\nfurthest point south about December 21. (The dates vary slightly\nowing to Leap Year). The dates on which the sun reaches his furthest\nnorth and furthest south points in this yearly journey are called the\n\u201csolstices,\u201d because his motion seems to be checked, and he pauses or\n\u201cstands\u201d before reversing his direction; the dates on which he passes\nthe midway point are the \u201cequinoxes,\u201d because at those points he is on\nthe equator, and makes day and night equal all over the earth.\n\nThe time taken by the sun to pass from one vernal (spring) equinox to\nanother is 365 days, 5 hours, 48 minutes, 45 seconds. Since this slow\nmotion along the zodiac is from west to east, contrary to the rapid\neast to west motion which he shares with all the stars, he takes a\nlittle longer to complete a daily revolution than they do; and if we\nreckon a solar day as consisting of 24 hours, a \u201csidereal\u201d (or star)\nday is equal to 23 hours, 56 minutes, 4 seconds.\n\nThese are very elementary facts, but they are the fundamental facts\nof astronomy, and without recollecting and holding them clearly in\nmind we cannot understand Dante\u2019s allusions, nor see the fitness of\nany astronomical system, ancient or modern. To those who have only\nread about astronomy in books, and have not watched the skies, they\nmay be puzzling, and I would beg these readers to make a few simple\nobservations for themselves, as this will help them more than any\nwritten explanation can ever do to see the heavens with Dante\u2019s eyes.\nTo appreciate the connected movement of the whole sky, some bright\nstars near the Pole should first be watched, such as the Great Bear\nand Cassiopeia, or for those in the southern hemisphere the Southern\nCross, Canopus, Achernar. Their motions should be compared with those\nof bright stars near the equator, such as Orion, Virgo, or Aquila. The\nconstellations of the zodiac should be studied, and notes made of the\nseasons at which each disappears in the rays of the sun.\n\nThe sun\u2019s north and south movements can be easily recognized by noting\nat what points of the horizon he rises or sets at different times of\nthe year; and the different heights to which he rises in the sky are\nmost simply observed by marking the length of the shadow of some tree\nor pole at midday. Or if some rough kind of gnomon[2] be made, even\na flat piece of wood, laid on a sunny window-sill, with a long nail\ndriven vertically into it, the movement and varying length of the\nshadow, from hour to hour, and from day to day, will make one realize\nvividly the diurnal and the seasonal movement of the sun. This device,\nin one form or another, was probably the first astronomical instrument\ninvented, and by its means ancient astronomers in many lands solved\nimportant problems.\n\n------------------------------------------------------------------------\n[2] Greek _gnomon_, an interpreter. A pole set up in order to show the\nlength of shadow thrown by the sun.\n------------------------------------------------------------------------\n\nIt is not necessary to explain that the daily apparent movements are\ncaused in reality by the earth\u2019s rotation on her axis, and the yearly\napparent movements by her revolution round the sun. These are the\nbook-learned facts which for the most part obscure our perception of\nthe very things on which they are based. I would ask the reader to do\nhis best, for the moment, to forget them.\n\nThe movements of the moon among the stars are much more easily observed\nthan those of the sun, since we can see the stars at the same time, and\nher revolution is much more rapid. She also is apparently carried round\nwith the daily east to west movement, and she also has a west to east\nmotion of her own, but so fast that it takes her round the star sphere\nin one month, instead of one year. This revolution also takes place in\nthe zodiac. She is first visible as a fine crescent, just following\nthe sun, in the west, after he has set; next night she is markedly\nfurther from the sun, on her eastward course, and is a larger crescent;\nshe continues increasing her distance from the sun and the size of her\ndisc, until, as full moon, she is rising in the east when the sun sets\nopposite her in the west, and setting when the sun rises. After this,\nshe begins to wane, and, still travelling in the same direction, rises\nlater and later at night, and sets in the day; she draws gradually\nnearer to the sun on the western side, till at last, as a fine crescent\nwith the horns turned in the other direction (_i.e._ always away from\nthe sun), she appears just before the rising sun in the east. Then for\na short time she is lost in his rays, till she emerges as a new moon on\nthe sunset side again.\n\n[Illustration: Fig. 2. The Moon at Sunset.]\n\nThe moon completes a revolution among the stars in 27 days, 8 hours;\nbut it takes her a little longer to come up with the sun again, since\nhe has meanwhile been moving in the same direction along his yearly\npath; and the \u2018synodic\u2019 month, or period from one new moon to the next,\nis 29 days, 13 hours.\n\nAs well as the moving sun and the moving moon, there are five other\nbodies, visible to the naked eye, which move among the stars. They look\nlike stars, but their movements would lead us rather to class them with\nsun and moon. They also are in the zodiac, and they also, while carried\nround with the universal movement from east to west, revolve slowly,\neach in its own period, from west to east. But their motions are more\ncomplicated than those of sun and moon. Two, which we call Venus and\nMercury, are never seen very far from the sun, and they oscillate\nfrom side to side, sometimes appearing before him near sunrise, and\nsometimes after him at sunset. Mercury keeps closest to the sun, and is\nnot so bright, and therefore less easy to see; but Venus is a brilliant\nobject when she gradually swings out further from the sun, remaining\nlonger each evening after sunset in the western sky. Then she gradually\ndraws back, closer to the sun, is lost in his rays, and a few days\nafter begins to appear on his other side, as a Morning Star, visible in\nthe east before sunrise. Here she swings out again, like a pendulum, to\nher furthest distance west, and then draws in again, just as she did on\nthe sunset side of the sun.\n\nIn this way, swinging slowly from side to side of the sun, Mercury and\nVenus make with him the circuit of the zodiac, completing a revolution\nfrom west to east in about a year. The average period of Mercury\u2019s\noscillation, counting, for instance, from one Greatest Western\nElongation (_i.e._ furthest distance from the sun on the west) to the\nnext, is 116 days; that of Venus is 584 days.\n\n[Illustration: Fig. 3. The Path of Mars among the Stars, 1909.]\n\nThe other three \u201cwandering stars\u201d\u2014or \u201cplanets,\u201d[3] as they were named\nby the ancient Greeks\u2014Mars, Jupiter and Saturn, are also often seen as\nmorning or evening stars near the sun, but they do not always accompany\nhim, like Venus and Mercury. They may be seen at any distance from\nhim, even exactly opposite, so that they rise as he sets. They keep as\nstrictly to the zodiac, however, and travel in it from west to east, in\nperiods of approximately two, twelve, and thirty years respectively;\nand their paths are also complicated by oscillations. Periodically\nthey slacken speed, stop, and go back a little distance among the\nstars, then they slacken, stop, and advance again. These changes are\ntechnically called direct motion, stations or stationary points, and\nretrograde motion.\n\n------------------------------------------------------------------------\n[3] Greek _planetes_, a wanderer. This name was originally given to\nMercury, Venus, Mars, Jupiter, Saturn, and also to sun and moon, for\nit indicated all the known heavenly bodies which changed their places\namong the stars. In modern usage it is not applied to the sun, but only\nto his satellites, of which many more are now known.\n------------------------------------------------------------------------\n\nIt must have originally taken many years of patient watching to\ndiscover and distinguish all these planets. In these days, by means of\nan almanac and some knowledge of the constellations, they may easily be\nfound and traced. Mars and Venus move quickly during part of the time\nthey are visible, and if sketches be made of their positions among the\nstars, and their paths marked for a few weeks, a very good idea may be\ngained of the motions of planets as seen in the skies.\n\nOnce again, it is not necessary to explain here that these movements\nof the planets are due partly to their revolution round the sun, and\npartly to the Earth\u2019s motion. Nor need we, for our present purpose,\nconsider them in any detail: all that is important to realize is the\ngeneral character of the movements, and their likeness to those of sun\nand moon.\n\nThe distances, and therefore the sizes, of all the heavenly bodies are\ncompletely beyond measurement, except with instruments and refined\nmethods; their physical nature could only be guessed at before the\ndiscoveries of universal gravitation and spectrum analysis, in the 17th\nand 19th centuries of our era. All that can be observed by naked eye\nastronomy is difference of brightness and colour; as for instance the\ncontrast between ruddy Mars and white Jupiter; the steadier light of\nall the planets as compared with stars; and the interesting fact that\nthe moon shines by reflected sunlight, which is made evident by the\nconnection between her phases and her position with regard to the sun.\nHer surface, too, is clearly seen to be diversified by dark markings of\ndefinite shape, but on no other body in all the sky can we make out the\nleast detail without a telescope.\n\nThe movements of the heavenly bodies, therefore, which still form one\nof the most important parts of astronomy, were almost all that could be\nstudied by ancient astronomers, and gave them the only key they had to\nthe problems of the universe.\n\nTo sum up:\u2014The chief apparent movements of the heavens, visible to the\nnaked eye, are eight, viz:\u2014\n\nThe daily revolution of the entire heavens, carrying with it every\nvisible celestial body, in a little less than 24 hours; the revolutions\nof sun, moon, and five naked eye planets, in seven different periods.\n\nThe first of these is from east to west, and is by far the most rapid.\nThe axis of revolution passes through two points which we call the\ncelestial poles, and the motion is parallel to the celestial equator.\n\nAll the others are in the main from west to east, though the progress\nof the planets is complicated by periodical retrograde movements. All\ntake place in the zodiac, which is a series of constellations forming\na great band round the heavens. The path of the sun is a great circle\nthrough this, called the Ecliptic (because eclipses can only happen\nwhen the moon is also on it); and the paths of moon and planets are\nslightly and variously inclined to it.\n\nThus the daily path of a star is affected only by the simple uniform\nmovement of the entire heaven (in reality the rotation of the Earth)\nbut the daily path of a planet, or of the sun or moon, results from a\ncombination of this general movement with its own peculiar movement,\nwhich is generally in the opposite direction.\n\n[Illustration: Fig. 4. The star sphere.]\n\nIf it is difficult to conceive a body moving simultaneously in two\ndifferent directions, an earthly analogy will make it easy. On a great\nmoving platform, such as that which encircled the Paris Exhibition in\n1900, there are fixed posts etc. which revolve exactly as the whole\nplatform revolves and do not move about amongst themselves. These are\nlike the fixed stars on the (apparently) revolving sphere. But human\nbeings are free to add their own movements to that given them by the\nplatform on which they stand. One man turns his back and walks steadily\nand very slowly in the opposite direction, and so he neutralizes part\nof the platform movement and is not carried onward quite so quickly\nas the stationary posts: he is the sun. A woman walks as he does, but\nmuch more quickly, so that she rapidly passes many posts, although all\nthe time she is being carried backwards with them: she is the moon.\nChildren run backwards and forwards: they are the planets. Finally,\nif all these people are also constantly crossing the platform slowly\nfrom right to left and back again, their movements will be oblique to\nthe platform movement and will imitate the north and south movements of\nsun, moon, and planets.\n\nIt is in this fashion that the movements of the skies present\nthemselves to careful observers on this seemingly stationary earth; and\nin the youth of the world these apparent movements were believed to be\nreal. The ancients thought that the sky was actually revolving round a\nsteadfast earth, while the sun and moon and certain other \u201cwandering\nstars\u201d had in addition various motions peculiar to themselves.\n\nThe table of periods which follows (see pp. 22-23) will be found useful\nfor occasional reference. Some of the terms used will be explained\nlater.\n\n[Illustration: Fig. 5. Diagram illustrating Synodic and Sidereal\nPeriods.\n\n The arrows show the direction of the Moon\u2019s monthly\n and the Sun\u2019s yearly revolutions in the zodiac, as\n seen from Earth.\n\n When the Moon is opposite the Sun, for instance in\n Libra while he is in Aries, she is full. In 27\u00bd\n days she returns to the same place among the stars,\n and this is a SIDEREAL MONTH. But the Sun\n meanwhile has moved into Taurus, and not until the\n Moon has reached Scorpio, opposite to him, will\n she be full again, and complete her SYNODIC\n MONTH (29\u00bd days).]\n\n REVOLUTIONS OF SUN, MOON, AND PLANETS\n AS SEEN FROM THE EARTH.\n\n _Days. Hrs. Mins. Secs._\n Tropical Solar Year: period from one\n vernal equinox to another, or from\n one summer solstice to the next, &c. 365 5 48 45\u00b75\n (Our civil year is based on this).\n Sidereal Year: period between two\n successive returns of the sun to any\n star on his path 365 6 9 8\u00b79\n The difference between these two kinds of year is due to Precession\n of the Equinoxes, _vide infra_, p. 23.\n\n _Days. Hrs. Mins. Secs._\n Solar Day: period between two successive\n passages of the sun across\n the meridian (noon) \u2014 24 0 0\n Sidereal Day: period between two\n successive passages of a star across\n the meridian \u2014 23 56 4\n The difference between these two kinds of day is due to lag of the\n sun behind the stars, his daily motion westward being slightly\n retarded by his slow yearly motion eastward.\n\n _Days. Hrs. Mins. Secs._\n Mean Synodic Month: period between\n two full moons 29 12 44 2\u00b78\n\n Mean Sidereal Month: period between\n two successive returns of moon to\n any star on her path 27 7 43 11\u00b75\n The difference between these two kinds of months is due to the fact\n that while the moon is making her revolution among the stars, the\n sun is also moving slowly on in the same direction.\n\n _Days. Hrs. Mins. Secs._\n Mean Anomalistic Month: period\n between perigee and perigee\n (_vide infra_) 27 13 18 37\u00b74\n\n PLANETS:\u2014Mean Synodic Revolution: period\n between two successive conjunctions with the sun,\n and mean zodiacal revolution: period of revolution\n round the zodiac.\n\n _Mean Synodic Revolution. Mean Zodiacal Revolution._\n Mercury 116 Days[4] 1\u00b70 Years\n Venus 584 \u201d 1\u00b70 \u201d\n Mars 780 \u201d 1\u00b788 \u201d\n Jupiter 399 \u201d 11\u00b786 \u201d\n Saturn 348 \u201d 29\u00b746 \u201d\n\n------------------------------------------------------------------------\n [4] Fractions omitted.\n------------------------------------------------------------------------\n\n PRECESSION OF EQUINOXES: 50\u00b725 seconds of arc\n in one year; that is, 360 degrees (a revolution\n among the stars of the zodiac) in 25,800 years\n nearly.\n\n\n\n\n_II. THE BEGINNINGS OF ASTRONOMY._\n\n\n Note.\n\n As these pages are passing through the press,\n a letter from Mr. Maunder appears in _The\n Observatory_ for August 1913 on \u201cThe Origin of\n the Constellations,\u201d and this should be consulted\n by anyone interested in the subject. Mr. Maunder\n points out that Ptolemy gives us much more precise\n information than Aratus regarding the southern\n limits of the ancient constellations, and that the\n changes which he says he ventured to make in their\n traditional forms are extremely insignificant.\n\n Mr. Maunder further observes that the celestial\n equator of Aratus cannot give any clue to the\n origin of the constellations (as R. Brown\n suggested), but only to the date of the work from\n which Aratus copied, when some astronomer had drawn\n the equator through the constellations. A slight\n alteration of the text, Mr. Maunder says, would\n give a correct equator for the date B.C.\n 1000.\n\n See also Mr. and Mrs. Maunder\u2019s article in _Monthly\n Notices of the Royal Astronomical Society_ for\n March 1904.\n\n Proctor\u2019s \u201cOrigin of the Constellation Figures\u201d is\n in his book _Myths and Marvels of Astronomy_.\n\n\n\n\nII. THE BEGINNINGS OF ASTRONOMY.\n\n\nThe sky appears to us like an arch, embracing all our lives, Dante\nsays.[5] From the dawn of intelligence man must have recognized his\ndependence upon the all-embracing heavens, especially the sun, without\nwhich life would be impossible. The consciousness expressed itself in\nmany ways: in adoration of the sky, the sun, moon, and hosts of heaven;\nin superstitious fear which regarded events on earth as directly\ncontrolled by the heavenly bodies; in careful watching and recording of\ntheir movements for useful purposes. Thus, long before astronomy became\nan exact science, and was studied simply for its own sake, patient\nobservers had laid the foundations, and were familiar with many of the\nmovements we have been describing.\n\n------------------------------------------------------------------------\n[5] Conv. IV., xxiii. 56, 57.\n------------------------------------------------------------------------\n\nThese are of great importance to primitive man. Sun, moon, and stars\nare invaluable as guides, especially at sea, and we know that the\nancient Greek mariners used to steer their ships by observations of the\nGreat Bear, while the Phoenicians preferred to use the Little Bear for\nthis purpose. But the strongest and most universal incentive to careful\nand prolonged study of the skies is our complete dependence upon them\nfor the measurement of time.\n\nIn the earliest period of their history, the Jews, the Greeks, and\nprobably every other nation, divided the day simply into morning,\nnoon, and evening, according as the sun was rising, or apparently\nstationary, or sinking, with regard to the horizon; and the passage\nof some bright stars indicated the time at night. But at a very early\nperiod the first of all astronomical instruments was invented, by which\nthe sun\u2019s varying height can be measured: hence the time of noon, the\ndates of equinoxes and solstices, and the length of the solar year\ncan be determined. The gnomon in its simplest form is a pole set up\nvertically on a smooth level surface, on which its shadow as cast by\nthe sun can be observed. The moment of shortest shadow marks the middle\nof the day, the shortest midday shadow marks the summer solstice,\nthe longest the winter solstice, the equinoxes falling between. The\ninstrument also indicates the points of the compass, for the sun is\nalways due south in northern latitudes at midday: hence the Latin word\n_meridies_ (French _midi_) means south as well as midday, and the\nMeridian in astronomy is a line which passes through the north and\nsouth points and the zenith, and is crossed by the sun at midday.\n\nThe gnomon was said to have been introduced into Greece by Anaximander\nabout 600 B.C., and the Babylonians claimed to be the inventors, but\nit was probably invented independently by several races. The Chinese\ncertainly observed the length of the shadow more than two thousand\nyears B.C., and the very interesting fact has recently come to light\nthat a tribe in a hitherto unexplored part of Borneo use such an\ninstrument, invented by themselves. They set up a post about 6 ft.\nhigh, and throw over the top a piece of string weighted at each end to\nshow when it is vertical; the length of the shadow cast by the post is\nmeasured with a notched stick. By this means they tell the time of\nday; and they also observe the sun (presumably with the gnomon) to know\nthe right season for planting their rice.[6]\n\n------------------------------------------------------------------------\n[6] Dr. C. Hose, in \u201cTravel and Exploration,\u201d for Feb. 1910, quoted in\n\u201cNature,\u201d Feb. 17, 1910.\n------------------------------------------------------------------------\n\nHowever rough the first gnomon may have been, its importance can\nscarcely be overrated, for it introduced measurement and calculation\ninto observation of the sun\u2019s movements, and it is the ancestor of our\nmodern sextants, transit telescopes, and other instruments of precision.\n\nIt was also the beginning of the sundial. The course followed by the\nmoving end of the shadow was traced on the ground, and divided into\nequal parts: hence arose the custom which the Greeks adopted from\nthe Babylonians of counting twelve hours in every day, from sunrise\nto sunset, and twelve hours in every night, from sunset to sunrise,\nregardless of the varying lengths of day and night at different\nseasons. This is known as the system of \u201ctemporary hours.\u201d If we used\nit in England, the twelve hours of a midsummer day would take twice as\nlong to pass as the twelve fleeting hours of a midsummer night; but in\nGreece the inequality is much less, and in the latitudes of Babylonia\nit is never striking. The skill and knowledge of the Greeks enabled\nthem, later on, to construct dials of different kinds, which marked\n\u201cequal hours,\u201d such as we use now; but the system of \u201ctemporary hours\u201d\ndid not altogether die out till after the invention of pendulum clocks\nin the 17th century of our era.\n\nClepsydras, or water-clocks, were also used in Egypt and Babylonia,\nand ancient Greece; and there is still a large one in Canton, where\na reservoir is placed in a tower, and the water falling, drop by\ndrop, into a receiver whose depth is marked in figures on the wall,\nindicates the passing of time just as sand does in running through an\nhour-glass. These clocks cannot have kept very good time, however, or\nthey would have been more used by the Babylonian and Greek astronomers\nwho took pains to ascertain the exact positions of the stars. Owing to\nthe diurnal revolution of the skies, the time at which any celestial\nbody rises or crosses the meridian after another is an index of their\ndistance apart, east and west on the sphere, and this is how it is\nreckoned by modern astronomers. But the ancients seem to have been\nnever able to trust their clepsydras sufficiently to use this method,\nand only referred to them for approximate time.\n\nThe gnomon, valuable as it is for marking the sun\u2019s daily course, and\nthe north and south part of his yearly motion, is a limited instrument.\nIt cannot show his westerly motion on the sphere, nor is it of any use\nfor the planets. To trace these motions, and the monthly journey of\nthe moon, the first step is to distinguish the stars, by grouping and\nnaming them, especially those which lie in the path of sun, moon, and\nplanets. The invention of some kind of zodiac is probably older even\nthan the invention of the gnomon, and also originated independently\namong different races. The germ of the idea may be found to-day among\nraces low in the scale of civilization. The Australian aborigines are\nfamiliar with that unique star-cluster which we call the Pleiades,\nand know that its appearances and disappearances are periodical and\ncoincide with the seasons. A Queensland tribe, for instance, has\na legend in which the stars figure as six sisters who have been\ntransported to the skies, and it is said that they sometimes appear\nbefore the sun in order to throw down icicles, an evident allusion\nto the fact that the Pleiades begin to appear just before sunrise in\nMay, the Australian winter. The natives of Tahiti divide their year\ninto \u201cMatarii i nia\u201d and \u201cMatarii i raro,\u201d which means Pleiades Above\nand Pleiades Below (_i.e._ the horizon at the beginning of night). Sir\nNorman Lockyer has shown that the mysterious alignments of stones found\nat Stonehenge, Carnac, and other places, may have been so arranged\nin order to show the direction, some of the sun at his rising on\ncertain dates, notably the morning of the summer solstice, and some\nof the Pleiades or other striking stars, whose rising just before the\nsun would enable ancient astronomers to fix the dates of important\nfestivals.\n\nSuch observations as these, of which many instances might be drawn from\nmany parts of the world, are first steps towards studying the whole\npath of the sun through the stars, and of forming a calendar with a\nname or number for every day in the year. Until the stars are known,\nand a calendar fixed, the motions of sun and moon cannot be learned\nin detail, the planets can scarcely be distinguished from the stars\nand from one another, and there are no settled dates from which to\ncalculate their periods.\n\nThe first zodiac of which we have written record is a lunar one of\n28 constellations, which is referred to in the \u201cCanon of the Emperor\nYaou,\u201d a Chinese emperor who began to reign in B.C. 2356. \u201cYaou\ncommanded He and Ho, in reverend accordance with their observation\nof the wide heavens, to calculate and delineate the movements and\nappearances of the sun, the moon, the stars, and the zodiacal spaces,\nand so to deliver respectfully the seasons to the people.\u201d That these\nastronomers studied \u201cthe movements and appearances\u201d of the sun by\nmeans of the gnomon as well as observations of the stars is plain from\nwhat follows, where directions are given for determining the solstices.\nOne astronomer was commanded by the Emperor to \u201creside at Nankeaou and\narrange the transformations of the summer, and respectfully to observe\nthe extreme limit of the shadow. The day, he said, is at its longest,\nand the star is _Ho_: you may thus exactly determine midsummer.\u201d _Ho_\n(= fire) is the fiery red Antares in Scorpio. The star of the winter\nsolstice, when \u201cthe day is at its shortest\u201d was Maou, which is the\nPleiades. Directions are also given for observing the spring and autumn\nequinoxes, when day and night are of medium length, and certain other\nstars are to be observed.[7]\n\n------------------------------------------------------------------------\n[7] Journal of the British Astronomical Association, June 24, 1909,\nreport of a lecture on Chinese astronomy by E. B. Knobel, F.R.A.S.\n------------------------------------------------------------------------\n\nThe Hindus had also a lunar Zodiac, but with only 27 constellations,\nand the Arabs had their 28 \u201cMansions of the Moon.\u201d These 27 or 28\nasterisms were evidently suggested by the moon\u2019s sidereal period of 27\u00bc\ndays. But her synodical period, _i.e._ her revolution with regard to\nthe sun, in which she runs through her phases, is much more convenient\nfor marking a period of time for general uses, and this month of about\n30 days has been almost universally adopted by primitive peoples, the\nfirst day being counted when the crescent new moon begins to be seen\nafter sunset. From this custom arose another, that of counting the\nbeginning of the day from sunset, but in various times and places other\nstarting-points have been chosen\u2014sunrise, midday, or midnight.\n\nTwelve of these synodical lunar months are nearly equal to one solar\nyear, and this doubtless suggested the solar zodiac of twelve\nconstellations, each constellation marking the portion of sky passed\nover by the sun in a month. The Chinese \u201cYellow Path of the Sun\u201d\ncontained twelve animals, the Mouse, Cow, Tiger, Rabbit, Dragon,\nSerpent, Horse, Ram, Ape, Hen, Dog, and Pig. These animals were widely\nadopted by other nations\u2014the Koreans and the Japanese, the Mongols of\nTibet, the Tartars, and the Turks.\n\nAnother zodiac, however, was destined to have an even wider popularity,\nspreading, in the course of centuries, from Greece to Arabia,\nPersia, India, and China, where it finally superseded the native\nconstellations; it crossed the Mediterranean into Africa, conquered the\nwhole of Europe, and is used to-day over the whole civilised world.\n\nThe names of these twelve zodiacal constellations are familiar to us\nall:\u2014\n\n _English Names. Latin Names._\n Ram Aries\n Bull Taurus\n Twins Gemini\n Crab Cancer\n Lion Leo\n Virgin Virgo\n Scales Libra\n Scorpion Scorpio\n Archer Sagittarius\n Capricorn Capricornus\n Water-Bearer Aquarius\n Fishes Pisces.\n\nStrange to say, we cannot tell with any certainty where, when, or by\nwhom, this ancient series of constellations was devised and named. The\nearliest full description which we possess is by a Greek poet of the\n4th century B.C., Aratus. A line from the prologue to his \u201cPhenomena\u201d\nwas quoted by St. Paul in his address to the Athenians on Mars\u2019 Hill.\n\n \u201cFrom Zeus we lead the strain, he whom mankind\n Ne\u2019er leave unhymned; of Zeus all public ways,\n All haunts of men are full, and full the sea\n And harbours; and of Zeus all stand in need.\n We are his offspring;[8] and he, mild to man,\n Gives favouring signs and rouses us to toil,\n Calling to mind life\u2019s wants; when clods are best\n For plough and mattock, when the time is ripe\n For planting vines and sowing seeds he tells.\n Since he himself hath fixed in heaven these signs,\n The stars dividing; and throughout the year\n Stars he provides to indicate to men\n The seasons\u2019 course, that all things duly grow.\u201d[9]\n\n------------------------------------------------------------------------\n[8] Acts, xvii. 28.\n\n[9] _The Phainomena of Aratos, done into English verse by Robert\nBrown_, lines 1-13.\n------------------------------------------------------------------------\n\nBut Aratus did not know who had invented the names of the star-groups\nwhich he describes. \u201cSome man of yore,\u201d he supposes,\n\n \u201cA nomenclature thought of and devised,\n And forms sufficient found. For men could not\n Or tell or learn the separate names of all,\n Since everywhere are many, size and tint\n Of multitudes the same, but all are drawn around.\n So thought he good to make the stellar groups,\n That each by other lying orderly,\n They might display their forms. And thus the stars\n At once took names and rise familiar now.\u201d[10]\n\n------------------------------------------------------------------------\n[10] _Ibid._, 373-382.\n------------------------------------------------------------------------\n\nIt is, to say the least, exceedingly doubtful, whether the naming of\nstar-groups was so promptly carried out by one individual, especially\nas Aratus\u2019 poem includes, besides the twelve zodiacal constellations,\nthirty-six others, which contain all the bright stars of the sky\nexcept those too far south to be seen in the temperate regions of\nour northern hemisphere. The spaces thus left blank were afterwards\nfilled up, chiefly in the 17th and 18th centuries of our era, and the\nregions round the South Pole are now crowded with a mixture of birds\nand scientific instruments; but the names and the figures of the\ntraditional forty-eight constellations still find undisputed places on\nour globes and star-maps.\n\nSome of these figures are very strange and suggestive. We have a maiden\nwith wings, a centaur shooting arrows, a flying horse, a water-snake\nwith a crow and a cup on its back, a charioteer with a goat on his\nshoulder, a man strangling a serpent, another pouring water into the\nmouth of a fish, and a strange beast like a goat with a fish\u2019s tail.\nAll had their meaning, doubtless, to their originators, but to us\nthey are cryptic characters, hard to decipher. Among the zodiacal\nconstellations only one is obvious, Libra the Scales, the sign in which\nthe sun is when days and nights are perfectly balanced in length; but\nthis is comparatively recent, for Aratus and his contemporaries give\nin its place the Claws of the Scorpion, the latter being an enormous\nmonster extending over the space of two asterisms. The figures may have\nbeen religious symbols, or an illustration of some myth concerning\nthe sun\u2019s yearly course, or each of the twelve may have indicated the\nweather or the occupation suitable to the month it represented. The\near of corn in the hand of the Virgin, and the juxtaposition of three\nwatery figures in Capricornus, Aquarius, and Pisces, suggest the latter\nexplanation. Many different ideas probably played a part in the origin\nof these mysterious constellation-forms. The Greeks, and after them the\nRomans, when adopting the old constellations, sometimes adopted also\nthe old myths which still clung about them; sometimes they ascribed\nlegends to them from their own mythology. Thus, the kneeling figure\nwith his foot upon a dragon, became and remains the hero Hercules,\nalthough Aratus only describes him as a man toiling at some unknown\ntask, and says he is called simply the Kneeler. Successive generations\nof astronomers altered some of the figures, but probably only to a\nslight extent.[11]\n\n------------------------------------------------------------------------\n[11] Ptolemy says he made a few changes, as his predecessors had done.\n(Delambre, _Histoire de l\u2019Astronomie Ancienne_, ii. 261).\n------------------------------------------------------------------------\n\nThe poem of Aratus enjoyed an immense popularity in classical times\nand throughout the Middle Ages, and no doubt helped to stereotype the\nforms whose origin was already forgotten when he wrote. He was not\nan astronomer, however, and the poem is only a popular paraphrase of\na lost work by Eudoxus. This Greek astronomer had lived a hundred\nyears earlier, and it is thought that he himself copied from an older\nsource. The attempt to discover this source has been the object of\nmany ingenious conjectures, and much research among ancient monuments\nand writings. Some of the old constellations are met with in Isaiah\nand Job, in Homer, on tablets found at Nineveh, and an immense\nantiquity is sometimes claimed for them. Dupuis, writing at the end of\nthe eighteenth century, thought he had conclusively proved that the\nfigures of the zodiac were designed in Egypt 15,000 years ago![12] Miss\nPlunkett, in her \u201cAncient Calendars and Constellations\u201d assigns them to\nthe seventh millenium before Christ.\n\n------------------------------------------------------------------------\n[12] _Origine de tous les cultes, ou Religion universelle_, by C. F.\nDupuis.\n------------------------------------------------------------------------\n\n[Illustration: THE OLD CONSTELLATION FIGURES.\n\nSOUTHERN HEMISPHERE.]\n\n[Illustration: NORTHERN HEMISPHERE.\n\nTHE OLD CONSTELLATION FIGURES ACCORDING TO ARATUS.\n\n_In Ptolemy\u2019s Catalogue Equuleus and Corona Australis are added to\nthese._\n\n_(From Peck\u2019s \u201cConstellations and How to Find Them.\u201d)_]\n\nAn ingenious theory, suggested independently by Schwartz and Proctor,\nand developed by Mr. E. W. Maunder,[13] is founded on an examination\nof the space round the South Pole which was left blank by the ancient\nconstellation designers. From its extent, Proctor concluded that they\ncannot have seen further south than about 40\u00b0 from the South Pole, and\ntherefore that they must have lived in a latitude of about 40\u00b0 north of\nthe equator (say, central Asia or Asia Minor); from the position of its\ncentre, which must have been the Pole, he concluded that the date was\nabout B.C. 2200. For the centre of the circular patch seems to lie near\nthe star _Delta Hydri_, which was the South Pole star at that time.\n(This movement of the Pole among the stars, due to \u201cprecession,\u201d will\nbe explained later). This date does not differ much from that found\nby Robert Brown, from the position of the celestial equator among the\nstars, as described by Aratus; he says B.C. 2084.[14] Schwartz gave\nB.C. 1400; Mr. Maunder, from additional considerations of the positions\nof various constellation figures, says that they must all have been\noriginally designed about B.C. 2800.\n\n------------------------------------------------------------------------\n[13] _Journal of the British Astronomical Association_, \u201cThe Oldest\nAstronomy,\u201d July 1898, June 1899, April 1904, May 1909; _The\nObservatory_, December 1898; _Knowledge_, October 1904; and elsewhere.\n\n[14] _The Phainomena of Aratos_, by Robert Brown. See also his\n_Eridanus, River and Constellation_; _Primitive Constellations_, and\nother works.\n------------------------------------------------------------------------\n\nUnfortunately the descriptions of Aratus are neither very\nprecise nor consistent with one another, and he is our oldest and\nour main authority for the forms and positions of the ancient\nconstellations.[15] It may, however, be taken as practically certain\nthat they had been designed many centuries before he wrote, and that\nthe Greeks received them from the Babylonians. Orion and the Pleiades,\nthe Great Bear and Arcturus, and perhaps many others, were familiarly\nknown in the Levant as early as the tenth century before Christ; and we\nfind traces of our zodiac, or its beginnings, in Babylonia at least as\nearly as the eleventh. It is always to Egyptians and Babylonians that\nthe Greeks referred as their predecessors and teachers in astronomy,\nbut the native constellations of Egypt seem to have been different, and\nso far as we know at present the Babylonians began earlier and made\ngreater progress in star-lore than any other nation before Greece.\nThe latest results of expert investigation of astronomical tablets\ndiscovered in the ancient clay libraries of Babylonia and Assyria,\ntend to show that astronomy was of native growth there, and developed\nvery slowly.[16] Star-worship and the need for a calendar led their\ninhabitants to observe the skies thousands of years ago; but their\nearly work was naturally vague and rude.\n\n------------------------------------------------------------------------\n[15] We are not sure what limits Aratus intended to set in the south\nto Centaur and Argo, and notably to the River Eridanus, which used to\nflow beneath the Sea-Monster (Cetus), joining the Water poured out\nby Aquarius. It changed its bed (like the Euphrates, of which it is\nperhaps the heavenly counterpart), and now has left the Sea-Monster\nhigh and dry, while on its ancient banks a chemist\u2019s furnace and a\nsculptor\u2019s workshop have been set up.\n\nThe Celestial Equator of Aratus fails to agree with the Equator of B.C.\n2084, not only in passing over the head of Orion, instead of through\nhis belt, as Brown himself points out, but also in running through\nthe eye of the Bull, instead of his \u201ccrouching legs alone,\u201d so this\npart is altogether too far north. The Equator some 1200 years later\nagreed better here, and equally well elsewhere, except in the opposite\npart of the sky where it was then too northerly for Aratus, leaving\nCorvus to the south of the line. Much the same may be said about the\ntropical circles. Either Aratus was careless, or the globe from which\nhe took his descriptions was incorrect: in any case, there results an\nuncertainty of many centuries and many degrees in date and latitude.\n\n[16] Epping and Strassmeier, _Astronomisches aus Babylon_, Kugler\u2019s\n_Babylonische Mondrechnung_, and _Babylonische Sternkunde_.\nSchiaparelli\u2019s two monographs on Babylonian Astronomy, from which much\nof the information here given is derived, are chiefly based on these\nworks.\n------------------------------------------------------------------------\n\nThis star-worship and star-study seems to have been learned by the\nSemitic Babylonians, and their descendants and rivals the Assyrians,\nfrom a race with whom they met and mingled in the grey dawn of history,\nbut whose existence was unknown to us before the middle of last\ncentury.\n\n[Illustration: The Moon-God of Ur. [_To face p. 36._\n\nFrom a cylinder-seal in the British Museum, dated about B.C. 2400.\n\nReproduced by permission of the Trustees.]\n\n[Illustration: Fig. 6. The triple star-sign of the Babylonians.]\n\nThis people, who belonged to a totally distinct family of nations, and\nare known to us now as Sumerians, had settled near the mouth of the\nPersian Gulf, when it ran further inland than it does now, and more\nthan five thousand years ago used a kind of writing on soft stones\n(later, on bricks) which had obviously arisen from some form of picture\nwriting, and ultimately developed into cuneiform. Their reverence\nfor the heavenly bodies is shown by the fact that the familiar star\nsign, [star sign] which appears on very early Sumerian inscriptions,\ndenotes their word for god or lord, and on the monuments of Babylonia\nand Assyria we meet constantly the triple sign This, we learn from\nthe inscriptions, stood for three great deities, the Moon-god, the\nSun-god, and the goddess of the planet Venus. Our illustration shows an\ninscription in early Babylonian script, and a scene which represents\nthe vassal of a king of Ur (Abraham\u2019s \u201cUr of the Chaldees\u201d) being\nled into the presence of the Moon-god.[17] It is believed to date\nfrom about B.C. 2400. The Babylonians were an intensely superstitious\npeople, and a large part of their omens were drawn from observations of\nthe skies. Every city from this period onward had its ziggurat or great\ntower formed of several superimposed cubes, usually seven in number,\ndiminishing in size and probably crowned by the shrine of the local\ndeity. It is not certain what purposes were served by these towers,\nbut the successive platforms may well have been the observatories from\nwhich the Babylonian priests, gazing through the clear air and over\nthe level plains, watched, year after year, and century after century,\neclipses of sun and moon, risings and settings of stars and planets,\nand all the changing pageant of the skies, which to them were eloquent\nof peace and prosperity, or of war and misfortunes in their land.\n\n------------------------------------------------------------------------\n[17] King, History of Sumer and Akkad, p. 246.\n------------------------------------------------------------------------\n\nAlthough this illusory art chiefly occupied the early Babylonian\nastronomers, they made some observations of real value, and gradually\nacquired true knowledge concerning the movements of the heavenly bodies.\n\nTablets a few centuries older than the Chinese _Canon of Yaou_\ncontaining lists of the Sumerian names of twelve months, show that\nthis people had established a luni-solar year. Fortunately for the\nprogress of astronomy the year does not contain an exact number of\nmonths, or even of days: at the end of twelve lunar months, a few\nmore days and hours must elapse before the sun has returned to his\noriginal place among the stars, and before the round of the seasons is\ncompleted. Therefore the first rough approximation had to be constantly\ncorrected if calendar festivals were to recur at the same seasons; and\nthus the priests, who in early times were usually the calendar makers\nand keepers, became gradually better and better acquainted with the\nmovements of sun and moon, and the appearance of star-groups. It is\ninteresting to compare the different ways in which various races have\nsolved the problem of calendar-formation.\n\nThe Chinese had a year of twelve months, and added an intercalary month\noccasionally, in such a way that the average length of the year was\nbrought up to 366 days. The written character for \u201cintercalary\u201d in\nboth Chinese and Japanese is a compound of the characters for \u201cgate\u201d\nand \u201cEmperor,\u201d because in ancient days the Emperor used to perform the\nceremonies proper to each of the twelve months in the special room of\nhis palace dedicated to that month, but in the intercalary month he\nperformed them in the doorway of the palace.\n\nThe Egyptians and the Arabs seem to have given up the attempt to\nharmonize the two periods, though both of these nations reckoned twelve\nmonths in their years. The Egyptians counted thirty days to each month,\nand added five days more at the end of the twelfth, so that the months\ncan have had no connection with the moon: the year had, in fact, been\ncalculated from the position of the sun among the stars, beginning\nwith the morning on which Sirius rose just before it. This \u201cheliacal\nrising\u201d of Sirius heralded the great event of their year, the overflow\nof the Nile. The Arab year, on the contrary, was purely lunar, for\nit consisted of twelve months which were alternately of twenty-nine\nand thirty days: they therefore corresponded pretty closely with the\nmoon\u2019s phases, but had no connection with the sun or the seasons. The\nMahomedans still use this lunar year.\n\nThe new moon festivals of the Hebrews prove that the moon was important\nto their calendar, but the three chief feasts of First-fruits, of\nIngathering, and of the Passover, were so closely connected with\nthe seasons that their year must have been luni-solar. It consisted\nof twelve months, one of which was sometimes doubled, but how they\ndecided when this was necessary is nowhere described in the Old\nTestament. Some think, that as an offering of first-fruits was to be\nmade on a certain day of a certain month, the month preceding it was\ndoubled in every year in which it was evident that the crops would\nnot be far enough advanced for the first-fruits to be gathered so\nsoon: in this way no direct observations had to be made of the sun\u2019s\nmovements, but the year was accommodated to them by observations of the\nseasons.[18]\n\n------------------------------------------------------------------------\n[18] Schiaparelli, _L\u2019 Astronomia nell\u2019 Antico Testamento_, chap. vii.;\nWellhausen, _History of Israel_, chap. iii.\n------------------------------------------------------------------------\n\nThe Babylonian calendar is the most interesting of all, for it was the\nmost intimately connected with star-observation. At first an extra\nmonth seems to have been added to the usual twelve, in an irregular\nway, whenever found necessary, judging by a tablet of the great king\nHammurabi, who united all the cities of southern Babylonia under one\nrule, and gave them the famous Code of Laws, communicated to him by the\nSun-god. The tablet runs as follows:\u2014\n\n \u201cThus saith Hammurabi: the year having gone wrong,\n let the coming month be registered by the name of\n Ululu the second. And instead of the payment of\n taxes being made on the 25th day of Tasritsu, let\n it be made on the 25th day of Ululu the second.\u201d\n\nHammurabi reigned about B.C. 2200. A thousand years or more after\nthis, we find that royal decrees for correcting the calendar were\nnever necessary, for the astronomers had invented more than one system\nfor keeping the year right. One of these was to observe, like the\nEgyptians, the heliacal rising of certain stars. The little group of\nthree stars in the head of the Ram, which we call Alpha, Beta, and\nGamma Arietis, was found very convenient for this purpose. When it\nrose just before the sun in the month Nisan, the observers knew that\nall the twelve months would fall in their right seasons, but when it\nremained invisible (hidden in the morning twilight) until the following\nmonth, the calendar was evidently running ahead of the sun, and that\nyear was lengthened by adding a thirteenth month. This is the meaning\nof the directions given on a tablet now in the British Museum:\u2014\n\n \u201cThe asterism Dilgan[19] rises heliacally in the\n month of Nisan. Whenever this asterism remains\n invisible, let its month be forgotten,\u201d\n\n------------------------------------------------------------------------\n[19] Sayce and Bosanquet identify Dilgan with Capella, not with\npart of Aries, and consider that a date of about B.C. 2000 is\nindicated\u2014(_Monthly Notices_ xxxix, 454). But in any case the method of\ncalendar formation is the same.\n------------------------------------------------------------------------\n\nthat is, let it be taken over again, as if it had not already been\ncounted. Similar directions are given for some other asterisms and\ntheir corresponding months. But a second method, which was peculiar,\nso far as we know, to the Babylonians, was that of using the moon as\na pointer to indicate the place of the sun. Whereas the sun\u2019s place\namong the stars can only be inferred, the moon\u2019s can be plainly seen,\nand her phase indicates her distance from the sun at any time. A tablet\nof unknown date, belonging to the last millenium before our era, or a\nlittle earlier, gives the following directions:\u2014\n\n \u201cWhen on the first day of the month of Nisan the\n asterism Mulmul (the Pleiades)[20] and the Moon are\n seen together, the year will be normal. When on the\n third day of Nisan the asterism Mulmul and the Moon\n are together, the year will be full\u201d (that is, will\n contain 13 months).\n\n------------------------------------------------------------------------\n[20] Sayce and Bosanquet understand Capella here also.\n------------------------------------------------------------------------\n\nEach Babylonian month began when the new moon was first visible after\nsunset; if at this moment she was seen with the Pleiades, it is clear\nthat the sun, which had just set, was not far west of the cluster; if\nhowever, it was not till the moon was three days old that she was seen\nwith the Pleiades, she would then be some distance above the horizon at\nsunset: consequently the sun was some distance west of the Pleiades.\nIn this case he would also be west of Dilgan, the Ram\u2019s Head, so those\nstars would rise after him in the morning, and be hidden in his light:\ntherefore, both the morning and the evening observation combined to\nshow that his course was not completed, and that the year must be\nlengthened by the addition of an extra month.\n\n[Illustration: Fig. 7. First Year, normal. New Moon near the Pleiades\nafter sunset on the 1st of Nisan.\n\n The position of the young moon (which always\n closely follows the sun) showed that the sun was\n not far west of the Pleiades; and about 1000\n B.C. this proved that it was near the\n vernal equinox. The sun\u2019s position is given for\n about half an hour after sunset, when the Pleiades\n would first be visible.]\n\n[Illustration: Fig. 8. Second Year, normal. New Moon not far from\nPleiades on the 1st of Nisan.\n\n It takes the sun 365 days to return to the same\n place among the stars, but the Babylonian year of\n 12 lunar months (each of 29 or 30 days) was 11 days\n short of this: therefore on the 1st of Nisan in\n this year the sun had still 11 days\u2019 march before\n him ere he returned to the position of Fig. 7. This\n is equal to about 11\u00b0, so the young moon was also\n about 11\u00b0 west of her former position, near the\n Pleiades. But as she travels about 13\u00b0 eastward\n every day, she would be near the Pleiades on the\n following evening, the 2nd of Nisan, so this year\n was also counted normal.]\n\n[Illustration: Fig. 9. Third Year, \u201cfull.\u201d New Moon distant from the\nPleiades on the 1st of Nisan.\n\n The sun is now 2\u00a0\u00d7\u00a011\u00a0=\u00a022 days\u2019 march, or about\n 22\u00b0, short of his first position, and the young\n moon consequently about 22\u00b0 west of the Pleiades,\n so she will not come up with them until the 3rd\n Nisan, after travelling 2\u00a0\u00d7\u00a013\u00a0=\u00a026\u00b0. The year was\n therefore \u201cfull,\u201d that is an extra month of 29 days\n was added, which is more than the 22 days needed to\n enable the sun to reach his first position by the\n 1st of Nisan in the fourth year.\n\n It appears, therefore, that the extra month must\n have been added once in three or four years.]\n\nSeveral lists of stars and star-groups indicating the months in this\nway have been found, the early lists containing only a few, the later\ntwelve. If our zodiac originated with the Babylonians, there is little\ndoubt the idea took its rise from these monthly stars, but it is not\npossible, with our present knowledge, to say when these old astronomers\nfirst linked the isolated stars into a continuous series of twelve\nstar-groups and connected the idea of the month with the invisible\ngroup among which the sun was known to be shining, instead of with the\nstars seen east or west of him, or in conjunction with the crescent\nmoon.[21]\n\n------------------------------------------------------------------------\n[21] If Taurus was originally considered the first constellation of\nthe zodiac, instead of Aries, of which there are some indications, the\nchange may well be explained by this change of method. It does not\nnecessarily imply that the equinox was in Taurus when our zodiac was\ninvented. It was near \u03c9 Arietis in B.C. 1000.\n------------------------------------------------------------------------\n\n[Illustration: Fig. 10. The Scorpion.\n\nFrom a boundary stone (now in the British Museum) set up in the reign\nof Nebuchadnezzar I., king of Babylonia, about 1100 B.C.]\n\n[Illustration: Fig. 11. The Goat, with Fishes\u2019 Scales.\n\nFrom a Babylonian boundary stone.]\n\nA Scorpion with immense claws, and a Goat with fishes\u2019 scales appear\nseveral times on monuments at least as old as 1000 B.C. and it is very\nprobable, although this fact alone would not prove it, that they were\nthen used as constellation figures. It has been definitely proved from\ninscriptions that before 600 B.C. the name of Scorpion was applied to\nsome stars of our present Scorpion, that there was a Lion corresponding\nwith ours, and the principal star in that asterism, which was called\n\u201cThe King\u201d by Greeks and Romans (Basiliskos and Regulus), bore a name\nwith the same meaning in Babylonia; the Celestial Bull seems to have\nbeen the group of the Hyades, and the Great Twins were the two stars\nCastor and Pollux. The last two identifications seem to show how the\nsingle stars or small groups of the monthly lists were expanded into\nthe large zodiacal constellations, for the Hyades cluster is in our\npresent Bull, and Castor and Pollux are in our Twins.\n\nUnder the great Assyrian kings who in the 8th and 7th centuries\nB.C. made Nineveh the capital of their empire, Babylonian astronomy\nflourished exceedingly, and it made much progress through all the\npolitical changes which followed, until the beginning of our era.\nThe motions, phases, and eclipses of the moon were carefully studied\nand could be accurately predicted, the positions of many stars were\ndetermined; the zodiac was divided into twelve equal spaces, which\nafterwards became 36 by sub-division (the constellations being too\nunequal in size for convenience); and finally the whole circle was\nmarked out in 360 degrees. The movements of all the naked eye planets\nwere well understood, their positions being constantly compared with\nthose of a number of standard stars, mostly in the zodiac; and after\nwatching and recording these for a number of years the astronomers\nwere able to calculate where each planet would be found at future\ndates. Tables have been found on clay tablets of the 2nd century B.C.\npredicting the heliacal risings and settings, and the stations and\nretrogressions etc., with considerable accuracy.\n\nWhen astronomy had reached this stage of accurate prediction, it was\nno longer in its infancy, but was fairly on its way to become a true\nscience.[22]\n\n------------------------------------------------------------------------\n[22] A Babylonian treatise on astronomy recently published by the\ntrustees of the British Museum supports Kugler\u2019s view that truly\nscientific methods were not adopted before the sixth century B.C. This\ntreatise formed the subject of a lecture given by Mr L. W. King before\nthe Society of Biblical Arch\u00e6ology on Feb. 19, 1913.\n------------------------------------------------------------------------\n\nNevertheless, the astronomy of the Babylonians, advanced as it was,\nseems never to have progressed beyond the empirical stage. With them,\nthere seems to have been no desire to group the facts they so patiently\nand skilfully collected into a system, and form a theory to explain\nthem.\n\nAnd this must be said of other ancient nations also. The Egyptians made\ncareful observations, especially of the heliacal risings of different\nstars, by means of which they determined the length of the year, as we\nhave already mentioned, and oriented their temples and pyramids. They\nworshipped the sun in all his aspects, and their astrology so much\nresembles the Babylonian that it is believed to have been derived from\nit. The Babylonians seem to have been more interested in the planets\nthan any other nation of antiquity, but they were known also in other\ncountries. The Chinese recorded comets, and all races were greatly\ninterested in eclipses, which they were able to predict with some\naccuracy, having discovered that they occur in cycles. Yet we find no\nmore rational attempt to explain these phenomena than the Hindu legend\nof a great dragon that attacks the sun, or the Egyptian story of a sow\nthat swallows the moon; and their cosmogonies can only be regarded as\npoetical descriptions or survivals of early childlike notions of the\nuniverse.\n\nThe Hindu world resting on the back of an elephant, and that on a\ntortoise, is no doubt but an allegory. The Egyptians pictured the\nearth as a great parallelogram, long from north to south but narrow\nfrom east to west, like their own land, with the sky over it, upheld\nby huge pillars or lofty mountains. The stars were set in this domed\nlid of the world, but sun, moon, and planets were floating each in its\nown boat on a great celestial river which ran just below the summits\nof the mountains, and whose course was hidden towards the north. The\nbark of the sun came nearer to Egypt in the summer, because at that\ntime the celestial river overflowed its usual bank, like the Nile. The\nred _Doshiri_ was said to sail backwards, referring no doubt to the\nretrograde movement of Mars.\n\nIn Eridu, one of the oldest cities of southern Babylonia, on the\nPersian Gulf, the great abyss of the ocean was looked upon as the\norigin of all things, and it was believed that it encircled the\nearth like a great river. Later on, we find the world described as a\ngreat mountain, resting on the watery deep, and under the mountain\nis the abode of the dead. It is entered from the west, which surely\nwas suggested by the setting of the heavenly bodies in the west. The\nvaulted sky above the earth has divisions: the rim of the lowest part\nrests upon the supporting watery deep; above it are the upper waters\n(the source of rain); and above this again is the dwelling-place of the\ncelestials. The sun issues forth each morning from a door in the upper\nheaven, or from the mount of sunrise, and enters another heavenly door,\nor the sunset mountain, at night.\n\nThe similarity to these Babylonian ideas of the Hebrew \u201cfirmament,\u201d\nthe \u201cwaters above the firmament,\u201d and the \u201cof the great deep,\u201d in the\nbook of Genesis,[23] and Ezekiel\u2019s \u201cSheol\u201d in \u201cthe nether parts of the\nearth,\u201d[24] has often been noted.\n\n------------------------------------------------------------------------\n[23] Gen. i. 6, 7; vii. 11.\n\n[24] Ezek. xxxii. 18, 24.\n------------------------------------------------------------------------\n\n[Illustration: The Boat of the Sun travelling over the sky. [_To face\np. 46._\n\nFrom an ancient Egyptian papyrus.\n\n The recumbent figure covered with leaves symbolizes\n the earth; the figure leaning over Earth, covered\n with stars, is the sky; the boat of the rising sun\n and of the setting sun floats over it. The central\n figure represents Maon, the Divine Intelligence\n which preserves the order of the universe.\n\n(_Reproduced from Flammarion\u2019s \u2018Astronomical Myths,\u2019 by permission of\nMessrs. Macmillan & Co._)]\n\nTo sum up:\u2014\n\nIf we include as astronomy any observation of the heavenly bodies which\nleads to a recognition of order and periodicity in their movements\nand a power of forecasting their positions, then every race and age\nhas had its astronomers, rough though their methods may be at first.\nWith growing civilization more refined methods are used; the gnomon is\ninvented for studying the movements of the sun; the changing positions\nof moon and planets are noted by means of certain stars; finally, all\nthe visible stars are grouped into constellations, and it is recognized\nthat a great band of star-groups crosses the sky, which forms the\npathway alike of sun, moon, and planets; the length of the month and of\nthe year are determined more or less accurately, and when an unvarying\ncalendar has been formed, the celestial cycles can be better recorded\nand studied. But in all this there is as yet no scientific motive\nproperly so called, no curiosity regarding the phenomena for the simple\npleasure of knowing and understanding them, no attempt to group them\ninto a system or to explain their underlying causes. The primitive idea\nthat the heavenly bodies exist for the convenience of earth-dwellers\nis illustrated by the Egyptian hieroglyph for night, [glyph] which\nconsists of the sign for sky [glyph] combined with a star suspended\nlike a lamp; the other idea that they are mysterious divinities is\nshown by the Babylonian star-sign for a god or king, [glyph]. The\nancients found that the stars were of great use, especially for\nmeasuring periods of time; they recognised also in them a marvellous\norder and regularity, of which they dreamed that they found an echo on\nearth, and endeavoured to divine the future by watching the skies. Can\nwe doubt that they were also attracted by the beauty that calls all men\nthrough all ages to lift their eyes and look upward?\n\n\n HYMN TO THE SETTING SUN.\n\n _Sung by the Priests of Babylon._\n\n Sun-god, in the midst of heaven,\n At thy setting\n May the latch of the glorious heavens\n Speak thee peace.\n May heaven\u2019s door to thee be gracious,\n May the Director, thy beloved messenger, direct thee.\n\n Lord of E-bara, may the road of thy path be prosperous,\n Sun-god, cause thy highway to prosper,\n Going the everlasting road to thy rest.\n Sun-god, thou art he who is judge of the land,\n Causing her decisions to be prosperous.\n\n From a lecture by T. G. PINCHES.\n (_Nature_, Dec. 31, 1891).\n\n\n\n\n_III. GREEK ASTRONOMY._\n\nFIRST PERIOD. B.C. 900 TO B.C. 350.\n\n\n \u201cGreat men! elevated above the common standard\n of human nature by discovering the laws which\n celestial occurrences obey, and by freeing\n the wretched mind of man from the fears which\n eclipses inspired! Hail to you and to your genius,\n interpreters of heaven, worthy recipients of the\n laws of the universe, authors of the principles\n which connect gods and men!\u201d\n\n PLINY\n (_Apostrophe to Thales and Hipparchus._)\n\n\n1. HOMERIC GREECE.\n\nTo turn from the astronomy of Egypt and Assyria to the astronomy of\nthe Greeks is like coming to a sudden bend in a river which has flowed\nthrough level country for many miles in a slow majestic course, and\nfinding beyond the bend a series of rapids and waterfalls. Instead of\npatient age-long accumulation of observations, instead of a mystical\nadoration of stars, supposed to be beyond man\u2019s power to understand,\nwe find that the Greek\u2019s first instinct is to inquire into the meaning\nand the origin of what he saw, even before he had taken time to\ninvestigate. Behind the varied splendours of earth and skies which\nfascinated his bodily eyes, his intellect divined laws and forces which\nheld the whole together in a wonderful harmony. Then, as fresh facts,\nor a fresh point of view, thrust itself upon him, a new explanation\nmust be attempted, and thus many complete systems of the universe were\nevolved. Not the name only, the idea of Cosmos was Greek.\n\n[Sidenote: Homer _c._ 900 B.C.]\n\n[Sidenote: Hesiod _c._ 800 B.C.]\n\nThe first ideas of astronomy among the Greeks were as primitive as\nthose of any other race in its early stages. They evidently had no\nconception of the sky as a sphere, or of the revolution of the stars\nas a whole, round fixed poles, though they watched the motions of\ncertain bright star-groups, and called them by the names that we use\nnow (however these names may have reached them), as we see in Homer\nand Hesiod. Ulysses, guiding his raft cunningly by night, keeps on his\nleft the Bear, also called the Wain, which turns round in her place and\nkeeps watch on Orion, and never bathes in ocean; he watches also the\nPleiades and the \u201cslow-setting Ploughman\u201d (Bo\u00f6tes)\u2014an apt description,\nas anyone may see who watches Arcturus, the brightest star of Bo\u00f6tes,\nwhen low on the western horizon. Being a northern star, its motion\nseems very slow, and makes so small an angle with the horizon that for\na long time Arcturus glides above it before finally dropping below;\nwhereas the Pleiades, or any other stars near the equator, move very\nquickly and almost at right angles to the horizon, and so drop below it\nquite suddenly. It is Ulysses also who warns his companion, when they\nare setting out to spy upon the Trojan camp, that two watches of the\nnight are already past, \u201cfor the stars have gone forward.\u201d The stars\nalso announced the seasons, for Hesiod says that the time of harvest is\nindicated by the heliacal rising of the Pleiades, and when Orion with\nSirius stands in mid-heaven, and Arcturus rises in morning twilight, it\nis time for the vintage.\n\nHomer and Hesiod both mention Venus, as a morning star \u201cthe brightest\nof all the stars, which comes to herald the light of dawn,\u201d and also as\nan evening star, apparently without recognizing that it was the same\nstar; as they do not mention any other planet we do not know if the\nothers were known to the ancient Greeks.\n\nThe first appearance of the new moon\u2019s slender crescent was watched for\nfrom hill-tops, and celebrated by sacrifices, and this\u2014as with other\nancient nations\u2014fixed the first day of their month.\n\n[Sidenote: Mimnermus _c._ 580 B.C.]\n\nDay seems to have been divided into three parts, morning, midday, and\nevening, according as the sun was rising, or nearly stationary, or\nsinking. The sun was thought to rest upon and slide over the solid dome\nof the sky, otherwise perhaps it would have fallen to the ground; and\nat night it was supposed to go behind Mount Atlas, and then to travel\nbehind high northern mountains to its rising place in the east. This\nprimitive explanation of its movements is so poetically described by\nan early poet, Mimnermus, that I cannot resist a quotation, though the\nlines can hardly be regarded as an astronomical fragment. They may be\nfreely rendered thus:\u2014\n\n Endlessly toiling Helios speeds.\n No rest for him or for his steeds\n When Dawn has climbed the height.\n Soon as he lays his weary head\n Upon the golden wing\u00e8d bed\n Made by Hephaestos\u2019 might,\n It bears him sleeping o\u2019er the seas,\n Far from the fair Hesperides,\n Through realms of darkest night;\n Till in the Ethiopian land\n He sees his horses ready stand;\n And when the child of light,\n The rosy-fingered, early-born,\n Has ushered in another morn,\n He mounts his chariot bright.\n\nThe earth, as pictured on the shield of Achilles, was flat and round,\njust as it appears from a height, and of course Greece was the centre,\njust as Egypt was the centre of the Egyptian, and Babylon the centre\nof the Babylonian cosmogonies. It was a small earth: a few countries\nlay round the Middle Sea, and further to the south was the land of the\nEthiopians where the Sun passes overhead and burns the inhabitants\nblack; there was another sea to the north, over which the Argonauts\nsailed, and in the extreme east was the Lake of the Sun, out of which\nhe rose every morning. This was a great gulf of the River Oceanus which\nencircled the whole earth. Its sources were in the furthest west, just\nbeyond the Pillars of Hercules, and thence it flowed north, east, and\nsouth, finally returning into itself. A branch from near the source,\ncalled the Styx, flowed down into the underground world of Hades, the\nabode of the dead, and beneath this again was Tartarus, where were\nimprisoned the Titans who had fought against Jove.\n\nAbove the flat earth the blue dome of heaven was spread like a tent,\nand across it travelled\n\n \u201cThe never-wearied Sun, the Moon exactly round,\n And all those stars with which the ample brows of\n heaven are crowned.\u201d\n\nWhat a compact little universe, and how important a part of it was man!\nBut as thought developed, the universe expanded.\n\n\n2. THALES AND ANAXIMANDER.\n\n[Sidenote: B.C. 585.]\n\n[Sidenote: Thales _c._ 600 B.C.]\n\nIn the sixth year of the war of the Lydians against Cyaxares, king of\nthe Medes, just when a battle was about to begin, day was suddenly\nchanged into night by an eclipse of the sun, and Herodotus adds: Thales\nhad told the Ionians of this before, and in what year it would happen.\nThis does not necessarily imply any accurate understanding of eclipses\non the part of the Ionian philosopher. He had visited Egypt, and may\nhave learned from the priest-astronomers there that eclipses recur in\ncycles and so can be predicted. But Thales was not content with cycles.\nHe wanted to know, not only that eclipses would happen at such and such\ntimes, but _how_ they happened. Perhaps from reports of Babylonian\nobservations, perhaps from questions put to Egyptian astronomers, he\nlearned that solar eclipses only happen when the moon is new and in\nthe ecliptic, that is, in the same part of the sky as the sun, and\nthat the black body then seen on the sun has always a rounded edge.\nThese no doubt were the arguments on which he founded his assertion\nthat solar eclipses are caused by the moon passing in front of the sun;\nand he further added that this shows the moon to be of an \u201cearthy\u201d\nnature, that is, not made of fire or any substance either luminous\nor transparent, but of opaque matter, probably having weight and\nsubstance, and not altogether unlike what we know on earth. He is said\nto have stated also that the moon receives her light from the sun,\na conclusion which would follow from a little attention and thought\nbestowed on her phases.\n\nBesides his speculations regarding the moon, Thales took pains to note\nthe sun\u2019s movements as accurately as possible, by means of gnomons,\nwith a view to discover the exact length of the solar year, and it was\nhe who advised the Greeks to adopt the Phoenician method of directing\ntheir course at sea by the Little Bear instead of the Great Bear, which\nappears to have been the constellation used in Homeric times.\n\nThales imagined that Ocean did not merely encircle Earth, but that the\nwhole Earth, which was a thin flat disc, floated upon the Ocean.\n\nThis zealous observer must have had something of the absent-mindedness\nof his great successor, Newton; for it is told of him that while\nstar-gazing he fell into a well!\n\n[Sidenote: B.C. 611-545. Anaximander]\n\nIt is evident that the moon\u2019s passing in front of the sun implies a\nlesser distance from us, and it must have been this which suggested her\nplace in the scheme of Anaximander. This scheme is rather difficult to\nunderstand, from the allusions and quotations of later writers, for\nwe have no original writing by Anaximander; but we can gather enough\nto show that already in the sixth century B.C. the Greek philosophers\nwere asking themselves what was the explanation of the movements and\nappearances of the heavenly bodies, how they were supported in the\nsky, what force moved them, how large and how distant they were, and\nwhat they were made of. Anaximander asserted boldly that sun and moon\nwere larger than the whole earth: he thought the sun might be 27 and\nthe moon 19 times as large. How he reached this conclusion it is\nimpossible to say. The Egyptians had already tried to measure the\napparent size of the sun as compared with the circumference of the sky,\nby noting how long it took to set from the moment the lower rim touched\nthe horizon to the moment when the whole disc disappeared: this,\ndivided by the 24 hours taken by the sun to traverse the 360 degrees of\nthe sky, gave the sun\u2019s size in degrees (it is about half a degree),\nand had they been able to find the actual distance of the sun from the\nearth, they could have deduced its actual size, but this they had no\nmeans of determining.\n\nThere are two possible ways of seeing that the moon is smaller than\nthe sun, although they usually appear to us the same size. Anaximander\nmay have seen or heard of an \u201cannular\u201d eclipse, in which the moon is\nrather more distant from us than at a total eclipse, and therefore\nher dark body just fails to cover the whole sun, and a bright ring of\nlight surrounds her. More probably he realized what was implied in\nThales\u2019 explanation of solar eclipses, and concluded that the moon must\nbe smaller than the sun, because she looks no larger although she is\nnearer to us.\n\nHis scheme is the first of which we have any knowledge in which the\nmovements of the heavenly bodies are explained by supposing them not\nall in one sky together, but placed in a series of heavens, one above\nthe other: hence it is of peculiar interest to the Dante student, for\nin it we trace the first attempt towards the theory of the Revolving\nSpheres. It is true that the Babylonians and Hebrews divided their\nheaven into three parts, one above the other, but this was only to\ndivide the place of atmospheric phenomena from the dwelling-place of\nthe gods, and sun, moon, planets and stars all moved in the same\nheaven. Here, in the universe of Anaximander, we find one heaven, the\nlowest, for air, rain, etc., another for all the stars, a higher heaven\nfor the moon, a yet higher for the sun, and above all the region of\nfire, the brightest, lightest element, whose nature it was to ascend\nand which therefore is outside all, as it was the nature of earth\nto descend and therefore to be at the bottom. Probably either in or\nabove the heaven of celestial fire was the heaven of the gods, for, as\nAristotle remarks, all our ancestors, indeed all who believe in gods at\nall, whether Greek or of any other race, place the dwelling-place of\nthe gods above in high heaven, as the unchanging, unmoving region of\neternity.[25]\n\n------------------------------------------------------------------------\n[25] _De C\u0153lo_ I. 3, and II. 1.\n------------------------------------------------------------------------\n\nUnfortunately we do not know what would be of great interest, whether\nAnaximander also provided separate heavens for the planets, or found\na home for them in the heaven of the stars. Perhaps he hardly knew of\ntheir existence, or said with Aratus who wrote nearly 800 years later:\u2014\n\n \u201cOf these I dare not speak with certainty,\n As of the fixed stars\u2019 orbits.\u201d\n\nThe successive heavens were in layers, as it were, one above the\nother, \u201clike the bark enclosing a tree,\u201d but they were transparent and\ninvisible. The heavens themselves were not in motion, carrying the\nstars, sun, and moon; Anaximander had an ingenious mechanical scheme\nof wheels or rings to carry them inside their respective heavens,\nwhich doubtless was clear to himself, though unfortunately it is not\nat all clear to us. Some writers have maintained that these heavens\nwere spheres, but for several reasons it is difficult to believe this,\nand probably the sky was still to Anaximander, as to the Homeric\nGreeks, a slightly flattened hemisphere,[26] only divided into these\nlayers, and instead of ending at the horizon it continued a little\nbelow, to allow of the passage of the heavenly bodies between setting\nand rising. Perhaps it was for this reason that he gave the earth a\ngreater thickness than the disc of Thales, comparing it to a short\nthick pillar, three times as broad as high, the top of which only was\ninhabited. His Cosmos, then, would be something like the diagram, with\nregard to the disposition (though not the relative sizes) of Earth and\nthe heavenly bodies.\n\n------------------------------------------------------------------------\n[26] But see note, pp. 75, 76.\n------------------------------------------------------------------------\n\n[Illustration: Fig. 12. The Universe according to Anaximander.]\n\nSomewhat timidly the barriers have been thrust back. The earth goes a\nlittle deeper into the dark unknown, the sky is wider and higher, the\nheavenly bodies are much larger and more distant and go under Earth\u2019s\nsurface; but they are cautiously upheld by solid domes, and worked by\nwheels. Earth is still the floor of the World, and Heaven\u2014now a series\nof heavens\u2014the vaulted roof above.\n\n\n3. LATER FLAT EARTH SYSTEMS.\n\nIt is interesting to see how long this timidity persisted among the\nGreek philosophers, especially of the Ionian school, in spite of the\nfact that other schools had advanced much bolder ideas, as we shall\npresently see. Quite a number of universes were constructed somewhat\nafter the pattern of Anaximander\u2019s, with Earth as floor of the world;\nbut some placed the stars beyond moon and sun, some definitely included\nthe planets, though they do not seem to have explained their motions;\nand there were various ways of supporting the flat earth, and of\nsupporting and moving the heavenly bodies.\n\n[Sidenote: Anaximenes _c._ 550 B.C.]\n\n[Sidenote: Empedocles _c._ 450 B.C.]\n\n[Sidenote: Anaxagoras died 428 B.C.]\n\nAnaximenes, a follower of Anaximander, having doubtless pondered\nthe fact that very heavy bodies can float in water if only they are\nthe right shape, and that Earth itself was supposed by Thales to be\nfloating on the Ocean, suggested that the moon is so broad a disc that\nshe floats in the ether, \u201clike a leaf,\u201d and of course the same would\napply to the sun. Two later philosophers, Empedocles and Anaxagoras,\nheld that a great whirlwind swept continually round the Earth, which\nboth kept the heavenly bodies from falling down upon it and drove them\nacross the sky.\n\nEqually diverse were the opinions as to the nature and composition of\nthe heavenly bodies. Most philosophers of this age believed that they\nwere of pure fire, or else that they were vessels containing fire,\nwhich was extinguished, or in one way or another became invisible to\nus, during eclipses and when they set. Others held, as we have seen\nwith Thales, that they were of an earthy nature; and Anaxagoras, seeing\na meteorite which had fallen from the sky during the daytime, thought\nhe actually held a piece of the sun in his hands, and concluded that\nthe sun was an enormous mass of iron, \u201cmuch greater than Peloponnesus,\u201d\nand shone because it was red-hot. But the popular idea still was that\nthe sun was a god, or the chariot driven by a god across the sky, and\nAnaxagoras was banished from Athens for his impious words.[27] The\nmarkings on the face of the moon were thought to prove that she was of\nmixed composition: she was made of air mingled with only a little fire,\nor earth mingled with fire; but according to Democritus the markings\nwere shadows of mountains on her surface, and Anaxagoras is reported to\nhave said that the moon was inhabited, and the markings were \u201cplains\nand valleys.\u201d\n\n------------------------------------------------------------------------\n[27] His life was saved by his illustrious pupil, Pericles, of whom\nthe story is told that on one occasion, just as his army was embarking\nfor an expedition, the sun was eclipsed, and his pilot was terrified.\nPericles snatched off his cloak, and held it so as to hide himself from\nthe man\u2019s eyes. \u201cIs that terrible? is that an evil omen?\u201d he cried.\n\u201cThen do not fear the disappearance of the sun, for it is just the\nsame, only the thing that hides it is larger than my cloak.\u201d\n------------------------------------------------------------------------\n\nAnaxagoras suggested that the stars were fragments torn off the\ncircumference of the earth by the encircling whirlwind, and that they\nglowed with the heat caused by friction, though they were too distant\nfor us to feel this heat, being far beyond the sun. The Milky Way was\na source of speculation: some said it was the former path of the sun,\nand still burning from his heat, but Democritus explained it as caused\nby the shining of innumerable stars, too faint and close together to be\ndistinguished separately.\n\nThe doctrines of the different philosophers as to origin and first\nstages of the universe do not concern us here, but we must mention that\nof Empedocles, as his views are directly referred to by Dante.\n\nThis philosopher was the first to assert that everything consists of\nthe four elements, earth, air, water, and fire, pure or in combination;\nand the combinations he supposed to be brought about by two forces, one\nattractive, the other repulsive, which he named Love and Discord. Of\nthese, one alternately predominates at different ages of the world, and\nthus its history is divided into periods of different character.\n\nA great step forward was taken when it was realized that the sky is not\na hemisphere, ending at the horizon, or even extending a little way\nbelow, but that it surrounds Earth in every direction, like a sphere.\nThis idea probably originated with the Pythagoreans, or it may have\noccurred independently to several thinkers, when the diurnal motion of\nthe heavens was better observed, and geometrical conceptions understood\nand applied. Now it became no longer necessary to extinguish and\nrekindle the stars, nor to send the sun round swimming on River Ocean\nbehind northern mountains, or creeping through strange underground\nregions, through the night. It was clearly recognized that the visible\ncourse of each heavenly body was part of a circle, the whole of\nwhich we could see if we could only travel fast enough and go to the\nunderside of the earth.\n\n[Illustration: Fig. 13. The Universe of Leucippus.]\n\n[Sidenote: Leucippus _c._ 450 B.C.]\n\n[Sidenote: Democritus _c._ 430 B.C.]\n\nBut this was just what never could be done, for outside the schools\nof the Greeks in Italy (Pythagorean and Eleatic), Earth still had\nan uninhabitable underside. Distinguished men like Leucippus and\nDemocritus sought to combine the belief in an all-surrounding spherical\nheaven with a flat supported earth which might still give them a solid\nfloor beneath their feet. Leucippus made the earth a hemisphere, with a\nhemisphere of air above, the whole surrounded by the supporting crystal\nsphere which held the moon. Above this came the planets, then the sun,\nand probably the stars were outside this. His disciple, Democritus, on\nthe other hand, retained the disc-like earth, raised a little at the\nrim, to secure its contents, and made it divide the sphere of air into\ntwo parts, so that it rested upon air, and air was also in the sky\nabove. The underside of the disc was not inhabited, no doubt because\nno one could stand upside down. His order of the successive heavens is\nnot quite the same as that of Leucippus, as he puts the moon and the\nMorning Star together, and the rest of the planets beyond the sun.\n\n[Illustration: Fig. 14. The Universe of Democritus.]\n\nThis scheme gave the universe a beautifully symmetrical form, which\nmust have pleased the Greeks, but now they were puzzled to know why\nthe heavenly bodies did not circle symmetrically with regard to the\ncentral earth. Why was not the pole in their zenith and the equator on\nthe horizon? They could only guess that it must have been so at first,\nand that the disc had slipped out of position, either through some\nirregularity in its weight, or in the density of the underlying air.\nCompare Milton\u2019s\u2014\n\n \u201cSome say He bid His angels turn askance\n The poles of Earth twice ten degrees and more,\n From the Sun\u2019s axle; they with labour pushed\n Oblique the centric globe.\u201d\n _Paradise Lost_, Bk. X., 563-566.\n\nAll these theories and guesses may seem to us very crude and fanciful,\nand we may compare them to the eager questionings of intelligent\nchildren, too impatient to consider whether the answers given are\nsatisfactory explanations or no. But we must remember that all we know\nof the early cosmogonies is from allusions and descriptions by later\nwriters, who often\u2014like Aristotle, for instance\u2014only quote to condemn.\n\u201cIf each could defend his own opinion, may be we should see that there\nis truth in all.\u201d (Conv. IV. xxi. 25-7).\n\nAt least we find a keen and disinterested desire to penetrate the\ncauses of things, and a fertile imagination, without which science\ncan make no advance: moreover there was a progress in true knowledge.\nIt was discovered that the (apparent) diurnal paths of sun, moon, and\nevery star were circles, although only a part of the paths could be\nseen; and that, although all were seen projected on a sphere, their\nactual distances from earth were very varied.\n\nIt is disappointing to find no record of observations of the planets,\nand from the almost random way in which they were placed in the heavens\nit seems that but little attention had been paid to them as yet. In\nfact, Seneca tells us that Democritus knew neither their number nor\ntheir names. They were often classed with comets, and thought to be\nentirely erratic, and the Greek mind was more attracted towards those\nphenomena which were seen to be orderly.\n\n\n4. PYTHAGORAS AND HIS FOLLOWERS.\n\n _Socrates._ As the eyes are appointed to look up\n at the stars, so are the ears to hear harmonious\n motions, and these are sister sciences. That is\n what the Pythagoreans say, and we, Glaucon, assent\n to them?\n\n Yes, he replied.\n\n[Sidenote: Pythagoras _c._ 540 B.C.]\n\nAbout the same time that Anaximander was inventing solid hemispheres\nand rings to hold and move the heavenly bodies round about a flat\nearth, Pythagoras was founding a school in southern Italy which gave\nto the world a very different scheme. One of the characteristics of\nhis school was secrecy, its methods were oral, and his later followers\nwere fond of attributing to their master everything which had gradually\ngrown out of his teaching: it is difficult therefore to say with\ncertainty what he himself taught. It has often been stated by modern\nwriters that he anticipated Copernicus, and discovered that the earth\nrevolves round the sun. Though this is a mistake, we may venture to\nbelieve that Pythagoras taught that the earth is a sphere, hanging\nfreely in space.\n\nWe are so familiar with this idea from childhood, that it is difficult\nto imagine what a tremendous innovation it was. Pythagorean noviciates,\ndoubtless after solemn initiation and preparation, were told: This\nearth, which seems to you the floor of the world, with heaven stretched\nover it like a tent, is a round globe, with men like you living on\nthe other side of it, and yet they do not fall, and earth does not\nfall, for it is poised in the centre of the world, and has no tendency\nto fall in one direction rather than in another. Earth, itself a\nperfect sphere, is in the centre of an infinitely greater sphere, the\nstar-set heaven; and within this seven heavenly bodies move in perfect\ncircles, each at its proper distance and pace, all needing no support\nand no force to drive them, for harmony is the motive power of the\nCosmos. Their distances are proportional to the intervals between\nmusical notes, and as they circle they make heavenly music, which we\nshould hear did we not always hear it, like one who lives beside a\nwaterfall[28]. There is no below, and no above, for above is below and\nbelow above to our antipodes: there is but the centre, where we live,\nand Heaven is all around.\n\n------------------------------------------------------------------------\n[28] Some late followers said that Pythagoras, alone amongst men, could\nhear the music of the spheres.\n------------------------------------------------------------------------\n\nHow did Pythagoras reach this great and startling truth of the round\nunsupported earth?\n\nHis school relied more on experiment and observation than the Ionian,\nand the colonizing Greeks of Italy had travelled. They might have\nnoticed the curvature of the sea, and the varying height of the Pole\nStar according to latitude. We know that in early days the Greeks were\nstruck by the remarkable fact that the brilliant star Canopus (second\nonly to Sirius in brightness), which was invisible in Greece, could\njust be seen close to the southern horizon in Rhodes, and was well\nseen in Egypt. Then the moon may have helped once more. When it was\nunderstood that lunar eclipses only happen at full moon, when we are\nbetween her and the sun, and that they may therefore be explained by\nthe earth\u2019s shadow falling on the moon, then, since the edge of that\nshadow is always a circle, it is demonstrable that the body throwing\nthat shadow can have no form but that of a ball.\n\nSun and moon are obviously round: it was guessed that they also are\nglobes rather than discs, and the spherical shape of all heavenly\nbodies was a doctrine of the later if not the earliest Pythagoreans.\n\nWhatever may have been the steps which led to these two great\ndiscoveries that Earth is a sphere, and that the apparent path of\nevery celestial body is a circle, the sphere and the circle were soon\naccepted as the only forms suitable for celestial bodies and their\norbits. The founder of the school was a great mathematician, and it\nis not strange that these forms should have commended themselves to\nhis disciples. The sphere, which has its surface everywhere similar,\nand its contents greater than those of any other figure with equal\nsurface, was the \u201cmost perfect\u201d of solids; and the circle, which has\nno beginning and no end, is alike in every part, and presents ideas\nof haunting suggestiveness to the geometer, was the \u201cmost perfect\u201d of\nlines.\n\nIn the system of Pythagoras we first find the five planets distinctly\nenumerated, and playing as important parts as sun and moon. Number was\nthe principle of this universe, and the planets with sun and moon made\nthe sacred number of seven. Among the Greeks, and through the middle\nages, all these bodies are spoken of as planets or \u201cwanderers,\u201d in\ndistinction from the \u201cfixed\u201d stars which do not appear to move amongst\nthemselves. These seven \u201cplanets\u201d represented the seven notes of a\nmusical scale, and the star sphere made up the octave. Pythagoras is\nsaid to have been the first to teach that Phosphor and Hesperus, the\nmorning and the evening star, were the same. When, however, we ask\nwhat was the order of the planets in his scheme, we meet with many\nconflicting reports, and a serious difficulty suggests itself. If\nthe planets had really been observed with care, it must have been\nseen that their motions could not be accounted for by simple circular\nmovement. The large oscillations of Mercury and Venus on either side\nof the sun would strike an observer before he thought of tracing their\nmovements among the stars, and noting that they made a circuit of the\nzodiac. Similarly, the other planets are most conspicuous, rising after\nsunset and remaining long visible through the night, at the very time\nof their retrograde movements, so these must have been noticed if a\nlong enough series of observations had been made to distinguish them\nfrom one another. The only solution of the difficulty seems to be that\nPythagoras, on the journeys into Egypt and Babylon which he is said\nto have made, learned that there exist planets to the number of five,\nwhich move in regular periods, and he may also have learned the length\nof their zodiacal periods at the same time, or perhaps these were only\nknown to his school much later. If the order assigned to them was that\nwhich was finally and generally accepted by the ancient world, the\nperiods must have been known, for this is the only possible clue to the\norder Moon, Mercury, Venus, Sun, Mars, Jupiter, Saturn. The planet with\nshortest period (the moon, with a month) was naturally placed by the\nGreeks nearest to earth, with the smallest circle to traverse, and so\non outwards.\n\nIt is very possible, however, that the early Pythagoreans, at least,\ndid not venture to assert more than that there were five planets,\nwithout assigning to them any order, for Aristotle tells us that their\nuniverse was divided thus:\u2014\n\nFrom Earth to Moon was the Ouranos, or sky, within which exists all\nthat is changing and corruptible.\n\nCosmos, the place of ordered movement, was the region of Sun, Moon, and\nPlanets.\n\nOlympos, the place of pure elements, held the stars; the region of\nCelestial Fire came beyond this, and the Apeiron, the Infinite Space,\nor Infinite Air, from which the world draws its breath, was outside all.\n\n[Sidenote: Philolaus towards end of 5th century B.C.]\n\nThe diagram shows, then, the earliest form of the Pythagorean universe.\nBut they did not remain content with this. Out of it grew a most\ninteresting scheme (referred to by Dante), which is usually attributed\nto one Philolaus, of whom hardly anything is known, not even his date.\n\nIt seems to have struck Philolaus as a difficulty that the seven\nplanets, which were circling round Earth in the same direction but\nat very different distances and speeds, and also the immense sphere\nof stars beyond, were all sweeping together at the same time in an\nopposite direction, and at the almost incredible pace of one revolution\nin a day. The brilliant idea occurred to him: Leave the stars at rest,\nlet the seven planets revolve in their seven orbits, the nearer to the\ncentre the faster, and let earth herself revolve fastest of all, viz.\nin twenty-four hours, in the same direction. If she keeps one face\nalways turned towards the centre, like the moon, this will account\nquite as well for the apparent diurnal revolution of all the heavenly\nbodies, and the change of day and night on the earth.\n\nPhilolaus did not make Earth remain stationary and simply turn on her\naxis, which would have had just the same effect on the apparent motions\nof the heavens; for it seemed more natural that she should revolve as\ndid the rest. The five naked eye planets are all mentioned by name in\nhis scheme.\n\n[Illustration: Fig. 15. The Universe of Pythagoras.]\n\nWas the centre, deprived of Earth, to be left empty? No, the centre\nwas the Watch Tower of Zeus, the Hearth of the Universe, and here they\nplaced the purest element, fire. It was invisible to us, because we\nlive on the side of the earth-sphere turned away from the centre; and\nalso invisible to us was another planet, Antichthon, or Counter-Earth,\nfor this revolved within our orbit, and also in twenty-four hours. It\nwas added to the system, because the addition of Earth as a heavenly\nbody spoiled the sacred number of seven, but by adding Antichthon, and\ncounting the star sphere as another, the total was brought up to ten,\nanother sacred number.\n\nThe objection was made that, if Earth is moving in space, this must\nbring about a change in the apparent sizes of sun and moon, as Earth is\nnearer or farther from them, but the Pythagoreans were quite ready to\nbelieve that all the heavenly bodies are so distant that this journey\nof Earth makes no difference to their apparent size or brightness. The\nplanets were thought to be worlds like ours, and inhabited; and it was\neven guessed that plants and animals on the moon must be fifteen times\nas strong as ours, apparently because there the average day consists of\nnearly fifteen of our days (of twenty-four hours), and the nights are\nequally long.\n\nIt was the braver of the Pythagoreans to shake the steady earth from\nher centre, and set her whirling in the depths of space, that they\nrealized, as no one had done before, how large she must be; for Greece\nand the surrounding lands, the Middle and the other seas, instead of\nmaking the whole of the earth, were now understood to be only a portion\nof a great globe.\n\n[Illustration: Fig. 16. The System of Philolaus: night on earth.\n\nOnly the side turned away from the centre is inhabited: consequently\nthe Central Fire and Antichthon are invisible.]\n\n[Illustration: Fig. 17. Twelve hours later: day on earth.\n\nEarth has made half a revolution and her outer side is now lighted by\nthe sun, which has only moved about half a degree forward in its yearly\norbit. Antichthon has also made half a revolution, therefore remains\ninvisible.]\n\nHere, then, is a conception of the Universe widely different from\nHomer\u2019s. The little flat disc has become a great round ball, a planet\namong planets, swiftly moving through space; the crystal dome that\ntenderly covered it like a bell-glass over some fragile flower, has\nlifted, and the vast sphere is seen, infinitely distant, and studded\nwith enormous stars. Man himself is now a tiny creature on a great\nearth, and his world but one among many, but if he is humiliated by his\ninsignificance, is he not elevated by the vastness of his outlook?\n\n[Illustration: Fig. 18. Earth and sun according to Heracleides.\n\nIn the upper figure it is day, in the lower, night, on the inhabited\nside of Earth. The sun is on the equator, as at the time of equinox.]\n\n[Sidenote: Heracleides _c._ 370 B.C.]\n\nBut not even here did the Greeks stop. It was taking a less startling\nstep than they had already taken, to reach the truth that Earth was\nmerely rotating on her axis once in a day, and so causing the apparent\ndiurnal revolution of the heavens. This step was taken (it is said)\nby a Pythagorean called Hicetas of Syracuse, who is quoted as saying\nthat the earth, \u201cwhile it turns and twists itself with the greatest\nvelocity round its axis, produces all the same phenomena as if the\nheavens were moved and the earth were standing still.\u201d We are told also\nthat \u201cHeracleides of Pontus and Ecphantus the Pythagorean let the earth\nmove, not progressively, but in a turning manner like a wheel fitted\nwith an axis, from west to east round its own centre.\u201d\n\nA brilliant guess,[29] which seems fully justified by facts, has\nrecently explained the personalities of these two mysterious\nPythagoreans of unknown date, Hicetas and Ecphantus, whose names have\nbeen coupled for centuries with that of Heracleides, as teaching the\nrotation of Earth on her axis. It seems that they resemble the Shadow\nin Hans Andersen\u2019s tale, which became a man and lived apart from the\nman to whom it originally owed its existence, for it is now thought\nthat they were speakers introduced by Heracleides into one of his\ndramatic dialogues to discuss astronomy.\n\n------------------------------------------------------------------------\n[29] See Heath\u2019s _Aristarchus of Samos_, pp. 187-189 and 251, 252.\nI very much regret that as Mr. Heath\u2019s book was only published this\nyear, I have been unable to make use of it while writing of early Greek\nastronomy. I can now only advise any readers who may be interested in\nmy brief sketch of this period to read Mr. Heath\u2019s history, where they\nwill find the opinions of modern writers summarized and discussed,\nand also the full text (in English) of the most ancient and reliable\nsources of information. It is a great encouragement to find that my\nstatements are in agreement with his in nearly all essential points,\nbut readers will mark the following important differences:\u2014\n\n1. Anaximander\u2019s heavens are said to have been spherical, not\nhemispherical, and this seems to be clearly proved by the evidence\nquoted from ancient writers.\n\n2. Anaxagoras, not Thales, is said to have been the first to explain\ncorrectly the cause of solar eclipses and of the moon\u2019s phases, viz.\nthat the moon is an opaque body, shining only by reflected sunlight,\nand periodically hiding the sun from us when she passes in front of\nit. Mr. Heath regards the authorship of Anaxagoras as conclusively\nproved: readers will be able to judge of this from his quotations.\nPersonally they seem to me to prove no more than that Anaxagoras agreed\nwith others on this point, and was the first to express it clearly in\nwriting. It is difficult to see why Mr. Heath denies that Parmenides\nheld the same views before Anaxagoras: Parmenides\u2019 own words seem to\nprove it, and his theory that the moon was composed of air and fire\nmingled is rather in favour of it than otherwise. He surely meant that\nthe moon was not wholly bright, like the sun; yet that she had some\nlight of her own must have seemed evident from the faint illumination\nwe see during total lunar eclipses and on the part of her surface not\nlighted by the sun. (See Dante\u2019s views, p. 402 of this book.)\n\nThe connection between her phases and her distance from the sun in the\nsky is so extremely obvious that I can hardly think the Greeks drew no\ninference from it until the fifth century B.C., and I cannot see why\nwe should refuse to credit Thales with the discovery attributed to him\nthat her light came in some way from the sun. Gruppe acutely observes\nthat the reason why Thales\u2019 pupil Anaximander did not accept the true\nexplanation of lunar phases and solar eclipses may have been because\nhe felt it necessary to have a theory which would apply equally well\nto eclipses of the moon; and as he believed in a flat earth he could\nnot advocate the true explanation here. This was why he invented a new\ntheory (viz. that both sun and moon were fire shining through holes in\nhollow rings, and that the occasional stopping up of these holes caused\nboth lunar and solar eclipses, and also the lunar phases).\n\nBut Parmenides had learned the Pythagorean doctrine of Earth\u2019s\nspherical form, hence he was able to accept the older theory that the\nmoon obtains her light from the sun, and sometimes eclipses the sun by\nher opaque spherical body, for he could have added that the moon is\neclipsed in like manner by the opaque spherical body of the earth.\n\nHeracleides, therefore, was the sole author of this remarkable\ndiscovery.\n\nIn this way Earth was restored to her central position, but as a\nrotating sphere, and the later Pythagoreans apparently tried to\nreconcile their new scheme with the old by calling Antichthon the\nuninhabited hemisphere of Earth, and placing the central fire within\nthe earth.\n------------------------------------------------------------------------\n\n\n\n\nIV. GREEK ASTRONOMY.\n\nSECOND PERIOD. B.C. 400 TO A.D. 150.\n\n \u201cChiamavi il cielo, e intorno vi si gira,\n Mostrandovi le sue bellezze eterne.\u201d\n\n\n1. PLATO.\n\nThe Ionian school of philosophy died about the middle of the fifth\ncentury B.C., and the Pythagorean towards the end of the fourth. But\nmeanwhile a new school of astronomers was growing up. The philosophers\nstill laid down general principles, founded on abstract reasoning,\nwhich they believed must regulate the nature and movements of the\nheavenly bodies, but astronomy began to be regarded as a branch of\nmathematics, not of philosophy, and the mathematicians, leaving\nproblems of ultimate causes to the philosophers, devoted themselves\nto observation and calculation. They carefully studied the peculiar\nmotions of each planet, and their chief aim was to represent these\ngeometrically by some scheme which should include them all, and make it\npossible to predict the places of the heavenly bodies in the sky for\nany given date.\n\nOne cause of this great progress in methods was no doubt the natural\nintellectual growth of the Greek race, as they discovered that their\neager curiosity concerning nature could only be satisfied by patient\ninvestigation. The value of observation was taught, in the latter half\nof the fourth century, by the philosophy of Aristotle, and a great\nimpetus must have been given by the campaigns of Alexander, in which\nthe Greeks saw distant countries, new climates, strange peoples and\ncustoms.\n\n[Sidenote: Callisthenes _c._ 330 B.C.]\n\nBut a potent cause of the advance in astronomy seems to have been the\ncloser connection between Greek astronomers and those of Egypt and\nBabylon. The astronomer Callisthenes went with Alexander to the East,\nand received a letter from Aristotle praying him to send to Athens the\nBabylonian eclipse records which were centuries old; and Aristotle\nmentions, when speaking of the motions of the planets, that the\nBabylonians and Egyptians had furnished trustworthy information about\neach one of them. Even before this, we find that the Greek descriptive\nnames of the planets were changed for names of Greek deities which\nare believed to correspond with the Babylonian gods and goddesses\nwho presided over the planets. Thus Plato speaks of \u201cthe star sacred\nto Hermes\u201d as well as Stilbon the Glitterer, and he is the last to\nuse commonly the name of Phosphor for the planet which henceforth\nwas known as Aphrodite among the Greeks, and Venus among the Romans,\ncorresponding with the Babylonian Ishtar; and so on with the rest.\nInstead of vague records of journeys in Egypt or Babylonia, we have a\ndefinite statement that Eudoxus, who was the founder of the new school,\nwent to Egypt about 378 B.C., with letters from the king of Sparta\nto the king of Egypt, and we are told that he studied the planetary\nmotions under a priest of Heliopolis. It seems highly probable, to say\nthe least, that Eudoxus was the first Greek to appreciate the value\nof those methods of observation and continuous recording of phenomena\nwhich he found among the Egyptians, and to understand the wonderful\nregularity which was hidden behind the seeming irregularities of the\n\u201cwandering stars.\u201d He was also, apparently, the first Greek to write a\ndetailed description of the forty-eight ancient constellations.\n\nBut if Egypt and Babylonia gave to Greece records of celestial\nphenomena, and set the example of accurate and long-continued\nobservations, Greece made the new knowledge her own, and transformed\nit. The legend that Eudoxus applied his mathematical skill to the\nancient monuments of the Egyptians, and showed them how to calculate\nthe height of the Great Pyramid by measurements of its shadow, is\ntypical of the history of Greek treatment of Oriental astronomy.\nOne geometrical theory after another was invented to represent\nthe planetary motions, was compared with the skies, and rejected\nor improved, and meanwhile observation became much more close and\naccurate; new instruments were introduced, new methods of calculation\ninvented, new motions discovered which had to be accounted for;\nfinally, five hundred years after Eudoxus\u2019 visit to Egypt, the result\nof all this labour was summarized in a truly epoch-making work,\nwhich remained the standard treatise on astronomy until the time of\nCopernicus.\n\n[Sidenote: Plato _c._ 427-347 B.C.]\n\nEudoxus was born at Cnidos, in Asia Minor, but at the age of\ntwenty-three he went to Athens, and studied under Plato. It is said to\nhave been Plato who inspired the young man with the idea of devoting\nhis brilliant mathematical powers to solving the problem of celestial\nmotions, and with this view he went to Egypt. The story is easy\nto believe when we recall the many passages in the _Dialogues_ in\nwhich Plato uses the splendid imagery of the skies to illustrate his\nphilosophic doctrines, dwelling especially on the perfect though little\nunderstood symmetry of the celestial motions, and it will be remembered\nthat astronomy was one of the subjects to be learned by the rulers of\nhis ideal state.\n\nIt is true that Glaucon is gently but decidedly snubbed by Socrates in\nthe _Republic_, for suggesting that the study of astronomy is valuable\nbecause of its use in navigation, husbandry, and the arts of war. This\nis \u201cvulgar praise,\u201d but has there ever been nobler praise of astronomy\nthan that which Socrates himself then proceeds to give? Although he\nbelieves that true knowledge, knowledge of realities, is only to be\nobtained by the exercise of pure reason without the aid of sense, he\nconsiders that the study of celestial motions is one of the best means\nof training the mind to reach those heights, and he does not hesitate\nto say that sight was given to us in order that we might look at the\nskies. For the embroidery of heaven, says Socrates, though wrought upon\na visible ground, is the fairest and most perfect of visible things;\nand it is displayed to our mortal eyes as a pattern of the eternal\nrealities which are granted to the vision of the soul.\n\nIn the _Timaeus_ this idea is elaborately developed, and it undoubtedly\nhad an effect on Plato\u2019s contemporaries, although his direct influence\non astronomy cannot be compared with that of Aristotle. The _Timaeus_\nwas widely read also in the Middle Ages, during the long period when\nPlato\u2019s other writings were unknown, and it is quoted by Dante.\nWe are often reminded of him when reading the astronomical and\nquasi-astronomical parts.\n\nTimaeus, who is introduced to Socrates by Critias as \u201cthe most of an\nastronomer among us, and one who has made a special study of the nature\nof the Universe,\u201d[30] describes the Creation as he conceives it most\nprobable that it took place. He assumes a chaos to begin with, where\nthere is no order, and no matter which can be distinguished by name,\nbut all is confused and seething with random restless motions.\n\n------------------------------------------------------------------------\n[30] I follow the translation of Jowett.\n------------------------------------------------------------------------\n\nOf this, in order to produce something which should express his own\ngoodness,[31] the Creator formed the four elements,\u2014earth, water,\nair, and fire,\u2014and of them he made a world, which became a fair and\nintelligent being, animated by a living soul. He made it in the most\nperfect form, that of a sphere, polished and smooth on the outside, \u201cas\nif from a lathe.\u201d The soul was placed in the centre, and hence diffused\nthroughout the whole bodily frame. It is the cause of the harmonious\nmotions of the stars, and of these there are two kinds: the motion\nof the Same (the diurnal revolution of the whole heavens) is in the\nnoblest direction, simple and uniform; the motion of the Diverse is in\nthe opposite direction and diagonal to the first, and it is divided\ninto seven parts (the seven orbits of the planets), which bear certain\ndefinite ratios to one another.\n\n------------------------------------------------------------------------\n[31] Compare _Par._ vii. 64-66.\n------------------------------------------------------------------------\n\nTimaeus does not name the planets, but in the _Republic_ Socrates\nnames some, and indicates the rest by their colour or other\ncharacteristic,[32] so we know that the order which he assigns to them,\ncounting outwards from the central earth, is: Moon, Sun, Mercury,\nVenus, Mars, Jupiter, Saturn.\n\n------------------------------------------------------------------------\n[32] See his famous description of the eight spheres, on each of which\nstands a siren, singing, while the whole system turns upon a diamond\nspindle, the end of which rests upon the knees of Necessity. This book\nwas not known in the Middle Ages.\n------------------------------------------------------------------------\n\nIt was in order to make the world like its eternal pattern that the\nCreator made a \u201cmoving image of eternity,\u201d which we call Time, in the\nrevolutions of the heavenly bodies; and to make it visible he \u201clighted\na fire which we now call the sun, in the second of these orbits, that\nit might give light to the whole of heaven [note that the stars shine\nby reflected sunlight, as well as moon and planets], and that the\nanimals who were by nature fitted might participate in number: this\nwas the lesson they were to learn from the revolutions of the Same\nand the Like. Thus, then, and by these means, the night and the day\nwere created, being the period of the one most intelligent revolution.\nAnd the month was created when the moon had completed her orbit and\novertaken the sun; and the year, when the sun had completed his own\norbit. The periods of the other stars [the planets] have not been\nunderstood by men in general, but only by a few, and they have no name\nfor them, and do not estimate their comparative length by the aid of a\nnumber, and hence they are hardly aware that their wanderings, which\nare infinite in number and admirable for their variety, make up time.\nAnd yet there is no difficulty in seeing that the perfect number of\ntime completes the perfect year when all the eight revolutions, having\ntheir relative degrees of swiftness, are accomplished together, and\nagain meet at their original point of departure, measured by the circle\nof the Same moving equally.\u201d\n\nThe heavenly bodies, according to Timaeus, are all divine intelligent\nbeings. In form they are perfect spheres, like the world of which they\nform part, and they are composed of fire. The stars have two motions,\nfor each rotates on its own axis while it is carried round the centre\non the rotating star sphere.\n\nEarth is also a sphere, immoveable at the centre of the World. Of her\nTimaeus says: \u201cThe earth, which is our nurse, encircling the pole\nwhich is extended through the universe, he made to be the guardian and\nartificer of night and day.\u201d\n\nThis passage has given rise to the idea that Plato believed the\napparent diurnal revolution of the heavens to be caused by earth\u2019s\nrotation on her axis; but the word here translated \u201cencircling\u201d[33] may\nmean\u2014as that does\u2014either motion or situation round about something,\nand the whole context ascribes the diurnal movement so clearly and\nemphatically to the heavens, that it seems evident Plato could only\nhave meant that earth was guardian and artificer of day and night by\nvirtue of her position. The only strong argument in favour of the\nother meaning is that Aristotle, when speaking of Earth as supposed\nby some to be central in the Universe but moving, quotes Plato and\nthe _Timaeus_. It might easily happen, however, that Aristotle knew\nfrom other sources, perhaps from conversation with Plato, that at some\ntime the latter had inclined towards belief in Earth\u2019s motion, and\nremembering the ambiguous expression in the _Timaeus_ he quoted it from\nmemory as a statement of Plato\u2019s belief.\n\n------------------------------------------------------------------------\n[33] \u03b5\u03b9\u03bb\u03bb\u03bf\u03bc\u03b5\u03bd\u03b7.\n------------------------------------------------------------------------\n\nThere is some evidence that late in life Plato accepted the doctrine\nof Philolaus that Earth was not only in motion, but in motion round a\nCentral Fire. There is a legend that he bought the books of Philolaus\nat a great price, and Theophrastus, a disciple of Aristotle, is\nreported by Plutarch to have said that \u201cPlato when old assigned to\nEarth another place, the central and nobler place being reserved for\nsomething else more worthy of it.\u201d However this may be, he does not\nteach either theory in his writings. His views seem to be quite the\nsame as those of Pythagoreans of the old school, whom he sometimes\nquotes.\n\nAfter describing the creation of the Universe, Timaeus relates that\nthe Creator deputed the gods whom he had made (including the stars)\nto create living beings on the earth, he himself creating directly\nonly their immortal part, which he made of the same essence as the\nWorld-Soul, but diluted. Then follows the passage which came to the\nmind of Dante when he met the first spirits of Paradise in the moon.\n\n \u201cAnd when he had framed the Universe, he\n distributed souls in equal numbers to the stars,\n and assigned each soul to a star; and having placed\n them as in a chariot, he showed them the nature of\n the Universe, and the decrees of destiny appointed\n for them, and told them that no one should suffer\n at his hands, and that they must be sown in the\n vessels of the times severally adopted to them....\n He said that he who lived well during his appointed\n time [on earth] would return to the habitation of\n his star, and there have a blessed and suitable\n existence.\u201d If he lived ill, he would be a woman\n at his second birth, if a bad woman, then a beast,\n and as long as he continued to do ill he would \u201cnot\n cease from his toils and transformations until he\n followed the original principle of sameness and\n likeness within him.... When he had given all these\n laws to his creatures ... he sowed some of them in\n the earth, and some in the moon, and some in the\n other stars which are the measures of Time.\u201d\n\nThe creation of man\u2019s body and all the remainder of the _Timaeus_ does\nnot concern us here, except that when speaking of the highest use of\nman\u2019s faculty of sight, we realize how near Dante and Plato are in\ntheir feeling for the revolving heavens:\n\n\u201cGod invented and gave us sight to this end, that we might behold the\ncourses of intelligence in the heaven, and apply them to the courses\nof our own intelligence which are akin to them, the unperturbed to the\nperturbed; and that we, learning them and being partakers of the true\ncomputations of nature, might imitate the absolutely unerring courses\nof God and regulate our own vagaries.\u201d\n\n\n2. EUDOXUS.\n\n[Sidenote: Eudoxus 408 B.C. to _c._ 355 B.C.]\n\nWith words like these ringing in his ears, Eudoxus went from the\nGreek philosopher to the Egyptian priest, and studied \u201cthe courses of\nintelligence in the heaven.\u201d Legend says that the sacred Egyptian Bull\nlicked his garment, and the priests no doubt were encouraged by this\nomen to divulge their secrets to a person so highly favoured by the\ngods. They prophesied that he would have a short but very illustrious\nlife.\n\nAfter a year, or perhaps more, spent in Egypt, Eudoxus returned to his\nown city, set up an observatory of his own, received pupils, and worked\nout an exceedingly ingenious and original planetary scheme. He did not\naccept (if he knew of them) the risky theories of the Pythagoreans as\nto Earth\u2019s motion, but assumed a central stable earth, round which\ncircled the stars and the seven planets, according to the teaching of\nPlato and the general belief among educated Greeks of his day. But\nEgyptian observation and Greek geometry enabled him to describe for the\nfirst time the complicated movements of the planets, and to represent\nthem by an imaginary mechanism.\n\nThis was a series of spheres, or hollow balls, fitting inside one\nanother, and gradually diminishing in size like the ivory boxes of a\nChinese puzzle, or the coats of an onion. Their size was stupendous,\nfor the outer one, which contained all the rest, was nothing less\nthan the sky we see, and was encrusted all over with stars. Of the\ninner smaller spheres, one bore, fixed in it like a jewel set in a\nring, the sun; and six others bore, in the same way, the moon and\nthe planets, one in each. All these hollow spheres were symmetrically\nplaced so that all centred in a single point, and at this point was a\nsolid sphere, exceedingly small in comparison, which was the earth. The\nstar sphere, without moving from its place, rotated round this central\nEarth, and this caused the diurnal motion that we see in the stars.\nEach planet-bearing sphere rotated also, but the special characteristic\nof Eudoxus\u2019 system is that each of these was surrounded by its own\ncomplete set of spheres, bearing no planet, but all attached together,\nthe poles of one sphere resting on the surface of the next, and moving\nwith different speeds, in different directions, and with differently\ninclined axes: these motions being all communicated to the innermost\nsphere on which the planet was fixed, the net result was the movement\nof the planet as we see it in the sky. Each planetary set was quite\nseparate from the rest, and did not interfere with their movements,\nalthough each set was enclosed within the next larger. Since all the\nplanets have a diurnal motion like the stars, as well as their own\nproper motions, each set had to be provided with a sphere which moved\nexactly like the great all-enclosing star sphere.\n\nThus, the sun had one sphere turning like the star sphere, and within\nthis was a second, on which the sun was fixed, which turned round in\na year, in a west to east direction. The sun, carried along by the\ncombined motion, travelled through the sky with the daily and yearly\nmotions, as we see them.\n\n[Illustration: Fig. 19. The spheres of the sun in the system of Eudoxus.\n\nThe outer sphere turns on its axis _A A_ in a day and night; the inner\non its axis _a a_ in a year, in the opposite direction.]\n\nThe planetary spheres were much more difficult to arrange. Eudoxus used\nfour spheres for each, and these had in every case to be carefully\nadjusted to the very different periods and amplitudes of the planetary\noscillations. It must be confessed that the scheme failed with the\ndifficult case of Mars, and was not quite satisfactory with Venus, but\nit represented remarkably well the movement\u2014so far as then known\u2014of\nSun and Moon, Saturn, Jupiter, and Mercury. It was certainly a feat\nfor those days, whether we consider it merely as the solution of a\nmathematical problem, or as an embodiment of astronomical knowledge.\nThe periods of the planets as known to Eudoxus, stated in round numbers\nonly, are given in the following table. They are taken from Simplicius,\nwho describes the system of Eudoxus, but as in the so-called Papyrus\nof Eudoxus the synodical revolution of Mercury is given as 116 days,\nthe same as the modern value, Eudoxus may have had much more exact\ndata. It will be seen that his synodic period for Mars is the only one\nwhich is totally wrong, and the large error is difficult to explain.\n\n _Modern Zodiacal Modern_\n _Planet. Synodic Period. Value. Period._[34] _Value._\n\n Mercury 110 days 116 days 1 year 1.0 year\n Venus 19 months 584 \u201d \u201d 1.0 \u201d\n Mars 8 months, 20 days 780 \u201d 2 years 1.88 \u201d\n Jupiter 13 months 399 \u201d 12 \u201d 11.86 \u201d\n Saturn 13 months 378 \u201d 30 \u201d 29.46 \u201d\n\n------------------------------------------------------------------------\n[34] The period in which a planet is seen to revolve round the zodiac,\nand return to the same star, varies greatly, because complicated by\nits retrograde movements; but if the average of a sufficient number of\nperiods be taken, it coincides for Mercury and Venus with the sidereal\nyear; for Mars, Jupiter, and Saturn, with the period in which each is\nactually revolving round the sun (its \u201csidereal period\u201d).\n------------------------------------------------------------------------\n\nIt is disappointing, after the splendid hypotheses of the Pythagoreans,\nto be back again on a central stationary Earth among mechanical\ncontrivances for moving the heavenly bodies, which remind us of\nAnaximander\u2019s series of hemispherical heavens and heavenly wheels, but\nat least the earth is spherical, owing to the Pythagoreans, and the sky\nextends like a sphere all round, and we shall never have a flat Earth\nor a hemispherical sky again among the Greeks. We do not know whether\nEudoxus regarded his spheres as convenient mathematical abstractions\nonly, or whether he reasoned that the stars were evidently set in an\ninvisible uniformly rotating sphere, and Plato considered this kind\nof movement the most suitable for all heavenly bodies; that therefore\nhe would try whether a series of similar spheres interacting on one\nanother would account for the complicated motions of a planet, and\nfinding that they would, taught that they must truly exist. In any case\nthe basis of his system was a detailed knowledge of planetary motions\nhitherto unapproached by the Greeks, and its chief merit was that it\nchallenged comparison with the skies.\n\n\n3. CALIPPUS.\n\n[Sidenote: Calippus _c._ 330 B.C.]\n\nThe challenge was soon taken up, for twenty or thirty years later one\nof the pupils of Eudoxus, Calippus of Cyzicus, undertook to improve the\nsystem. The defects in the theories of Mars and Venus had evidently\nbeen discovered, for Calippus added another sphere to each of these,\nas well as one to Mercury, which would be quite enough to bring the\ntheories into better agreement with the facts.\n\nWith regard to the sun and moon, Calippus had paid special attention to\ntheir movements, for he made an improvement in the old luni-solar cycle\nof Meton, to which we shall return later. Eudoxus had ignored a very\nimportant fact discovered by Meton and Euctemon about B.C. 430, viz.:\nthat the seasons are of unequal length, showing that the sun takes\nunequal times to pass over the four arcs of his orbit lying between the\nfour points of the vernal and autumnal equinoxes and the summer and\nwinter solstices. \u201cWhy,\u201d exclaims a later writer[35] \u201care there unequal\nnumbers of days in the four seasons, seeing that the course of the\nheavenly bodies must be regular, not being swayed by human passions or\naffairs?\u201d\n\n------------------------------------------------------------------------\n[35] Geminus.\n------------------------------------------------------------------------\n\nCalippus considered this question very seriously, and made a careful\ndetermination of the length of the four seasons. It seems at first\nsight impossible to reconcile their inequality with uniform circular\nmotion of the sun round the earth, but he found that he could do it by\nadding two more spheres to the sun\u2019s set, rotating uniformly but so\narranged that their motion, added to the others, would result in an\nactual velocity in the sun itself varying just in the way required by\nthe facts. The same had to be done for the moon, for the same reason,\nso the number of spheres, which Eudoxus had made twenty-seven, was\nbrought up to thirty-four (including the star sphere). The varying\nvelocity of the five planets had not yet been perceived.[36]\n\n------------------------------------------------------------------------\n[36] This varying velocity is due to the fact that all celestial\norbits are not true circles, but ellipses, which was first discovered\nby Kepler (1609 A.D.).\n------------------------------------------------------------------------\n\n\n4. ARISTOTLE.\n\n[Sidenote: Aristotle B.C. 384-322.]\n\nCalippus went up to Athens about 330 B.C. to lay his scheme before the\ngreat master, Aristotle, and it had his cordial approval. But Aristotle\ndefinitely accepted the spheres as things having a concrete existence,\nfor he says (_De C\u0153lo_ II, 12) that we must regard them as heavenly\nbodies like the stars and planets, and that they are composed of the\nsame celestial stuff.\n\nHe made one change, when incorporating the system in his scheme of\nthe Universe. He was not satisfied that each set of spheres should\nwork quite independently of the rest, and thought that the outermost\nsphere of stars ought to communicate its motion to those below\n(_i.e._ nearer Earth); and no doubt it did seem rather clumsy to\nhave a separate sphere in every set rotating in exactly the same\nmanner as the star sphere. But how could the impulse be communicated\nwithout disturbing the other movements? Aristotle introduced below\neach set another set of \u201cunrolling\u201d spheres, as he called them, which\nsuccessively neutralized the rotations of all spheres in that set\nexcept the one with diurnal rotation, hence this movement alone was\ncommunicated to the set next below. This seems, however, more clumsy\nthan the defect it was intended to remedy. Aristotle was perhaps led to\nit by his wish to give greatest importance to the star sphere; and if\nso, he acted on the principle which he blamed in the Pythagoreans, of\nmaking deductions not from things as they are seen, but as, according\nto his own ideas, they ought to be.\n\nFor indeed Aristotle, in spite of his own doctrines, and the great\nimpulse which he gave to truly scientific methods of observation and\nexperiment, could not rise altogether above the prejudices of his age,\nand consequently his Cosmos is a curious mixture of sound reasoning,\nbased on observation, and of metaphysics, the latter predominating. For\ninstance, it is only at the end of his second book _On the Heavens_,\nafter he has \u201cproved,\u201d from purely metaphysical reasons, that Earth\nmust necessarily be spherical and at the centre of the World, that he\nadds in support of his assertions the fact that the curved line of\nEarth\u2019s shadow seen on the moon during eclipses is always round, that\nstars vary in visibility as we change our horizon, and that astronomers\nsay that the celestial phenomena occur as they would if Earth were at\nthe centre of the World.\n\nNevertheless, Aristotle\u2019s teaching had so overwhelming an influence,\nnot only throughout this epoch, but in the age of Dante, and the latter\nwas so greatly influenced by him, both directly and indirectly, that\nit is exceedingly interesting to know his ideas about the Cosmos. We\nfind them in the two books _On the Heavens_, in the _Meteorology_, the\n_Metaphysics_, and some other works. A special treatise on Astronomy,\nto which he refers[37], is unfortunately not extant.\n\n------------------------------------------------------------------------\n[37] _De C\u0153lo_ II. 10.\n------------------------------------------------------------------------\n\nThe form of the Universe, Aristotle says, must be a sphere, because a\nsphere is the most perfect of solids and a solid is more perfect than a\nsurface or a line, because it is in three dimensions, and three means\ncompletion, perfection.[38]\n\n------------------------------------------------------------------------\n[38] Thus, (he adds) time also is threefold, for we have Beginning,\nMiddle, and End. Therefore we apply three to Divine things, and also\nin common speech we call two \u201cboth,\u201d and only say \u201call\u201d when we reach\nthree, following Nature\u2019s law. The Pythagoreans say \u201cThe all and all\nthings are bounded by the number three.\u201d\u2014_De C\u0153lo_ I. 1.\n------------------------------------------------------------------------\n\nThe Universe had no beginning, and will have no end; and this\nconclusion, drawn from reasoning, is supported by the belief which all\nhave who believe in gods, \u201cwhether Greeks or not Greeks,\u201d that the\ngods, who are immortal, live in the highest heaven, which is therefore\nalso immortal; and by the fact that no one, throughout the ages, so far\nas we know, has ever seen any change in it.\n\nBut it is of finite dimensions, for no infinitely great body could\nrotate in a finite time; and it is the only universe which exists or\never can exist: outside is neither space, nor void, nor time. For space\nis that which is or may be occupied by matter, and time is the measure\nof motion occurring in matter, and no matter exists or can exist there.\nTherefore that which exists there is not in space nor is altered by\ntime, but lives for ever the best and the self-sufficing life (_i.e._\nthe purely spiritual).\n\nAs matter has three dimensions, so motion is of three kinds: viz. (1)\nin a straight line down, that is, towards the centre of the World; (2)\nin a straight line up, that is, towards the circumference; (3) in a\ncircle round the centre. Thus simple heavy bodies such as all kinds\nof earth, have a simple motion downwards; simple light bodies such as\nfire, move upwards; and when they reach their respective goals they\nremain where they are, unless disturbed by external force\u2014earthy things\non the earth, fiery vapours in the upper atmosphere. Composite bodies\nhave composite motions, the motion proper to the predominant substance\npredominating. But for the heavenly bodies the only possible motion is\nin a circle, where there is neither beginning nor end, no goal and no\nlimit, hence this motion is eternal.\n\nThus Aristotle solved for himself the problem of the early\nphilosophers: how the stars in the sky remain there, for ever circling\nround us, and never falling to the ground. There is no need, he says,\nto assume an Atlas to support the sky on his shoulders, as in the old\nmyths, nor a whirlwind such as Empedocles suggested, nor a Soul of the\nWorld, as Plato said; for the heavenly bodies are not heavy things\nlike Earth to need support, and they are not moved by force, but are\neternally in motion from the nature of their being.\n\nIn the same way he disposes of the difficulty of supporting Earth,\nhaving first \u201cproved\u201d that because there is an ever-circling spherical\nHeaven, there must also be an ever-resting spherical central Earth;\nthere must be its opposite, the ever upward-striving Fire; and there\nmust be the intermediate pairs of opposites, Air and Water. It is\nindeed, he says, a strange thing, and one to set any thoughtful man\nthinking, that the smallest clod of earth, when thrown up into the air,\nimmediately falls down, and presumably would never stop falling if the\nearth were suddenly removed from beneath it; yet here is Earth herself,\nso large and heavy, not falling, but remaining steady in one place. But\nthe explanations given by philosophers are more difficult than the fact\nthey seek to explain. Xenophanes of Colophon said that the earth roots\nin the infinite, which simply saved him the trouble of considering\nfurther; others that the earth rests on water, which is our oldest\ntradition, said to be derived from Thales; but on what then does water\nrest and how can water, which is lighter than earth, support it? Do we\nnot see that even small pieces of earth sink in water, and larger ones\nstill more quickly? Anaximenes, Anaxagoras, and Democritus said that\nEarth rests on air, through her flat shape, as a leaf can float on the\nwind, and they added that the air cannot escape because the flat earth\nfits close down upon it, like a lid, which is also the reason that\nit can support the earth, because it is compressed, and they brought\nforward many proofs to show that air, when compressed and still, can\nsupport great weights. Others, like Anaximander, said that Earth rests\nbecause she is in equilibrium, for there is no reason why she should\nmove in one direction rather than another. But all earthy things (says\nAristotle) do not merely remain at the centre when there, they move\nthither whenever displaced. They are not suspended like a hair which\nis powerfully but uniformly stretched, and so never breaks, nor like\na man who is equally hungry and thirsty, and has meat and drink at\nequal distances from him and therefore starves.[39] No, the truth is\nthat Earth, and every particle of Earth, tends naturally towards the\ncentre of the Universe, and rests when at its goal. We must remember\nthat on every part of the sphere of Earth, heavy bodies fall vertically\nto its surface, showing that it is not to the surface in general that\nthey fall, but exactly to the centre, which is also the centre of the\nUniverse.\n\n------------------------------------------------------------------------\n[39] _Par._ iv. 1-3.\n------------------------------------------------------------------------\n\nOf course it was no solution of the mystery, but only moving it a\nstep back, to say that the stars circle because it is their nature to\ndo so, and heavy bodies fall to Earth because that is their nature.\nBut the interesting point is that the Greeks did reason about these\ntwo motions, and compare them; that they clearly grasped the fact\nthat \u201cweight\u201d simply means a tendency to move, and that the motion\nof falling bodies at Earth\u2019s surface is invariably towards Earth\u2019s\ncentre, accelerating as it appproaches the surface (_De C\u0153lo_ I. 8).\nIt is only the fresh mind of a little child, or of a really intelligent\nman, which is forcibly struck by the mystery of everyday sights, such\nas stones falling, and stars _not_ falling but eternally moving in the\nsky. The force which makes bodies move towards one another we still\ncall \u201cheaviness,\u201d _i.e._ gravity, and the mystery of its ultimate\nnature and mode of action is still unsolved. It is so weak and so often\ncomplicated by other forces that, except in very delicate experiments\nor with the mind\u2019s eye, we can only see it in action when bodies fall\nto the ground; and thus Nature guarded for centuries the secret that\nevery tiny particle on the whole earth attracts every other, and also\nthe earth itself, as surely as the earth attracts them. The further\ngrand secret concerning this force Eudoxus had unwittingly set out\nto discover, with his planetary periods learned from the Egyptians,\nand his three motions of the moon. For when this study was far enough\nadvanced, the necessary data were at hand for Newton, as he pondered\nthe mystery which had baffled Greece; and he was able, from the\nmoon\u2019s motions, to verify his guess, that even the heavenly bodies\nare in truth always falling, falling, towards one another, exactly as\nAristotle\u2019s \u201csmallest clod of earth\u201d fell to the ground.\n\nFrom the theory of the three simple motions, it obviously follows that\nEarth must be at the centre of the world, that her particles must be\narranged in a spherical form round the central point, also the sphere\nmust be at rest.\n\nBut all are not agreed about this, says Aristotle. All who consider the\nUniverse finite say Earth is at the centre; but the philosophers in\nItaly, the so-called Pythagoreans, on the contrary, say that in the\ncentre is Fire, and that Earth, which is one of the stars, is in motion\nround the centre, and so causes day and night. They also assume a\nCounter-Earth, merely from pre-conceived ideas, not from observation of\nfacts. And some agree about the Central Fire, from pre-conceived ideas,\nbecause they think that the noblest should have the noblest place: fire\nis nobler than earth, and boundary nobler than what is bounded, and\ncircumference and centre are both boundaries; therefore (they say) Fire\nand not Earth is at the centre. Moreover, the Pythagoreans say that the\nmost important part of the Universe is the best guarded, and that the\ncentre is such a part, and they call it the Watch Tower of Zeus.\n\nTo these metaphysical reasons Aristotle replies that the centre is not\na true boundary, it is rather an end than a source, it is the material,\nthe limited, while it is the circumference which limits, encloses, and\ngives the form. Besides, the centre of a thing is not necessarily the\ncentre of its being; as with animals the centre of their life (meaning\nthe heart) is not the centre of their body. So the philosophers need\nnot disturb themselves to put Earth out of her local centre, but they\nwould be wiser to examine that other centre of the Universe (meaning\nthe sun), and find out what is its nature and its place, for it also is\na point of origin, and noble.\n\nHe continues \u201cSome also assert that though Earth is at the centre,\nit is wound and moving round the axis which is extended through the\nUniverse, as is written in the _Timaeus_.\u201d Plato\u2019s actual words in the\n_Timaeus_ will not bear this interpretation, as we have already seen\n(p. 85). It is a little surprising that Aristotle does not mention the\nnames of Ecphantus the Pythagorean and Heracleides of Pontus in this\nconnection, since the latter was his contemporary, and perhaps the\nother also, for they are mentioned together as teaching the doctrine\nof Earth\u2019s rotation on her axis.[40] Also Aristotle seems hardly fair\nto either this or the Central Fire theory, in that he only answers the\nmetaphysical reasons of the Pythagoreans, and omits to mention that\neither would unify the diurnal celestial motions in a much simpler way\nthan all his \u201cunrolling\u201d spheres. If he had not especially mentioned\nthat Earth\u2019s motion was supposed by the Pythagoreans to cause day and\nnight, we should be inclined to think that he did not understand that\nthe period was twenty-four hours, and that its effect would be to\nproduce the apparent diurnal rotation of all the heavens.\n\n------------------------------------------------------------------------\n[40] See p. 75, note.\n------------------------------------------------------------------------\n\nThe passage, however, has been a cause of endless controversy from\nthe earliest commentators of Aristotle to the present day, and such a\nthorny question would have been avoided altogether in this book were it\nnot that it is actually quoted by Dante in the _Convivio_.\n\nAs to the size of the earth, Aristotle held that it was not a large\nsphere, and small when compared with the stars. For, he says, if we\ntake quite a short journey to north or south, our horizon changes\nmarkedly, so that the stars above us look quite different, and we do\nnot see the same stars; for some which are well seen in Egypt and near\nCyprus are not visible at all in northern parts, and those which in the\nnorth are always in the sky, set when we go south. And therefore, he\nadds, those who say that the regions near the Pillars of Hercules are\nconnected with India, so that the ocean is one, are not saying anything\naltogether incredible; and their proof is that there are elephants\nboth in the extreme east and the extreme west. He does not mean,\nevidently, that there was no sea at all between, but only that one\ncould quickly travel from one to the other, always going west: there is\nno immense stretch of land or sea between west Africa and east India,\nnor are they the extremities of a flat disc-like earth. Aristotle\ntells us, moreover, that the mathematicians, who have tried to measure\nthe circumference of the earth, find that it is about 400,000 stadia.\nThis is the first time we hear of an attempt to measure the earth, but\nunfortunately we do not know what stadium was used, nor what was the\nmethod employed.\n\n * * * * *\n\nAristotle\u2019s Cosmos is arranged as follows:\u2014\n\nUpon the central spherical Earth rests water, and above this is air,\nbut these intermingle more or less, and are not sharply divided; in\nthe same way, though fire rises highest of the four elements, there is\nnot a distinct sphere of fire, but the higher part of the atmosphere\nis chiefly composed of it. It is in this upper fiery atmosphere that\nshooting stars are produced: hot and dry exhalations rising from Earth\ntake fire there, but are quickly consumed. Comets have their origin in\nthe same place, when large masses of vapour rise and are directly below\nthe sun (had the Greeks noticed that comets\u2019 tails are always streaming\naway from the sun?). Aristotle also explains that the Milky Way is\nformed from these constantly-rising vapours, but under the influence of\nthe stars, for it always has the same position amongst them, and that\nis where the most numerous and brightest stars congregate.\n\nThus within and below the fiery atmosphere constant changes are taking\nplace, and all things are perishable, but as soon as we reach the\nlowest of the heavenly spheres, the moon\u2019s, we enter another world.\nAll is changeless, eternal, divine. Motion is in circles, space is\nfilled with ether, the heavenly bodies as well as their spheres are of\nan ethereal substance.\n\nThe Pythagorean idea of music made by the spheres, Aristotle dismisses\nas very pretty but unfortunately not true. For if in truth these\nimmense spheres made a sound as they moved, even if we could not hear\nit (as they said) we should feel it, for even earthly thunder bursts\nrocks asunder! And there is no reason why they should make any sound,\nfor nothing moves out of one place: the spheres are simply rotating,\nwhich is the natural movement for a sphere, unless it rolls along,\nwhich they are not doing. If nature had wished the spheres or the stars\nand planets to move forward, she would not have treated them worse\nthan terrestrial animals, in giving them no limbs by which they could\nprogress! The stars and planets have no motion themselves of any kind,\nbut are simply carried along by their rotating spheres, as we can\nplainly see by the moon turning always the same face towards us: hence\nthey make no more noise than a ship\u2019s mast set in a ship, or the whole\nship as it glides down a river.\n\nStress is laid both by Plato and Aristotle on this absence of any\nmotion of translation in the heavenly bodies and their spheres;\nboth insist that a movement of rotation, in which the moving body\ncontinually occupies the same place, is the only movement existing in\nthe heavens. One wonders whether the spheres of Eudoxus suggested or\nresulted from this idea.\n\nAristotle does not enter into detail about the separate planetary\nmotions, in any extant work, but explains as the general principle that\nthe outermost, the prime movement of the whole universe, is simple,\nand the most rapid, while the inner are complex, slower, and in the\ncontrary direction; so that the planet nearest to the prime movement\n(Saturn) is longest in making his own revolution, because most affected\nby it, and the others less so in proportion to their distance. He\nrefers his readers to the mathematicians, and quotes the Egyptians and\nBabylonians as having furnished satisfactory proofs of the relative\npositions of the planets, by such observations as occultations of\nother planets by the moon, which show that she is below them (_i.e._\nnearer to us). The passage is quoted by Dante[41], in which Aristotle\ndescribes how he himself once saw an occultation of Mars. \u201cWhen the\nmoon was a half sphere, she passed beneath Mars and he disappeared\nunder her dark side, but came forth again on her bright illumined side.\nAnd the same kind of thing,\u201d he adds, \u201cis reported to happen with the\nother planets also, as those tell us who for a vast number of years\nhave made observations, viz. the Egyptians and Babylonians.\u201d\n\n------------------------------------------------------------------------\n[41] _Conv._ II. iii. 59-65.\n------------------------------------------------------------------------\n\nThere is one point which is elaborately discussed in the _De C\u0153lo_,\nwhich seems very curious to us, but the main point must be noted here,\nsince it is of some interest to the Dante student. Aristotle tells\nus that he considers the sphere of the Universe to have a top and a\nbottom, and that the Pole which is not seen by us (the south) is at the\ntop. One cannot help thinking that Dante had this in mind when he chose\nthe southern hemisphere for the mount of Purgatory, whither, after all\ntheir mistakes and wrong-doing on this underside of the earth, souls go\nto purify themselves on the upper side, under the stars of the southern\npole.\n\nIn his book on metaphysics, Aristotle gives a very brief sketch of the\nspheres of Eudoxus and his own \u201cunrolling\u201d spheres; and says that all\nthese planetary movements prove the existence of Essences, eternal\nand immoveable themselves, who cause these movements. And it has been\nhanded down to us in a mythical way, from the most ancient teachers,\nthat these eternal Essences are gods. Above all these must be a First\nMover, the Primum Movens Immobile, who is one, eternal, and enjoys\nfor ever the kind of existence which we only experience in our best\nmoments. Upon this First Mover depend the whole heaven and all nature.\n\n\n5. ARISTARCHUS.\n\nWith a system of revolving spheres accepted by the mathematical\nastronomers, and sanctioned by the great philosopher Aristotle, it\nmay be thought that we are within sight of our goal, the system\nof Greek astronomy which was to dominate the scientific world for\nmany centuries, including the age of Dante. But so exacting had\nthe careful observers become that the system of Eudoxus must be\ncompletely transformed, by aid of two quite new hypotheses, before\nit would satisfy their demands. Also, about half a century after the\nconsultation of Calippus and Aristotle in Athens, a strange new theory\nwas propounded, the boldest and strangest of all.\n\n[Sidenote: Aristarchus _c._ B.C. 281.]\n\nNearly two thousand years before Galileo was summoned before the\nInquisition, and forced to recant upon his knees his \u201cmost damnable\nheresy\u201d that the earth goes round the sun, Aristarchus of Samos was\naccused of impiety by his countrymen for the same crime. But he met\nan even sadder fate than Galileo\u2014neglect. His daring scheme was\nalmost ignored by his contemporaries, and but for a casual mention by\nArchimedes and by Plutarch, we should know nothing about it.[42]\n\n------------------------------------------------------------------------\n[42] It is also mentioned in a compilation of philosophers\u2019 opinions,\nprobably made in the fifth century A.D. by Stob\u00e6us, who is very likely\nquoting Plutarch.\n------------------------------------------------------------------------\n\nHe was, however, very famous as a mathematician, and also as an\nobserver. Ptolemy quotes his determination of the summer solstice of\nthe year b.c. 281, and this tells us the date at which he flourished.\nHe was renowned for a very ingenious method by which he tried to\ndiscover how much further from us the sun is than the moon. When the\nmoon is half full the angle sun-moon-earth is a right angle, and if\nthe angle sun-earth-moon be measured, by pointing the astrolabe first\nto sun and then to moon, the third angle, at the sun, may be computed,\nand then the ratio sun-earth to moon-earth will be known. The method\nis perfect theoretically, and if the sun were comparatively near, say\nabout ten times the moon\u2019s distance, it would be practicable; but the\ndistance is really so much greater that the angle at the sun almost\nvanishes, and a very small error in estimating it causes an error\nequal to many millions of miles in the result. It is also impossible\nto determine from looking at the moon the exact time when the division\nbetween light and dark is a straight line. Aristarchus made the angle\nat Earth 87\u00b0 instead of 89\u00b0 50\u2032, and this gave the sun a distance of\nabout 19 times as far as the moon, instead of 400 times, which is the\ntrue value.\n\n[Illustration: Fig. 20. Method of Aristarchus for finding the distance\nof the sun.]\n\nThe foolish fad (as they thought it) about Earth\u2019s motion, held by this\notherwise great man, is described quite clearly by the two writers\nabove-mentioned. He suggested that the stars might be immoveable, and\nEarth be turning on her axis at the same time that she moves in a\ncircle round the sun. Moreover realizing all that this implies with\nregard to the immense distance of the stars, he said that the circle\nin which Earth revolves round the sun, compared with the sphere of the\nstars, is as the centre of a sphere compared with its circumference.\nThat is, not only Earth, but Earth\u2019s whole orbit, shrinks to a point\nwhen compared with the infinite distance of the stars.\n\nWe have unfortunately absolutely no information as to the way in which\nAristarchus was led to these remarkable truths, and can only make\nconjectures from what we know of his times. Evidently the Central\nFire theory was a suggestive step, and so was another theory which\nwas afloat about this time, and has been called the \u201cEgyptian system\u201d\non the authority of Macrobius in his commentary on Cicero\u2019s _Dream of\nScipio_. No one really knows where it arose, but it is ascribed with\nmuch probability to Heracleides of Pontus. According to this, the\ntwo planets Mercury and Venus circled round the sun, and all three\ntogether circled round Earth, which still remained the centre of the\nUniverse and of the other celestial motions. It was an idea which might\nhave occurred to any unprejudiced observer, since the oscillations of\nMercury and Venus from side to side of the sun are more striking than\ntheir movements through the stars. They never go far from him in the\nsky, like the other planets, and seem to belong to him.\n\nFurther, the clear understanding of the periodic motions of Mars,\nJupiter, and Saturn, and the accurate observation which had been\nintroduced by Eudoxus, must have revealed the fact that the loops in\nthe orbits of these planets are connected with the apparent movement of\nthe sun; and the varying brightness (especially noticeable with Mars)\nis inconsistent with the assumption of unvarying distance from Earth.\n\nThe great importance of the sun, above all the other planets, had of\ncourse always been recognised, and it is possible that Aristarchus\nwas struck by an unconscious suggestion in Aristotle\u2019s advice to the\nPythagoreans to examine the nature and place of the sun, \u201cthat other\ncentre of the Universe,\u201d for that was also a point of origin, and\na noble one.[43] His own work, too, would lead him to attribute a\ncommanding position to the sun, for as it was nineteen times as distant\nas the moon, it must also be nineteen times as large (since they appear\nequal), so he must have felt certain that it was a very great size,\nprobably much the largest of all bodies in the Universe.\n\n------------------------------------------------------------------------\n[43] See page 101.\n------------------------------------------------------------------------\n\nIt was the grandest and truest of all the Greek astronomical theories.\nBut it was not accepted, it was hardly even discussed, and we can\nscarcely be surprised at this. Such an improbable theory needed\nmany more convincing proofs than Aristarchus could bring forward.\nObservation, calculation, comparison of theory with facts, this was\nwhat was needed before safe ground could be won for belief, and in\nthis Eudoxus was a true pioneer. But freedom of thought and courage in\nimagination is needed also in science, and Aristarchus seems to have\nbeen almost the last to possess this.\n\n[Sidenote: Seleucus B.C. 160.]\n\n[Sidenote: Aryabhata born A.D. 467.]\n\nA certain Babylonian, named Seleucus, who lived about B.C. 160, perhaps\non the Tigris, and an Indian astronomer, Aryabhata, of the fifth\ncentury A.D., both taught that Earth turns on her axis, but Aristarchus\nstood alone in suggesting that she also has a movement of revolution\nround the sun. The possibility of Earth\u2019s motion was alluded to but\nseldom by classical and medi\u00e6val writers, and then almost always as a\nfoolish fancy hardly worth discussion;[44] until at last Copernicus,\nhardly daring to publish his bold idea in sixteenth century Europe,\nfor fear of persecution, sought and found among the followers of\nPythagoras, and in Aristarchus of Samos, kindred spirits with his own.\n\n------------------------------------------------------------------------\n[44] Indian astronomers also refused to accept the doctrine of\nAryabhata. Var\u00e2ha Mihira (sixth century A.D.) says:\u2014\u201cOthers maintain\nthat the earth revolves and not the sphere: if that were the case,\nfalcons and other birds could not return from the ether to their nests.\u201d\n------------------------------------------------------------------------\n\n\n6. THE SCHOOL OF ALEXANDRIA.\n\nThe spheres of Eudoxus would not work. The system was already\noverladen, and more variations in velocity were becoming known.\nObservation shows, too, that the planets, especially Mars and Venus,\nvary greatly in brightness, in regular periods which correspond with\ntheir movements, and this could not be accounted for by any possible\nnumber or arrangement of spheres if all were to remain concentric to\nEarth, so that every planet remained always at a uniform distance. Yet\nAristotle had said that Earth must be at the centre of the Universe.\nThe new philosophers of the Stoic school agreed with him, and among\nmathematicians only Aristarchus dared to disagree.\n\nBut they were not long at a loss. The homocentric spheres[45] were\nthrown aside, and during the third century two new hypotheses were\nsuggested (beside that of Aristarchus), and although we do not\ncertainly know by whom, there is little doubt as to the place in which\nthey originated. By a strange fate, Egypt, the home of astronomy many\ncenturies before, became the seat of the latest, most brilliant, and\nmost successful astronomical school of ancient times, and the knowledge\nwon there in the five centuries between B.C. 300 and A.D. 200 spread,\nfollowing in the wake of Alexander\u2019s conquests, over the whole of the\ncivilized world.\n\n------------------------------------------------------------------------\n[45] Spheres all centring in one point.\n------------------------------------------------------------------------\n\nIt was a purely Greek school, however. Greece lost her independence\nunder Alexander, and was finally crushed by Rome in 146 B.C., but never\nwas Greek learning and culture so much honoured and sought after as\nin this age. In Egyptian Alexandria, Greek men of science found a\nwelcome, and opportunities of research which did not exist in any other\nplace in the world. In the Museum, founded and liberally endowed by\nthe royal Ptolemies, was a great library whose custodians were bidden\nto obtain every book that had ever been written, and it is said that\nwhen any stranger arrived with a new book it was taken from him and\ncopied for the Museum, and the copy returned to the owner. Within the\ngreat marble colonnaded building were lecture-halls, and reading rooms,\nand laboratories; there were gardens for botanists and zoologists, and\nobservatories for astronomers. These astronomers were all Greeks, and\nthough now living in Egypt they do not seem to have learned anything\nmore from the Egyptians. Perhaps the priests resented the intrusion,\nand kept their secrets jealously to themselves; perhaps Eudoxus and\nhis immediate followers had learned all they had to teach. This seems\nthe more probable because, although the Greeks of this age did use\nBabylonian records of eclipses to form a lunar theory, they complained\nof the insufficient accuracy of all available planetary records.\nMoreover, they were not hindered from learning astrology: the sacred\nbooks of the Egyptians which taught its principles were translated into\nGreek about 300 B.C.; but it was always treated by them as quite a\nseparate branch of study. Their geometrical methods were entirely their\nown. They introduced a system of notation which greatly simplified\ncalculation[46]; their discovery of the principles of spherical\ntrigonometry inaugurated a new era in astronomy; and they invented a\nnew class of astronomical instrument.\n\n------------------------------------------------------------------------\n[46] Mahaffy, _The Progress of Hellenism in Alexander\u2019s Empire_, p.\n119.\n------------------------------------------------------------------------\n\nWe know what these instruments were like, and it is even possible to\ngive an illustration; for, from descriptions in Ptolemy\u2019s _Almagest_,\nwe find that the \u201cwell-made copper circles,\u201d the gnomons, and the\ncelestial globes, which were set up in the Square Portico of the\nMuseum, were of the same pattern as instruments which existed in Pekin,\nin the ancient observatory on the ramparts, until they were looted by\nthe Germans during the late Chinese war. The Alexandrian instruments\nwere not supported on their stands by beautiful bronze dragons, but on\nthe other hand the circles were more accurately divided, which after\nall was of more importance from the astronomers\u2019 point of view. Fig. 21\ngives a general view of the Pekin Observatory, and Fig. 22 one of their\nastrolabes dating from the 13th century A.D.\n\nAt first glance there seems to be here absolutely nothing like our\nmodern observatories. Ancient and medi\u00e6val astronomers had indeed no\ntelescopes, being ignorant of the properties of lenses: therefore they\nwere unable to study the features of any heavenly body except the\nmoon, and they had no way of finding out anything about their physical\nconstitution; but they had many ways of measuring their distances\nand motions, and even the angular sizes of sun and moon, and their\ninstruments were the forerunners of our sextants, micrometers, and\ntransit instruments, our chronometers and sidereal clocks.\n\n[Illustration: PEKIN OBSERVATORY. [_To face p. 114._\n\n_From a photograph taken in 1888, and published in the \u201cBulletin de la\nSoci\u00e9t\u00e9 belge d\u2019Astronomie\u201d._]\n\nThe gnomon has been already described[47], and it was one of the most\nvaluable instruments used by the Greeks. The Pekin gnomon at the right\nof figure 21 was more than 40 feet in height, and on the top had a\nlittle plate of copper which was pierced by a hole as fine as the eye\nof a needle: the observations made with this were much more exact than\nobservations of the end of the shadow, which must always be vague, and\nthe Chinese records of the sun\u2019s movements made with this instrument\nbetween 1270 and 1280 A.D. are of great value in modern research.\nPtolemy explains that his gnomon was made accurately vertical by the\nuse of a plumb-line, and that one way of testing the level of the\nsurface on which the shadow fell was to flood it with water.\n\n------------------------------------------------------------------------\n[47] See p. 26.\n------------------------------------------------------------------------\n\nClepsydras, or water-clocks, were used by the Greeks, and many kinds\nof sundials for telling the time by day. Tables were also made of the\nrisings of bright stars which served for clocks by night.\n\nThe instrument in the middle of the platform is a quadrant, and beyond\nthis on the left is a large celestial globe, which, however, only\ndates from the Jesuit missionaries of the seventeenth century. Ptolemy\nsays that his globe was made the colour of the night sky; Sirius being\nmarked in his proper place, all other stars were placed relatively to\nhim, and in their own colours as nearly as might be; the Galaxy was\ndrawn, and the figures of the constellations outlined. The globe was\narranged to turn on either the poles of the ecliptic or of the equator;\ncircles of wood represented the horizon and meridian, and the pole\ncould be arranged at any altitude according to the latitude of the\nplace.[48]\n\n------------------------------------------------------------------------\n[48] _Almagest,_ Bk. viii.\n------------------------------------------------------------------------\n\nBut perhaps the most interesting are the astrolabes, and these owe\ntheir origin to the Greeks. The essential part of any instrument for\ndetermining angular distances is a divided circle and a pointer: the\npointer is directed first to one object then to another, and the angle\nbetween them is then read off on the circle. In the astrolabe, the\npointers themselves were also circles, provided with little perforated\nrods for \u201csights.\u201d (These are not visible on the instrument in Fig.\n22, and have probably been broken off.) There were two fixed circles,\nset in the plane of the ecliptic and perpendicular to it. Three other\ncircles could be rotated round the poles of the ecliptic. One of these\nwas directed (by means of the sights), to some body whose position\nwas already known, another to the body whose position was to be\nascertained, and the angle between them was read off on the ecliptic\ncircle; on the third the angular distance north or south of the\necliptic circle could be read. This last and the ecliptic circle were\nboth divided into 360 degrees, and as many fractions of a degree as\nspace and skill would allow.\n\nThe equinoctial astrolabe was similar, but the fixed circle was in the\nplane of the equator, instead of the ecliptic. One of each of these is\nseen in the view of the Pekin Observatory.\n\nBut how did the old astronomers know how to find the ecliptic and the\nequator in the sky, and set their circles in those planes? This they\ndid by means of the sun\u2019s motion. The gnomon told them the day of\nthe equinox (see p. 25), and on that day the sun was in the equator:\ntherefore, if a circle was set up so that the shadow of the upper part\nfell symmetrically upon the lower, with a little line of light each\nside, it must be exactly in the plane of the equator. In the Square\nPorch such a circle was erected, a large one of copper, and when once\ncorrectly adjusted it was a standard plane, and also showed the date of\nthe equinoxes, as accurately as the gnomon itself. Since the ecliptic\nis the path of the sun as seen in the sky, it is obvious that it could\nbe determined from a number of different observations of his position\nat different times of the year.\n\n[Illustration: A PEKIN ASTROLABE OF THE 13TH CENTURY, A.D. [To face p.\n116\n\n_From a photograph taken in 1888, and published in the \u201cBulletin de la\nSoci\u00e9t\u00e9 belge d\u2019Astronomie\u201d._]\n\nFinally, accurate solar tables were drawn up, showing the sun\u2019s\nposition in the sky in degrees for different dates, and then from these\nit was possible to find the places of planets and stars. They could\nnot of course be compared directly, but the position of sun and moon\nwere compared during the day, when both were in the sky, and then after\ndark the planets and stars were compared with the moon, allowing for\nher motion among the stars in the meantime. Or secondly, when the moon\nwas eclipsed, and therefore known to be in the ecliptic and exactly\nopposite the sun, the places of stars could be found directly.\n\nThis very brief description will give some idea of the chief\ninstruments and methods used, and when we see how very rough and\nelementary they were, and remember that the Greeks had to work out\ntheir observations without algebra, or decimal notation, we are amazed\nat their results, and their far-reaching ambitions.\n\n[Sidenote: Eratosthenes B.C. 276-194.]\n\nAlready in the very early days of the Museum, Eratosthenes, a\ncelebrated geographer, made a bold attempt to utilize observations\nof the sun measuring the size of the earth. It was known that in\nSyene (the modern Assuan) on the day of the summer solstice at noon\nno shadows were thrown, and the bottoms of wells could be seen:\nevidently therefore the sun was in the zenith. Eratosthenes found\nthat the sun\u2019s distance from the zenith in Alexandria at noon on\nthe same day was 7\u00b0\u00a012\u2032, or one-fiftieth of the circumference of\nthe heavenly sphere, consequently the two towns must be distant\nfrom one another (assuming them to be nearly in the same meridian)\none fiftieth of the circumference of the earth. The distance from\nAlexandria to Meroe was known, and from Meroe to Syene had been paced\nby the king\u2019s professional pacers; the whole was 5000 stadia. 50 times\n5000\u00a0=\u00a0250,000. The figure always quoted by the ancients is however\n252,000. If the stadium used by Eratosthenes was the measure generally\nused for long distances which have been paced, this estimate is equal\nto 24,662 miles, only about 200 miles less than the modern value. It\nwas partly by luck that Eratosthenes got such a good result, for he was\nevidently only working with round numbers, and the extra 2000 stadia\nseem to have been added in order to make one degree equal to exactly\n700 stadia. But in any case it was a highly creditable performance.\n\n[Sidenote: Euclid _c._ B.C. 300.]\n\n[Sidenote: Apollonius _c._ B.C. 270.]\n\nThere were celebrated mathematicians and geometers at Alexandria, whose\nwork was most useful to astronomy, such as Euclid, and Apollonius of\nPerge. The latter is specially mentioned by Ptolemy in connection with\nthe new theory of \u201cmoveable eccentrics,\u201d which was invented to account\nfor the varying brightness of the planets, as well as their peculiar\nmovements.\n\nFig. 23 explains this theory. Let P A be a great revolving circle upon\nwhich Mars is fixed. (In the hands of the Alexandrian mathematicians\nthe spheres almost disappear, and they deal practically only with\ncircles.) If the earth were at its centre, as Eudoxus demanded,\nMars must always be at the same distance, but if we make the circle\neccentric to Earth, by putting its centre at C while Earth is at E,\nthen the distance and consequently the brightness will constantly vary,\nand Mars will be brightest when at perigee P (point nearest Earth), and\nfaintest when in apogee A (point furthest from Earth).[49]\n\n------------------------------------------------------------------------\n[49] Greek _peri_ near, _apo_ away from, _ge_ Earth.\n------------------------------------------------------------------------\n\n[Illustration: Fig. 23. The Moveable Eccentric.]\n\nBut, as the Greeks had discovered, Mars attains his greatest brilliance\nat different points of the zodiac, so P must be made moveable, and\nit always happens when he is opposite the sun, therefore P must keep\npace with the sun\u2019s apparent motion in the zodiac and P E always point\ntowards him. This was accomplished by making P C A turn round upon the\nfixed point E, so that for instance when the sun had moved through a\nquarter of his circle (in three months) P A had moved to P\u2032 A\u2032, and the\nwhole eccentric had moved into the new position shown in the diagram,\nits centre C being now at C\u2032. In other words, the centre of the\neccentric moves round Earth in the same time and in the same direction\nas the sun, that is in one year, and \u201cwith the signs\u201d (from west to\neast).\n\nAt the same time, Mars is moving in an opposite direction on the\neccentric, and without entering into all the details of the problem,\nwe may add that the Greek geometers found that by determining the\nproper relative sizes of the large and the small circle they could make\nthe two motions neutralize one another when the planet reached its\nstationary points, and the retrograde motion prevail over the direct\nwhen it retrograded. A similar arrangement was made for Jupiter and\nSaturn.\n\nIn this very ingenious way the varying brightness as well as the\nvarying motions of these three planets were accounted for, without\nviolating the principle of uniform circular motion, and without\nremoving Earth from the centre of the Universe. She was also still\nthe centre of planetary motion, in a certain sense; but to place the\ntrue centres of these planets\u2019 spheres _outside Earth and in the\ndirection of the sun_ was a very suggestive step, and may well have\nhelped Aristarchus to his bold hypothesis. For he had only to put the\nsun, not at some indefinite point along the line E A, but exactly at\nthe point C, and it became the centre of motion for Mars, Jupiter, and\nSaturn, just as in the \u201cEgyptian theory\u201d it was the centre of motion\nfor Venus and Mercury. In this way he would arrive at the conception\nof the sun circling round Earth and carrying all the planets with him,\n(a theory which was held by the great astronomer Tycho Brah\u00e9 in the\nsixteenth century A.D.). Then a flash of insight may have revealed to\nhim the fact that this motion of the sun is apparent only, being but\nthe reflection of Earth\u2019s own motion; for she is circling round the sun\nlike all the other planets.\n\nIt is, however, only a guess that the Moveable Eccentrics played this\npart in the theory of Aristarchus. They did not long hold the field,\nbecause they were not applicable to Venus and Mercury, which are never\nseen in opposition to the sun. So they were thrown aside for another\nsystem, the Epicycles, which illustrates much more simply the stations\nand retrogressions of the planets, and can be used for them all.\n\nLater on, when more irregularities of motion were discovered, it was\nfound necessary to combine eccentrics and epicycles, and by means of\nthis joint system it became possible at last to represent completely,\nand as accurately as they could be observed, all the apparent movements\nof the heavens. First, however, an immense amount of work had to be\ndone, and new methods devised, both in observation and mathematics.\nThe man who contributed most, in both ways, to make it possible, was\nHipparchus.\n\n\n7. HIPPARCHUS.\n\n[Sidenote: Hipparchus _c._ 140 B.C.]\n\nOf this great man we know scarcely anything but what can be gathered\nfrom the work he did, and this corroborates Ptolemy\u2019s description of\nhim: \u201cHipparchus, lover of toil and truth \u03c6\u03b9\u03bb\u03bf\u03c0\u03bf\u03bd\u03bf\u03bd \u03ba\u03b1\u03b9 \u03c6\u03b9\u03bb\u03b1\u03bb\u03b7\u03b8\u03b5\u03b1.\u201d\nHe lived about B.C. 140, since this is the date of the only book of\nhis still extant, and his work was not done in Alexandria, though he\nmay have studied there in his youth, and he used the Museum records.\nWe count him among the Alexandrians, as he belongs to this era, but\nhe seems to have been a private astronomer, who set up an observatory\nof his own in Rhodes, his native place. Here we seem to see him,\nsurrounded by his primitive instruments and his papyrus books, patient,\neager, modest, seeking no fame and no reward but the joy of his work.\nBy day he would keep watch over the sliding shadow of his gnomon,\nwould write up his observations, make long calculations, and devise\nnew methods in mathematics, improve and modify his astrolabes and his\nclepsydras; at night he would spend long hours with moon, planets, and\nstars, making up for the defects and shortcomings of his instruments by\nthe skill and care with which he applied them to measure positions in\nthe sky. Nothing but the most loving and conscientious care could have\nraised his work to such a pitch of accuracy, and made such rude means\nsuffice for such splendid achievements.\n\nThe book we possess, apparently an early one, is chiefly concerned with\nthe positions, the risings and the settings, of stars, and at the end\nis a list of sixteen which came to the meridian at intervals of an\nhour: from this list and the knowledge of spherical trigonometry which\nhe possessed, it would be possible to calculate the time at night to\nwithin about a minute.\n\nHipparchus was able to construct a satisfactory theory of the sun\nand to some extent of the moon, but he found more irregularities in\nthe planetary motions than Eudoxus had suspected. The records of his\npredecessors were not accurate enough for him to construct a theory\nfor the planets, and he soon realized that one life-time would not be\nlong enough to collect all the data necessary, so, as Ptolemy tells us,\n\u201cHipparchus, who loved truth above all things,\u201d quietly set to work to\nmake as good and as many observations as possible, leaving it to his\nsuccessors to complete and explain them.\n\nIn the same spirit he undertook the laborious task, of which Pliny\nspeaks with awe as a presumptuous scheme, even for a god, \u201c_rem etiam\nDeo improbam_,\u201d of numbering the stars. Pliny says he was led to do\nthis by the appearance of a New Star, which blazed out suddenly in\nthe constellation of Scorpio in b.c. 136, just as Nova Persei did in\nPerseus in February 1901. He saw that even in the upper regions of the\neternal heavens, which Aristotle had supposed absolutely changeless,\nchanges may occur, and in order that even the least of these should\nnot pass unnoticed, he set to work to note the number, brightness,\nand position of all he could see. This great catalogue of 1080 stars,\ncopied by Ptolemy in his _Almagest_, was the basis for all succeeding\ncatalogues, from Spain to Turkestan, until quite modern times. In it,\nfor the first time, the places of the stars were not merely described\naccording to their position in the constellation figures, but were\nnoted in degrees on the sphere, as is done to-day.\n\n[Sidenote: Timocharis _c._ B.C. 280.]\n\nOne day, when comparing his notes with those of Timocharis, who had\nworked at Alexandria about a century and a half earlier, he found that\nthe brilliant star Spica, the Ear-of-Corn which the Virgin carries\nin her hand, had apparently moved nearer to the autumnal equinox by\nabout 2\u00b0. (Two degrees is about four times the angular diameter of the\nsun). Of course he or Timocharis might have made a mistake, or Spica\nmight really be moving among the stars, or she might be carried along\nwith the rest by a slow movement of the whole star sphere. Apparently\nHipparchus satisfied himself that he could rely upon Timocharis\u2019\nobservation, and took pains to verify his own; the second hypothesis\ncould be disproved by the fact that Spica does not change her place\nperceptibly among her neighbours; and finally it became clear that her\nmotion is part of a slow apparent movement of the whole heavens.\n\n[Illustration: Fig. 24. The movement of Spica.]\n\nHere was a discovery of first importance, an unexpected reward of\npatient accuracy, of which the white Spica, flashing down from summer\nskies, may always remind us. Hipparchus had discovered the grand cycle\nwhich we call the \u201cPrecession of the Equinoxes,\u201d and before Spica\nreturns to the same position in which he saw her then, when she led\nhim to his great discovery, she will have been watched by generations\nof astronomers for another twenty-four thousand years. No notice\nof the cycle has been found as yet among the records of any other\nnation, although it seems as if the astronomers of Babylon and Egypt,\nand other countries where observations had been carried on for many\ncenturies, must have been aware of it. We can only imagine that at long\nintervals of time they found that the stars had somehow changed, and\nmade corrections accordingly, but without understanding the nature of\nthe change. What Hipparchus thought about its cause we cannot tell:\nprobably he left all speculations to future astronomers, and confined\nhimself to noting the fact.\n\nThe displacement of Spica which he observed is shown in the diagram.\n\nBoth Timocharis and Hipparchus evidently measured her position\nindirectly by comparing it with that of the moon, which was eclipsed at\nthe time,[50] and therefore known to be in the ecliptic and opposite\nthe sun. To find the sun\u2019s distance from the equinox was an easy\nmatter, since his yearly course had long been carefully studied, and\nthe days on which he passed the equinoxes were regularly observed with\nthe gnomon. Spica, then, had moved eastward along an arc parallel to\nthe ecliptic, and since celestial latitude and longitude are referred\nto the ecliptic, we may define her apparent movement in astronomical\nlanguage by saying that while her latitude had remained constant, her\nlongitude had increased by about two degrees; and further, as the\ncelestial equator is oblique to the ecliptic, this implied that her\ndeclination (position north or south of the equator) had also varied.\nThe diagram shows that she had a less northerly declination than before.\n\n------------------------------------------------------------------------\n[50] _Syntaxis_, book VII.; Delambre, _Histoire de l\u2019Astronomie\nAncienne_ Vol. II. page 247 (1817 edition).\n------------------------------------------------------------------------\n\nAt this rate, Spica, which was now only 6\u00b0 from the autumnal equinox,\nwould reach it in less than five hundred years, and thereafter would\nlie east instead of west of it; and that she has in fact done so, may\nbe seen by consulting a modern star atlas. She is now 22\u00bd\u00b0 of longitude\neast of the autumnal equinox, and nearly 11\u00b0 south of the equator. Her\nsouth declination will continue to increase for about five thousand\nyears, after which she will come north again.\n\nPtolemy says that Hipparchus examined other stars, and found that they\nalso were increasing their longitude at what appeared to be the same\nrate as Spica. The yearly amount of the movement, derived from the\nSpica observations, is within a few seconds of arc of the true value,\nwhich is 50\u00bc seconds; but Hipparchus would not fix any value until it\nhad been tested by further observation, and merely stated that it could\nnot be _less_ than one degree in a century _i.e._ 36 seconds per annum.\n\nThis is a very uncomfortable phenomenon for astronomers, since every\nstar is for ever changing its measured position on the celestial\nsphere. Take three stars, one at the north pole, another on the\nequator, and a third in the southern hemisphere. After some years,\nthe first will no longer be a pole star, the second no longer an\nequatorial star, and the third may have so far increased its south\ndeclination that it will be invisible at latitudes in our northern\nhemisphere where formerly it used to rise above the horizon. One\ncompensation for this inconvenience is that if we know what star was\nnear the pole, or which stars lay along the equator, on any given\noccasion, we can calculate the date. Thus it is believed that the Great\nPyramid was built when Alpha Draconis was the Pole Star, that is,\nnearly 3000 years B.C.; and by a similar method Mr Maunder determines\nthe epoch at which the ancient southern constellations were invented,\nas we have already seen.\n\nThe greatest inconvenience, and also the greatest historical interest,\nattaches to stars like Spica which belong to constellations of the\nzodiac, for if they are not stationary with regard to the equinoxes and\nsolstices they are not such simple guides to the length of the solar\nyear as the ancients supposed them to be. The scheme of the Babylonians\nfor beginning their month Nisan when the stars of Dilgan rose just\nbefore the sun was an excellent one for a time, but if they had\ncontinued it for many centuries they would have found that their year\nwas too long, and the months were all falling in the wrong seasons.\nThis has actually happened with Hindus and Parsis, who now keep their\nNew Year in the middle of our April, although when their calendar was\nfixed, about thirteen hundred years ago, the years began at the spring\nequinox. For the sun is like a runner in a circular race-course who\nthinks he has completed a lap when he returns opposite a group of\nspectators originally standing at the starting-point, but after several\nlaps he finds that the spectators and the goal no longer coincide;\neither they, and also all the others surrounding the course are walking\naway from it, or an unseen hand has been moving the flag towards him,\nand so shortening the lap.\n\nIt is the flag which must count, in any case, not the spectators, and\nwith the sun it is the equinox which must count, and not the stars, for\nthis is the point at which he crosses the equator, making day and night\nequal, and from this we count the beginning and ending of our seasons.\nSo our year is counted from equinox to equinox, and is twenty minutes\nshorter than the \u201csidereal,\u201d or star year, of the ancient Babylonians.\nHipparchus, from observations of equinoxes and solstices, made the year\n365 days 5 hours and nearly 55 minutes, which is only 6 minutes longer\nthan the correct value.\n\n[Illustration: Fig. 25. The Sun and the Equinox.]\n\nAfter Hipparchus had made his discovery, astronomers agreed upon a\nsomewhat clumsy and very confusing device, by which the zodiac was\ndivided into twelve equal \u201csigns\u201d of 30 degrees, which bear the same\nnames as the zodiacal constellations, but whose beginning is always\nreckoned from the vernal equinox. These twelve \u201csigns of the zodiac,\u201d\ntherefore, do not now agree with the twelve constellations of the\nzodiac, and our present \u201cfirst point of Aries,\u201d which marks the vernal\nequinox, is in the _constellation_ of Pisces.\n\nWhat is the true cause of this strange phenomenon? Are the stars really\nall in motion, or is it the equinox which moves?\n\nThe successors of Hipparchus, who believed that the stars were fixed\non a sphere, found no great difficulty in conceiving that this sphere\nhad a very slow easterly motion, round the poles of the ecliptic,\ncompleting a revolution once in 36,000 years (_i.e._ one degree in\ncentury). To us, however, it is impossible to believe that the stars,\nwhich we have found to be at enormous and varied distances, are all\nrevolving at one rate, parallel to the ecliptic. The ecliptic, to us,\nis simply the plane of Earth\u2019s own orbit, and as she moves in it she\nhas a very slow \u201cwobbling\u201d motion on her axis, as well as the rapid\nspinning of the diurnal motion, like the \u201cwobble\u201d of a spinning top.\nThe top has this motion because gravity is trying to pull it down from\nits upright position; the earth because the sun is trying to drag her\nslightly protuberant equator into the plane of her orbit.\n\nThe resulting motion is not a revolution of the earth, nor an apparent\nrevolution of the star sphere round Earth: what really happens may be\nillustrated with the traditional orange and knitting needle.\n\nIgnoring all motions but the one we are speaking of, let the points of\nthe knitting needle (Earth\u2019s axis of rotation) trace out small circles\nin space, and the equator of the orange will be seen to alter the\ndirection of its tilt, but without turning round (Fig. 26). Stick a pin\nin the equator, and others in north or south latitudes, between equator\nand pole; these will always remain facing you, but while the pole makes\nits small circle, the equatorial pin will be seen to move up and down,\nwhile the tropical and temperate pins trace out ellipses. These are the\nmovements which we see reflected in the stars; and if Earth\u2019s diurnal\nrotation were suddenly to cease, while her revolution in her orbit\nand the movement of \u201cprecession\u201d continued, we should see Spica, for\ninstance, sink slowly lower in the southern sky and after ages rise\nagain northwards, but there would be very little preceptible movement\neast or west.\n\nThe movement observed by Hipparchus, then, was not a movement of Spica\nand other stars, but a movement of the equinox. For the celestial\nequator is simply a reflection of Earth\u2019s equator in the skies, and as\nit keeps changing the direction of its tilt in the way described, it\nchanges the point at which it cuts the ecliptic. This may best be seen\nby taking two rings or hoops (two large curtain rings, for instance),\none of which just fits inside the other. Tilt the inner ring, so that\nhalf of it is above and half below the other ring, and they touch\nat two points, 1 and 2 (Fig. 27). The outer ring is the Ecliptic,\nthe inner the Equator, and where they touch each other are the\nEquinoxes. Now move the inner ring, not sliding it round, nor making\nany difference in the angle between the two, but simply so that they\ntouch at fresh points, 1\u2032 and 2\u2032. In this way you may make the points\nof contact revolve entirely round. This is what the real equinoxes are\ndoing: while the equator opposite the group of stars in figure 25 rises\nand falls, the equinox travels on, and finally returns to the same\nplace.\n\n[Illustration: Fig. 26. The movement of Earth\u2019s axis, which is the true\ncause of Precession.\n\n _V_ is the vernal equinox, at the intersection\n of the equator and plane of the ecliptic: _APX_\n the earth\u2019s axis, which always preserves the same\n inclination (23\u00bd%) to the plane of the ecliptic. As\n _APX_ slowly revolves round _T_ in the direction of\n the arrow, the vernal equinox is gradually shifted\n to _V_\u2032, and so on.\n\n(_From Young\u2019s \u201cManual of Astronomy,\u201d 1902._)]\n\nThe phenomenon is called \u201cprecession of the equinoxes,\u201d because they\nthus move on to meet the sun in his yearly course.\n\n[Illustration: Fig. 27. Precession of the equinoxes.]\n\nThe discovery of precession is what has chiefly made Hipparchus famous,\nbut the invention of the astrolabe and of spherical trigonometry,\nboth believed to be due to him, his star catalogue, and his many\nobservations, more accurate than any made before, were so valuable as\npioneer work that Ptolemy justly called him the Father of Astronomy.\nIf Hipparchus could visit one of our observatories to-day, and see the\nclock-driven equatorials, the transit instruments, the beautifully\ndivided circles read with microscopes, and the sidereal clocks, one\nwonders whether he would be more astonished at the advance on his\nastrolabes and clepsydras or at the homage paid to him as one in whose\nfootsteps all astronomers are proud to tread.\n\n\n8. PTOLEMY.\n\n _Claudius Ptolem\u0153us._ I know that I am mortal\n and ephemeral, but when I scan the multitudinous\n circling spirals of the stars, no longer do I touch\n Earth with my feet, but sit with Zeus himself, and\n take my fill of the ambrosial food of the gods.\n\nFor more than two centuries after Hipparchus very little original work\nwas done in astronomy, and no one seems to have had the courage to take\nup his unfinished task and study seriously the difficult problem of\nplanetary motions.\n\n[Sidenote: Posidonius _c._ 135 B.C. to _c._ 50 B.C.]\n\nPosidonius the Stoic, who lived for some years in Rhodes, made a\nfresh determination of the earth\u2019s circumference, basing it not on\nobservations of the sun, like Eratosthenes, but of the star Canopus,\nwhich in his time was just visible at Rhodes while in Alexandria it\nrose \u201ca quarter of a sign\u201d (_i.e._ 7\u00bd degrees) above the horizon. By\nhis method, the earth was a little smaller, (240,000 stadia instead\nof 250,000), but it must have been difficult to measure the distance\nbetween Rhodes and Alexandria over the sea, and it is impossible to\nsay when a star is exactly on the horizon. Posidonius also observed\nthe tides in the Mediterranean, and showed that \u201cOcean follows the\nmovements of the heavens,\u201d and especially of the moon, having daily and\nmonthly periods.\n\n[Sidenote: Geminus _c._ 70 B.C.]\n\nA little later Geminus wrote an Introduction to Astronomy, which was an\nexcellent little book as far as it went, but although he was apparently\na native of Rhodes, and speaks of Hipparchus, he seems to know nothing\nof his work, for he does not quote his careful determination of the\nlength of the year, nor his discovery of precession.\n\n[Sidenote: Cleomedes _c._ 20 B.C.]\n\n[Sidenote: Theon of Smyrna _c._ 100 A.D.]\n\nNor were other writers, such as Cleomedes and Theon of Smyrna, better\ninformed, and they added nothing new to the advance of astronomical\nscience.\n\n[Sidenote: Ptolemy _c._ 140 A.D.]\n\nBut at last a worthy successor arose at Alexandria, the immortal\nPtolemy, whom Dante met in that Limbo of antique spirits which was\nalmost Elysium, although on the brink of the Inferno.\n\nWe do not know when Ptolemy was born nor when he died, nor where was\nhis native town: we only know that his first recorded observation was\nmade in the eleventh year of the Emperor Hadrian, that is A.D. 127, and\nhis latest in A.D. 150, and that he lived and studied in Alexandria. He\nhad splendid opportunities for carrying on the work of Hipparchus, for\nbesides the use of the instruments in the Museum Observatory, he had at\nhand all the Museum records, which included the writings of Hipparchus.\nPtolemy was not so painstaking and accurate an observer as Hipparchus,\nbut he was a very able mathematician to whom it was evidently a joy\nto handle figures and work out problems. By examining a number of\nobservations spread over several centuries, and combining them with his\nown, he was able to accomplish the task in which so many others had\nfailed, and to frame a system which embraced all the celestial motions\nthen observed. The monumental summary in which he set forth this system\ncontains a great deal of interesting information about his methods\nand instruments, and about the work of Hipparchus, for whom he always\nexpresses the most generous admiration. The original name of his book\nwas the \u201cMathematical System of Astronomy,\u201d but his admirers having\ncalled it the \u201cGreat System,\u201d _Megiste Syntaxis_, the Arabs affixed\ntheir article _al_ and gave it the name it preserves to this day, of\n_Almagest_. It remained the standard treatise on astronomy until the\n_De Revolutionibus Orbium Celestium_ of Copernicus appeared in 1543.\n\nThe name of his book indicates the scope of Ptolemy\u2019s work. It was to\nrepresent all the observed motions of the heavenly bodies by means of a\nmathematical system, so that they became amenable to calculation; but\nto explain the causes of these motions was thought to lie quite outside\nan astronomer\u2019s province. It was not for a mere observer and calculator\nto determine which motions were real and which apparent, else Ptolemy\nmust have decided in favour of Earth\u2019s rotation, for he says that\nit would be much easier to account for celestial motions on this\nassumption. Nor was it his business to investigate the substance of the\nstars. Little did he dream that astronomers would one day solve such\nproblems, and uphold their conclusions in the face of all the world:\nfor him, as for his contemporaries, the decisions of the philosophers,\nand especially of Aristotle, were final, and his task was to describe\nwhat he saw in the light of their teaching.\n\nHe brings forward, in the introduction to his book, a few arguments\nagainst the absurd notion, taught by some, that Earth is in motion,\nturning on her axis or moving through space; but all that he proves\nis the immense difficulty, even to a trained mind, of accepting these\ntheories, and the great authority of the philosophers who denied\nthem on abstract principles. Educated Greeks might still discuss the\nnature of the heavenly bodies, as in Plutarch\u2019s delightful dialogue\n_On the Face of the Moon_, (written about half a century before the\ndays of Ptolemy), and might ridicule the law of gravity, laughing at\nthe absurdity of supposing that if the middle of a man\u2019s body were at\nthe middle of the earth, his feet as well as his head would be \u201cup,\u201d\nand that falling weights if they reached this point would stop short,\nor oscillate to and fro. Yet even they all agreed that the fixed\nstars do most probably move \u201cin a circle of eternal and never-ending\nrevolution,\u201d and that they are of a pure and eternal substance unlike\nEarth; and for the professional astronomers of Alexandria these axioms\nwere assumed as the basis of all their work. Earth must be immoveable\nat the centre of the Universe because the heavy stuff of which she is\nmade sinks necessarily to the centre and there remains in globular\nform without need of support; the heavenly bodies must be in motion,\nbecause, being of ethereal substance, it is their nature to revolve\neternally in circles.\n\nThis being granted, we can feel nothing but admiration for the extent\nof Ptolemy\u2019s knowledge, the comprehensiveness of his scheme, and the\nskill and patience with which he overcame its difficulties.\n\nEarth, according to Ptolemy, is but a point compared with the immense\nsurrounding sphere in which the stars are set, and this turns always\nround us, communicating its motion (he does not inquire how) to sun,\nmoon and planets, so that day follows night, and the heavenly bodies\ndaily rise and set. For the slow movement of precession, which also\naffects all heavenly bodies, Ptolemy accepted the least value of\nHipparchus, one degree in a century, only testing it in rather a\nperfunctory way, which was a great pity, for he might have determined\nit much more closely after an interval of some 250 years. But one man\ncannot do everything, and he doubtless thought it best to spend more\ntime on the planets, whose intricacies had baffled Hipparchus and gave\nhim also a great deal of trouble.\n\nHe retained the great spheres which were supposed to carry them round\nEarth, inside the star sphere, but the chief feature of his system is\nthe use of small spheres, which were fixed on the larger, and therefore\ncalled \u201cepicycles,\u201d while the large were known as \u201cdeferents\u201d or\ncarriers. The general principle of epicycles is very simple, as may be\nseen by comparing the two diagrams.\n\nFig. 28 shows the path of Mars as we saw it among the stars of Pisces\nin the year 1909. Throughout July the planet was travelling in its\nusual direction, \u201cwith the signs,\u201d but on August 22nd it came to a\nstop, then turned and travelled backwards \u201cagainst the signs\u201d until\nOctober 26th, when it stopped again, reversed its direction once more,\nand during the rest of the year moved rapidly forward.\n\nFig. 29 shows the principle on which Ptolemy would have explained this\ncurious track. Each planet was supposed to be fixed on a small circle,\nthe epicycle, and this was fixed upon a large circle, or deferent, upon\nwhich it travels in the direction shown by the arrow, at a uniform\nspeed, returning to the same place in the sidereal period of the\nplanet. Thus Mars, as seen from Earth, which is near C the centre of\nthe deferent, makes a great circle through all the zodiac in two years,\nJupiter in twelve, and so on. But meanwhile the epicycle is rotating\nround its own centre, C1, and when the planet reaches the point\nmarked S, the two motions neutralize one another, so that it appears\nstationary, as Mars did on August 22, 1909. After this, the motion of\nthe epicycle more than counter-balances the motion of the deferent, and\nthe planet seems to reverse its direction until it reaches the point on\nthe epicycle marked S\u2032. After this the two motions are once more in the\nsame direction, so the planet is seen to move rapidly forward, as Mars\ndid after October 26.\n\n[Illustration: Fig. 28. The Path of Mars among the Stars, 1909.]\n\n[Illustration: Fig. 29. The Epicycle.\n\nPtolemy\u2019s method of accounting for movements such as those shown in\nFig. 28.]\n\n[Illustration: Fig. 30. Planet retrograding, and in opposition (_i.e._\nin opposition to the sun.)]\n\nIn this extremely ingenious way the strange planetary oscillations were\naccounted for, without violating the law of uniform circular motion,\nand in a more convenient and satisfactory way than by the concentric\nspheres of Eudoxus or the moveable eccentrics of Apollonius. Each of\nthe five planets was provided with an epicycle and a deferent, and\nthese were made of the proper relative size and given the right speed,\nso that the motions should correspond with what we see in the sky.\n\nPtolemy calls the oscillation a planet\u2019s \u201canomaly with regard to the\nsun,\u201d because (as we have seen when discussing the moveable eccentrics)\nit was known to be connected in every case with a planet\u2019s angular\ndistance from the Sun. On September 24, when Mars was in the middle\nof his retrograde arc in Pisces, the sun was exactly opposite, in\nthe constellation of Virgo. This is found to be always the case, not\nonly with Mars, but with Saturn and Jupiter too. Whenever one of\nthese planets has the position O on its epicycle, and therefore is\nretrograding, the sun will be found to be exactly opposite in the\nsky. Mars comes into this position, and is opposite the sun, once in\n780 days; this, therefore, Ptolemy called the period of his epicycle,\nwhile a little less than two years was the period of the deferent. The\ntwo periods of Saturn are 378 days and 29\u00bd years nearly; of Jupiter 399\ndays and nearly 12 years.\n\n[Illustration: Fig. 31. Venus, Mercury, and the sun.]\n\nVenus and Mercury betray their dependence upon the sun in more striking\nfashion, for since these planets simply oscillated from one side to the\nother of the sun, their epicycles must be supposed to be keeping pace\nwith him all the way round the zodiac. Fig. 31 shows their relation\nto one another. On September 25, 1911, Mercury was seen from Earth as\na morning star as far west of the sun as it is possible for him to\ntravel, while Venus, after shining as an evening star all the summer,\nhad come into line with the sun and become invisible.[51] On December\n7 following, the rotation of the epicycles (Ptolemy would say) had\nbrought both planets to new positions, Mercury now being an evening\nstar at his \u201cgreatest elongation east,\u201d and Venus a morning star. But\nthe centres of the two epicycles always remain in a line with one\nanother and the sun, and so their periods on the deferents are the same\nas his, viz. one year. The epicyclic periods, or intervals between two\n\u201cgreatest elongations\u201d west or east, are 116 days for Mercury, 584 days\nfor Venus.\n\n------------------------------------------------------------------------\n[51] Venus had passed her \u201cinferior conjunction with the sun\u201d on Sept.\n15.\n------------------------------------------------------------------------\n\nWe still explain the complicated course of the planets by resolving\nit into two approximately circular motions, but we know now that only\none belongs to the planet itself, the other is Earth\u2019s own motion. The\nreason why the sun\u2019s position affects the position of every planet\nis simply that the epicycles of Mars, Jupiter, and Saturn, and the\ndeferents of Venus and Mercury are reflections of Earth\u2019s yearly\njourney round the sun.\n\nPtolemy had by no means finished with the planets when he had provided\neach one with an epicycle to represent the \u201canomaly with regard\nto the sun.\u201d Hipparchus had noticed that there was another lesser\nirregularity, which seemed to be periodical likewise, although no\nformer system had taken it into account; and this he called the\n\u201canomaly with regard to the zodiac,\u201d because the speed of each planet\nand the amplitude of its loop varies slightly according to the part of\nthe zodiac it happens to be in. He suggested that this might be dealt\nwith by combining the two theories of epicycles and eccentrics, and\nthis suggestion Ptolemy adopted with success. He placed each deferent\nwith its centre not exactly at the earth, but at a certain small\ndistance which was different for each planet. (This is not shown on our\nsmall-scale diagrams, therefore Earth appears at the exact centre.)\nThe true explanation of this irregularity is that each planet\u2019s path\nis not strictly circular, but elliptical.\n\nBesides this, Ptolemy had to represent the planet\u2019s movements north and\nsouth (note how this varies in fig. 28.). This was partly managed by\nthe aid of small wheels, rotating in such a way that they lifted and\nlowered the epicycle as required.\n\nAlthough Ptolemy quotes Babylonian observations of lunar eclipses\ndating back as far as the eighth century B.C., the oldest planetary\nobservations that he uses were made only four hundred years before his\ntime, and they were probably Greek. Even these were generally very\nrough. For instance:\u2014\n\n In the 496th year of Nabonassar, on the 17th day\n of Choeac, in the morning, Mercury was three\n moon-breadths north of the tail of Capricorn.\n\n In the same year, Phamenoth the 30th, Mercury was\n three moon-breadths south of the horn of Taurus\n which is also the foot of the Charioteer.\n\nThe first year of Nabonassar (a Babylonian epoch) corresponds with\nB.C. 747, so the 496th year is B.C. 251. The months used by Ptolemy\nare usually Egyptian. The later observations, made with an astrolabe,\nwere much more precise; Ptolemy quotes one from Theon of Smyrna, which\nstates that Mercury was 3\u00b0 50\u2032 in advance of the Heart of the Lion\n(Regulus), and for his own observations he also usually gives the sign,\ndegree, and minute. Sometimes the planets had been observed so near\nstars that their positions could be very accurately determined by the\naid of Hipparchus\u2019 star catalogue. Timocharis, on a certain morning in\nthe 13th year of Ptolemy Philadelphus (B.C. 273), saw Venus beside the\nlast star in the wing of the Virgin (Beta Virginis); Ptolemy himself\nsaw her so close behind a certain star in Aquarius that she seemed\nto touch it with her rays; and in the 83rd year after the death of\nAlexander, Jupiter had been observed to eclipse the Southern Ass, that\nis the southernmost of the pair of stars on either side of the little\ncluster in Cancer which the ancients called the Manger.\n\n[Illustration: Fig. 32. The sun\u2019s Deferent. (Its eccentricity is\nexaggerated).]\n\nThe sun was much easier to manage than the planets. Moving always\nin the same direction, he needed no epicycle, and remaining always\nin the ecliptic, no wheels. His one irregularity, the varying speed\nin different parts of the zodiac, which Meton had discovered and\nCalippus confirmed, Hipparchus accounted for by placing him on\neccentric deferent; Ptolemy adopted this without change, and made the\nyear the same length as Hipparchus had done. As the slowest motion\nwas observed when the sun was in the sign of Gemini (at the time of\nyear corresponding with the end of our month of May), the eccentric\nwas placed as in the diagram; and the sun, supposed to be revolving\nuniformly round the centre C, had a slower motion as seen from Earth\nwhen he went north, because he was then more distant.\n\nWe know now that it is really Earth which revolves round the sun, but\nthe elliptical shape of her orbit is not unlike the eccentric deferent\nwhich the Greeks gave to the sun, and they guessed quite rightly from\nhis motion that he is further from us in one part of the year than\nin the other. This is easily proved to-day by the fact that he grows\napparently smaller, as shown by photographs or measurements taken at\ndifferent times of year, but the change was not perceptible to the\nrougher methods of the ancients.\n\nIt was a pity that Ptolemy did not take more pains to verify the work\nof Hipparchus on the sun, for the sun\u2019s \u201capogee,\u201d or point of greatest\ndistance from Earth, has an extremely slow motion among the stars which\nought to have been quite perceptible in nearly three centuries;[52] but\nhere again he seems to have thought that where Hipparchus had given so\nmuch attention he might pass on to something else, and so missed an\ninteresting discovery.\n\n------------------------------------------------------------------------\n[52] It amounts to 5 degrees of longitude in 300 years.\n------------------------------------------------------------------------\n\n[Illustration: 1911, July 1. 1912, Jan. 3.\n\nFig. 33. Apparent Variation in the Size of the Sun. [_To face p 146_\n\nTwo half photographs of the Sun, taken at Kodaikanal Observatory. The\nsmaller was taken two days before apogee, the larger on the day of\nperigee.]\n\nInstead, he worked very hard at the moon, and added another periodical\nirregularity to those already known. Perhaps his feelings were somewhat\nmixed when this happened, his pride and pleasure in his important\ndiscovery being counter-balanced by the consciousness that it would\nstill further complicate his lunar theory. Our satellite is acted\nupon by ourselves as well as by the sun, so that she suffers many\nperturbations, for Earth, though so small compared with the sun, is\ncomparatively near. Ptolemy\u2019s discovery was a difference in her speed\nat full and new, as compared with her intermediate phases, and this\nperiodic difference is called by modern astronomers the \u201cevection.\u201d It\nwas already known that her nodes, or the points at which she crosses\nthe ecliptic, are in constant retrogressive motion, just like the\nequinoctial points, where the sun crosses the equator; but the moon\u2019s\ncrossing points, instead of taking thousands of years to circle the\nzodiac, run round in about eighteen years. This was discovered early,\nbecause observations were chiefly made during eclipses, and at these\ntimes the moon is always at a node, that is to say, she is crossing the\necliptic, the sun\u2019s path; otherwise the eclipse could not happen. It\nwas also known that she has a varying speed in the zodiac, and that her\napogee, where the motion is slowest, instead of being apparently fixed,\nlike that of the sun, also runs round the zodiac, but with a direct\nmotion, and in a period of about nine years.\n\nWe need not enter into all the details of Ptolemy\u2019s arrangements for\nthe moon, which are exceedingly complicated, but it is interesting to\nnote that he does not explain her varying velocity by an eccentric, as\nwith the sun and the planets. She has an eccentric, but Ptolemy needed\nit for representing his own discovery, the evection, so he gave her an\nepicycle, using it in quite a different way from the epicycles of the\nplanets. This epicycle also revolved while moving on the eccentric, but\nin the opposite direction, and there was so little difference in speed\nbetween the two motions that it never brought the moon to a stop, nor\nreversed her direction, but simply increased and retarded her motion\nalternately during her monthly revolution. Thus, when the moon was at\nM, in what Ptolemy called the upper apsis (or arc) of her epicycle, or\nas we should say in her apogee, the motion on the epicycle was contrary\nto her motion on the eccentric, and made it seem slower. When the\nepicycle had travelled halfway round the eccentric, it had also made\nnearly half a revolution on its own axis: consequently the moon was at\nM\u00b9, near the lower apsis, or perigee, and the motion on the eccentric\nseemed to be accelerated.\n\n[Illustration: Fig. 34. The moon\u2019s epicycle and deferent.]\n\nThe slight difference in speed between the two motions accounted for\nthe continuous displacement of the apogee in the zodiac, as may be seen\nfrom the diagram. For suppose that when in apogee at M the moon is seen\nfrom Earth among the stars in the middle of Taurus. At the return of\nthe epicycle to this place next month, she has not yet quite completed\na revolution on her epicycle but is at M\u00b2, and will not be in apogee\nuntil the centre of her epicycle is advanced 3\u00b0 further in Taurus.\nAfter some time (five months), apogee does not occur until the moon is\nin Gemini, and it will be nine years before it occurs again in Taurus.\n\nThese are the leading features of the system by which Ptolemy\nrepresented the motions of the planets, the sun, and the moon. He is\nuncomfortably conscious that it may strike us as very complicated, and\nin his last book he makes a kind of apology. We must remember, he says,\nthat we are not dealing with earthly machines which jar and wear, but\nwith celestial bodies which have no weight, cause no friction, and are\neternally the same. Delambre somewhat cruelly retorts that he need not\nhave wasted time in writing such rubbish, but have been content to put\nhis results into tables.\n\nBut what true astronomer could be content with tables and nothing\nmore? He must try to understand their significance. Nearing the end of\nhis great work, which had cost so much labour, and was so brilliant\na success within its limits, Ptolemy allows us to see in this little\nparagraph that he felt he had but touched the hem of Nature\u2019s veil,\nand longed in vain to lift it. The circles which he manipulated so\nskilfully were only mathematical abstractions to him:[53] what was\nthe reality behind? What were the stars? whence came their unwearied\nstrength, their eternal calm? The power of Egypt, of Assyria, and of\nPersia had declined, Greece was now laid low, and it was the day of\nRome, but still Venus pursued her ancient path among the little stars\nof Aquarius, and when all faded in the solemn dawn, the sun arose in\nhis ancient majesty. Then Ptolemy looked at his circles and triangles,\nand felt how inadequate they were; yet it was the nearest approach he\ncould make to truth.\n\n------------------------------------------------------------------------\n[53] This is evident from the way he treats them, picking up an\nepicycle or a deferent just as best suits the purpose in hand and\nexplaining sometimes that either would answer equally well.\n------------------------------------------------------------------------\n\nThey did indeed represent very beautifully the celestial motions, and\nalso in a general way the variations in brightness or diameter, but\ntheir unreality is betrayed by the fact that the latter was often\ngrossly exaggerated, as for instance with the moon, whose epicycle had\nto be so large, in order to represent her motions, that at perigee\nshe ought to appear twice as large in diameter as at apogee! Ptolemy\ncan hardly have failed to notice this, though he does not mention it.\nWith regard to the planets, he is careful to tell us that he knows no\nway of finding their real distances: the ratios of their epicycles\nto their deferents he had carefully computed in each case, but to\nestimate the diameters in stadia was utterly beyond his powers. He\nbelieved, however, that all were very much nearer than the stars, and\nmore distant than the moon, and he found universal agreement among\nastronomers in placing Saturn, Jupiter, and Mars, beyond the sun, in\norder of the periods of their deferents, which were all longer than\na year. Venus and Mercury, however, had periods the same as the sun:\non which side of him, then, must they be placed? Some modern authors,\nPtolemy says, thought they were beyond the sun, but he agrees with\nthe most ancient, and places them between sun and moon. The general\ndisposition of the heavenly bodies according to Ptolemy is shown\nin Fig. 35, with the periods of epicycles and deferents, and the\ndirections of the several movements, but epicycles and spaces between\ndeferents are all made equal. It will be noted that the sun has no\nepicycle and that the moon turns on hers in a reverse direction, that\nthe centres of those of Mercury and Venus are in a line with the sun,\nwhile the lines joining Mars, Jupiter, and Saturn to the centres of\ntheirs are in each case parallel with the line joining Earth and Sun.\nBeyond all the wandering stars is the sphere of the fixed stars, moving\nin its vast period of 36,000 years; and the whole system is carried\nround Earth in one great revolution of a day and a night.\n\n[Illustration: Fig. 35. The Ptolemaic system.\n\nThe arcs of circles are portions of the deferents which carry round the\nsmaller circles (the epicycles) in the periods named at the side.]\n\nAnd here we have to note one astonishing fact. Although the planets\nwere all beyond reach of measurement, it was not so with the moon,\nwhich the Greeks rightly recognized as our nearest neighbour. They had\nactually achieved the long-desired feat of measuring her real size and\ndistance.\n\nThe fundamental principle on which they worked is easily explained. If\nwe look out of a window at a tree in the garden, it appears against\na background of some distant scenery; if we alter our position by\nwalking to another window, the tree changes its place with regard to\nthe relatively motionless background, and its apparent change of place\nbears a definite proportion to its distance from us. A tree near the\nhouse changes its position greatly, a tree at the far end of the garden\nmuch less. From careful measurements of the angle through which the\ntree appears to have moved and the distance we have walked between the\ntwo windows, the distance of the tree from the house may be easily\ndeduced.\n\nThe tree in the garden is the moon, the distant landscape is the\nstar-spangled sky. The space between the two windows must be increased\nto thousands of miles, but the astronomer need not walk it. If he makes\nhis first observation when the moon has just risen, carefully measuring\nher position among the stars, the revolving Earth will carry him to\na new position in a few hours, when with the moon high in the sky he\ncan once more compare her position with the same stars, and from the\nchange he then finds he can deduce her distance. The Greeks thought\nit was the sky, and not the earth which moved, but this makes no\ndifference, as the question is one of relative motion only.\n\nThe problem, however, when applied to the moon, is a complicated one,\nimplying not only skill in trigonometry and the possession of suitable\ninstruments for measuring the necessary angles, but also accurate\nknowledge of the size of the earth and the motions of the moon, since\nher progress eastward among the stars during the interval between the\ntwo observations must be allowed for. Hipparchus and the astronomers\nof Alexandria were the first to qualify themselves for attacking this\ndifficult problem, and the proof of their success is that Ptolemy\u2019s\nvalue for the distance of the moon is very near the truth as obtained\nby modern methods. The same method is now used, only it is found\nbetter to do what was not possible for the Greeks, namely to compare\nobservations made at places several thousands of miles distant, for\ninstance Greenwich and the Cape, instead of allowing the same place to\nbe moved by the earth\u2019s rotation.\n\nWhen the distance of the moon had been thus discovered, it was a very\nsimple matter to find her real size from her apparent size.\n\nThe distances of all other heavenly bodies are too great to be\ndetermined by naked eye methods, for the displacement (technically\ncalled \u201cparallax\u201d) is so small that it is quite invisible without a\ntelescope. Hipparchus had tried repeatedly to measure the distance of\nthe sun, but recognized that neither the method of Aristarchus nor any\nother was really conclusive. It was, however, the best attempt that had\nbeen made, and Ptolemy assumed that he knew the distance to be about\ntwenty times that of the moon, so he gave the sizes and distances of\nthese two bodies as follows, taking Earth\u2019s semi-diameter as unit:\u2014\n\n According to Ptolemy. Modern Values.\n _Semi-diameter. Distance. Semi-diameter. Distance._\n Moon \u2075/\u2081\u2087 (=0\u00b7290) 59 0\u00b7273 60\u00b73\n Sun 5\u00bd 1210 109\u00b74 23,439\n\nIn Books VII and VIII of the _Almagest_ Ptolemy describes the\n48 ancient constellations and the course of the Milky Way among\nthem. The position of each star is noted as it appears in its\nconstellation-figure, but the celestial latitude and longitude is also\ngiven, and this great catalogue is evidently taken from Hipparchus.\n\n PTOLEMY\u2019S FORTY-EIGHT CONSTELLATIONS.[54]\n\n------------------------------------------------------------------------\n [54] Taken from the _Almagest_ catalogue, as given in Delambre\u2019s\n History.\n------------------------------------------------------------------------\n\n Ursa Minor Pegasus\n Ursa Major Andromeda\n Draco Triangulum\n Cepheus Cetus\n Auriga Orion\n Corona Borealis The River (Eridanus)\n The Kneeler (Hercules) Lepus\n Lyra The Dog (Canis Major)\n The Bird (Cygnus) Canis Minor (Procyon)\n Cassiopeia Argo\n Perseus Hydra\n B\u00f6otes Crater\n Ophiuchus Corvus\n Serpens Centaur\n Sagitta The Wild Beast (Lupus)\n Aquila Ara\n Delphinus Corona Australis\n Equuleus Piscis Australis,\n Aries, Taurus, Gemini, Cancer, Leo, Virgo, Libra, Scorpio,\n Sagittarius, Capricornus, Aquarius, Pisces.\n\nPtolemy sometimes remarks on the colour of the brighter stars, and\nalways mentions the brightness, or \u201cmagnitude\u201d as we call it now, for\nthe classification of Ptolemy (or Hipparchus?) was found convenient\nand accurate enough to be retained by modern astronomers, and the same\nsystem is now continued with the faint telescopic stars.\n\nThe stars ranked as \u201cfirst-magnitude,\u201d or brightest of all, are fifteen\nin number, and as these are evidently the \u201cquindici stelle\u201d[55] alluded\nto by Dante in _Par._ xiii. 4, it will be interesting to give a list of\nthem here.\n\n------------------------------------------------------------------------\n[55] Fifteen stars.\n------------------------------------------------------------------------\n\n PTOLEMY\u2019S FIRST-MAGNITUDE STARS.\n\n _Name and Description Modern Name and Meaning._\n _in the Catalogue._\n 1. Arctouros, fire-coloured Arcturus (the Bear-Watcher).\n 2. The brightest star in the Vega, in Lyra. (Falling Eagle,\n Lyre Arabic).\n 3. Aichs (the Goat) Capella (Little Goat, Latin).\n 4. The brightest star of the Aldebaran. (The follower,\n Hyades, fire-coloured because following the\n Pleiades, Arabic).\n 5. Basiliskos (the royal), on Regulus (Latin equivalent).\n the heart (of Leo).\n 6. The tip of the tail (of Leo ) Denebola (Lion\u2019s Tail, Arabic).\n 7. Stachys (Ear-of-Corn) Spica (Latin equivalent).\n 8. The last of the Water and Fomalhaut. (Mouth of the\n Mouth of the Southern Fish, Arabic).\n Fish.\n 9. The fire-coloured bright Betelgueux. (Shoulder of\n star on the shoulder Giant, Arabic).\n of Orion.\n 10. On the left foot of Orion, Rigel. (Foot of the Giant,\n common to the Water. Arabic).\n 11. The last of the River Achernar (Arabic equivalent).\n 12. The very brilliant star, Sirius (Greek _Seirios_, or\n fire-coloured, at the _Sothis_, from the Egyptian\n mouth of the Dog, _Sept_),in Canis Major.[56]\n called the Dog.\n 13. Prokuon (the preceding Procyon (in Canis Minor), which\n Dog), on the thigh of rises before Canis Major.\n Prokuon\n 14. Canopos, on the rudder Canopus (an Egyptian god, and\n (of Argo) a town on the Nile delta).\n 15. The tip of the right forefoot Alpha Centauri.\n (of the Centaur).\n\n Altair and Antares were counted as second magnitude,\n though we now class them among the first.\n\n------------------------------------------------------------------------\n[56] Lockyer, _Dawn of Astronomy_, p. 196.\n------------------------------------------------------------------------\n\nIt will be seen from the above that only two of these fifteen\nbrightest stars of Ptolemy\u2019s still bear their Greek names, Arcturus,\nand Procyon; but most of the other modern names are direct translations,\neither into Latin or Arabic, of Ptolemy\u2019s description or name for the\nstar, while Vega and Aldebaran have preserved their original Arabic\nnames (much corrupted), and Canopus and Sirius are derived from the\nEgyptian. Regulus-Basiliskos apparently comes from Babylon, for the\nname of this star on tablets of the second century B.C. was Shar-ru,\nwhich means \u201croyal.\u201d\n\nPtolemy\u2019s \u201cLast of the River\u201d was taken by his Arab and other\ncommentators to be the first-magnitude star which consequently they\nnamed Achernar, but this was too far south to be visible at Alexandria,\nthough possibly he heard of it or saw it himself at Syene, where it\nrose over the horizon in his times. Delambre thinks it is the same as\nFomalhaut, which already belongs to two other constellations in the\nstar catalogue; Brown suggests it was Theta Eridani, which may have\nbeen brighter sixteen centuries ago. Perhaps it was the star we now\ncall Alpha in the Phoenix, for this lies between the last bend of the\nRiver and the Water of Aquarius, and its magnitude is between first and\nsecond. The stars of the Southern Cross are included by Ptolemy in the\nstars about the hind feet of the Centaur, though it is difficult to\nidentify each one with certainty: the positions are not very accurately\ngiven.\n\nPtolemy wrote also on Astrology, or as it was then called Judicial\nAstronomy, and his work on the subject, which is in four books,\nreceived the name of the _Tetrabiblios_. It seems that astrology was\nnot very much believed in by the Greeks, for he protests that the\ninfluences of the stars are real, and can be known and predicted, but\nallows that this part of astronomy is much more difficult than the\nmathematical part, with which he had dealt in the _Syntax_, and that\nit has not yet been perfected, and therefore it is sometimes slandered\nas untrue. Astrologers sometimes make mistakes, like doctors, yet both\nastrology and medicine are useful arts. He mentions especially the\nEgyptians as practising it.\n\nOnly second in importance to the _Almagest_, and even better known in\nold days, was Ptolemy\u2019s work on Geography. In this he shows how the\nsize of the earth and the latitudes and longitudes of places on Earth,\ncan be discovered by observations of the heavens. For Earth\u2019s diameter\nhe adopts the value found by Poseidonius. His terrestrial globe had a\nmoveable half-circle attached to the poles, which was divided into 90\u00b0\nfrom the equator in both directions, so that by placing this against\nany spot on the globe, its latitude north or south of the equator\ncould be immediately read off. Only half the equator was marked on\nthis globe, and divided into 180\u00b0, for the known part of the earth\nall lay within these limits. The parallels of latitude marked were\nnot the same as we use, though the most northerly fell very close to\nthe Arctic Circle: it showed the latitude of the Island of Thule, far\naway \u201ctowards the Bears,\u201d as Ptolemy expresses it, meaning that it lay\nunder the constellations near the North Pole. The most southerly was\nnot far below the equator, and others were marked between these which\ndivided the known Earth into \u201cclimates,\u201d according to the height of the\nPole and the length of the longest day in each. Among the many towns\nwhich figured on this globe we may mention Alexandria, Rome, Athens,\nJerusalem, Florence, Cadiz, Paris, Strasburg, London, Bath. Meridians\nwere marked at every 5 degrees. From this globe Ptolemy shows how a\nplane map may be constructed. He took Rhodes as the central meridian,\nbecause it had a nearly central position among the \u201cclimates,\u201d and was\nthe place in which Hipparchus had observed.\n\nPtolemy also wrote books on Optics, on the theory and construction of\nDials, and on Music!\n\n\n\n\nV. RETROSPECT.\n\n\nThe _Almagest_ is the last word of Greek astronomy. We have seen how\nfrom the dawn of Greek history, as far as we can trace it back in\nliterature, the Greeks were familiar with the skies, and how the most\nancient of their philosophers had tried, chiefly by abstract reasoning,\nto discover the cause of the circling motions\u2014never changing, never\nceasing\u2014of sun and stars. When the seemingly unruly movements of the\nplanets were known, they still felt sure that there must be some\nunderlying principle which would bring all into harmony. Inspired by\nPlato, and helped by the Egyptians, Eudoxus took the first step towards\nfinding this principle by careful study of the planetary motions,\nand at last, after many generations of observers and mathematicians,\nPtolemy was able to describe these motions as accurately as was\npossible with the methods available.\n\nAt first the heavenly bodies had been thought of as gods, then as\nworlds like our own, then as spheres of ethereal fire. They were\nswept round by a mighty wind, they ran on wheels, they floated in the\nether, they were set in crystal spheres; the controlling force was\nthe principle of number or harmony, an all-pervading World-Soul, a\nhost of immaterial intellectual Beings subject to one eternal First\nMover. It was also suggested that the greater part of the motions were\napparent only, that Earth was really in motion, spinning on her axis,\nrevolving round a Central Fire, or revolving round the Sun. But these\nideas had not enough evidence to support them when suggested. Had a\ngreat imaginative thinker, a Pythagoras or an Aristarchus, arisen\nafter Ptolemy, he could have shown in detail how by assuming these\ntwo motions the phenomena could be more simply accounted for, and he\ncould have made out a very good case for their probability.[57] But the\ntime was past then for such bold originality, and the explanation of\nAristotle was universally adopted. He, as we saw, placed the abode of\nthe gods, the rulers of the universe, beyond the outermost sphere, and\nfound the principle for which all were seeking, which should be the key\nto all celestial motions, in the law of circular motion.\n\n------------------------------------------------------------------------\n[57] The changing latitudes of the planets, for instance, which gave\nPtolemy much trouble, are much more easily explained when it is granted\nthat they partly depend upon Earth\u2019s motion in an orbit whose plane is\nslightly inclined to the planes of their orbits.\n------------------------------------------------------------------------\n\nThe Greeks had at first thought that the earth was a disc, under a\ntent-like sky; then it was a cylinder, with the sky in tiers above;\nthen a huge hemisphere filling half the universe. But they discovered\nthat it was a sphere, surrounded on every side by the heavens; and they\nfound its true size, and that the portion of it which was known to\nthem was less than a quarter of its whole extent. They explained the\nmarvel of Earth\u2019s remaining unsupported in space by the known facts of\ngravity, arguing that the falling of every particle of earth towards\nEarth\u2019s centre proved that it was also the centre of the Universe, and\nthat every heavy thing tended thither by a law of nature.\n\nThey also knew the size and the distance of the moon; they realized\nthat the planets were all immeasurably remote, and the stars vastly\nmore distant still. They believed that there were great intervals\nbetween the planets, corresponding to the differences in their periods\nof revolution, but the stars were always thought of as set in a great\nsphere, and therefore all at the same distance from Earth at its\ncentre. The relative positions of the stars on this great sphere,\nand times of rising and setting of many of them had been known in\na rough way for many ages, through the familiar appearance of the\nconstellations, named we know not by whom; but Hipparchus measured\ntheir positions in degrees, and was able to foretell where any star\nwould be in the sky for any place or time. He also discovered the\nPrecession of the Equinoxes, and this was thought to prove a slow\nrotation of the star sphere.\n\nAstrology was learned by the Greeks in Egypt and the East, but was\nnever practised with the enthusiasm shown by their teachers.\n\nAs regards the division of time, the Greeks adopted from the\nBabylonians the twenty-four hour day which we still use, and their\nmonths began with the young moon. Their year therefore had to contain\na whole number of months, and it had sometimes twelve, and sometimes\nthirteen, as with the ancient Babylonians, but the system by which\nthis was arranged was quite different, as they did not depend upon\nobservations of the stars, but counted the number of days between\nequinox and equinox by means of gnomons. Great difficulties were\nfound in trying to reconcile the lunar and solar periods. The ancient\n12-month year, used in the time of Hesiod, was found to be much too\nshort, and alternate years of 12 and 13 months made the period too\nlong; then an eight-year cycle was invented, but this had to be\nconstantly corrected, which led to great confusion. As we have seen how\ncarefully Meton and Euctemon had determined the length of the tropical\nyear, even before the days of Eudoxus, surprise may be felt that a\ncalendar year was not fixed to correspond accurately with the movements\nof the sun, ignoring the irreconcileable movements of the moon, but it\nis difficult for us to realize in these days how wrong and strange it\nseemed if a new moon occurred in the middle or at the end of a month,\ninstead of at the beginning. In Aristophanes\u2019 play of _The Clouds_,\nwhich was acted in B.C. 423, the moon was said to grumble because men\nwould not keep the months as she showed them:\u2014\n\n \u201cYet you will not mark your days\n As she bids you, but confuse them, jumbling them all sorts of ways,\n And she says the gods in chorus shower reproaches on her head,\n When in bitter disappointment they go supperless to bed,\n Not obtaining festal banquets duly on the festal day.\u201d\n\nThen Meton made his celebrated discovery that nineteen tropical years\ncorrespond almost exactly with 235 synodic months (the difference is\nin fact only a few hours), and a cycle of 19 years was arranged, which\nwas adopted by all Greek states and dependencies. Some of the years had\ntwelve and some thirteen months, and some of the months 29 and others\n30 days, but all followed in a regular order, and when one cycle was\ncompleted another was begun. The total number of days in each cycle\nwas 6940, and as this is only 9\u00bd hours longer than 19 true tropical\nyears, it follows that the average year in the Metonic cycle was only\nhalf an hour longer than it should have been.[58] The average month was\nnot quite two minutes longer than the true synodic month.\n\n------------------------------------------------------------------------\n[58] It therefore really approached more nearly the sidereal year,\nalthough the cycle was based on the tropical year.\n------------------------------------------------------------------------\n\nAn improvement even on Meton\u2019s cycle was made by Calippus, who\nproposed to correct its too great length by quadrupling the period,\nand then deducting one day from the whole. This would have given a\ncycle of 76 calendar years, in which the average year was 365\u00bc days, or\nonly 11\u00bc minutes too long. It does not seem, however, to have been ever\nbrought into actual use as a calendar, but Ptolemy often refers to the\nCalippic epoch as a date from which to calculate celestial phenomena.\n\n[Sidenote: Theon of Alexandria _c._ 380 A.D.]\n\nAfter Ptolemy, the Alexandrian school of astronomy produced only\ncopyists and commentators, the last of whom was Theon, who saw his\ndaughter Hypatia murdered and the library burned by fanatical mobs. It\nonly remains for us to see how the Greek system of astronomy, brought\nto so great perfection in the _Almagest_, was neglected for many\ncenturies, and by whom it was at length rediscovered and made to live\nagain.\n\n\n\n\n_VI. ASTRONOMY UNDER IMPERIAL AND CHRISTIAN ROME._\n\nB.C. 46 TO A.D. 1000.\n\n\n _Vos O clarissima mundi_\n _Lumina labentem c\u0153lo qu\u00e6 ducitis annum._\n Georgic I.\n\nNo new school of astronomy arose under the Roman Empire, nor do we even\nknow of one Roman who devoted his life to the science. The genius of\nthis people lay in other directions, and Dante truly says:\u2014\n\n \u2018\u201cNature ordained in the world a place and a people\n for universal command ... to wit, Rome and her\n citizens or people. The which our poet too has\n touched upon right subtly in the sixth [Virgil, in\n the sixth book of the \u00c6neid], introducing Anchises\n admonishing \u00c6neas, the father of the Romans, thus:\u2014\n\n \u201cOthers shall beat out the breathing bronze more\n softly, I do well believe it! And shall draw the\n living features from the marble; shall plead causes\n better, and trace with the rod the movements of the\n sky, and tell of the rising stars. Roman! do thou\n be mindful how to sway the peoples with command.\n These be thy arts: to lay upon them the custom of\n peace, to spare the subject and fight down the\n proud.\u201d\u2019[59]\n\n------------------------------------------------------------------------\n[59] _De Mon._ II. vii., \u201cTemple Classics\u201d edition.\n------------------------------------------------------------------------\n\nYet there were some enthusiastic amateur astronomers in Rome, for\nCicero tells us of one who had felt old age to be no burden because he\nwas so eager over his astronomical studies, sitting up sometimes all\nnight to finish his calculations, and delighted when an eclipse he had\nforetold came to pass.[60] This ardent amateur, Sulpicius Gallus by\nname, had found such knowledge of practical value in his younger days,\nwhen he was with the legions in Macedonia, for he had been able to\npersuade the troops not to be alarmed by an eclipse of the moon which\nwas about to happen, explaining how it was due to natural causes; and\nwhile the soldiers in the opposite camp were shrieking and moaning,\nbelieving that the eclipse portended the death of their king, the Roman\nsoldiers remained quite calm. This was on the eve of the battle of\nPydna, in B.C. 168, a little before the time of Hipparchus.\n\n------------------------------------------------------------------------\n[60] _De Senectute._\n------------------------------------------------------------------------\n\n[Sidenote: Ovid B.C. 43-A.D. 17.]\n\n[Sidenote: Virgil B.C. 70-19.]\n\n[Sidenote: Manilius _c._ A.D. 10.]\n\n[Sidenote: Cicero B.C. 106-43.]\n\nIn Cicero\u2019s own life-time, and throughout the early days of the Empire,\nit was the fashion to have at least a smattering of Greek astronomy.\nOvid tells legends of the constellations; Virgil, at his farm where he\nlingered happily among his vines, his cattle, and his bees, studied the\nvarying aspects of the constellations in connection with the seasons\nand the weather; Manilius wrote a long poem in five books on astronomy\nand astrology; Cicero himself was quite learned in the subject, and\nmade a translation of Aratus, which had a great vogue.\n\nVery popular also, both in classical and medi\u00e6val times, was his _Dream\nof Scipio_, which was an imitation of Plato\u2019s fable of the vision of\nEr, in the _Republic_. The moral is that earthly fame is valueless,\nsince Earth itself is insignificant compared with the starry heavens,\nbut that those who practice virtue for its own sake shall return to\nthe stars whence their souls originally came. The youthful Scipio is\ntransported to the skies in a dream, and meets the souls of his father\nand of the elder Scipio Africanus in \u201ca radiant circle of dazzling\nwhiteness, which you have learned from the Greeks to call the Milky\nWay.\u201d There he sees \u201cstars which we never saw from this place, and\ntheir magnitudes were such as we never imagined, the smallest of which\nwas that which, placed upon the extremity of the heavens, but nearest\nto the earth, shone with borrowed light.\u201d But the shining globes of the\nstars are so great that Earth seems to have contracted to a point, and\nScipio gazes at it, grieved.\n\n\u201cHow long will your gaze be fixed on Earth?\u201d cries Africanus. \u201cDo you\nnot see into what temples you have entered?\u201d and he points out nine\nspheres which compose the whole universe. The outermost, in which\nthe stars are fixed, is most divine, and within this are seven, one\nof which contains the planet called Saturn upon earth, the next the\nglorious Jupiter, friendly and helpful to mankind, then Mars, ruddy\nand terrible, and the next place in the middle region is held by the\nsun, the leader, prince, and governor of all other luminaries, the soul\nof the world, filling all things with his light. Venus and Mercury\nfollow him in their courses, like attendants, and in the lowest sphere\nrolls the moon, kindled by his rays. Below this, all is mortal and\ntransitory, except the souls given to the human race by the grace of\nthe gods; above the moon all is eternal. Earth, which is at the centre\nand forms the ninth sphere, is immoveable and below all the rest; and\nall weights, by their natural gravitation, fall towards her.\n\nScipio then asks what is the sound which fills his ears, so loud and\nyet so sweet? and he is told that he hears the music of the spheres,\nwhich is too great for mortal ears, just as the sun is too bright for\nhuman eyes to look upon. Yet those who make music upon Earth, with\nstrings or voice, like all others who follow heavenly pursuits, are\nopening for themselves a path by which to return to the stars, the true\nhome of the soul.\n\n[Sidenote: Strabo born _c._ B.C. 63.]\n\n[Sidenote: Seneca B.C. 3-A.D. 65.]\n\n[Sidenote: Pliny _c._ A.D. 23-79.]\n\n[Sidenote: Proclus died _c._ 480 A.D.]\n\n[Sidenote: Martianus Capella, 5th century A.D.]\n\n[Sidenote: Simplicius 5th century A.D.]\n\nOther famous Latin authors who wrote on astronomy were Strabo,\nSeneca, and Pliny, who quote Eudoxus and Aristotle, Poseidonius, and\nHipparchus. When Ptolemy\u2019s work was done there was no great writer to\npopularize it. Three hundred years later Proclus writes a commentary\non it, and Martianus Capella mentions it, but Simplicius, in his\ncommentary on Aristotle\u2019s _De C\u0153lo_, though he speaks of \u201cthe admirable\nPtolemy,\u201d is evidently unacquainted with his work.\n\nNo Roman added anything new to astronomy, and the most precious parts\nof their writings for the history of astronomy are some fragmentary\nnotes of early Greek astronomers whose original works are lost.\n\nThe practical use of astronomy for measuring time appealed, however,\nto the Roman people. The most ancient Roman year (said to have been\nintroduced by Romulus) had only ten months, March being the first,\nwhich explains why the ninth to the twelfth of our present months have\nthe names of September, October, November and December, as if they came\nin the order of seventh to tenth. Two more months were added later,\nand at some unknown date the old Octennial or 8-year Cycle was adopted\nfrom the Greeks. This involved the use of intercalary months of varying\nlength, and the priests were entrusted with the business of arranging\nthem. But the priests thought it much more important that the length\nof the year should suit their convenience than that it should conform\nto the celestial movements, so they made it long or short according as\nthey approved or not of the persons holding office at the time; and by\nthe time of Julius C\u00e6sar the calendar had fallen into such confusion\nthat March 25, which was supposed to be the date of the spring equinox,\ncame in the middle of winter!\n\n[Sidenote: Julius C\u00e6sar and Sosigenes B.C. 46.]\n\nA drastic reform was necessary. Julius C\u00e6sar called in the Alexandrian\nastronomer Sosigenes, and gave the Empire the calendar which, with the\nexception of one small reform made since, we still use. The moon was\nthrown over altogether: there were to be no more intercalary months,\nand every year was to be exactly like the last, except for the addition\nof one day in every fourth year, so as to make the average year equal\nto 365\u00bc days. Since the tropical solar year is only 11 minutes, 14\nseconds shorter than this, many centuries would elapse before the\nmonths of this calendar would depart from their proper seasons. March\n25 was restored to the time of the vernal equinox, but the first\nday of the new year was to be January 1, and Julius C\u00e6sar gave his\nown name to the old fifth month of Quintilis. Each month was to be\nalternately of 31 and 30 days, except February, which would only have\nits full complement of 30 days in the fourth year (Leap Year), and 29\nevery other year. This reform was regarded by some as an unwarrantable\ninterference by a despot. Cicero, when some one mentioned that the\nconstellation Lyra would rise at a certain hour, answered bitterly,\n\u201cYes, if the edict allows it!\u201d\n\nUnfortunately, the simplicity of the scheme was a good deal spoiled\nby the folly of Augustus, who could not bear that the month of his\npredecessor should have 31 days while the next, the old Sextilis, which\nhe turned into August, named after himself, should have only 30. So he\nmade two months of 31 days come together, and took away a day from\nFebruary. Afterwards, Nero gave his name to April, and Domitian his to\nOctober, but this was more than a long-suffering world could bear, and\nthe new names were gladly forgotten as soon as the tyrants were dead.\n\nAlthough, therefore, Rome was obliged to apply to Alexandria, that is\nto Greek astronomy, to carry out the project, it was Rome that gave us\nthe most correct and convenient calendar which exists, better in both\nrespects than that which had been used in Greece itself.[61]\n\n------------------------------------------------------------------------\n[61] The _average_ year was the same, 365\u00bc days, in the old 8-year\ncycle of the Greeks, and also in the Calippic cycle, which did not come\ninto practical use. The average year of the Metonic cycle was longer,\nand therefore departed further from the true tropical year.\n------------------------------------------------------------------------\n\nBut alas! the celestial science, a willing servant as time-measurer for\nthe daily uses of humanity, a docile captive to adorn the triumph of\nliterature, was doomed to a baser servitude. It was in the early days\nof the Empire, and all through the Middle Ages, that the pseudo-science\nof Astrology was pursued with passion, and men spent their lives\nin studying the paths of planets and positions of the stars, urged\nsolely by the delusive hope of being able therefrom to read the book\nof fate and guide the lives of their superstitious clients. From\nChaldea, its ancient home, came the most famous astrologers, but their\nart was soon learned in every country of Europe, and its professors\nwere sought after by peasants and kings\u2014now reviled and banished as\nimpious and leagued with devils, now loaded with honours and rewards,\nrevered, hated, welcomed, forbidden, but always believed in. Although\nwhen Christianity was established the seven planets could no longer\nbe regarded as great gods ruling over the lesser gods of the stars,\nthey were still thought to be mighty revealers of fate. Each had his\nspecial attributes and influence over man: the fiery colour of Mars\nno doubt suggested the warlike and hostile spirit ascribed from time\nimmemorial to this planet-god; the slow motion of Saturn in his distant\nsphere gave an impression of a mournful morose being, the \u201cfrigida\nSaturni stella\u201d of Virgil; Venus was the planet of love; the sun, of\nhonour and power, and so forth. Each planet was also mysteriously\nconnected with a colour, and, the alchemists said, with a metal; the\nsun with gold, the moon with silver, Saturn with pale heavy lead, etc.\nEach also influenced a special part of the body: thus, if Mercury were\nunfavourably placed at the moment of a child\u2019s birth it would be liable\nto suffer from lung-disease; the moon\u2019s position affected the brain;\nthe sun\u2019s the heart, etc.\n\nAs the planets had distinct and often contrary influences in different\npositions, it was necessary, in determining a man\u2019s fate, to consider\nthe aspect of the whole heavens, especially at the moment of his birth,\nbut horoscopes were also cast for any period in his career, past,\npresent, or to come, enabling him to guard against threatening evils\nor bad tendencies, and to seize favourable opportunities. The method\nwas as follows: the sky-sphere, as it appeared at the given time and\nplace, was divided into twelve \u201chouses,\u201d by drawing meridians (called\n\u201ccircles of position\u201d) 30\u00b0 apart. The house just about to rise on the\neastern horizon was called the \u201cascendant,\u201d and was the first and most\nimportant, planets situated there having more power than anywhere else;\nbut each house had its special significance, the second (just above the\neastern horizon) being the House of Riches, the seventh of Marriage,\nthe twelfth of Enemies, etc. The kind and the strength of each planet\u2019s\ninfluence depended mainly upon the house in which it happened to be,\nand was strongest when the planet was in its own house and also in its\nfavourite zodiacal sign. The sun was considered to be most at home in\nLeo, the moon in Cancer, and each of the other five planets owned two\nof the remaining signs. Another important point was the \u201caspect\u201d of the\nplanets with regard to one another, that is, their angular distance\napart on the sky-sphere. If Mars and Jupiter, for instance, were in\n\u201copposition,\u201d _i.e._ 180\u00b0 apart, the portent was unfavourable, but in\n\u201ctrine\u201d or \u201csextile\u201d aspect (120\u00b0 or 60\u00b0 apart), favourable.\n\nIt is evident that for casting horoscopes it was necessary to be able\nto calculate for any given time or place the positions of the heavenly\nbodies; and for this the skies must be watched, and the movements\nknown of the stars, of sun and moon, and of planets. To this extent,\ntherefore, an interest in genuine astronomy was kept alive; but on the\nother hand, the system fostered belief in the overwhelming importance\nof Earth in the Universe, and the existence of the heavenly bodies\nfor the sole purpose of ruling and foretelling human destinies: no\none cared to inquire what were the underlying laws, and what the real\nnature, of the heavenly phenomena.\n\nClosely allied to this superstitious belief in planetary influences,\nwas the dread of comets, meteors, and eclipses, which were everywhere\nregarded as omens. It was in vain that Seneca urged the greater\nimportance of investigating the nature of the heavenly bodies about\nwhich something was already known, and of trying to solve the problem\nworthy of highest consideration, viz. whether the earth, as some had\nasserted, was turning rapidly, or was stationary in a turning World.\nHis very protest, as well as his lengthy dissertation on comets, shows\nhow far less interesting, alike to philosophers and public, were the\nordered courses of stars and planets, than the startling apparition of\nsuch rare objects as that great \u201chairy star\u201d which, appearing suddenly\nduring the games instituted by Augustus after the assassination of\nJulius C\u00e6sar, was thought to be the soul of the dead Emperor. Augustus\nerected a temple in its honour.\n\nRome, considered as the metropolis of the dominant temporal power,\nfailed to encourage astronomy; Rome as the centre of the spiritual\npower directly discouraged it.\n\n[Sidenote: Cosmas _c._ 540 A.D.]\n\n[Sidenote: Augustine 354-430 A.D.]\n\nIn the fourth and fifth centuries after Christ \u201cthe old heathen\ntheory\u201d that Earth is a sphere was opposed by some of the Fathers,\nas inconsistent with certain expressions in the Bible; and in the\nsixth an Egyptian monk, Cosmas Indicopleustes, formulated a scheme of\nthe Universe according to which the Jewish Tabernacle was a type and\npattern of the World. The earth is the flat oblong floor, surrounded\nby four seas; these are enclosed by four massive walls which support\na roof (the firmament or sky), and above this live the angels, who\nmove the sun, moon, and stars across the firmament, and let down rain\nthrough its window. This childish cosmogony, supposed to be in entire\naccordance with Genesis, Isaiah, and the Psalms, bears a curious\nsimilarity to one of the oldest \u201cheathen theories\u201d of all, born in the\nland where Cosmas lived.[62] Saint Augustine, however, author of the\nparalysing doctrine: \u201cNothing is to be accepted save on the authority\nof Scripture,\u201d does not seem to have considered belief in a spherical\nEarth forbidden, but it was to him a matter of perfect indifference,\nwhile he upheld as an article of faith that in no case could any\nantipodean inhabitants exist. For they could not be descendants of\nAdam, nor ever hear the Gospel, since everyone knew the torrid zone to\nbe an impossible barrier between north and south. Another favourite\nChurch doctrine was that Jerusalem was the centre of the earth: this\nidea, which it will be remembered has a place in Dante\u2019s cosmogony, was\nbased on the words in Ezekiel:[63] \u201cThis is Jerusalem: I have set it in\nthe midst of the nations and countries that are round about her.\u201d Good\nbishop Arculf, and other pilgrims, were shown a pillar \u201con the north\nside of the holy places, and in the middle of the city,\u201d which marked\nthe exact spot, and were told in proof of the assertion that at midday\nat the summer solstice this pillar cast no shadow! How this proved its\ncentral position is a mystery, and if true the pillar must have been\ndeplorably crooked, for the sun can never pass overhead in Jerusalem,\nin a latitude of nearly 32\u00b0 north.\n\n------------------------------------------------------------------------\n[62] See p. 45.\n\n[63] _Ezekiel_, v. 5.\n------------------------------------------------------------------------\n\nThe Church, like the State, saw that astronomy had one use, and\napplied, like the State, to Greek astronomy for a calendar. It was\nnecessary that the ecclesiastical calendar should be luni-solar, since\nEaster, which corresponds with the Jewish passover, must fall on the\nSunday following the first full moon after the Vernal Equinox. By 325\nA.D., when the Council of Nice was held, at which this question was\nsettled, the Vernal Equinox fell on March 21 instead of March 25,\nowing to the neglected eleven minutes in the Julian year. March 21 was\ntherefore adopted by the Church as the date of the equinox, which was\nassumed to remain constant; and the old luni-solar cycle of Meton was\nused, and still is used in all churches which celebrate Easter, as a\nbasis for the ecclesiastical calendar.\n\nThe custom of reckoning years forwards and backwards from the birth of\nChrist was first introduced by a Roman abbot, Dionysius Exiguus, in the\nsixth century, but it did not become general in Christian countries\nuntil the ninth century. Dionysius adopted as the first day of the\nepoch, not January 1, but March 25, the old Roman date of the vernal\nequinox. This was because it was Annunciation Day, and it was a belief\nof the Middle Ages that the Annunciation and also the Crucifixion\nactually took place on this day, and also that the Creation began on\nthe same date.\n\n[Sidenote: Martianus Capella 5th cent. A.D.]\n\n[Sidenote: Cassiodorus _c._ 530 A.D.]\n\n[Sidenote: Bo\u00ebthius died 525.]\n\nAt the break-up of the Roman Empire some fragments of classical\nlearning were saved from the wreck, mainly in the text-books of the\n\u201cheathen\u201d writers, Capella, Cassiodorus, and Bo\u00ebthius. These were\npreserved by the Church, now the only repository of learning. The\nsecular instruction given to churchmen included astronomy, for while\nthe \u201cTrivium\u201d comprised the three elementary sciences of Grammar,\nRhetoric, and Dialectic, the \u201cQuadrivium\u201d comprised the four advanced\nsciences of Arithmetic, Astronomy, Geometry, and Music. But only a\nmere smattering of the \u201cQuadrivium\u201d was taught in this period, and\nscarcely more of astronomy than was necessary for determining the date\nof Easter. The intimate knowledge and ingenious theories of the Greeks\nconcerning the celestial motions interested no one any more.\n\n[Sidenote: Charlemagne 732-814.]\n\n[Sidenote: Isidore died 636.]\n\n[Sidenote: Bede _c._ 673-735]\n\n[Sidenote: Fergil, 745.]\n\n[Sidenote: Dicuil, 825]\n\nFrom the seventh century, however, the ignorance began to be less\ndense. Charlemagne established many schools, and there were enlightened\nmonks here and there\u2014Saint Isidore of Seville, the Venerable Bede,\nand Irish scholars like Fergil and Dicuil\u2014whose teachings show that\nthe elements of astronomy as taught by the Greeks were not totally\nforgotten everywhere. From the beginning of the ninth century all\nfamous monasteries had schools for laymen as well as for monks.\n\nIn Italy the darkness was never quite so deep as in northern Europe,\nfor traditions of classical culture never quite died out. And although\nthroughout the long period from Ptolemy to the end of the tenth\ncentury, astronomy had been almost completely neglected in Europe, the\nway was slowly being made plain for a great revival. The ideal Empire,\ngoverning the whole world from the Eternal City, and the ideal Church\nmaking all men brothers, though neither has ever existed in fact, did\nso in men\u2019s minds, as we see clearly in Dante, and both exercised a\npowerful influence. The Roman Empire and the Roman Church did impress\na kind of unity on Europe as it grew: there was one civilization, one\nreligion, one language in which new thoughts could be conveyed to all.\nThus the ground was prepared, and whenever a new school of astronomy\nshould arise or be imported, it would not remain the property of one\nnation surrounded by barbarians, but might at once be shared in and\nadvanced by the whole of Europe.\n\n\n\n\n_VII. ARAB ASTRONOMY._\n\nA.D. 750 TO 1250.\n\n\nARAB ASTRONOMY.\n\nOnce more the scene changes. While European science is at low ebb,\nif we look to the banks of the Tigris, not many miles from the ruins\nof ancient Babylon, we find the centre of a new and famous school of\nastronomy.\n\n[Sidenote: Al Mansur 753-775 A.D.]\n\nFrom the deserts of Arabia an immense empire had arisen, which in less\nthan a century spread eastwards as far as India, and westwards to\nMorocco and Spain. Its first capital was Damascus, but in 755, after\nthe defeat of the Omeyyad dynasty, the new Caliph fixed his capital\nat Baghdad, the wondrous city of the Thousand and one Nights. This\nCaliph was the renowned Al Mansur. To his court there came one day a\nscholar from India, who was skilled in the knowledge of the stars, and\nhe laid before the Caliph a book which treated of things celestial and\nshowed how to foretell eclipses. Al Mansur was profoundly interested,\nand ordered a translation of the book to be made into Arabic. The\nastronomical system of the Hindus was at that time very similar to the\nGreek, and there can be no doubt that Greek astronomy had found its way\nto India several centuries before this.\n\n[Sidenote: Haroun al Raschid 786-809 A.D.]\n\nShortly after this the writings of Greek philosophers and astronomers\nwere brought to the court at Baghdad. They had been carefully\npreserved, copied, and translated into Syriac, by Nestorian monks in\nsome of the many monasteries which were founded in Persia and other\ncountries of the East when these heretic Christians were driven out\nof Europe in the fifth century; and many of the Court physicians of\nBaghdad came from a Nestorian school of medicine. Haroun al Raschid,\nson of Al Mansur, gave orders for Ptolemy\u2019s _Syntax_ to be translated\ninto Arabic, and it now received its name of _Almagest_: several other\ntranslations were made later, and Aristotle was eagerly studied. This\nCaliph sent an embassy to Charlemagne, and among the presents sent by\nthe East to the West were an elephant and a clepsydra.\n\n[Sidenote: Al Mamun 813-833 A.D.]\n\nAl Mamun, son and successor of Haroun Al Raschid, is said to have\nlearned astronomy under a Persian teacher. He also added to his\nfather\u2019s library, and one of the terms of a treaty he made with\nMichael, the Greek emperor, was that a collection of Greek writings\nshould be made throughout the empire, and forwarded (originals or\ncopies) to Baghdad. Moreover, he was not content with merely reading\nastronomy, Greek, Persian, or Hindu: he ordered Ptolemy\u2019s estimate\nof the size of the earth to be tested, by measuring an arc of a\nmeridian in his own country, and he founded a splendid observatory\nin the province of Baghdad. The instruments were of the same kinds\nas the Alexandrian, but they were larger, and better made, and the\ncircles were more accurately divided. The Arab astronomers were good\nobservers, and among them for the first time we hear of astronomers\nwinning fame by skill in instrument making. Their dials were superior\nto those of any other race, and they made some important improvements\nin mathematics, which were immensely useful to astronomers. One great\nservice was the introduction of the decimal notation, which they\nlearned from the Hindus.\n\nAstrology is forbidden by the Koran, but it was practised eagerly,\nnevertheless, by the Arabs, who constructed tables for this purpose,\nand made improvements in the methods used.\n\nTraces of Arab contributions to astronomy survive in our words \u201czenith\u201d\nand \u201cnadir,\u201d and \u201calmanac\u201d; our word for a \u201ccipher\u201d is the Arabic\n\u201czifra,\u201d and indicates the main advantage of the decimal notation in\narithmetic; while \u201csine\u201d is the Latin translation of an Arabic word,\nand reminds us of the great improvements made in trigonometry.[64]\n\n------------------------------------------------------------------------\n[64] Arabic _gib_ = Latin _sinus_, a fold; _i.e._ the chord folded in\ntwo.\n------------------------------------------------------------------------\n\n[Sidenote: Alfraganus _c._ 840 A.D.]\n\n[Sidenote: Albategnius _c._ 900 A.D.]\n\n[Sidenote: Abul Wefa 940-998.]\n\nAmong the many names of Ptolemy\u2019s successors at Baghdad, strange and\nuncouth to our ears, the three most famous are Mohammed ebn Ketir\nof Fargana, Mohammed ben Geber Albatani, and Mohammed Abul Wefa al\nBuzjani, which became known to the West under the shortened forms of\nAlfraganus, Albategnius, and Abul Wefa.\n\n[Sidenote: Ebn Jounis died 1009.]\n\nEgypt too had her Arab school of astronomy, as she had had her Greek.\nA little later than Abul Wefa, Ebn Jounis drew up the famous Hakemite\nTables of the sun, moon, and planets, under the patronage of the Caliph\nHakem of Cairo.\n\nAt the western end of the Arab dominions there were centres of\nintellectual activity in Morocco and southern Spain. Cordova, the city\nof the marvellous mosque, had also, in the tenth century, an Academy,\nand a library which rivalled that of Baghdad; and here, in the midst of\nalmost ceaseless public strife and agitation, in a strangely mingled\natmosphere of cultured refinement unknown to the rest of Europe, and\nof ferocious barbarism, of tyranny and tolerance, heroic deeds of\nchivalry and treacherous intrigues, there lived and dreamed and worked\nmen of science and philosophers, poets, and artists.\n\n[Sidenote: Arzachel _c._ 1080.]\n\n[Sidenote: Averro\u00ebs 1126-1198.]\n\n[Sidenote: Al Betrugi _c._ 1150.]\n\n[Sidenote: Abul Hazan _c._ 1200.]\n\nThe best known of the Spanish Arabs whose names are connected with\nastronomy are Arzachel, who drew up the Tables of Toledo; Averro\u00ebs, the\ngreat philosopher, author of _De Substantia Orbis_, and a commentary on\nAristotle\u2019s Metaphysics, who saw \u201ca black spot on the sun\u201d on the day\nhe had predicted a transit of Mercury; and Al Betrugi (or Alpetragius)\nwho wrote on the Spheres. There was also a certain Abul Hazan, a\nrenowned geographer, who travelled across North Africa, and made a\ncatalogue of 240 stars, including some not given by Ptolemy.\n\nOf all the astronomical writings of the Arabs, one of those which\nbecame earliest and best known in Europe was the _Elements of Astronomy\nand Chronology_ of Alfraganus. This was actually used by Dante as his\nfavourite text-book, and he mentions it in the _Convivio_. I shall\ntherefore give a short account of its contents, following the edition\nof Golius, printed in Arabic and Latin at Amsterdam in 1669.\n\nIn the first chapter Alfraganus gives an account of the calendars used\nby different nations\u2014Arabs and Berbers, Syrians, Romans, Persians, and\nEgyptians. After this he plunges at once into a description of the\nUniverse, as portrayed by Ptolemy, and follows his master so closely\nthat his book is almost a much-abridged and simplified _Almagest_, with\na few additions, and with all the mathematics left out.\n\nIt is accepted almost without dispute among learned men, says\nAlfraganus, that the sky is spherical, and rotates on two fixed poles,\none north, one south. This is proved by the observed movements of the\nstars. Equally undisputed among the learned is the fact that Earth and\nwater together form a globe, which is surrounded by air. The spherical\nform of Earth is proved by the fact that phenomena such as lunar\neclipses and shooting stars are seen at a later hour by observers in\nthe East, and by the changing height of stars above the horizon as one\ntravels north or south. Earth is at the centre of the universe, and is\nbut a point compared with the heavens.\n\nThere are two principal celestial motions: (1) the \u201cprime motion\u201d which\ncauses the whole sky to revolve with every celestial body, and produces\nday and night; (2) the proper motions of the sun and other stars in the\nopposite direction and round other poles. The great circle of the first\nmotion Alfraganus calls the Equator of the Day; that of the second, the\nStar-bearing Circle, _i.e._ the zodiac, or more precisely, the ecliptic.\n\nThe twelve zodiacal signs are then described, with the division of\neach into degrees and minutes, the positions of the equinoxes at the\nbeginning of Aries and Libra, and of the solstices at the beginning of\nCancer and Capricorn. The Colure is described as a great circle cutting\nthe zodiac (_i.e._ ecliptic) and equator at the points where they are\nfurthest apart (_i.e._ at the solstices). This greatest difference\nwas found by Ptolemy to be 23\u00b0 51\u2032 but according to the measurement\nordered to be made by Al Mamun of pious memory, which was carried out\nby a number of experts, it is 23\u00b0 35\u2032. This value is adopted and quoted\nsubsequently throughout the book of Alfraganus.\n\nAlfraganus then proceeds to explain very clearly how the movements of\nsun and stars appear from different latitudes on Earth\u2014on the equator,\nat stations further north, and finally at the pole. He shows how it\nhappens that on the equator day and night are always of equal length,\nand the sun passes exactly overhead twice a year; whereas day and night\nvary more and more in length, according to season, as one travels\nfurther north, and the sun is lower; until at last at the pole the year\nconsists of one long day and one equally long night, the celestial pole\nis in the zenith and the celestial equator on the horizon, so that the\nsky revolves like a mill-stone (_i.e._ the stars do not rise and set,\nbut trace out horizontal circles, like a wheel which is not upright but\nflat on the ground).\n\nThe circumference of Earth, as determined by Al Mamun of glorious\nmemory, is 20,400 miles, and the diameter, therefore, is nearly\n6500.[65] Alfraganus deduces from this the area of the whole Earth and\nalso of the habitable portion of Earth. The latter extends only from\nthe equator to 66\u00b0 25\u2032 North, and its longitude at the equator is equal\nto 180\u00b0 or 10,200 miles, at the northern limit to 4080 miles. This is\ndivided into seven \u201cClimates,\u201c as in Ptolemy\u2019s Geography, the first\nlying a little north of the equator. Alfraganus gives for each the\nlength of the longest day, the height of the pole above the horizon,\nthe extent of territory, and the principal regions and towns comprised.\nHe admits that south of the first climate as far as 0\u00b0 is some land,\nsurrounded by sea, and sparsely inhabited, and north of the seventh\nclimate are a few towns, but these are of no account.\n\n------------------------------------------------------------------------\n[65] The Arabian mile was equal to 4000 \u201cblack cubits,\u201d and if this is\nthe Egyptian and Babylonian cubit, the values are rather too large,\nbeing in round numbers 26,500 and 8,500 English miles, instead of\n25,000 and 8000.\n------------------------------------------------------------------------\n\nOur author treats next of the risings and settings of the zodiacal\nsigns, and of the division of the day into 24 equal or 24 \u201ctemporary\u201d\nhours (see p. 26).\n\nAfter this, the unanimous opinion of wise and learned men concerning\nthe spheres is duly set forth in seven chapters; how there are eight\ngreat Orbs, the smaller enclosed within the greater, the star sphere\nbeing the outermost and largest of all; how epicycles are fixed in\nthese; how only the star sphere has its centre exactly in Earth,\nthe others being slightly eccentric; what are the positions of the\npoles and centres of the great spheres and the small epicycles, their\nrelative sizes, and their different velocities as they turn; finally,\nhow well the system represents the movements of sun, moon, stars, and\nplanets. The moon\u2019s mean daily motion, resulting from a wonderful\ncombination of five circular motions, amounts to about 13\u00b0 11\u2032; the\nsun\u2019s is 59\u2032, and he completes a revolution in 365\u00bc days \u201cless an\ninsignificant fraction.\u201d (This being a popular treatise Alfraganus\napparently thinks it unnecessary to state the length of the year\nmore precisely). The sluggish motion (\u201cmotus tardissimus\u201d) of the\nstar sphere, which is communicated to all the rest in addition to their\nown motions, is 1\u00b0 in a century, according to Ptolemy, so that it\ncompletes a revolution in 36,000 years.\n\nComing now to the fixed stars, their number, and brightness, Alfraganus\ndoes not copy Ptolemy\u2019s great catalogue, but informs us that learned\nmen (\u201csapientes\u201d) did number all the fixed stars as far south as they\ncould see in the 3rd climate, and divided them according to magnitude\ninto six classes. \u201cTo the first class they assigned the bright and\nshining stars such as Canis (Sirius) and Procyon, Vultur Cadens (Vega)\nand Cor Leonis (Regulus). Stars a little less bright they called second\nmagnitude: such are Alfarcatein and Benet Naax,\u201d Arab constellations\nwhich the Latin version describes as the two bright stars of Ursa\nMinor, and those brilliant ones in the tail of Ursa Major. Thus they\nproceeded with the other magnitudes, the smallest measured being of the\nsixth magnitude. The number of stars in each class is given, and the\ntotal of 1022;[66] then a list of the 15 first-magnitude stars, which\nare the same as Ptolemy\u2019s (See p. 155). This is followed by a list of\nthe Arab \u201cMansions of the moon.\u201d\n\n------------------------------------------------------------------------\n[66] The Catalogue of Hipparchus is said to have contained 1080 stars,\nbut Ptolemy\u2019s has only 1022.\n------------------------------------------------------------------------\n\n[Illustration: Fig. 36. Method (erroneous) of estimating planetary\ndistances, described by Alfraganus.\n\nThe distance _E A_ being known, and _E p_ being assumed equal to it,\nthe distance _E a_ can be calculated from the known ratio _E a_: _p a_.]\n\nSo far (with the exception of the mansions of the moon) the Arab\nwriter has followed the Greek, but we have now reached a point where\nhe diverges. Ptolemy, he says, only tells us the distances and sizes\nof the sun and moon, and said nothing about the other heavenly bodies;\nbut if we suppose the greatest distance of the moon to be the same as\nthe least distance of Mercury, and from this calculate his greatest\ndistance (for the ratio is known), and if we proceed in the same way\nwith Mercury and Venus, we shall find that the greatest distance\nof Venus equals the least distance of the sun as given by Ptolemy.\nPtolemy\u2019s least distance for the sun, which was totally wrong, was\n1160 Earth-radii: the greatest distance of Venus, calculated in this\nway from Ptolemy\u2019s figures, was 1150. Alfraganus takes this unlucky\ncoincidence as an indication that there is only just sufficient space\nbetween each sphere and the next to allow their respective epicycles\nto pass one another, and upon this entirely erroneous assumption he\nproceeds to lay down the distances of each planet from the earth,\nand finally of the stars, which are all supposed to be at the same\ndistance, equal to the greatest distance of Saturn.\n\nWho first suggested this method of estimating distances we do not know:\nthe first mention of it occurs in Europe in the fifth century A.D. The\nfollowing table shows the distances obtained in this way:\u2014\n\n GREATEST DISTANCE.\n\n _In Semi-Diameters of Earth._\n Moon 64\u215b\n Mercury 167\n Venus 1120\n Sun 1220\n Mars 8876\n Jupiter 14,405\n Saturn and Stars 20,110\n\nIn this, the moon\u2019s distance is approximately correct, but the sun\u2019s\nis not much more than one-twentieth of its true value. To set the\nstars at a distance of only twenty thousand times Earth\u2019s semi-diameter\nseems to us to bring them very close,[67] but they would still be\nbeyond measurement by naked eye methods, so it is no contradiction to\nAlfraganus\u2019 earlier statement that Earth is a point compared with the\nheavens.\n\n------------------------------------------------------------------------\n[67] Earth\u2019s diameter, and even Earth\u2019s distance from the sun, is too\nsmall a unit. Light, travelling 186,000 miles a second, takes 4\u00bc years\nto reach us from the nearest star.\n------------------------------------------------------------------------\n\nThe Arabs also believed that they had succeeded in measuring the\napparent diameters of the planets and even of the points of light which\nare all we can see of stars, so Alfraganus gives the accepted sizes of\nall. I give them below in descending order of size. The modern values\nin the third column show how false were the results obtained by this\nmistaken method.\n\n DIAMETER: EARTH = 1.\n\n _Alfraganus. Modern Values._\n Sun 5\u00bd 109\u00bd\n The 15 first-magnitude { Arcturus, Sirius,\n stars 4\u00be { Spica, and others, much\n { larger than the sun.\n Jupiter 4\u2079/\u2081\u2086 11\n Saturn 4\u00bd 9\n Other stars, in order of { Various. Some certainly\n magnitude, 2nd to 6th ... { larger than the sun.\n Mars 1\u215b \u00bd\n Earth 1 1\n Venus \u00b3/\u2081\u2080 \u2079/\u2081\u2080\n Moon \u2075/\u2081\u2087 \u00bc\n Mercury \u00b9/\u2081\u2088 \u2153\n\nIn the above table the size of the moon (whose parallax had been found\nby the Greeks) is the only one which is nearly right. The sun is far\ntoo small, and so are the stars. We cannot yet know with certainty the\ndiameter of any star, but they are all comparable with the sun, and\nmany are enormously larger.[68] As their distances are all different,\nsome of the brightest may be comparatively small, and some of the\nfaintest the largest of all.\n\n------------------------------------------------------------------------\n[68] It is impossible to measure the diameter of any star, even with\nthe help of the most powerful telescopes, but in the case of a double\nstar at a known distance the movement of the components as they\ntravel round their common centre of gravity enables us to determine\nthe gravitational force they exercise on each other, and thus their\ncombined mass; and their spectra give some idea of their density. For\ninstance, the mass of the double star Alpha Centauri is nearly twice\nthat of our sun; and as the components appear to be about equal to\neach other, and both show a spectrum resembling that of the sun, we\nmay conclude that Alpha Centauri consists of two stars, each of which\nhas about the same diameter as our sun. Arcturus has a diameter far\ngreater, some say ten times, some not less than twenty-five times as\ngreat as the sun!\n------------------------------------------------------------------------\n\nThe Arabs took a backward step in adopting these imaginary\nmeasurements, for Hipparchus had recognized that only the moon was near\nenough to measure, and although Ptolemy accepted Aristarchus\u2019 value for\nthe sun, he distinctly stated that the planets had no parallaxes and he\ncould not tell their distances.\n\nThe next four chapters describe briefly the risings, settings, and\nmeridian transits of stars as seen from different latitudes on Earth;\nthe heliacal risings and settings and the conjunctions with the sun\nof planets, stars, and moon: the phases of the moon and the direction\nof her horns at different times of the year. Parallax is then clearly\ndefined and discussed.\n\nA description follows of the earth\u2019s shadow, thrown by the sun into\nspace\u2014its tapering form, its position, always pointing away from the\nsun, its width at the distance of the moon, and its length according\nto Ptolemy. This is stated to be 268 times Earth\u2019s semi-diameter,\nwhich is nearly correct,[69] for although Alfraganus believed (from\nPtolemy\u2019s erroneous parallax) that the sun, was much nearer than it\nreally is, it followed from this\u2014since the size was deduced from\nthe distance\u2014that he also thought it much smaller, and the length of\na shadow thrown by any dark body is longer the nearer it is to the\nlight-source, but shorter, the smaller is the light-source.\n\n------------------------------------------------------------------------\n[69] The mean length of Earth\u2019s shadow (which varies a little with\nher distance from the sun,) is 857,000 miles, or 216 times her\nsemi-diameter.\n------------------------------------------------------------------------\n\n[Illustration: Fig. 37. Earth\u2019s Shadow.]\n\nThe two last chapters are devoted to eclipses, lunar and solar, and\nAlfraganus points out that, unlike lunar eclipses, eclipses of the sun\nvary in duration and magnitude according to the place on Earth from\nwhich they are viewed.\n\nThe book concludes: \u201cEnough having now been said concerning the\neclipses of sun and moon, by the goodness of God we have been enabled\nto bring this writing to an end; and for this _Deo Laus et Gloria_.\u201d\n\nThe time at which Alfraganus lived is not precisely known, but it seems\nto have been in the first half of the 9th century, since from internal\nevidence he wrote after, but probably not much after, the death of\nAl Mamun. His name indicates that he was a native of the beautiful\nand fertile country, shut in by lofty mountains, which lies on either\nside of the ancient river Jaxartes. He was surnamed the Calculator,\nand wrote on sun dials and the astrolabe, but we do not know of any\nobservational work of his.\n\nLater Arab writers although they all continued to base their work on\nthat of Ptolemy, improved on some of his estimates. Albategnius began\nhis book \u201cOn the Number and Motions of the Stars\u201d by saying that having\nstudied Ptolemy\u2019s _Syntax_ and mastered the Greek methods, and having\nnoticed some errors in the positions of the stars, he felt impelled\nto add to Ptolemy\u2019s observations, as the latter had added to those of\nAbrachis (Hipparchus), for it is not given to man to attain perfection.\nHe gives a much more accurate value for precession than Alfraganus had\ndone, who merely copied Ptolemy, for he makes it 54\u00bd seconds yearly,\nor one degree in 66 instead of in 100 years. His tropical year,\ntoo, is only two minutes shorter than the modern value, so that he\nimproved upon Hipparchus in this respect; and he made the discovery\nwhich Ptolemy missed, the motion of the sun\u2019s apogee. He merely notes,\nhowever, that the position found by himself differed from that given in\nthe _Almagest_, so it is doubtful whether he realized his discovery, or\nmerely thought that a large error had been made.\n\nAlthough some of Ptolemy\u2019s values were thus corrected by the Baghdad\nastronomers, no change was made in his theory of epicycles and\neccentrics, which all accepted as having a concrete existence, partly\nbecause at first they did not distinguish between these and the spheres\ndiscussed by Aristotle, which he had described as formed of the same\nmaterial as the planets. As Ptolemy does not explicitly state that his\ncircles were only symbols, this is not surprising. They are formed, say\nthe Arabs, of the fifth essence al-acir (the \u00e6ther); and they conceived\nthe epicycle as gliding over the outer surface of the deferent, like a\nsmall soap-bubble on the back of a big one. This notion, coupled with\nPtolemy\u2019s erroneous distance of the sun, misled them, as we have seen,\ninto their imaginary discovery of planetary distances.\n\n[Sidenote: Tabit ben Korra 826-901.]\n\nIt was also partly due to Ptolemy\u2019s unfortunate habit of adopting\nthe doubtful or merely provisional results of his predecessors, and\nrepresenting them as well established and confirmed by himself, that\nthey fell into another error. Tabit ben Korra, noting the discrepancy\nbetween the Greek and the Arab value of precession, investigated\nthe question, and put forward a theory that the motion varies both\nin amount and direction. In his book \u201cOn the Motion of the Eighth\nSphere\u201d he describes an elaborate apparatus which he had invented to\naccount for this variation, but he is very modest about it, and after\nnarrating the results obtained by others, and how they had left them to\nbe judged by posterity, he adds \u201cAnd this is what we have done, with\nGod\u2019s blessing.\u201d Then follow his figures and tables. This imaginary\ndiscovery was accepted by some of the Arab school, and it appears in\nmany medi\u00e6val tables, instead of precession, under the name of the\n\u201ctrepidation.\u201d\n\nThe belief in the material reality of the spheres caused the Arabs\nto add a ninth sphere to the eighth of Ptolemy and Alfraganus, for\nthey thought it was enough to demand of the eighth that it should\ncarry all the stars and give them their slow movement of precession\n(or trepidation). This ninth sphere, therefore, enveloped the whole\nuniverse: upon it were fixed no epicycles, no stars, no planets, but it\noriginated the \u201cprime motion\u201d by turning once in a day and night, and\ncommunicating this revolution to all the inner spheres. It became known\nin medi\u00e6val astronomy as the Primum Mobile or first moving.\n\n[Sidenote: Nasir-ed-din 1201-1274.]\n\n[Sidenote: Alfonso 1223-1284.]\n\nThe Baghdad school of astronomy came to an end with Abul Wefa in\n998, and the Spanish schools died out when Seville and Cordova were\ncaptured by the Christians in the thirteenth century; but the impetus\ngiven to the study of Greek astronomy and astronomical observation was\ncarried on by other nations. In Persia a fine observatory was founded\nby Nasir-ed-din; in Spain the Christian king, Alfonso X, ordered tables\nto be drawn up to replace those of Arzachel, and the _Libros de Saber_\nto be compiled. The movement in Persia was short-lived, but in Europe\nthe revival of astronomy had begun.\n\n\n\n\n_VIII. THE RETURN OF GREEK ASTRONOMY TO EUROPE._\n\nA.D. 1000 TO 1300.\n\n\n \u201cHe hath made everything beautiful in His time; also He hath set\n the infinite in their heart.\u201d\n\nIn the whole cycle of the changing year there is no moment so wonderful\nin northern climes as that which comes in early February, when winter\nis not yet past, but for the first time the promise of spring is felt\nin the air. Not a leaf has unfolded its green, but the swelling buds on\nthe trees make a purple flush all over the woods, the blackbird sings\nan exultant strain, and in some sheltered copse you may find a delicate\ndaring primrose already in bloom.\n\nSuch a moment in the history of Europe was the year 1000 Anno Domini.\nAfter the apathy, the ignorance, the despair of the Dark Ages, a new\nspirit began to breathe hope into the hearts of men. A love of beauty,\na new religious fervour, a passionate desire for knowledge took\npossession of them. Yet it was nearly a hundred years before the great\nuniversities which were one expression of this new spirit sprang up\nin Paris, Bologna, Oxford, to be followed later by similar centres of\nintellectual activity in all parts of Europe.\n\nBy the end of the twelfth century it is said that there were 100,000\nstudents in Bologna. A large number were foreigners from many lands,\nfor as Latin was the universal tongue in education, all nations could\nunderstand each other, and scholars often wandered from one university\nto another, attracted by the fame of some great master. Similarly the\ndoctors would teach first in one town and then another. Men of all\nages and classes met together, for among the students were young boys\nand elderly ecclesiastics, poor scholars who begged their bread, and\nrich nobles who came with a tutor, a chaplain, and a whole suite of\nservants. There were no colleges or even lecture-halls: the students\njoined together in small groups to take a house and share expenses, and\nthe professor lectured in his own house, or in a hired room, or, if the\naudience was large, in a city square, speaking from an open-air pulpit.\nAll were united in the ardent pursuit of learning, and none complained\nif the floors were merely covered with straw, and the lectures, which\noften lasted three hours, began before sunrise on winter mornings in\nrooms which had no light and no fire. Was it not enough that when\nleaving at the end of university life one was technically said to be\n\u201cgoing home a wise man\u201d?\n\nOne cause of this intellectual fervour was the influence of Arab\nculture, with which Europe came into contact through the crusades,\nand through the Saracens in Sicily, and the Moors in Spain. For this\nreason astronomy and astrology took a high rank among the new studies.\nTo distinguish between the two is quite a modern idea, and in medi\u00e6val\ntimes either name was used indifferently to cover both subjects. In\nBologna university in the thirteenth century an important school of\nmedicine and arts arose, through Arab influence, and the Arab doctors\nof medicine introduced the system of astronomy which they had learned\nfrom the Greeks. \u201cA doctor without astrology,\u201d it was said, \u201cis like\nan eye that cannot see;\u201d and before prescribing for a patient it was\nthought quite as important to determine the positions of the planets,\nas the nature of the disease. By the beginning of the fourteenth\ncentury there were salaried professors of astrology in Bologna, and\nthey were more highly esteemed than any other professors except those\nof philosophy.\n\n[Illustration: A MEDI\u00c6VAL ASTRONOMER. [_To face p. 200._\n\n_From a painting by Gerard Dow._]\n\n[Sidenote: Cecco d\u2019Ascoli _d_. 1327.]\n\nOne of their duties was to provide \u201cjudgments\u201d (_i.e._ to cast the\nhoroscope) gratis for students. But the dignity was a perilous one.\nLegitimate prediction by astrology bordered close on necromancy, which\nwas banned by the Church, and one of Bologna\u2019s most famous professors\nin astrology, the learned Cecco d\u2019Ascoli, was burned at the stake in\nFlorence in 1327 for the crime of sorcery.\n\nAstronomy, like other subjects, was taught chiefly by lectures and\n\u201crepetitions,\u201d or classes for catechizing the students on what they had\nalready heard. Books could also be had, though they were dear, on hire\nor purchase, from the university \u201cstationers\u201d or librarians.\n\nThe first books on Greek astronomy which found their way into European\nuniversities were Latin translations of Arabic commentaries and\nparaphrases of Aristotle, which travelled from Moorish academies in\nSpain to Paris. The astronomical treatises with strange technical terms\nin Arabic were hard work to translate, especially when they had already\npassed through several languages, as often happened. Thus it was\npossible to possess a work of Aristotle which was a Latin translation\nof a Hebrew translation of a commentary upon an Arabic translation of a\nSyriac translation of the original Greek text!\n\n[Sidenote: Urban IV., pope 1261-1264.]\n\nBut meanwhile some of Aristotle\u2019s works in the Greek entered Italy from\nthe East, as a result of the crusading conquest of Constantinople in\n1204. The first translations of these into Latin were very poor, but\nlater on St. Thomas Aquinas, with the help of Pope Urban IV., had a\nbetter version made.\n\n[Sidenote: Frederick II. 1194-1250.]\n\n[Sidenote: Sacrobosco died _c._ 1256.]\n\n[Sidenote: Roger Bacon _c._ 1214 to _c._ 1294.]\n\nIt was long before a good Latin version of Ptolemy\u2019s _Almagest_ could\nbe obtained. A translation was made from the Arabic in 1230, at the\nbidding of the Emperor Frederick II., who did much, at his Sicilian\ncourt, to encourage Arab literature, but this translation was not\nmuch known or used.[70] The teachings of the _Almagest_ became known\nchiefly through popular expositions such as those of Alfraganus,\nAlbategnius, and John Halifax of Holywood, an English monk who became\nfamous under his Latinized name of Sacrobosco. He was not an astronomer\nbut had studied Greek and Arab writings, and finding that the study of\nastronomy was neglected because books on the subject were difficult\nboth to procure and to understand, he compiled a useful handbook, which\nbecame widely popular and remained so for several centuries. Several\nother writers, notably Roger Bacon, wrote on the spheres, on the use of\nastrolabes, and on astrology. The books prescribed in Bologna for the\ncourse in Astrology and Mathematics were as follows:\u2014\n\n------------------------------------------------------------------------\n[70] It was also translated from Arabic into Latin at Toledo, in 1175.\n------------------------------------------------------------------------\n\n A work on Arithmetic or Algebra.\n Euclid, with a thirteenth century commentary.\n The \u201cTheorica Planetarum,\u201d which was either a free translation\n of Ptolemy\u2019s _Almagest_ or an exposition of its principles.\n The Alfonsine Tables.\n The Canons of De Ligni\u00e8res (of Amiens, 1330 A.D.),\n _i.e._ rules for the use of astronomical tables to determine\n the motions of the heavenly bodies.\n Portions of the Canon of Avicenna (the Arab philosopher).\n A treatise on the Astrolabe by a Jewish astrologer of the\n ninth century.\n A treatise on the Quadrant.\n The astrological works of Ptolemy, with a commentary.\n A book by Alchabicius (fl. _c._ 850 A.D.),\n probably his work on astrology.\n A book on astrological medicine.\n\n[Sidenote: Alfonso X. 1223-1284.]\n\nFrom the above we gather that a past master in Astrology would\nunderstand the elements of mathematics, and all the astronomy that\nPtolemy\u2019s translator or commentator could teach; that he had learned\u2014at\nleast in theory\u2014the use of astronomical instruments and tables, and\na good deal of astrology, including its use in medical practice.\nThe tables were intended mainly for astrological predictions. The\nstandard Alfonsine Tables had been drawn up in 1252 by Christians,\nJews, and Moors, under the direction of Alfonso X. king of Castile.\nThey contained lists of positions of the planets, dates of Easter\nmoons, \u201cgolden numbers\u201d and \u201cdominical letters\u201d of the ecclesiastical\ncalendar, times and other details of eclipses, together with methods\nfor finding the places of planets, and for casting horoscopes. This\nis the Alfonso who was so much shocked at the complexity of Ptolemy\u2019s\nmultitudinous circles that \u201cthe ointment of his name is marred,\u201d says\nFuller, \u201cwith the dead fly of his atheisticall speech\u201d: \u201cIf only the\nCreator had consulted me, when He made the world, I would have given\nsome good advice!\u201d\n\n[Sidenote: Sylvester II. (Gerbert) Pope, 999-1003.]\n\nNot one of all these books pretended to add any new discovery\nto astronomy: all intellectual energy was absorbed in eagerly\nassimilating the knowledge stored by Greeks and Arabs. Nor were any\ngreat observatories founded in Europe yet, in imitation of Alexandria,\nRhodes, or Baghdad. The instruments in use were celestial globes and\nsmall portable astrolabes and quadrants for determining positions\nand angular distances between the heavenly bodies. The learned pope,\nSylvester II., who had studied astronomy among the Moors in Spain, was\nso skilful in making astrolabes that some accused him of gaining the\nart by selling his soul to the devil!\n\n[Sidenote: Albertus Magnus 1193-1280.]\n\n[Sidenote: Aquinas 1225-1274.]\n\nWhen Aristotle first came to Paris (about 1200 A.D.), in Oriental\ndress, and accompanied by Moslem authors, the Council of Paris\ndenounced him as an infidel; yet in less than fifty years all his works\nwere placed on the list of books prescribed in the university course.\nThis was brought about by the Dominicans. In six of his twenty-one\nponderous volumes the German friar Albertus Magnus paraphrased the\nwhole of Aristotle\u2019s works, and stripping his philosophy of the\npantheistic and materialistic garb in which the Spanish Arab Averro\u00ebs\nhad clothed it, presented the Greek philosopher as an ally of\nChristianity. The Italian saint, Thomas Aquinas, pupil of Albertus,\nin his much more readable commentaries and treatises, popularized\nthis idea so successfully that Aristotle\u2014_the_ Philosopher, as he was\ncalled\u2014speedily became as great an authority on every other subject as\nhe had always been on logic.\n\nIt was a mutual victory. Aquinas captured the Greek for the Christian\nfaith; Aristotle won the western world to accept his theories. No\nlonger was the doctrine of a spherical Earth called \u201can old heathen\ntheory\u201d: it was almost an integral part of the Catholic faith.\nAristotle\u2019s demonstration that there must be a First Mover, himself\nunmoved, became an argument for the existence of the Christian Deity;\nthe intelligences which preside over the celestial movements were\ninterpreted as the nine hierarchies of angels whose existence was\ntaught by the Church. To the eight spheres of the Greeks and the\nPrimum Mobile of the Arabs, the thirteenth-century Christians added\nthe all-embracing heaven of heavens, the Empyrean, to be the abode of\nthe Creator and blessed spirits. Within the central immoveable earth\nthey placed Purgatory and the fires of Hell. They accepted the limits\nof the habitable earth as laid down by Ptolemy, but kept Jerusalem as\nthe centre by asserting that it was situated 90\u00b0 from the Pillars of\nHercules, and 90\u00b0 from the mouths of the Ganges. Eden, the earthly\nparadise of Adam and Eve, was represented on contemporary maps as in\nthe extreme East, separated by sea from the eastern boundary of the\ninhabited earth.\n\nThus theology and science supported one another. All learning was\nsacred, and all that man\u2019s mind is capable of understanding he might\naspire to know, for the search if rightly pursued would lead at last\nto the perfect bliss of beholding with unveiled eyes the Source of all\nTruth.\n\n\n\n\n_SECOND PART._\n\nTHE ASTRONOMY OF DANTE.\n\n\nI. POPULAR ASTRONOMY IN ITALY IN DANTE\u2019S TIME.\n\nIn the first part of this book we have sketched the story of man\u2019s\nthoughts about the stars, from primitive days until the thirteenth\ncentury of our era. We have seen what a wealth of imagination and\ninvention the Greeks brought to bear on the purely empirical science of\nEgypt and Babylon and Homeric Greece, and how out of all the systems\ndevised by them between 600 B.C. and 100 B.C. one survived, which\nwas completed and expounded by Ptolemy in the second century after\nChrist in his great _Syntax_ or _Almagest_. Its fundamental principles\nwere that Earth is a sphere, at rest in the centre of the Universe,\nsurrounded on all sides by spherical heavens, and that the movements\nof all the heavenly bodies are explained by a combination of uniform\ncircular movements.\n\nIn the succeeding centuries there were few who could appreciate his\nwork, and during the Dark Ages it was scarcely known in Europe, but\nwas preserved by Nestorian Christians in schools and monasteries of\nPersia, whence it was unearthed by Mahomedan princes, five centuries\nafter Ptolemy\u2019s death; and when another five centuries had passed it\nwas brought back to Europe, tinged with Oriental thought, and almost\nimmediately became immensely popular among scholars.\n\nThen there arose one of the world\u2019s greatest poets, and, a thousand\nyears after Ptolemy\u2019s death, immortalized his work, writing in a tongue\nunknown to Ptolemy, and for nations which in his day were only just\nstruggling into existence. As Homer reflects to us man\u2019s primitive\nconceptions of the Universe, so Dante reflects the ideas of Ptolemy and\nhis school.\n\nAnd because he lived just at this time he was able to write with\nperfect confidence, quoting Ptolemy and the Catholic Faith side by\nside as infallible authorities in astronomy. Had he lived in the early\nChristian centuries he would have been obliged to choose between\nclassical and orthodox views; had he been born three centuries later,\nhe would have found Copernicus and Galileo ranged against Ptolemy and\nthe Church. Even Milton writing a hundred years after the death of\nCopernicus, could not make up his mind which system to adopt, and the\nastronomy of _Paradise Lost_ is a curious jumble of ancient, modern,\nand transitional ideas. He describes the Primum Mobile as a \u201cfirm\nopacous globe\u201d[71] on which Satan alights and walks about, yet later on\ntells us that we need not believe in its existence if Earth is turning\non her axis;[72] the archangel Raph\u00e6l describes to Adam the Creation,\nat which he was present, yet declares that he himself does not know\nwhether the sun circles round Earth, or Earth round the sun. This the\ngreat Architect had wisely concealed from man and angel,\n\n------------------------------------------------------------------------\n[71] _Paradise Lost_, II. 418.\n\n[72] _Paradise Lost_, VIII. 34-38.\n\n \u201cperhaps to move\n His laughter at their quaint opinions wide,\n Hereafter when they come to model heaven,\n And calculate the stars, how they will wield\n The mighty frame, how build, unbuild, contrive,\n To save appearances; how gird the sphere\n With centric and eccentric scribbled o\u2019er,\n Cycle and epicycle, orb in orb.\u201d[73]\n\n[73] _Paradise Lost_, VIII. 77-84.\n------------------------------------------------------------------------\n\nSuch inconsistencies are not found in Dante\u2019s work, and nothing could\nhave been further from his thoughts than to imagine the Creator mocking\nat man\u2019s mistakes and ignorance. Like the angelic doctor, Thomas\nAquinas, he considered man\u2019s desire for knowledge as one of his highest\nattributes, and believed that it had been given to him in order to be\nsatisfied.\n\nBut before we examine Dante\u2019s writings, it will be interesting to form\nan idea of the spirit in which astronomy was generally regarded by his\nfellow-countrymen, and what were his opportunities of studying it.\n\nDante Alighieri was born in Florence in or about the year 1265, and\ndied in 1321. There can be no doubt that the part of star-lore which\nappealed most to the general public in Italy at this time, educated and\nignorant alike, was the art of the astrologers. The movements of the\nheavenly bodies were regarded not merely as omens, but as the actual\ninstruments by which every event on Earth was brought to pass. Every\nclass of plants, every race of animals, was thought to be under the\nprotection of some planet or constellation; so if it was a bad year for\ncertain fruits, or if an epidemic broke out among the cattle, this was\nbecause the guardian planet was unfavourably placed, or an evil planet\nwas in the protecting constellation. Floods and drought, prosperity and\ndeath, properties of minerals such as the lodestone\u2019s attraction for\niron or the emerald\u2019s alleged power of blinding serpents, the instincts\nof animals and the impulses of men, all were subject to the influences\nof the stars; and naturally the men who understood and interpreted\ntheir movements were held in great repute.\n\nSome of them were unscrupulous quacks, like the one-eyed prophet of\nBrescia, mentioned by the gossiping friar Salimbene.[74] He \u201ccalled\nhimself an astrologer and diviner,\u201d and received daily \u201cten great\npennies of silver, and nightly three great Genoese candles of the\npurest wax\u201d from a political party in Modena, as a recompense for\nadvising them how to act. On one occasion he prophesied a victory for\nthem, but he had little faith in his own words, for being threatened\nwith violence if his prophecy should fail, he \u201ccarried off all that\nhe had gained and went his way without saluting his hosts.\u201d \u201cThen,\u201d\nadds the friar, \u201cthe men of Sassuolo began to mock them, as men who\nsacrifice to devils and not to God, as it is written in Deuteronomy.\u201d\n\n------------------------------------------------------------------------\n[74] All quotations from Salimbene\u2019s Chronicle are taken from Coulton\u2019s\n_From Saint Francis to Dante_.\n------------------------------------------------------------------------\n\nBut most of these men, like Asdente of Parma, sincerely believed in\ntheir own ability to foretell events, and they usually combined some\nother favourite forms of soothsaying, as well as a little alchemy,\nwith astrology. Asdente is described by Salimbene as \u201ca poor working\ncobbler, pure and simple, and fearing God, and courteous and urbane;\nilliterate, but with great illumination of mind.\u201d His proper name\nwas Master Benvenuto, but he was \u201ccommonly called Asdente, that is,\ntoothless, by way of contrary, for he hath great and disordered teeth\nand an impediment in his speech, yet he understands and is understood\nwell. He dwells at the bridge-head of Parma, hard by the city moat\nand the well, along the street which goes to Borgo San Donnino.\u201d This\nhumble prophet was said by Dante to be the best known citizen of all\nParma (_Conv._, IV. xvi. 65-71): he was asked to dinner by a bishop,\nand consulted by the warring factions of Reggio and Parma. He was said\nto have foretold the death of two popes, and a naval defeat of Pisa by\nGenoa.\n\nThe greatest generals of the day governed their tactics by the advice\nof astrologers who regularly accompanied them to the field and the\ncamp. The famous Ghibelline, Guido of Montefeltro, who is called\nby Villani the cleverest soldier of his times[75] retained Guido\nBonatti[76] in his service and was believed to have gained his great\nvictory at Forli (in 1282) through the advice of this astrologer.\nBonatti is diversely described as a tiler and a lawyer, but whatever\nhis original occupation may have been he found that the position of\nprivate astrologer brought him both more fame and more money. He wrote\na book on Judicial Astronomy, and Vincent de Beauvais describes him as\ncelebrated throughout the western world for his knowledge of the art.\n\n------------------------------------------------------------------------\n[75] _Croniche Fiorentine_, Bk. VII. par. 80.\n\n[76] _Inf._ xx. 118.\n------------------------------------------------------------------------\n\nBut Bonatti\u2019s fame was faint and fugitive compared with that of the\nwizard Michael Scot. He is one of the picturesque figures of the\nthirteenth century, round whom so many legends have gathered that the\nfacts of his life are difficult to glean. It seems that he was born\nin Fifeshire of a noble Scottish family, at the end of the twelfth or\nbeginning of the thirteenth century, that he studied in Oxford and\nParis, and then spent some time in Toledo. Here he learned Arabic,\nand probably also astrology, for it was so commonly practised there,\nespecially among the Arabs and the Jews, that it was sometimes called\nthe Toletan art. Afterwards he went to Germany, and was discovered by\nFrederick II., who took him to Italy. His great learning earned the\nadmiration of Pope Gregory IX., who speaks of him quite affectionately\nin a letter to the Archbishop of Canterbury; and it is said that\nHonorius II. would have liked to make him an archbishop. But Sir\nMichael the Scot found Frederick\u2019s court more congenial. The Emperor,\nwho was himself a poet, was a munificent patron of literature and art,\nand attracted to himself men of talent from all parts of the world. The\nculture of both East and West met at that brilliant Sicilian court[77]\nwhich was his for fifteen years before the title of Emperor was added\nto that of King of Naples and Sicily. Indeed it was his \u201cfellowship\nwith Saracens\u201d[78] which was one great reason for the accusation of\nheresy on account of which Dante placed him among the Epicureans in the\n_Inferno_. He knew Arabic, as well as French, German, Italian, Latin,\nand Greek. Michael Scot\u2019s acquaintance with Moorish literature and\nlanguage was a bond of sympathy between them; he became astrologer to\nFrederick, and at the Emperor\u2019s wish he superintended a new translation\nof Aristotle\u2019s works from Arabic into Latin. His taste for astronomy is\nevidenced by the fact that out of these he chose to translate the _De\nC\u0153lo_ himself.\n\n------------------------------------------------------------------------\n[77] _V. E._, I. xii. 20-35.\n\n[78] Villani, _Croniche Fiorentine_, VI. 1 and 24.\n------------------------------------------------------------------------\n\nAn absurd story is told by Salimbene about Frederick and Michael\nScot, which, however, shows what was believed of his capabilities as\nan astronomer. The Emperor one day asked him, when they were in the\npalace together, how far they were from the sky, and the astrologer\ntold him the distance. They then took a long journey together, during\nwhich the palace was secretly lowered, and on their return Frederick\nasked casually whether the sky could really be so distant as Michael\nhad said. \u201cWhereupon he made his calculations, and made answer that\ncertainly either the sky had been raised or the earth lowered; and then\nthe Emperor knew that he spake truth.\u201d\n\nMichael Scot is said to have warned Frederick that he would die in\nFlorence, for which reason the Emperor would not enter that city;\nbut having thoughtlessly gone to a town called Florentiola he died\nthere; \u201cfor this,\u201d adds the historian, \u201cis almost always the way, the\ndevil tricks one by a play upon words.\u201d It is curious to contrast\nthis remark, attributing Michael\u2019s prophecy to the evil powers, with\nSalimbene\u2019s quotation from him, in exactly the same spirit as if he\nwere quoting from an Old Testament prophet:\u2014\u201cthat the word of Michael\nScot may be fulfilled in them, which he wrote in his verses wherein he\npredicted the future, \u2018And the factions at Reggio shall hold ill words\ntogether.\u2019\u201d The same author brackets him with others who have foretold\nthe future, in a list which reads curiously to us\u2014\u201cAbbot Joachim,\nMerlin, Methodius and the Sybil, Isaiah, Jeremiah, Hosea, Daniel, and\nthe Apocalypse, and Michael Scot who was astrologer to the deposed\nEmperor Frederick II.\u201d\n\nBesides these prophetic verses, Michael wrote several books which treat\nalmost exclusively of astrology, alchemy, and other occult \u201csciences,\u201d\nand even in the fifteenth century it was said that his magic books\ncould not be opened without danger, because of the fiends who were\nthereby invoked! He seems to have returned to his native Scotland to\ndie, but the date is very uncertain. We do not know whether Dante\u2019s\npicture of him is drawn from memory, or hearsay of some who had seen\nthe lanky Scotsman among the southerners, by nature taller and thinner\nthan they, and worn by his prolonged studies.\n\n \u201cQuell\u2019 altro che ne\u2019 fianchi \u00e8 cos\u00ec poco\n Michele Scotto fu, che veramente\n Delle magiche frode seppe il gioco.\u201d[79]\n (_Inf._ xx. 115-117).\n\n------------------------------------------------------------------------\n[79]\n \u201cThat other, round the loins\n So slender of his shape, was Michael Scot,\n Practised in every sleight of magic wile.\u201d\n _Carey._\n------------------------------------------------------------------------\n\nIt was perhaps the winning personality or the prudence of the canny\nScot which enabled him to bring a brilliant career to a peaceful close,\nfavoured by the Church as well as by the excommunicated Emperor,\nalthough his studies were of so dubious a nature, and he was intimate\nwith heretic Mahomedans and Jews. Cecco d\u2019Ascoli was not so fortunate.\nThis learned Italian received the high and honoured post of professor\nof astrology in Bologna, where he lectured and cast horoscopes for his\nstudents. He was well versed in natural science, but the shady side of\nastrology had a fatal attraction for him: he fell under suspicion as a\nsorcerer, was condemned, and burned at the stake in Florence in 1327\n(six years after Dante\u2019s death).\n\nThe reputations achieved by these and other thirteenth-century\nastrologers in Italy, belonging to such different ranks of life, show\nwhat an immense importance was attached to their art by the general\npublic. Yet we shall be greatly mistaken if we think that it was only\nto acquire skill in this fascinating pursuit that men thronged to hear\nCecco lecture, or pored over Latin manuscripts. The intense ardour for\nknowledge which marks this period made them eager to understand the\nworld around them and the sky above their heads.\n\n[Illustration: ASTRONOMY.\n\n_From a fresco in the Spanish Chapel of Santa Maria Novella, Florence._\n\n[_To face p. 217._}]\n\nIt would be a shame, writes one, to live in a house and not know how\nit is built or what shape it has, never to examine the walls, and\nfloors, and ceilings, nor to consider the use of the wooden beams used\nin its construction. In like manner we should not be content without\nunderstanding the form and structure of the Universe in which we live.\nMan, with his upright attitude and his head held high, unlike the\nanimals, was designed by his Creator to look and listen, to know and\ncomprehend this marvellous Universe, and especially that noblest part\nof it above him, the heavens and their wonderful movements. For thus\nalone can he learn to know God Himself, the great Architect of the\nWorld.\n\nIn writing thus, Ristoro, the monk of Arezzo, was not only echoing\nthe thoughts of Plato and Cicero, he was expressing the feeling for\nastronomy as a noble and elevating study which was general among\nthoughtful men of his time. It was expressed also in contemporary art.\nVisitors to the \u201cSpanish Chapel\u201d in the cloisters of a Florentine\nchurch will remember seeing on the frescoed walls the figure of\nAstronomy as she was personified in Tuscany in the fourteenth century.\nShe sits among her peers, the sciences of the Trivium and Quadrivium,\nthe only one who wears a crown; her fair hair frames a spiritual face,\none hand is lifted heavenwards, the other holds a celestial sphere, on\nwhich the broad band of the zodiac crosses the \u201cequator of the day.\u201d At\nher feet sits a kingly figure in flowing robes, also crowned, and with\na face of singular beauty and refinement; he gazes up into the skies\nwith a rapt expression, and on his knee is a book in which he writes\nwhat he sees.\n\nThis nameless figure was identified doubtfully by Ruskin as Zoroaster,\nwho was considered by many as the inventor of astrology, but surely\nit can be no other than Ptolemy with his _Almagest_. For Ptolemy, the\nprince of astronomers, was often and naturally confused with the royal\nrace who had patronized astronomy at Alexandria; as for instance by\nOmons, a thirteenth-century writer, who says in his _Image du Monde_\nthat \u201cPtolemy king of Egypt\u201d wrote the _Almagest_. The curious mode\nof dressing the hair and beard may have been thought by the artist to\nrepresent an ancient Egyptian fashion.\n\nPtolemy, we know, was universely acknowledged at the time to be \u201cMaster\nof Astronomy,\u201d as Brunetto Latini calls him. His _Almagest_ was only\nknown indirectly, but it was believed to contain all that could be\nknown about the movements and the nature of the heavens. Some minor\nadditions and corrections had been made, as we have seen, by the Arab\nastronomers, but the system was accepted as a complete and satisfactory\nexplanation of all celestial phenomena. Hence no professional\nastronomer was expected to make discoveries; he was simply well versed\nin the work of those who went before him, skilful in the use of a few\nsimple instruments and tables, and practised in applying the principles\nof astrology.\n\nA general notion of the Ptolemaic system was widely diffused. For\nthose who could not read Latin there were encyclop\u00e6dic works written\nin the vernacular and in a popular style, such as the _Tr\u00e9sor_ of\nBrunetto Latini, and these always contained a section on astronomy.\nThe average educated man probably had only vague ideas about epicycles\nand eccentrics, and perhaps had never heard of the Arab estimates of\nthe sizes of the planets; but he would know that astronomy taught\nthat Earth is a globe, motionless at the centre of the universe, and\nsmaller than any of the stars; he would know the names of the seven\nplanets (including among these the sun and moon), and probably also\ntheir colours, their periods, and their astrological significance; the\nzodiacal constellations would be familiar, especially as they were\noften used decoratively; and he would believe that stars and planets\nare set in crystalline transparent spheres.\n\nMoreover, he would often be more of an astronomer than he knew, for he\nwould learn almost unconsciously many things of which modern men are\nignorant. The ill-lighted streets and the dangers of night journeys\nwould force him to be better acquainted with the motions and phases\nof the moon than most of us are to-day; he would know when and where\nto look for different stars; and the want of a watch would make it\nnecessary for him to be able to take his time from the sun at any\nseason of the year. He could, however, sometimes consult a sundial on\na church wall or in a private garden, and the church chimes rang out\nat tierce, and nones, and vespers. These were heard at intervals which\nwere much longer in summer than in winter, for the system of \u201ctemporary\nhours\u201d was used by the Church, and the service of tierce was held\nhalfway between sunrise and noon (or nones), and vespers was halfway\nbetween noon and sunset.\n\n\n_II. DANTE\u2019S STUDIES._\n\nDANTE\u2019S STUDIES.\n\nDante was far above the level of the average educated man. Not that\nhis scientific ideas were in advance of his age: on the contrary, one\nspecial interest that they have for us is that they illustrate, like\nhis political and religious views, the beliefs and feelings of the\nperiod. His authorities were the authorities of all, but he had studied\nthem and made their thoughts his own, as few others did, except some\nchurchmen and professed scholars. The extent and depth of his reading\nis evident from his own writings, and his great learning is noted with\nadmiration by all his biographers. Giovanni Villani, in the earliest\naccount we possess of Dante, says that he was \u201ca great scholar in\nalmost every branch of learning, although he was a layman.\u201d Boccaccio\nwould have us believe that while still a child, so young that he might\nbe expected to spend his time playing with other children or sitting\non his mother\u2019s knee, he gave the whole of his time to reading and\nlearning. Lionardo Bruni, however, assures us that though he was an\nardent student, and showed unusual powers at an early age, he by no\nmeans tried to \u201csever himself from the world, but living and moving\nabout amongst other young men of his age, he approved himself gracious\nand skilful in every youthful exercise.\u201d It was wonderful, he says, how\nDante maintained all his social and civic intercourse while he pursued\nhis studies so fervently.\n\nIn truth, the poet\u2019s troubled life was far removed from that life of\ncalm retirement which one thinks suitable for a scholar. In his early\nyouth he experienced a passionate love and sorrow; a year before the\ndeath of Beatrice he was fighting for Florence in the great battle of\nCampaldino, nor was it the first time he had borne arms; in 1296 he\nspoke in the council of the Hundred; in 1300 he was ambassador for the\nTuscan League to San Gemignano, and was elected to the highest office\na citizen could hold in his native city, that of Prior; in 1301 he\nwas ambassador to the Pope in Rome, and in the year following he was\nexiled. After this he was always wandering, often in great poverty,\ndependent on first one patron and then another, always hoping that some\nturn of affairs would restore him to Florence, always taking a keen and\nactive interest in Italian politics, until he died, still in exile, at\nRavenna. Add to this the difficulties common to all scholars of his\nday, viz. absence of printed books, public libraries, and journals,\netc., and we must marvel how he ever found the opportunities and the\nserenity of mind for his prolonged studies.\n\nBoccaccio adds another obstacle\u2014his wife! To console him for the death\nof Beatrice, his friends and relatives persuaded him to marry a wife of\ntheir choosing with melancholy results:\u2014\n\n \u201cDante formerly had been used to spend his time\n over his precious studies whenever he was inclined,\n and would converse with kings and princes, dispute\n with philosophers, and frequent the company of\n poets.... Now, whenever it pleased his new mistress\n he must at her bidding quit this distinguished\n company, and bear with the talk of women, and to\n avoid a worse vexation must not only assent to\n their opinions, but against his inclination must\n even approve them. He who, whenever the presence of\n the vulgar herd annoyed him, had been accustomed\n to retire to some solitary spot, and there to\n speculate on the motions of the heavens, or the\n source of animal life, or the beginnings of created\n things, or may be to indulge some strange fancy, or\n to compose somewhat which after his death should\n make his name live into future ages, he now, as\n often as the whim took his new mistress, must\n abandon all such sweet contemplation, and go in\n company with those who had little mind for such\n things.\u201d[80]\n\n------------------------------------------------------------------------\n[80] Boccaccio\u2019s _Vita di Dante_; Translation from Toynbee\u2019s _Dante\nAlighieri_ (Oxford Biographies), pp. 92, 93.\n------------------------------------------------------------------------\n\nHowever, after a long tirade against wives, Boccaccio owns that as far\nas concerns Dante the picture is entirely imaginary. He believes the\nmarriage was an unhappy one, because after his exile Dante and his\nwife never met again, but we have no evidence whatever that while they\nwere together their life was as Boccaccio depicts it. Doubtless family\nlife and the care of four children interfered to some extent with\nDante\u2019s studies, but the one detail Boccaccio affirms as fact among his\nfancies, namely that the poet refused for nineteen years to see his\nwife, seems rather to imply that one thing poor Gemma did know how to\ndo was to leave her husband in peace when he did not desire her company.\n\nWhen and where Dante began to study astronomy seriously it is not easy\nto say. His favourite study in his youth was poetry, but his parents\n(says Bruni) gave him a good general education, engaging such teachers\nas could be found in Florence, where as yet there was no university.\nBut seeing how clever the boy was, his relatives and friends helped and\nencouraged him, and among the latter Bruni mentions Brunetto Latini.\n\nThis famous Florentine was a very learned lawyer, who during Dante\u2019s\ninfancy and boyhood held high offices of state in the city. It is not\npossible, therefore, that he should have had pupils at this time, and\nhe cannot have been Dante\u2019s master in any strict sense of the word, as\nVasari affirms, and as many commentators have assumed on the strength\nof the moving interview between these two in the _Inferno_.[81]\nDante\u2019s affectionate greeting mingled with reverence, and the fatherly\nsolicitude of Brunetto, suggest just such a connection as Bruni\nindicates. The elderly man had taken an interest in the budding genius\nof the boy, and had held inspiring conversations with him from time\nto time on serious subjects, and by his own example had encouraged\nthe youth to win fame through his pen. For Dante was no doubt well\nacquainted with Brunetto\u2019s _Tesoretto_, and his more ambitious and\nvoluminous _Tr\u00e9sor_, which Brunetto specially commends to his care.[82]\nThis was a compendium of knowledge, a small part of which was devoted\nto the elements of astronomy, and it may well be that this short\nepitome was Dante\u2019s first introduction to the science.\n\n------------------------------------------------------------------------\n[81] _Inf._ xv. 23 _et seq._\n\n[82] _Inf._ xv. 119.\n------------------------------------------------------------------------\n\nSome have thought that Brunetto\u2019s advice to Dante to follow his star\n\u201cSe tu segui tua stella ...,\u201d[83] indicates that he had cast the poet\u2019s\nhoroscope; but there is no evidence that Brunetto had ever practised\nastrology, or even that he took special interest in it above other\nbranches of learning.\n\n------------------------------------------------------------------------\n[83] \u201cIf thou follow thy star,\u201d _Inf._ xv. 55.\n------------------------------------------------------------------------\n\nVillani and other biographers tell us that after his banishment from\nFlorence, therefore in middle age, Dante went to the University at\nBologna, but they seem to have made this statement rather because of\nits probability than because they knew it for fact. It is, however,\nquite possible that he spent a couple of years there, between 1304\nand 1306. He probably left his \u201cprimo rifugio\u201d[84] at Verona when\nBartolommeo della Scala[85] died in March 1304, and we know nothing of\nhis whereabouts till August 1306, when he was in Padua, as is proved by\na fifteenth century document.[86] Now in 1306 a number of Ghibelline\nstudents and professors left Bologna for Padua; and we know that Dante\nhad friends among the Bolognese professors, for later on he seems to\nhave corresponded with Cecco d\u2019 Ascoli,[87] and Del Virgilio entreated\nhim to come and receive the laurel crown, an invitation which the poet\nrefused in one of his Latin Eclogues. Bologna and the Bolognese are\nreferred to several times in Dante\u2019s works, and the friar Catalano is\nno doubt alluding to the school of theology at the University when he\nsays in _Inf._ xxiii. 142-144 that he used to hear at Bologna much\nabout the wickedness and the lies of the Devil. One vivid passage can\nhardly be anything but a personal reminiscence of the Carisenda, the\nleaning tower at Bologna. The poet compares his fear when he saw the\ngiant Ant\u00e6us stooping over Virgil and himself to the sensation of\nlooking up at the Carisenda from beneath the leaning side, when a cloud\nis passing over it, and the spectator feels that the tower is about to\nfall upon him.[88] (The tower was much higher in Dante\u2019s day than it\nis now, part having been pulled down in the middle of the fourteenth\ncentury).\n\n------------------------------------------------------------------------\n[84] \u201cFirst refuge,\u201d _Par._ xvii. 70.\n\n[85] _Par._ xvii. 71, 72.\n\n[86] Imbriani, _Dante a Padova_.\n\n[87] \u201c_Torno a Ravenna e de l\u00ec non mi parto_ (I am going back to\nRavenna, and shall not leave it again), is a line in the _Acerba_ which\nCecco d\u2019 Ascoli puts into the mouth of Dante, as though from a letter\nwritten to himself from the divine poet at the time\u201d (about the year\n1319). _Dante and Giovanni del Virgilio_, by Wicksteed and Gardner, p.\n84.\n\n[88] _Inf._ xxxi. 136-141.\n------------------------------------------------------------------------\n\nThe University at Padua was also famous, and as it was originally an\noffshoot from Bologna and modelled on the same plan, it is sure to\nhave included astronomy in its curriculum. But Dante does not seem to\nhave stayed here more than a few months.\n\nThere is also a tradition that he went to Paris, the greatest\nintellectual centre of his times, and that he himself heard those\nlectures of Sigieri, the philosopher, in the Street of Straw, of\nwhich he makes mention in _Par._ x. 137. This is possible, but quite\nuncertain; the allusion to Sigieri is no proof, since it has lately\nbeen discovered that he died in Italy, and his story was well known\nthere.\n\nAfter sifting all the evidence available, we can only echo Boccaccio,\nand say of Dante that \u201cAs it was at divers ages that he studied and\nlearned the divers sciences, so likewise it was at divers places of\nstudy that he mastered them under divers teachers.\u201d\n\n\n_III. BOOKS ON ASTRONOMY USED BY DANTE._\n\nBOOKS ON ASTRONOMY USED BY DANTE.\n\nWe shall probably be right if we conclude that Dante\u2019s knowledge of\nastronomy was principally gained from independent reading, and from\nconversation and discussion with learned men. Like a true scholar,\nhe was learning all his life, for in the _Paradiso_ he corrects the\nopinion expressed earlier in the _Convivio_ about the origin of the\nmarkings in the moon.\n\nBoccaccio\u2019s description of his planning out a course of study and\nattacking some subjects alone in his youth agrees with his own\naccount of his lonely struggles with Latin authors;[89] and it is\nquite credible that he suffered heat and cold, and went without food\nand sleep in his eagerness to learn, since he himself mentions quite\ncasually that at one time he injured his sight by constant reading, so\nthat the stars appeared blurred to him, until by rest and bathing with\ncold water it became strong again.[90]\n\n------------------------------------------------------------------------\n[89] _Conv._ II. xiii. 22-26.\n\n[90] _Conv._ III. ix. 146-157.\n------------------------------------------------------------------------\n\nHis diligence must have been great, and his memory wonderful, judging\nfrom the numerous quotations from classical and contemporary authors\nto be found in his writings. They seem to be chiefly from memory,\nand it is not likely that he can often have had many books by him\nwhen writing. If he gives a reference it is often a vague one, and\noccasionally wrong: his authorities on astronomical questions are\nsometimes \u201cthe mathematicians,\u201d \u201cthe astrologers,\u201d or \u201cthe sages of\nEgypt,\u201d by whom he means the Alexandrian astronomers.\n\nOne does not, of course, expect medi\u00e6val writers to verify their\nreferences, or to have our modern scruples about quoting other authors\nwithout acknowledgement: in those days they were only too glad to get\ntheir information wherever they could, often at second or third hand,\nand to make it their own by storing it in their memories. Nevertheless,\nfrom a careful study of Dante\u2019s direct quotations, and his allusions\nand reminiscences, which are sometimes unconscious, a good idea may be\ngained of his range of reading, and of the books and authors on whom he\nchiefly relied for his astronomical data.\n\nHis supreme authority was of course Ptolemy. But it would only be by a\nrare chance that he could see the _Almagest_, even in a translation,\nand all the evidence that we can find in his own writings points to\nits being entirely unknown to him. On each of the three occasions that\nhe quotes Ptolemy\u2019s opinion on subjects dealt with in the _Almagest_\nhe is wrong: once it is Ptolemy\u2019s view on the physical nature of\nthe Galaxy,[91] as to which none had been expressed, although its\nappearance was carefully described; in another case he implies that\nPtolemy discovered precession, and says that he added a ninth heaven\nto account for it,[92] and this double mistake was apparently copied\nfrom Albertus Magnus or Averro\u00ebs.[93] As we know, it was Hipparchus\nwho discovered precession, and Ptolemy gives him the credit for in the\n_Almagest_; it was the Arabian astronomers who added the ninth sphere.\n\n------------------------------------------------------------------------\n[91] _Conv._ II. xv. 73-77.\n\n[92] _Conv._ II. iii. 36-52, _V. N._ xxx.\n\n[93] Averro\u00ebs, in his commentary on Aristotle\u2019s _De C\u0153lo_, says\nthat the ancients believed the eighth, or starry, heaven, to be the\noutermost, but that Ptolemy assumed a ninth, \u201cbecause he said that he\nhad discovered a slow motion along the signs of the zodiac in the fixed\nstars.\u201d Albertus Magnus, in his _De C\u0153lo et Mundo_, Book II., says also\nthat the ancients, including Aristotle, believed that there were only\neight heavens, but that Ptolemy, so far as he can understand, believed\nin ten, on philosophical not mathematical grounds (compare _Conv._\nII. iii. 40, 41). Albertus accepted the theory of \u201ctrepidation,\u201d and\nthought this was the only movement which ought to be assigned to the\nstar sphere; there remained, therefore, two motions, which affect all\nthe planetary spheres and the star sphere, for which two more spheres\nmust be assumed, a ninth sphere for precession, and a tenth, the primum\nmobile, for the diurnal motion. Outside all was the Empyrean. Dante\nnever mentions trepidation, and evidently did not believe in it: he\nneeded only nine moving spheres, therefore, but counts the Empyrean as\na tenth heaven.\n------------------------------------------------------------------------\n\nOn the other hand Dante quotes twice quite correctly from the\n_Tetrabiblios_, which was more widely known.[94] He may, therefore,\npossibly have read it, and he alludes to it in the _Convivio_, though\nby a curious slip he does not give its name, thinking he has done so\nalready: \u201cTolommeo dice nello allegato libro....\u201d[95] This is in the\nfourteenth chapter of the second treatise, but so far from having just\nquoted any special work by Ptolemy he has said nothing at all about\nhim since the third chapter, and then it was only his opinion and name\nthat were mentioned. I have not been able to trace the quotation given\nin the _Qu\u00e6stio de Aqua et Terra_ (xxi. 29-31), where Ptolemy is said\nto have asserted that things on earth resemble things in heaven, but\nthis probably comes also (or was supposed to come), from the \u201cjudicial\nastronomy\u201d of the _Tetrabiblios_. It is not taken from the _Almagest_.\n\n------------------------------------------------------------------------\n[94] _Conv._ II. xiv. 198-202. _Ibid._ 249-253.\n\n[95] \u201cPtolemy says in the book above cited.\u201d\n------------------------------------------------------------------------\n\nThe elements of Ptolemy\u2019s system, however, could be learned indirectly,\nand it seems that Dante had recourse to the excellent epitome of the\nArab astronomer Alfraganus. It is true that his name is only mentioned\nonce, and his book once; but nearly all Dante\u2019s astronomical data\nappear to have been taken from him, and his very expressions are\nsometimes repeated.\n\nOne of the most striking examples of borrowing from the _Elementa\nAstronomica_ of Alfraganus occurs in the _Paradiso_, where Dante likens\ntwenty-four spirits to as many brilliant stars.[96] He makes up the\nnumber by taking fifteen specially bright stars from different parts\nof the sky, and adding to them the stars of Ursa Major and two stars\nof Ursa Minor. The seven chief stars of Ursa Major are well known,\nbut Beta and Gamma Urs\u00e6 Minoris are not conspicuous nor specially\nfamiliar; and why, if he takes fifteen unnamed, should he name any of\nthe twenty-four? Turning to chapter 19 of Alfraganus\u2019 book, we find\nthat he follows Ptolemy in enumerating fifteen first-magnitude stars in\ndifferent parts of the sky, and then he gives as examples of the second\nmagnitude (_i.e._ next in brightness) Benet Naax and Alfarcatein, Arab\nconstellations which correspond with the tail of Ursa Major, and Beta\nand Gamma of Ursa Minor.\n\n------------------------------------------------------------------------\n[96] _Par._ xiii. 1-13.\n------------------------------------------------------------------------\n\nThere is no reason to suppose that Dante knew Arabic, but there were\nseveral versions of Alfraganus in Latin, and it is even possible to\ndetermine with some certainty which of them he used. Speaking of\nthe movements of the planet Venus, he says that they may be found,\nsummarized from the best demonstrations of the astrologers, in the\n_Book of the Collection of the Stars_:\u2014\n\n \u201cLi quali, secondoch\u00e8 nel _Libro dell\u2019 Aggregazione\n delle Stelle_ epilogato si trova, dalla migliore dimostrazione\n degli astrologi ....\u201d\n (_Conv._ II. vi. 133-136).\n\nAlthough the usual name for the book of Alfraganus in Latin was\n_Elementa Astronomica_, the version for which medi\u00e6val students\nwere indebted to the indefatigable translator Gerard of Cremona\nbears in the MSS. the title _Alfragani liber de aggregationibus\nScienti\u00e6 Stellarum et de principiis c\u0153lestium motuum_. It is this\nbook, therefore, that Dante means, though he has translated the title\nsomewhat inaccurately.[97]\n\n------------------------------------------------------------------------\n[97] See Schiaparelli\u2019s letter in Lubin\u2019s _Dante e gli Astronomi\nItaliani_. The name is, however, also used as a sub-title in the\nprinted edition of Christmann, Frankfort, 1590, which was based not\non the translation of Gerard but of Johannes Hispalensis of Seville;\nand Toynbee thinks that this Frankfort edition represents most nearly\nthe version of Alfraganus used by Dante. It is the only one of the\nfive printed editions which gives the same figure for the diameter of\nMercury as that quoted by Dante. See Toynbee, \u201cDante\u2019s Obligations to\nAlfraganus\u201d in _Romania_ xxiv. 95, and Moore, _Studies in Dante_ iii.\np. 3, _note_.\n------------------------------------------------------------------------\n\nThere were several other books known to Dante from which he must have\ngleaned information about Ptolemy\u2019s system, but Alfraganus we may\nregard as his standard reference book. Many versions of Alfraganus are\nstill extant, and it is pleasant to feel that we can hold in our own\nhands Dante\u2019s text-book on astronomy. The best known is the printed\nedition of Golius, published in Amsterdam in 1669: it is in both Latin\nand Arabic, and opening in the middle we may turn the pages backwards\nto see the beautiful Arabic letters of Alfraganus\u2019 own language, which\nis written from right to left, or forwards to look at the Latin in\nwhich he became known to Dante.\n\nNext in importance to Alfraganus among Dante\u2019s authorities on astronomy\nwas Aristotle. We have seen how overwhelming his authority became in\nnatural science in the second half of the thirteenth century, and how\nfor some time scholars failed to distinguish between the system of\nspheres devised by Eudoxus, which was the scheme upheld by Aristotle,\nand the epicycles and eccentrics of Ptolemy. Among all Aristotle\u2019s\nadmirers none was more devoted than Dante: for him Aristotle is not\nonly \u201cIl Filosofo,\u201d the Philosopher _par excellence_, as he was\ngenerally called in that age; he is \u201cquello glorioso filosofo al\nquale la Natura pi\u00f9 aperse li suoi segreti,\u201d his intellect was \u201cquasi\ndivino,\u201d and his words are of \u201csomma e altissima autoritade.\u201d[98]\nThroughout Dante\u2019s own writings his references to Aristotle are so\nfrequent that Dr. Moore observes: \u201cThe amount and variety of Dante\u2019s\nknowledge of the contents of the various works of Aristotle is nothing\nless than astonishing.\u201d[99]\n\n------------------------------------------------------------------------\n[98] \u201cThat glorious philosopher to whom Nature most fully revealed her\nsecrets,\u201d _Conv._ III. v. 54-56; \u201calmost divine,\u201d _Conv._ IV. vi. 133;\n\u201csupreme and highest authority,\u201d _Ibid._ 52.\n\n[99] Moore, _Studies in Dante_ I. (Scripture and Classical Authors in\nDante), from which much of the information in this chapter has been\ntaken.\n------------------------------------------------------------------------\n\nHe does not, however, consider Aristotle infallible as regards the\ndetails of astronomy, for in these the philosopher was only following\nthe observers and mathematicians;[100] but in all matters which depend\nupon first principles, in which Dante would include the form of the\nearth, Aristotle\u2019s authority may not be called in question.[101] In\ncosmical physics, such as the doctrine of the four elements, and in\nmeteorology, Dante follows \u201cil mio Maestro\u201d[102] implicitly, and it is\nalso largely from the _De C\u00e6lo_ that he gained his knowledge of early\nGreek speculations regarding the universe.\n\n------------------------------------------------------------------------\n[100] _Conv._ II. iii. 19-21.\n\n[101] _Conv._ III. v. 62-65.\n\n[102] \u201cMy master.\u201d\n------------------------------------------------------------------------\n\nDante knew little more of Greek than of Arabic. His occasional use of\nGreek words is enough to prove this\u2014for example when he discusses the\nPythagorean theory of \u201cAntictona,\u201d using the accusative as if it were a\nnominative.[103] In several passages he implies that the language was\nnot known to him, and he distinctly states that he used translations of\nAristotle\u2019s works. Here again we are able to identify the versions he\nused. In _Conv._ II. xv. 59-73 he complains that it is impossible to\nknow what Aristotle believed about the Milky Way, because in the \u201cold\ntranslation\u201d he is made to say one thing, and in the \u201cnew translation\u201d\nquite another. From his quotations of these two conflicting opinions,\nwe are able to deduce that the \u201cold translation\u201d was that which Michael\nScot made from the Arabic, and the \u201cnew translation\u201d that of Aquinas,\nwhich was made direct from the Greek.\n\n------------------------------------------------------------------------\n[103] _Conv._ III. v. 32.\n------------------------------------------------------------------------\n\nHe had access, therefore, to more than one Latin translation of\nAristotle; and beside this, his quotations seem to have been often\ntaken from commentators and compilers of his own times, especially\nAquinas and Albertus Magnus. This was frequently the case with the\n_Meteorologica_ of Aristotle, for the _De Meteoris_ of Albertus Magnus\nseems to have been much used by Dante in place of Aristotle\u2019s own work.\nDante quotes it by name as _Meteora_ in _Conv._ II. xiv. 169, and also\nin _Conv._ IV. xxiii. 125-126, where he mentions \u201cAlberto\u201d as the\nauthor.\n\nThese two, then, the Arab Alfraganus and the Greek Aristotle, were\nDante\u2019s chief authorities in astronomy, both in Latin translations.\n\nBesides these, there is evidence in his writings that he was familiar\nwith several classical authors who treated of astronomy. He quotes\nfrequently from many of Cicero\u2019s works, and we find echoes, in two\npassages, of the _Dream of Scipio_,[104] which he is almost certain to\nhave read, since it was a favourite book in his time. There are several\nreferences to Seneca, but the only time that an astronomical phenomenon\nrecorded by him is mentioned[105] Dante is evidently quoting at\nsecond-hand from Albertus Magnus. With all the works of Virgil, and\nwith the _Metamorphoses_ of Ovid (from which he took his astronomical\nmyths)[106] he was evidently very familiar; and Lucan is one of his\nauthorities for the position of the earth\u2019s equator. In this case the\nname of the author and the number of the book are precisely stated.[107]\n\n------------------------------------------------------------------------\n[104] _Inf._ ii. 76-78; _Par._ xxii. 134-138.\n\n[105] _Conv._ ii. xiv. 174-176.\n\n[106] Pha\u00ebthon, _Conv._ II. xv. 53-55, _Purg._ xxix. 118-120; Latona,\n_Purg._ xx. 130-132; the Horses of the Sun, _Conv._ IV. xxiii. 134-139,\netc., etc.\n\n[107] _Conv._ III. v. 115-117.\n------------------------------------------------------------------------\n\nDante had a great reverence for Plato, whom he calls \u201cuomo\neccellentissimo,\u201d[108] and of whom he repeats the medi\u00e6val legend that\nhe was a prince who gave up all for the sake of acquiring wisdom.[109]\nOf his writings he only knew the _Timaeus_, probably the Latin\ntranslation and commentary of Chalcidius, which was widely known. Or he\nmay have been acquainted with Aquinas\u2019 commentary, which has since been\nlost. He also knew something of Plato\u2019s teachings through Aristotle and\nCicero, Albertus Magnus, and Aquinas, and perhaps St. Augustine. When\nhe feels obliged to dissent from the great philosopher\u2019s doctrine that\nthe souls of men come from the stars, he does so with reluctance and\ngreat gentleness.[110]\n\n------------------------------------------------------------------------\n[108] \u201cA man of supreme excellence.\u201d _Conv._ II. v. 21, 22.\n\n[109] _Conv._ III. xiv. 76-79.\n\n[110] _Par._ iv. 22-24, 49-60.\n------------------------------------------------------------------------\n\nAmong other Greek philosophers who speculated on astronomy, Dante\nmentions Thales[111] and Pythagoras. The date when the latter\nflourished he takes (he tells us) from Livy, and his theory that the\nUniverse is governed by the principle of number from Aristotle\u2019s first\nbook of Metaphysics. The astronomical theories of his school are also\ndoubtless taken from Aristotle. Dante tells the story of Pythagoras\nthat he was the first man to be called \u201cphilosopher,\u201d because when\nasked if he considered himself a wise man, he replied, \u201cNo, but only\na lover of wisdom.\u201d[112] Dionysius the Academician and Socrates are\nreferred to for their opinions on the influence of the stars upon\nhuman souls;[113] and Anaxagoras and Democritus for their galactic\ntheories,[114] which Dante obtained from Albertus Magnus.\n\n------------------------------------------------------------------------\n[111] _Conv._ III. xi. 39; _Inf._ iv. 137.\n\n[112] _Conv._ III. xi. 22-33; II. xiv. 144-147; III. v. 29-44; III. xi.\n41-47.\n\n[113] _Conv._ II. xiv. 34, 35.\n\n[114] _Conv._ II. xv. 56.\n------------------------------------------------------------------------\n\nExcept for Alfraganus, Dante refers but seldom to Arab astronomers.\nHe does not seem to have known Albategnius. The _De Substantia Orbis_\nof Averro\u00ebs is quoted in the _Qu\u00e6stio de Aqua et Terra_,[115] and it\nis possible that from this book Dante derived a theory about the moon\nwhich he expounds in the _Convivio_. He quotes Alpetragius on circular\nexistence (dependent on the spheres),[116] Avicenna on the Galaxy, and\nagain with Algazel on the influence of the spheres,[117] and Albumassar\non meteors.[118] The quotation from the latter, however, is second-hand\nfrom Albertus Magnus, and is a mistake, for the passage is not to be\nfound in that astronomer\u2019s works. He was born in Turkestan, in 805.\n\n------------------------------------------------------------------------\n[115] _Qu._ xviii. 38, 39.\n\n[116] _Conv._ III. ii. 37.\n\n[117] _Conv._ II. xv. 77, II. xiv. 32.\n\n[118] _Conv._ II. xiv. 170-174.\n------------------------------------------------------------------------\n\nWe may here remind our readers that the three Latin poets, Virgil,\nOvid, and Lucan, were among the world\u2019s five greatest poets met by\nDante in Limbo; that next to Aristotle among the philosophers stood\nSocrates and Plato, and near these were Democritus, Anaxagoras, and\nThales, Cicero and Seneca, Ptolemy, Avicenna and Averro\u00ebs.[119]\n\n------------------------------------------------------------------------\n[119] _Inf._ iv. 80, 81, 90, 131-144.\n------------------------------------------------------------------------\n\nAmong Christian writers, Dante may have gathered some information about\nancient Greek speculations from St. Augustine and Peter Lombard; and\nOrosius, the Spanish friend of Augustine, was his chief authority for\nthat geographical system which, in connection with astronomy, plays\nan important part in the time-indications of the _Divina Commedia_.\nOrosius had a great reputation among geographers and map-makers.\nHe had travelled much between Spain, Africa, and Palestine, and he\ndevotes a chapter to describing the different parts of the earth in his\nhistory _Adversus Paganos_, which he wrote to prove that Christianity\nhad not injured but benefitted the countries in which it had been\naccepted. This fifth century geography seems to have been largely based\non the first-century geography of Strabo, who quotes Eratosthenes,\nPosidonius, and Hipparchus among his authorities. Orosius states that\nthe land is entirely surrounded by Ocean, and is divided into three\ncontinents\u2014Asia, with the mouths of Ganges in the middle of its eastern\ncoast, Europe stretching vaguely very far to the north-east, and Africa\na narrow and long strip from east to west between the Mediterranean and\nthe southern ocean. This chapter is quoted in _De Mon._ II. iii. 87-90\nand _Qu._ xix. 43; and Orosius is almost certainly \u201cquell\u2019 avocato dei\ntempi cristiani,\u201d[120] seen by Dante among the learned doctors in the\nHeaven of the Sun.\n\n------------------------------------------------------------------------\n[120] \u201cThe advocate of the Christian centuries.\u201d (_Par._ x. 199).\nOrosius is also mentioned by name in _Conv._ III. xi. 27; _V. E._ II.\nvi. 84; and _De Mon._ II. ix. 26.\n------------------------------------------------------------------------\n\nThe speaker who points him out in these words also mentions his own\nname and that of the spirit nearest to him:\u2014\n\n \u201cQuesti che m\u2019\u00e8 a destro pi\u00f9 vicino\n Frate e maestro fummi, ed esso Alberto\n \u00c8 di Cologna, ed io Thomas d\u2019Aquino.\u201d[121]\n\n------------------------------------------------------------------------\n[121]\n \u201cHe who is nearest to me on the right\n My brother and master was, and he Albertus\n Is of Cologne, I Thomas of Aquinum.\u201d\n (_Par._ x. 97-99).\n------------------------------------------------------------------------\n\nThese two, so near in heaven, had been close companions on earth. The\nyouthful Thomas, son of Count d\u2019Aquino in southern Italy, after six\nyears\u2019 study at the University of Naples joined the Dominican Order,\nand went to Cologne to learn from Albert, who was also of noble\nfamily but born in Suabia on the Danube. Together they went to Paris,\ntogether returned to Cologne, but after six more years there their\npaths separated: Albert rose to be Bishop of Ratisbon; Aquinas, after\nlecturing in Paris, Rome, and Bologna, became a professor at Naples,\nand died in Italy in 1274. His master survived him by six years, dying\nat Cologne at the advanced age of eighty-seven in 1280.[122]\n\n------------------------------------------------------------------------\n[122] Toynbee, _Dante Dictionary_; the source also of many other\ndetails given in this chapter.\n------------------------------------------------------------------------\n\nThese two are in the foremost rank among authors of his own time who\ninfluenced Dante. He quotes both writers and several of their books by\nname,[123] and though he never mentions it he was very familiar with\nthe _Summa Theologica_ of Aquinas. To the works of these famous authors\nhe was frequently indebted for astronomical facts, theories, and\nhistory, as already noted. Besides this, his reverence for Aristotle,\nhis belief in the essential harmony between religion and science, and\nhis whole attitude towards knowledge, are greatly due to the influence\nof St. Thomas and his \u201cbrother and master,\u201d Albert of Cologne.\n\n------------------------------------------------------------------------\n[123] Albert in _Conv._ III. v. 113-115, vii. 26-28; IV. xxiii. 125-6;\nAquinas in _Conv._ II. xv. 125-6; IV. viii. 3-6, xv. 125-130, xxx.\n26-30; _De Mon._ II. iv. 5-8; and see _Purg._ xx. 69.\n------------------------------------------------------------------------\n\nThere are also three of Dante\u2019s own fellow-countrymen and\ncontemporaries whose books he is most likely to have read, although he\ndoes not mention them:\u2014Brunetto Latini the Florentine, Cecco d\u2019 Ascoli,\nprofessor at Bologna, and Ristoro the monk of Arezzo.\n\nBrunetto Latini is only mentioned once in Dante\u2019s works, besides the\npassage in the _Inferno_ already referred to. In the _De Vulgari\nEloquentia_ Brunetus Florentinus is mentioned with admiration as a\ndistinguished man of letters, but blamed with other Tuscans for writing\nin his own local dialect.[124] Brunetto, who was born in Florence\nabout 1210, was sent on an embassy in 1260 to Alfonso X. of Castile,\nthe learned king under whose guidance the famous astronomical Tables\nhad been drawn up. But on his way back to Florence he was met by the\nnews that the Florentine Guelphs had been defeated at the disastrous\nbattle of Montaperti,[125] and expelled from Florence; and as he\nbelonged to this party he took refuge in France, first at Montpellier\nand afterwards in Paris. When the Guelphs had regained the ascendancy\nthrough their victory at Benevento in 1266 (where Manfred lost his\nlife),[126] Brunetto returned to Florence, and his name subsequently\nappears in no less than thirty-five public documents as having been\nconsulted by the government of his native city on various important\nmatters. For the most part, moreover, it is recorded that his advice\nwas followed. He died at a venerable old age in Florence in 1294, and\nwas buried in the church of Santa Maria Maggiore.\n\n------------------------------------------------------------------------\n[124] _V. E._, I. xiii. 1-11.\n\n[125] _Inf._, xxxii. 81, and x. 85, 86.\n\n[126] _Purg._, iii. 112-129.\n------------------------------------------------------------------------\n\nIt was while exiled in France that Brunetto wrote the Italian poem\n_Il Tesoretto_, in which he represents himself as a pilgrim on\nan allegorical journey; and from this Dante perhaps derived some\nsuggestions for his Vision. The poem is incomplete, and breaks off\nat a tantalizing point, for Brunetto has just met Ptolemy on Mount\nOlympus, and has put a question to him: Ptolemy \u201crispose in questa\nguisa\u201d[127]\u2014and here the poem ends!\n\n------------------------------------------------------------------------\n[127] \u201cReplied after this fashion.\u201d\n------------------------------------------------------------------------\n\nIn France also he wrote _Li Louvres dou Tr\u00e9sor_, a great compendium of\nlearning, in French prose. The first part treats of the Creation and\nBiblical history, and of the natural sciences; the second of ethics,\nrhetoric, and politics. In the section on astronomy which is included\nin the first part, Brunetto gives a very brief account of Ptolemy\u2019s\nsystem, and the sizes and distances of the heavenly bodies as estimated\nby the Arabs: it seems to be based chiefly on Alfraganus. But beside\nthe periods of the planets he adds in each case their astrological\nproperties, as for instance:\u2014\n\n \u201cSaturnus, qui est le souverain sor tous, est cruex\n et felons et de froide nature ... Jupiter ... ast\n dous et piteus et plains de biens.... Mars et chaus\n et bataillereus, et mauvais, et est apelez Diex de\n batailles.\u201d[128]\n\n------------------------------------------------------------------------\n[128] _Li Louvres dou Tr\u00e9sor_, Chabaille, Paris 1863.\n------------------------------------------------------------------------\n\nWhen speaking of the two principal movements of the skies, he quotes\na curious old idea which had been mentioned by Isidore of Seville,\nthat they are in contrary directions because the tremendous speed of\nthe diurnal motion would shake the whole universe to pieces if it were\nnot that the seven planets go as it were to meet it, and soften its\nvehemence:\u2014\n\n \u201cLi firmamenz court de orient en occident entre\n jor et nuit une fois, si roidement et si fort\n que sa pesanteur et so grandor la feroient tout\n tressaillir, se ne fussent les VII. planetes qui\n vont aussi comme a l\u2019encontre dou firmament, et\n atemprent son cours selonc son erre.\u201d[129]\n\n------------------------------------------------------------------------\n[129] _Ibid._\n------------------------------------------------------------------------\n\nThe _Acerba_ of Cecco d\u2019Ascoli was another encyclop\u00e6dic work, but in\nItalian verse. It was very much the fashion in those days to undertake\na compilation of all kinds of knowledge, and this was doubtless very\nuseful when few books could be owned by any single reader. Cecco had a\nconsiderable knowledge of natural science, and astrology was of great\nimportance in his eyes. Though Dante never mentions him or his work,\nhe can hardly have been ignorant of it, especially as he himself is\nmentioned in it.\n\nNor does he mention Ristoro of Arezzo, yet we find many ideas and\nexpressions in Dante\u2019s writings which are also in the _Composizione del\nMondo_. Even if he did not borrow from it, the book is worth study by\nanyone interested in the popular astronomy of the thirteenth century.\nWe learn from the author that he wrote his book in Arezzo, finishing it\nin the year 1282, that is about thirty years before Dante\u2019s _Convivio_\nappeared. The opening words run:\u2014\n\n \u201cIncominiciasi il libro della Composizione del\n Mondo colle sue cagioni: composto da Ristoro di\n Arezzo in quella nobilissima citt\u00e0 ... etc.\u201d[130]\n\n------------------------------------------------------------------------\n[130] \u201cHere beginneth the book of the _Composition of the World\ntogether with its Causes_: written by Ristoro of Arezzo in that most\nnoble city.\u201d\n------------------------------------------------------------------------\n\nand the closing words are:\u2014\n\n \u201cCompiuto e questo libro sotto li anni di Cristo\n nel mille dugento ottantadue. Ridolfo imperadore\n aletto. Martino quarto papa residente. Amen.\u201d[131]\n\n------------------------------------------------------------------------\n[131] \u201cHere endeth this book, in the year of our Lord one thousand\ntwo hundred and eighty-two. Rudolph Emperor at this date. Martin IV.\nresident Pope.\u201d Amen.\n------------------------------------------------------------------------\n\nWe learn further that he was a monk and a native of Arezzo in an\ninteresting passage where he describes a total eclipse of the sun seen\nby himself from his monastery: the sky was very clear, and it must\nhave been a specially dark eclipse, for besides Mercury he saw many\nstars; totality lasted for as long as a man could easily walk 250\nsteps; there was a feeling of chill, and birds and wild animals were so\nfrightened that they allowed themselves to be caught. Fra Ristoro made\na calculation and found that on that day sun and moon were in the same\nposition in the sky. It was perhaps this event which induced him to\nstudy astronomy.\n\nThe extent and depth of Ristoro\u2019s reading evidently bore no comparison\nto Dante\u2019s, but he was able to sit writing in his quiet cell, day after\nday, and had such books as he wanted at hand. The monastery seems\nto have been furnished with astronomical tables, a celestial globe,\nand the books of Alfraganus and other Arab writers. All these he had\nstudied, and he was something of an observer too. Alfraganus must have\nbeen always at his elbow when writing, for he turns to it constantly,\nquoting (unlike Dante) the chapter referred to:\u2014\n\n \u201cAlfragano pose nell\u2019 ottavo capitolo;\u201d \u201c\u00e8\n testimonio l\u2019Alfragano nelli venti e due capitoli\n del suo libro;\u201d[132]\n\n------------------------------------------------------------------------\n[132] \u201cAlfraganus said in the 8th chapter\u201d; \u201cAlfraganus bears witness\nin the 22nd chapter of his book.\u201d\n------------------------------------------------------------------------\n\none chapter is avowedly taken whole from Alfraganus, and where the\nopinions of \u201cil grande Tolommeo\u201d[133] are quoted they are evidently\ncopied from the same source. Other Arab writers are quoted once or\ntwice, for instance, Albumassar,\n\n------------------------------------------------------------------------\n[133] \u201cThe famous Ptolemy.\u201d\n\n \u201cil quale fu altissimo maestro d\u2019astrologia,\u201d[134]\n\n[134] \u201cWho was a very great teacher of astrology.\u201d\n------------------------------------------------------------------------\n\nand several lines are copied from a Latin translation of Algazel,[135]\ngiving some astrological jargon about the twelve zodiacal signs.\n\n------------------------------------------------------------------------\n[135] \u201cAn Arabian philosopher of Baghdad, 1058-1111.\u201d\n------------------------------------------------------------------------\n\nWe have already quoted from Ristoro\u2019s preface, showing the high\nopinion he held of astronomy. But it is disappointing to find that the\ngreatest part of his book is devoted to the \u201ccagioni,\u201d that is, to\npurely fanciful \u201creasons,\u201d for all the facts and fallacies concerning\nnature which he has here brought together.\n\nHe gravely argues about the constellation figures as if they were real\npictures of animals and things pricked out by nature in stars on the\nvault of heaven, and not a human convention. He notes their paucity in\nthe southern hemisphere, and that nearly all have their heads towards\nthe north, and from this he draws the conclusion that the northern part\nof the sky is the nobler, for we can see it is the upper side, just as\nwe know the top side of a book by the position of its letters.\n\nIt is for this reason, he thinks, that only the northern hemisphere of\nthe earth contains land and is inhabited. Some, especially the great\nAverro\u00ebs, had indeed held that there is inhabited land south of the\nequator, because the sun goes there. But this is because his movements\nof recession and approach are necessary to produce the seasons, and\nhence the growth of plant life, in the north. The constellations are\nupside down for the south, so they can have no effect there, therefore,\nthere are no animals there (since every race of animals is under the\nprotection of a constellation); therefore no plants, since they exist\nfor animals, and therefore, Ristoro concludes his chain of argument\ntriumphantly, there are no men, and no lands, for land without life\nwould be useless.\n\nRistoro reproduces Alfraganus\u2019 description of the sun\u2019s movements as\nseen in different latitudes, quotes him as saying that the equatoral\nregions are inhabited, and Avicenna that the temperature there is\nequable because days and nights are always equal. The city Arym which\nis exactly on the equator has a perfect climate, and as it has two\nsummers and two winters there are two harvests; moreover, all the stars\nin the sky are visible at the equator; therefore, the best astronomers,\nand the wisest and richest men, ought to live there, says Ristoro. When\nwriting thus, he seems to have had before him one of the \u201cclimate maps\u201d\nwhich were common in Europe in the eleventh and following centuries,\nhaving been introduced by Arab cartographers, who adopted the idea from\nGreek maps. For he goes on to point out that the first \u201cclimate\u201d is\nmuch the longest, and that the others diminish gradually towards the\npole, all the \u201cterra scoperta\u201d[136] being thus contained in one quarter\nof the earth, and having the shape of the moon when we see it half\nfull.[137]\n\n------------------------------------------------------------------------\n[136] \u201cThe uncovered earth,\u201d _i.e._ not hidden under the ocean.\n\n[137] Bk. VI. cap. xi.\n------------------------------------------------------------------------\n\n[Illustration: Fig. 38. The half-moon shape of the habitable earth.\n(Ristoro).\n\n There is nothing but sea south of the equator, and\n the habitable earth lies wholly in one half of the\n northern hemisphere, the other half being sea. The\n habitable earth, therefore, is the same shape as\n the half-moon, _i.e._ a quarter sphere.]\n\nThe accompanying climate map shows all these features, the famous\ncity Arym\u2014occupying nearly half the space, although it is supposed to\nbe merely on the equator\u2014the seven climates, and the region beyond the\nseventh, near the north pole, marked as uninhabitable through the cold.\nThe half-moon shape of Earth\u2019s habitable quarter is obvious. The map\nbetrays Arab influence in the orientation, the south being at the top;\nand Arym, or Aren, was an Arab myth, perhaps derived from the Mount\nMeru of the Hindus, which is said in the Vedas to be \u201cin the middle of\nthe earth.\u201d\n\nAccording to Ristoro, the positions of the constellation figures do\nnot only explain why one hemisphere of earth has land and the other\nnone; they also explain the movements of the skies. For the figures\nof the zodiac face west (those that have faces), and this is why the\ndiurnal movement of the whole heaven is towards the west, so that the\nconstellations may move straightforward, in the natural way. On the\nother hand, the planets move in the opposite direction because it would\nnot be seemly for them to pass each figure of the zodiac arriving first\nat the back and moving on to the head. This is the true reason of the\ncontrary direction of the two principal celestial movements. Ristoro\ndoes not approve of the solution quoted by Brunetto Latini. He adds\nthat the width of the zodiac was designed to contain the figures of the\nanimals!\n\nAfter this, we are not surprised to hear that the red colour of the\nplanet Mars is the cause of its martial nature (not the reason for\nwhich such a nature is attributed to it). The markings on the moon\nRistoro explains by saying that some body must exist in the World\nwhich is neither polished and shining all over, like the stars, nor\naltogether rugged and dark, as the earth was supposed to be, but\npartaking of both natures; and this body must be the moon, because of\nher intermediate position between the earth and the nearest of the\nother planets (Mercury).\n\n[Illustration: CLIMATE MAP, OF ABOUT A.D. 1110. [_To face p. 248._\n\n_Reproduced by permission from Beazley\u2019s \u201cDawn of Modern Geography.\u201d_]\n\nOf the influence of the heavens on the earth Ristoro has very much to\nsay, from general statements such as that the spheres impress their\ninfluence on things of Earth, just as a seal impresses wax, down to\ndetails about the births of horses. If the moon is strong in Aries,\nand Aries is powerful, then, because the moon signifies white among\nthe colours and Aries signifies the head, the horse will be born\nwith a white mark on its head, and if the influence is very strong\nit will be a beautifully-shaped mark. Again and again he tells us\nabout the various properties and \u201cvirtues\u201d of the seven planets, but\nhe does not omit to mention that the powers which move the planets\nand cause them to influence Earth are spirits, which we call Angels,\nand the philosophers call Intelligences. These have their several\ndwelling-places in the spheres, and the nobler their nature the higher\nis the sphere which they inhabit.\n\nFrom these quotations the reader may judge of the general trend of the\neight books comprised in _La Composizione del Mondo colle sue Cagioni_:\nwe shall have occasion to refer to it again, by way of comparison and\ncontrast, when dealing with Dante\u2019s works in detail.\n\nIt is rather curious that there is no trace in Dante\u2019s writings of\nacquaintance with the great Roger Bacon, or with Sacrobosco, especially\nas Brunetto Latini knew the former personally, and Cecco d\u2019Ascoli\nwrote a commentary on the latter, but Dante may have known them, and\nalso the works of Isidore and Bede, who are both mentioned in _Par._,\nx. 131, as well as other books which are now completely lost. Those we\nhave described above would, however, be enough to supply him with all\nthe astronomical data, except one, which we find in his writings. It is\nnow time to examine these, and see what use he made in literature of\nthe knowledge he possessed.\n\n\n_IV. ASTRONOMY IN DANTE\u2019S WRITINGS._\n\nASTRONOMY IN DANTE\u2019S WRITINGS.\n\nIf we except the seven _Penitential Psalms_ and the _Profession of\nFaith_, which are only paraphrases, and are very doubtfully ascribed\nto Dante, no work of his can be mentioned which does not contain some\nreference to the heavenly bodies.\n\nWhen writing the _Vita Nuova_, that story of his love for Beatrice\nwhich he calls the work of his boyhood,[138] he was haunted by the\nsublime idea of the rolling spheres. Beatrice at her first appearance\nas a little girl of eight, and Beatrice when she died, suggested\nthoughts of the nine heavens;[139] almost the first words of the book\nallude to the circling spheres of the sun and of the stars:[140] and\nthe last sonnet soars beyond them all to the Empyrean.[141] Already he\nseems to have read Alfraganus, for he takes a suggestion which occurs\nin the first chapter of the _Elementa Astronomica et Chronologica_.\nAlfraganus there describes the different methods of reckoning days,\nmonths, and years, in use among different nations, and gives a special\nlist of the Syrian months with their corresponding Roman months; and\nDante, by using the Arabian system of days and the Syrian months, is\nable to prove to himself that the day and the month when Beatrice died\nwere both at the sacred number of nine.[142] According to our method of\nreckoning, the time was sunset on the eighth of June, but this was the\nfirst hour of the ninth day according to Arabian usage, and our sixth\nmonth corresponds with the ninth of the Syrians.\n\n------------------------------------------------------------------------\n[138] _Conv._ I. i. 125, 126. Compare _Conv._ IV. xxiv. 1-13.\n\n[139] _V. N._ ii. 9-12, xxx. 13-24.\n\n[140] _V. N._ ii. 1-12.\n\n[141] _V. N._ xlii. 47.\n\n[142] _V. N._ xxx. 1-6.\n------------------------------------------------------------------------\n\nDante had also read at this time Aristotle\u2019s doctrines about the\nspheres and their Movers, for he quotes from the _Metaphysics_,[143]\nand this is the work in which they are found.\n\n------------------------------------------------------------------------\n[143] _V. N._ xlii. 30.\n------------------------------------------------------------------------\n\nYet a familiarity with Alfraganus and Aristotle so early as this is\nhardly consistent with the difficulty he says he found in understanding\nLatin books of philosophy some time after the death of Beatrice.[144]\nPerhaps the latter part of the _Vita Nuova_ was written a good deal\nlater; or it may be not altogether frivolous to suggest that in his\nyouth Dante had read the first chapters of Alfraganus, which are easy,\nbut did not master the rest of the book till later.\n\n------------------------------------------------------------------------\n[144] _Conv._ II. xiii. 22-26.\n------------------------------------------------------------------------\n\nOut of his fifty-three short poems (including all in Moore\u2019s Oxford\nEdition, except those which form part of the _Vita Nuova_ or\n_Convivio_), twelve, or nearly a quarter, contain some reference to\nsun, moon, or stars, planets, or spheres; and from these alone we could\nform some idea of Dante\u2019s acquaintance with astronomy. He speaks of\nthe sun as measuring time,[145] and giving light to the stars[146]\n(according to the general belief); the moon[147] and each of the\nplanets[148] is mentioned, some of the constellations also,[149]\nespecially with reference to the seasons; the theory of the several\nheavens and their First Mover,[150] and the supposed influences of the\nstars and planets are alluded to.[151] These poems were written at\ndifferent times, and some belong to a much later period than the _Vita\nNuova_.\n\n------------------------------------------------------------------------\n[145] _Son._ xxxvi. 2; _Canz._ xx. 89.\n\n[146] _Canz._ xix. 117; _Canz._ ix. 16, 17.\n\n[147] _Canz._ xx. 89; _Son._ xxviii. 11.\n\n[148] _Son._ xxviii.; _Canz._ xv. 4, 7.\n\n[149] _Canz._ xv. 3, 29, 41.\n\n[150] _Son._ xxviii. 2.\n\n[151] _Son._ xxviii. _Canz._ xix. 77, _Ball._ vi. 11, 12, _Canz._ xv.\n41., _Son._ xxvi. 14.\n------------------------------------------------------------------------\n\nIt is when we come to examine the _Convivio_, the work of his\nmanhood,[152] that we find the clearest evidence of Dante\u2019s careful\nstudy of astronomy. This book was written with the professed intention\n(as one of its aims) of sharing with others the learning he had been\nhappy enough to acquire\u2014not indeed as one of the guests at the Table\nof Wisdom, but as one sitting at their feet and gathering up the\ncrumbs.[153] The thread which connects his discourse is a collection\nof his own Odes, on each of which he had intended to write a treatise\nor commentary, but the book never advanced beyond the fourth treatise.\nThese Odes were nearly all love-poems, but the poet explains that\nthey are a figurative expression of his devotion to Philosophy, and\nthe whole book is a glorification of the pursuit of knowledge. In the\nopening sentences, with the reference to Aristotle, the manner of\nreasoning, the assumptions of our innate desire for absolute knowledge\nand the bliss brought by its attainment, Dante is the spokesman of his\nperiod.\n\n------------------------------------------------------------------------\n[152] _Conv._ I. i. 111-113 and 125-127.\n\n[153] _Conv._ I. i. 67-86.\n\n \u201cSiccome dice il Filosofo nel principio della\n _Prima Filosofia_, Tutti gli uomini naturalmente\n desideranno di sapere: La ragione di che puote\n essere, che ciascuna cosa, da providenza di\n propria natura impinta, \u00e8 inclinabile alla sua\n perfezione. Onde, accioch\u00e8 la scienza \u00e8 l\u2019ultima\n perfezione della nostra anima, nella quale sta la\n nostra ultima felicit\u00e0, tutti naturalmente al suo\n desiderio siamo soggetti.\u201d[154]\n\n[154] \u201cAs the Philosopher says at the beginning of the _First\nPhilosophy_, \u2018All men naturally desire to have knowledge.\u2019 The reason\nof this may be that everything, being impelled by foresight belonging\nto its own nature, tends to seek its own perfection. Wherefore inasmuch\nas knowledge is the final perfection of our soul in which our final\nhappiness consists, all men are naturally subject to the desire for\nit.\u201d _Conv._ I. i. 1-11.\n------------------------------------------------------------------------\n\nAnd from a study of the _Convivio_ we may learn much of the authors\nmost esteemed, the methods of study pursued, and the results obtained,\nby thirteenth-century scholars seeking to gain the ultimate perfection\nof the soul.\n\nAstronomy is frequently introduced, especially in the second and third\ntreatises. The Ode which forms the text of the second treatise is\nthat which is quoted by Charles of Hungary in _Par._ viii. 37\u2014\u201cVoi\nche intendendo il terzo ciel movete,\u201d[155] and it gives Dante the\noccasion to speak first of the heaven of Venus, explaining Ptolemy\u2019s\nsystem of epicycles, and later of all the heavens in their order, and\nthe celestial bodies contained in them. The ode of the third treatise\ncontains the line \u201cNon vede il Sol, che tutto il mondo gira ...\u201d[156]\nand upon this he hangs a complete little essay describing the movements\nof the sun, and how they appear from different parts of the earth, as\nwell as a short dissertation on the question whether it is Sun or Earth\nwhich actually moves.\n\n------------------------------------------------------------------------\n[155] \u201cOh ye whose intellectual ministry\n Moves the third heaven.\u201d\u2014_Carey._\n\n[156] \u201cThe sun sees not, though circling all the world.\u201d\n------------------------------------------------------------------------\n\nThe Latin works, _De Monarchia_, _De Vulgari Eloquentia_, the\n_Eclogues_, and the _Letters_, do not give much scope for astronomical\nreferences; yet there are many similes drawn especially from the sun\nand moon, and the thought of the spheres as instruments of God\u2019s Will\nin bringing about events on earth is constantly recurring. In the\ncurious work _Qu\u00e6stio de Aqua et Terra_, Dante argues learnedly about\nthe spheres, the orbit of the moon, and her effect on the tides, and\nthe influences of the stars. The book purports to have been written at\nVerona in 1320 as the outcome of a discussion in which Dante had taken\npart as to the respective heights of land and ocean, a problem which\nhad been dealt with by Ristoro d\u2019 Arezzo some forty years earlier. Its\nauthenticity has been questioned, partly under the mistaken idea that\nfacts such as gravity, the spherical form of Earth, and the connection\nof tides with the moon were not known until much later; but as a matter\nof fact the discussion is quite in the manner of Dante\u2019s day, and no\nfacts or theories are put forward which he could not have learned\nfrom books with which we believe he was acquainted.[157] The internal\nevidence of his authorship is strong, and belief in it seems to be\ngaining ground among experts.[158]\n\n------------------------------------------------------------------------\n[157] The spherical form of Earth, and the action of gravity at the\nearth\u2019s surface, were commonplaces with the Greeks, as we have seen\nin Part I. of this book. Posidonius, Strabo, and other classical\nwriters speak of the tides as following the revolution of the heavens,\nand having periods similar to those of the moon; Albertus Magnus and\nAquinas ascribe them to the influence of the moon, and so does Dante\nhimself in _Par._ xvi. 83.\n\n[158] See Moore, _Studies in Dante_, II. \u201cThe Genuineness of the\n_Qu\u00e6stio de Aqua et Terra_,\u201d for a complete discussion of the question.\n------------------------------------------------------------------------\n\nFinally, the _Divine Comedy_, the work of Dante\u2019s maturity, which took\nhim so many years to write, and for which he had studied ever since he\nclosed the _Vita Nuova_ with the resolve to write more worthily one day\nof Beatrice,[159] focuses in one unique and finished work the thoughts\nand ideals, the knowledge and fancies, of the poet and his age. The\nsubject of the poem, taken in its literal sense, is cosmical, for it\ndescribes a journey in which the author penetrates to the centre of\nthe universe, and passes from planet to planet until he reaches the\noutermost sphere. Moreover, the journey is assumed to take a definite\nspace of time, and the passing of the hours by day and by night is\nindicated by the successive positions of sun or stars, and the phases\nand movements of the moon. The _Divine Comedy_ contains more than twice\nas many allusions to the heavenly bodies as all the other works of\nDante put together.\n\n------------------------------------------------------------------------\n[159] _V. N._ xliii. 3-7.\n------------------------------------------------------------------------\n\nBut we must discriminate in drawing conclusions from these\nastronomical references so freely distributed in all Dante\u2019s writings.\nIf he wrote the _Qu\u00e6stio_, it is his only professedly scientific\nwork, written for scientific men, and astronomy is only brought in\nincidentally. The _Convivio_, in which astronomical facts and theories\nare set forth in much greater detail and fulness than elsewhere, was\na popular work meant for those who had no inclination, or else no\nopportunity, for prolonged serious studies. We expect, therefore, that\ntechnical details will be avoided. Still more will they be omitted in\nthe _Divine Comedy_ and other poetical works, where difficult problems\nand pedantical accuracy would be most unsuitable. We can _infer_ the\nknowledge which lay in Dante\u2019s mind, behind his popular use of it in\nliterature; and we can often find an explanation in the prose of the\n_Convivio_ for a slight allusion in the poetical works; but we must\nnot deal with any as if they were text-books, and set forth precisely\nand completely all that Dante knew of his favourite science. It is\nthe poet\u2019s artistic use of the astronomy of his day which merits our\nadmiration quite as much as the scholar\u2019s proficiency.\n\nThis being premised, we may now proceed to quote from his works,\nshowing how he has dealt with first the facts, and secondly the\ntheories, of astronomy. Finally we shall be able to form a clear mental\npicture of the universe as it was believed to exist by Dante, and not\nonly by his contemporaries but by his successors for many generations.\n\n\n_V. OBSERVATIONAL ASTRONOMY._\n\n \u201cThe heavens declare the glory of God; and the\n firmament sheweth His handy-work. Day unto day\n uttereth speech, and night unto night sheweth\n knowledge. There is no speech nor language where\n their voice is not heard. Their line is gone out\n through all the earth, and their words to the end\n of the world. In them hath he set a tabernacle for\n the sun; which is as a bridegroom coming out of his\n chamber, and rejoiceth as a strong man to run a\n race.\u201d\n\n\n1. MOVEMENTS OF THE MOON.\n\nOf all the seven sciences of the Trivium and Quadrivium, Astronomy,\nDante thought, was the noblest, and for two reasons. Aristotle had said\nthat a science is noble in proportion to the nobility of its subject,\nand the certainty of its conclusions; and in both of these Astronomy\nexcels. Its subject is the Movement of the Heavens, and its certainty\nis perfect. \u201cE nobile e alta per nobile e alto suggetto, ch\u2019\u00e8 del\nmovimento del cielo: \u00e8 alta e nobile per la sua certezza, la quale \u00e8\nsenza ogni difetto.\u201d[160] If astronomers are sometimes mistaken, the\nfault lies in them, as Ptolemy said, and not in the science.\n\n------------------------------------------------------------------------\n[160] _Conv._ II. xiv. 244-217. \u201cIt is noble and lofty because of its\nnoble and lofty subject, which is the movement of the heavens; it is\nlofty and noble because of its certainty, which is without flaw.\u201d\n------------------------------------------------------------------------\n\nThis quotation from Ptolemy is from his book on \u201cjudicial\nastronomy,\u201d[161] and it may be that Dante was partly thinking of\nastrological predictions, as he almost certainly was in the passage\nthat follows, where he adds that astronomy takes a long time to\nlearn, not only because of its great range, but because experience is\nnecessary to form a correct judgment. Nevertheless, it is probable that\nby its flawless certainty he meant that unchanging laws govern the\ncelestial phenomena, so that they may always be predicted without error\nwhen the laws are known.\n\n------------------------------------------------------------------------\n[161] See p. 156.\n------------------------------------------------------------------------\n\nHis definition of astronomy was accurate, for it was not until the\nmiddle of the nineteenth century that physical astronomy began to take\nits place beside the old \u201castronomy of position,\u201d and in Dante\u2019s day\npractically the only subject open to research concerning the heavenly\nbodies was their movements. Of these, and especially the \u201cprime motion\u201d\nof the diurnal revolution, he was vividly conscious. His favourite name\nfor the heavens is \u201cwheels\u201d\u2014\u201cle ruote magne,\u201d \u201ceterne ruote,\u201d \u201cstellate\nruote\u201d;[162] and he often refers to them as a standard of motion. Thus\nwhen with Beatrice he was rapt from the summit of Mount Purgatory, to\nexpress the swiftness of their flight he says it was almost as rapid\nas the movement of the sky\u2014\u201cveloci, quasi come il ciel vedete.\u201d[163]\nConstantine moving the capital of the Roman Empire eastwards is\ndescribed as turning the Roman Eagle contrary to the course of the\nsky\u2014\u201ccontra il corso del ciel,\u201d[164] and the sky itself is described as\na sphere which is ceaselessly at play like a lively child:\u2014\n\n------------------------------------------------------------------------\n[162] \u201cThe great wheels,\u201d \u201ceternal wheels,\u201d \u201cstarry wheels.\u201d\n\n[163] \u201cSwift, almost as the heaven ye behold.\u201d _Par._ ii. 21.\n\n[164] \u201cAgainst the course of the sky.\u201d _Par._ vi. 2.\n\n ... \u201cla spera,\n Che sempre a guisa di fanciullo scherza.\u201d[165]\n\n[165] ... \u201cThat sphere,\n Which aye in fashion of a child is playing.\u201d\n _Purg._ xv. 2, 3. (_Longfellow_).\n------------------------------------------------------------------------\n\nTo Dante, as to the Greeks, it is not the unusual or startling that\nappeals, but the unfailing harmony of the regular celestial movements.\nComets he mentions only twice, and shooting stars twice, eclipses seven\ntimes; but there are scores of allusions to the rhythmical progression\nof Sun and stars, Moon and planets. The skies were familiar to him\nin all their daily aspects\u2014sunset and dawn and radiant noons; cloudy\nnights \u201csotto pover cielo,\u201d[166] brilliant starlit nights, nights of\nclear moonlight. He had seen the stars fade one by one, till at last\neven the brightest vanished in the glow of dawn:\u2014\n\n------------------------------------------------------------------------\n[166] \u201cUnder a poor sky.\u201d _Purg._ xvi. 2.\n\n \u201cE come vien la chiarissima ancella\n Del sol pi\u00f9 oltre, cos\u00ec il ciel s\u00ec chiude\n Di vista in vista, infino alla pi\u00f9 bella.\u201d[167]\n\n[167] \u201cAnd as advances, bright exceedingly,\n The handmaid of the sun, the heaven is closed,\n Light after light, to the most beautiful.\u201d\n _Par._ xxx. 7-9. (_Longfellow_).\n------------------------------------------------------------------------\n\nhe had watched for their first appearance in the evening twilight:\u2014\n\n \u201cE s\u00ec come al salir di prima sera\n Comincian per lo ciel nuove parvenze,\n S\u00ec che la vista pare e non par vera....\u201d[168]\n\n------------------------------------------------------------------------\n[168] \u201cAs at evening hour\n Of twilight, new appearances through heaven\n Peer with faint glimmer, doubtfully descried.\u201d\n _Par._ xiv. 70-72. (_Carey_).\n------------------------------------------------------------------------\n\nNumberless other passages and expressions will occur to every Dante\nreader, proving how keenly he felt the beauty of the skies.\n\nBut they prove more than this. Other authors have felt and have\ndescribed poetically the beauties of the skies, but they often remember\nimperfectly what they saw, or draw upon their imagination without any\nknowledge of the celestial movements, and so fall into absurd mistakes.\nThe moon especially is a stumbling-block, and it is quite a rare thing\nfor a modern novelist to introduce one without making it do something\nimpossible. A new moon will rise at midnight, or a waning moon at\nsunset; she has even been known to rise and then to set in the dark\nhours of one short midsummer night;[169] and a well known author sees\nher in two phases at the same moment: \u201cthe full moon rose, yellow _and\ngibbous_!\u201d[170]\n\n------------------------------------------------------------------------\n[169] In Kenneth Grahame\u2019s delightful book, full of sympathy with\nNature, _The Wind in the Willows_. The moon rose when it was \u201cpast ten\no\u2019clock,\u201d and \u201csank earthwards reluctantly and left them\u201d before dawn.\n\n[170] H. G. Wells, _The Time Machine_.\n------------------------------------------------------------------------\n\nDante\u2019s moon does indeed give us a little trouble once or twice, but\nhe never makes flagrant mistakes of this kind. His consistency and\ntruth of description prove his knowledge of astronomy, and also imply\nintelligent thoughtful watching of the celestial movements; for it\nis notorious that book-knowledge, if unassisted by acquaintance at\nfirst-hand with the facts of a subject like astronomy, will not save a\nwriter from glaring inaccuracies.\n\nHis allusions to the motions of the moon, both diurnal and monthly,\nshow plainly that he understood them well. His new moon appears in\nthe evening, his waning moon rises late at night and sets in morning\nsunshine,[171] and his full moon comes on the meridian at midnight, for\nwhen he wishes to describe her at her brightest, as a comparison with a\nvery brilliant light, he places her in a clear sky at midnight in her\nmid-month.[172] In the middle of a lunar month the moon is full, and\nbeing exactly opposite the sun will reach the meridian at midnight:\nthis therefore is the time when she gives all the light she possibly\ncan. In the _Qu\u00e6stio_[173] Dante mentions that the moon does not move\nin the celestial equator, but sometimes north of it, and sometimes an\nequal amount south; in the _Convivio_ he indicates the length of her\nperiod, and briefly describes her phases and their cause\u2014\u201cOra luce da\nun lato, e ora luce dall\u2019 altro, secondo che \u2019l sole la vede.\u201d[174]\n\n------------------------------------------------------------------------\n[171] _Inf._ xv. 18, 19; _Purg._ xviii. 76-81; _Purg._ x. 14, 15, _Cf._\nix. 44.\n\n[172] _Purg._ xxix. 53, 54.\n\n[173] _Qu._ xx. 61-63.\n\n[174] \u201cNow she shines on one side, and now on the other, according to\nthe way the sun looks upon her.\u201d _Conv._ II. xiv. 77-79.\n------------------------------------------------------------------------\n\nHer position in the zodiac is mentioned several times. In one passage\nhe indicates a very brief space of time in the following curious way:\u2014\n\n \u201cQuando ambo e due i figli di Latona,\n Coperti del Montone e della Libra,\n Fanno dell\u2019 orizzonte insieme zona,\n Quant\u2019 \u00e8 dal punto che il zenit inlibra.\n Infin che l\u2019uno e l\u2019altro da quel cinto,\n Cambiando l\u2019emisperio, si dilibra,\n Tanto, col volto di riso dipinto,\n Si tacque Beatrice.\u201d[175]\n\n------------------------------------------------------------------------\n[175]\n \u201cAt what times both the children of Latona,\n Surmounted by the Ram and by the Scales,\n Together make a zone of the horizon,\n As long as from the time the zenith holds them\n In equipoise, till from that girdle both\n Changing their hemisphere disturb the balance,\n So long, her face depicted with a smile,\n Did Beatrice keep silence.\u201d\n _Par._ xxix. 1-8.\n------------------------------------------------------------------------\n\nThat is to say, when Sun and Moon (the children of Latona) are both\non the horizon, but one being in Aries and the other in Libra they\nare opposite one another, the zenith for a moment holds them, as it\nwere, in balance; but the next moment one will drop below the horizon\nwhile the other rises above it, thus changing from the visible to\nthe invisible hemisphere and _vice versa_, as each frees itself (\u201csi\ndilibra\u201d) of the common horizon that girdled them. The pause of\nBeatrice was as brief as the time during which sun and moon would thus\nhang in the balance.\n\nYet, though Dante shows that he was familiar with the movements\nand appearances of the moon, his allusions to her are cold and\ncomparatively rare. Unlike modern poets, moonlight does not seem to\nhave had any great fascination for him. In all his works there are\nonly fifty-one references to the moon, and far the greater number of\nthese are remarks about the measurement of time, or else her phases,\nher markings, her share in causing eclipses etc. In all his short poems\n(including those of the _Vita Nuova_ and _Convivio_) there are but two\nreferences, and those as dry as possible. \u201cPi\u00f9 lune\u201d[176] is once used,\nmeaning several months, and in a sonnet which describes the influences\nof each heaven on his lady, all he can find to say of the moon\u2019s is \u201cE\n\u2019l primo ciel di s\u00e8 gi\u00e0 non l\u2019\u00e8 duro.\u201d[177]\n\n------------------------------------------------------------------------\n[176] \u201cMany moons.\u201d _Canz._ xx. 89.\n\n[177] \u201cAnd the first heaven is not grudging to her.\u201d\u2014_Sonetto_ xxviii.\n------------------------------------------------------------------------\n\nThe chill of moonlight is spoken of as with a shudder on the hill of\nPurgatory;[178] and its usefulness is recognized rather grudgingly\nwhen Virgil remarks that yesternight the moon was full, and adds that\nDante must remember it, since it did him no harm in the depths of the\nForest.[179] It is true there is some beauty in the description of the\naurora which preceded moonrise[180] on the first night in Purgatory,\nbut Dante gives it an ugly name, and the waning moon when seen on the\nfollowing night, four days after full, is oddly compared to a bucket\nin shape. Dante did not admire this gibbous form, for he instances\nthe outline of the moon when not quite full as an ignoble curve,\ncontrasting it with the beauty of a perfect circle.[181]\n\n------------------------------------------------------------------------\n[178] _Purg._ xix. 1, 2.\n\n[179] _Inf._ xx. 127-129.\n\n[180] _Purg._ ix. 1-9.\n\n[181] _Conv._ IV. xvi. 89-93.\n------------------------------------------------------------------------\n\n[Illustration: Fig. 39. Sun, moon, and zenith.\n\nTo illustrate _Par._ xxix. 1-6. (_See p. 265_).\n\nIn the first figure the sun and moon are balanced, as it were, being at\nequal distances from the zenith: in the second, a few minutes later,\nby the rising of the sun and the setting of the moon, the balance is\ndisturbed, and each changes its hemisphere.]\n\nHardly ever does he find a beautiful epithet for her: she is ruler of\nHell,[182] Cain and the Thorns[183] (in reference to the legend which\nsees this figure in her dark markings); or she is simply Delia,[184]\nTrivia,[185] the daughter of Latona,[186] or with a little warmth\nthe sister of the sun,[187] and with the sun one of the two Eyes of\nHeaven.[188] One exception to this harsh treatment is in the beautiful\ndescription of reaching the heaven of the moon,[189] for there she is\nthe first star, the eternal pearl; and the sudden burst of eloquence in\nthe midst of a grave argument in _De Monarchia_ startles us doubly when\nwe find that Justice is compared to the moon\u2014not, as one might expect,\nresplendent in a dark sky, but Ph\u0153be gazing at her brother opposite,\nin the purple of the morning calm.[190] The passage from _Par._ xxix.\nquoted above helps us to understand why the moon in this position\nshould symbolize Justice, for here again is suggested the perfect\nbalancing of the two great orbs, as the sun rises and the full moon\nsets.\n\n------------------------------------------------------------------------\n[182] _Inf._ x. 80.\n\n[183] _Inf._ xx. 126.\n\n[184] _Purg._ xxix. 78; _Ep._ vi. 54.\n\n[185] _Par._ xxiii. 26.\n\n[186] _Par._ x. 67; xxii. 139; xxix. 1.\n\n[187] _Purg._ xxiii. 120.\n\n[188] _Purg._ xx. 132.\n\n[189] _Par._ ii. 25-36.\n\n[190] _De Mon._ I. xi. 35-37.\n------------------------------------------------------------------------\n\nAdd to these passages two similes drawn not indeed from the moon\nitself but from the halo surrounding her,[191] and two descriptions\nof brilliant moonlight nights,[192] and we have all that Dante has\nwritten in praise of the moon. It is true that throughout the _Inferno_\nand _Purgatorio_ the sun typifies Divine Grace, and the moon is his\nopposite, but this cannot altogether explain the difference in their\ntreatment, even in the _Divine Comedy_. A deeper reason seems to be\nDante\u2019s true southerner\u2019s love of the sun; and he doubtless had the\nastronomer\u2019s feeling that moonlight always means loss of starlight,\nwhich he dearly loved (see _Purg._ xviii. 76, 77). Perhaps too the\nastrological views of the moon influenced him, consciously or not.\nAccording to Ristoro, the moon represents the poorest and lowest\nclasses of people, who are servants and messengers to the rest; and as\nall the planets were supposed to be either masculine or feminine, he\nungallantly adds\u2014\u201cE questa Luna, a cagione di sua vilt\u00e0, potemo dire\nper ragione ch\u2019ella sia femmina.\u201d[193] Her only house, too, which is\nCancer, is also poor and base. The moon, moreover, is nearer Earth than\nany other planet, and shows by her dark markings that she is less pure\nthan the rest.\n\n------------------------------------------------------------------------\n[191] _Par._ x. 67-69; and _Purg._ xxix. 78.\n\n[192] _Purg._ xxix. 53, 54; and _Par._ xxiii. 26.\n\n[193] \u201cAnd this moon, because of her inferiority, is rightly called\nfeminine.\u201d\n------------------------------------------------------------------------\n\n\n2. MOVEMENTS OF THE SUN.\n\nWhatever the reason, Dante\u2019s fifty-one references to the moon are in\nstrong contrast to his allusions to the sun. These are four times as\nmany, and they include warm expressions of admiration and delight,\nand beautiful epithets and similes. The sun is Titan with his chariot\nand horses,[194] he is a Mirror, a Car of Light, the Lantern of the\nWorld, the Prince of the Stars, the Father of all mortal life.[195] His\nbeautiful form is admired, \u201cla perfetta sua bella figura,\u201d[196] and his\nintense brilliance often noted.[197] He is the guide that leads all\naright,[198] to whom Virgil appeals:\u2014\n\n------------------------------------------------------------------------\n[194] _Ecl._ ii. 1-4.\n\n[195] _Purg._ iv. 62, 63; _Purg._ iv. 59; and xxix. 117, 118; _Par._ i.\n38; _Canz._ xix. 114; _Par._ xxii. 116.\n\n[196] \u201cThe perfection and beauty of his shape.\u201d _Canz._ xix. 76.\n\n[197] _V. N._ xlii. 29; _Canz._ ix. 2; _Conv._ II. xiv. 126, 127;\n_Purg._ xvii. 52, 53; _Par._ i. 54; and x. 48, etc.\n\n[198] _Inf._ i. 17, 18.\n\n \u201cO dolce Lume, a cui fidanza i\u2019 entro\n Per lo nuovo cammin, tu ne conduci.\u201d[199]\n\n[199]\n \u201cO pleasant light, my confidence and hope!\n Conduct us thou,\u201d he cried, \u201con this new way.\u201d\n _Purg._ xiii. 16, 17. (_Carey_).\n------------------------------------------------------------------------\n\nUnder his rays the rose expands, the air is gladdened, mists are\ndispelled, snow melts, and all things are quickened into life.[200]\nUnlike the moon, the sun is the bringer of warmth and comfort, chasing\naway cold and darkness,[201] sunrise is the hour of renewed hope and\nconfidence,[202] it strengthens our limbs, paralysed by the cold of\nnight,[203] it is eagerly awaited through the darkness by the little\nbird on her nest;[204] and delicate flowers, bowed and closed during\nthe cold night, rise upright on their stems and open as soon as the sun\nshines once more upon them.[205] The exquisite sunsets and sunrises of\nthe _Purgatorio_ are favourite passages with all readers.\n\n------------------------------------------------------------------------\n[200] _Par._ xxii. 55, 56; _Inf._ vii. 122; _De Mon._ II. i. 37-39; and\n_Par._ ii. 106-108; _Canz._ xi. 37; _Conv._ III. xii. 59, 60, etc. etc.\n\n[201] _Canz._ ix. 5.\n\n[202] _Inf._ i. 41-43.\n\n[203] _Purg._ xix. 10, 11.\n\n[204] _Par._ xxiii. 1-9.\n\n[205] _Inf._ ii. 127-129.\n------------------------------------------------------------------------\n\nLove is compared with the summer sun,[206] the generosity of a noble\nnature resembles \u201cthe great planet.\u201d[207] The Emperor Henry VII., from\nwhom Dante expected the regeneration of Italy and the whole Christian\nworld, is likened to the rising sun;[208] the birth of St. Francis is\ndescribed as \u201cnacque al mondo un sole,\u201d[209] and his birthplace ought\nrightly to be called not Assisi but Orient.[210] Virgil is addressed\nas \u201cO Sol che sani ogni vista turbata;\u201d[211] Beatrice is \u201cIl sol degli\nocchi miei.\u201d[212] Finally the sun is the best symbol of God,[213]\nand so it is used many times in the _Divine Comedy_: \u201cIl Sol degli\nangeli,\u201d[214] \u201cIl Sol che raggia tutto nostro stuolo;\u201d[215] a spirit\nturns to \u201cil Sol che la riempie,\u201d[216] and when Virgil laments that he\nis shut out of heaven it is in these words: \u201cHo i\u2019 perduto Di veder l\u2019\nalto Sol che tu disiri.\u201d[217]\n\n------------------------------------------------------------------------\n[206] _De Mon._ II. i. 36-41.; _Canz._ ix.\n\n[207] _Canz._ xix. 96-114.\n\n[208] _Ep._ v. 10; and vii. 19, 20, 25.\n\n[209] \u201cA sun rose upon the world.\u201d _Par._ xi. 50.\n\n[210] _Par._ xi. 52-54.\n\n[211] \u201cO sun that healest all imperfect vision,\u201d _Inf._ xi. 91.\n\n[212] \u201cThe sun of my eyes.\u201d _Par._ xxx. 75 (See also _Par._ iii. 1-3).\n\n[213] _Conv._ III. xii. 52-63.\n\n[214] \u201cThe Sun of the angels.\u201d _Par._ x. 53.\n\n[215] \u201cThat Sun which enlightens all our company.\u201d _Par._ xxv. 54.\n\n[216] \u201cThe Sun which satisfies it.\u201d _Par._ ix. 8.\n\n[217] \u201cI have lost the sight of that high Sun whom thou desirest.\u201d\n_Purg._ vii. 25, 26. Compare _Par._ xxx. 126; xv. 76; xviii. 105.\n------------------------------------------------------------------------\n\nBut we may not dwell on those thoughts of the sun as the typical giver\nof light and life; we must ask what Dante says about his movements,\nsince this was the chief subject-matter of medi\u00e6val astronomy.\n\nHis daily course, \u201cil cammin del Sole,\u201d[218] is often spoken of, and\nis indicated both by his position in the sky, and the length and\ndirection of shadows. The second _Eclogue_ begins with a description of\na breathlessly hot midday, when objects, which are usually shorter than\ntheir own shadows, now surpassed them in length.\n\n------------------------------------------------------------------------\n[218] \u201cThe path of the sun.\u201d _Purg._ xii. 74.\n\n \u201cResque refulgentes, solitae superarier umbris,\n Vincebant umbras.\u201d _Ecl._ ii. 5, 6.\n------------------------------------------------------------------------\n\nAt this time the sun appears most brilliant, and seems to move most\nslowly, since he is scarcely changing his position with regard to the\nhorizon.\n\n \u201cE pi\u00f9 corrusco, e con pi\u00f9 lenti passi,\n Teneva il sole il cerchio di merigge.\u201d[219]\n\n------------------------------------------------------------------------\n[219] \u201cShining more brightly and with slower steps, the sun had gained\nthe circle of midday.\u201d _Purg._ xxxiii. 103, 104.\n------------------------------------------------------------------------\n\nThe greatest number of references to the sun\u2019s daily journey occur in\nthe _Purgatory_, and we shall quote them in a later chapter.\n\nHis yearly journey through the zodiac is also very often referred to.\nWhen relating his first meeting with Beatrice, Dante names his age, not\nby simply saying that he was nearly nine years old, but by counting the\nnumber of the times that the \u201cheaven of light,\u201d that is, of the sun,\nhad returned to the same point since his birth:\u2014\n\n \u201cNove fiate gi\u00e0, appresso al mio nascimento, era\n tornato lo cielo della luce quasi ad un medesimo\n punto, quanto alla sua proprio girazione.\u201d[220]\n\n------------------------------------------------------------------------\n[220] \u201cNine times already since my birth had the heaven of light\nreturned to the selfsame point almost, as concerns its own revolution.\u201d\n\n _V. N._ ii. 1-4. (_Rossetti_).\n------------------------------------------------------------------------\n\nThe sun\u2019s \u201cown revolution\u201d is of course its apparent yearly movement,\nas distinct from the diurnal movement which it shares with all the\nheavenly bodies.\n\nThe same thought is expressed in a sonnet:\n\n \u201cIo sono stato con Amore insieme\n Dalla circolazion del Sol mia nona.\u201d[221]\n\nWe know further that Dante was born in either May or June, because he\nsays, when he finds himself among the stars of Gemini, that the sun was\nrising and setting in this sign at the time of his birth.[222]\n\n------------------------------------------------------------------------\n[221] \u201cI have dwelt with Love since my ninth revolution of the sun.\u201d\n_Son._ xxxvi. 1, 2.\n\n[222] See diagram on p. 276.\n\n \u201cO gloriose stelle\n Con voi nasceva e s\u2019ascondeva vosco\n Quegli ch\u2019\u00e8 padre d\u2019ogni mortal vita,\n Quand\u2019 io senti\u2019 da prima l\u2019 aer tosco.\u201d[223]\n\n[223]\n\n \u201cO glorious stars ...\n With you was born, and hid himself with you,\n He who is father of all mortal life,\n When first I tasted of the Tuscan air.\u201d\n _Par._ xxii. 112-117. (_Longfellow_).\n\nAt this date the sun entered the _constellation_ of Gemini on June\n1 (Old Style), but was in the _sign_ from May 11 to June 11, and it\nis always to the signs that Dante refers in the _Divine Comedy_. The\nanonymous fourteenth century commentator known as \u201cl\u2019Ottimo\u201d interprets\nthis passage as indicating the time \u201cbetween the middle of May and the\nmiddle of June.\u201d\n------------------------------------------------------------------------\n\nBoccaccio tells us that a Mayday feast, given by the father of\nBeatrice, was the occasion of Dante\u2019s first meeting with her, and also\nthat not long before his death in Ravenna he told a friend that he had\ncompleted his fifty-sixth year in the preceding May, so we may conclude\nthat May was the month of his birth.\n\nDante seems to have taken some trouble to find out the exact period of\nthe sun\u2019s revolution. His text-book, the _Elementa_ of Alfraganus, only\ngives it as 365\u00bc days nearly:\u2014\u201cSol ... orbem confecit diebus 365 et\nprop\u00e8 \u00bc.\u201d Ristoro d\u2019Arezzo and Brunetto Latini were content to repeat\nthis rough estimate, and call the year 365 days 6 hours, but Dante\nwished to be more exact, and somehow contrived to obtain a value which\nwas much nearer the modern estimate of 365 days, 5 hours, 48 minutes,\n46 seconds. We know this from two passages. In the _Convivio_ he gives\nthe half period as less than 182 days 15 hours; and in the _Paradiso_\nBeatrice says that January will in time cease to be a winter month,\nbecause of a neglected fraction of time.\n\n \u201cPrima che gennaio tutto si sverni\n Per la centesma ch\u2019 \u00e8 laggi\u00f9 negletta.\u201d[224]\n\n------------------------------------------------------------------------\n[224]\n \u201cEre January be unwintered wholly\n By the centesimal on Earth neglected.\u201d\n _Par._ xxvii. 142-143. (_Longfellow_).\n------------------------------------------------------------------------\n\nJanuary was in fact receding from the winter, and steadily though\nslowly advancing towards the spring, because the Julian year (as we\nsaw, p. 171) was 11 minutes 14 seconds longer than the true solar\ntropical year. When Julius C\u00e6sar reformed the Calendar, March 25 was\nmade (as of old) to coincide with the spring equinox, but by Dante\u2019s\ntime this date was 13 days late, and the true equinox fell on March 12.\nConsequently though the day called January 1 still came 84 days before\nMarch 25, it was only 71 days before the spring equinox.\n\nIf Beatrice meant to speak with scientific precision, and was correct\nin her hundredth part of a day per annum, that is, if the difference\nbetween the astronomical and the Julian year was one day in a hundred\nyears, it would be 7100 years before the first of January came to\ncoincide with the spring equinox, and January became a spring month.\nBut the error quoted is really rather too large, for a hundredth part\nof a day is 14 minutes 24 seconds, and it was in fact only 11 minutes\n14 seconds.\n\nIt would be interesting to know where Dante found this value, which\nis practically the only astronomical datum not given in Alfraganus.\nPtolemy, following Hipparchus, had given the tropical year as \u00b9/\u2083\u2080\u2080\npart of a day less than 365\u00bc; Albategnius gave a more accurate figure,\nand one which agrees well with the \u201ccentesma,\u201d for his tropical year\ndiffers from the Julian by a little less than \u00b9/\u2081\u2080\u2086 of a day; but he\nalso improved the value of precession, and Dante does not seem to have\nknown this, so he was probably not acquainted with this astronomer\u2019s\nwork. The Alfonsine Tables gave a value which was very close indeed to\nthe correct one, making the tropical year only 30 seconds longer than\nthe modern value, and the difference between the Julian and true year\n\u00b9/\u2081\u2083\u2084 of a day. (The correct value is \u00b9/\u2081\u2082\u2088). Either of these figures\nmay have been known to Dante indirectly: perhaps he had obtained the\nAlfonsine value in conversation with Brunetto Latini, who had visited\nAlfonso\u2019s court. His fraction was evidently only approximate, but it is\ninteresting to know that he had found out more than popular books could\ntell him about the period of the sun\u2019s revolution, and that he had been\nsufficiently struck by the small difference between the calendar and\nastronomical years to mention it in a picturesque way in his poem. It\nis possible that he had heard of Roger Bacon\u2019s appeal to the Pope in\n1267 to correct the calendar because the date of the spring equinox was\nof importance in connection with the observation of Easter.\n\nIt is hardly necessary to remind my readers that this was done by\nanother Pope three hundred years later, before January had made much\nmore advance towards becoming a spring month. The hundredth part of a\nday, of which Beatrice complained, is now subtracted from the year by\nomitting to make century years leap years; but as the error was really\nnot quite so great as she said, an exception is made for century years\ndivisible by 400. Thus 1600 was a leap year, but not 1700, 1800, or\n1900.\n\n[Illustration: Fig. 40. The Zodiac and the Months.]\n\nDante seems to have connected any season of the year with the sun\u2019s\npath in the zodiac as readily as with the name of a month. The sun\u2019s\nyearly course through the signs is shown diagrammatically in figure 40,\nand a glance at this will make clear a number of allusions without any\nexplanation.\n\nStarting from the first point of Aries at the spring equinox, which in\nDante\u2019s time fell in the middle of March, and taking one-twelfth of\nthe year to traverse each sign, it is evident that during the end of\nMarch and beginning of April the sun was in Aries; he entered Cancer\nand reached the summer solstice in June, the autumnal equinox in Libra\nin September, and the winter solstice when he entered Capricornus in\nDecember. The six signs above the horizontal line are northern, the six\nbelow are southern.\n\nThe following are a few typical examples.\n\nWhen Dante wishes to express the transition of his feelings from\ndespondency to courage, at seeing the stern and troubled face of his\nguide melt suddenly to a smile, he compares himself to a poor shepherd\nwho wakes early and sees the fields covered, as he thinks, with snow,\nbut in a short time finds that it is only hoar-frost which has put on\nthe semblance of her white sister, and seeing the face of the world\nchanged he gladly leads out his sheep to pasture. The time at which\nthis may happen is\n\n \u201cQuella parte del giovinetto anno,\n Che il sole i crin sotto l\u2019Aquario tempra,\n E gi\u00e0 le notti al mezzod\u00ec sen vanno.\u201d[225]\n\n------------------------------------------------------------------------\n[225]\n \u201cIn that part of the youthful year wherein\n The sun his locks beneath Aquarius tempers,\n And now the nights draw near to half the day.\u201d\n _Inf._ xxiv. 1-3. (_Longfellow_).\n------------------------------------------------------------------------\n\nThat part of the youthful year when the sun cools his locks beneath\nAquarius is clearly the end of January or beginning of February, but\nthe last line may bear one of two meanings. If we translate \u201cmezzod\u00ec\u201d\nas \u201chalf the day\u201d it means that the nights are growing shorter, and\nvery soon (in March) when the sun will have reached the equinox, they\nwill be just twelve hours long. If we take \u201cmezzod\u00ec\u201d as meaning \u201cthe\nsouth,\u201d we must interpret the passage in the light of others in the\n_Divine Comedy_ where Night is personified, and considered as circling\nin the zodiac always opposite to the sun. For instance in _Purg._ ii.\n1-6 (a passage which will be more fully explained later) Night is\ndescribed as circling opposite to the sun, \u201cLa notte, che opposita a\nlui cerchia,\u201d[226] and as the sun at that time was in Aries, Night was\nin Libra, \u201cle Bilance.\u201d Henceforth for six months the sun will be in\nthe northern signs, and the days longer than the nights, but as soon as\nNight begins to assert her supremacy, and the nights begin to be longer\nthan the days, the sun enters Libra and then it is not visible all\nnight. This is the meaning of\n\n------------------------------------------------------------------------\n[226] \u201cNight that opposite to him revolves.\u201d (_Longfellow_).\n\n \u201cle Bilance,\n Che le caggion di man quando soverchia.\u201d[227]\n\n[227]\n \u201cThe Scales, that from her hands are dropped\n When she reigns highest.\u201d\n _Purg._ ii. 5, 6. (_Carey_).\n------------------------------------------------------------------------\n\nWhen Night becomes dominant, the Scales fall from her hand, for the sun\nis in that sign.\n\nApplying this idea to the passage quoted above, it will mean \u201cThe\nnights are going southward,\u201d for the sun in Aquarius is not far from\nthe point where he crosses the equator to the north, therefore Night\ncircling opposite to him is nearing the point where she goes south.\nEither interpretation is faithful to fact, but perhaps the circumstance\nthat the plural noun is used favours the first.\n\n[Illustration: Fig. 41. The Ram on the Ecliptic. [_To face p. 279._\n\n_From the \u201cCosmi Historia\u201d of Robert Flud, a.d. 1612._\n\n(_Reproduced from Brown\u2019s Phainomena of Aratos._)]\n\nConrad Malaspina prophesied to Dante that his favourable opinion of the\nMalaspina family would be justified \u201cbefore the sun had come to rest\nagain seven times in the bed which the Ram covers and bestrides with\nhis four feet.\u201d\n\n \u201cEd egli: Or va, che il Sol non si ricorca\n Sette volte nel letto che il Montone\n Con tutti e quattro i pie copre ed inforca\n Che cotesta cortese opinione ...\u201d[228]\n\n------------------------------------------------------------------------\n[228]\n \u201cAnd he: Now go, for the sun shall not lie\n Seven times upon the pillow which the Ram\n With all his four feet covers and bestrides.\n Before that such a courteous opinion ...\u201d\n _Purg._ viii. 133-136. (_Longfellow_).\n------------------------------------------------------------------------\n\nThe sun was at the time in the Ram, and Malaspina means that less\nthan seven years would elapse, before his prophecy was fulfilled.\nThe aptness of the description may be seen by the figure of Aries\nas portrayed in an old seventeenth century book in which the Ram is\nuncomfortably trying to sit on the ecliptic.\n\nAnother instance is in the beautiful midwinter Ode, \u201cIo son venuto al\npunto della rota.\u201d[229] Each stanza pictures a feature of a severe\nwinter\u2014snow and rain, the absence of summer birds, bare trees and dead\nflowers, the favourite walk become a torrent; but the first describes\nthe position of stars and planets. When the sun sets, the Twins\nappear on the eastern horizon, hence we know at once that the sun is\nin Sagittarius and the time is November or December. To confirm his\nmelancholy, the poet adds that the Star of Love (Venus) is hidden from\nus by the sun\u2019s rays which now shine athwart her, and that the planet\nwhich strengthens the cold (Saturn, the \u201cfrigida stella\u201d of Virgil)\ndisplays himself in that arc of the sky in which all the seven planets\ncast the shortest shadow;[230] that is, either he is on the meridian at\nsunset, or he is in the most northerly part of the zodiac, in Gemini or\nCancer. A planet in this place, as for instance the sun at midsummer,\nis visible longer, describes a longer arc, and casts shorter shadows,\nthan in any other part of the zodiac. And as this is the part which\nrises over the eastern horizon as the sun sets, Saturn would also rise\nat that time and remain visible all night.\n\n------------------------------------------------------------------------\n[229] \u201cI have come to that part of the wheel.\u201d _Canz._ xv.\n\n[230] Like all medi\u00e6val writers, Dante includes the sun and moon among\nthe seven planets. The others do not cast perceptible shadows, except\nVenus and Jupiter at their brightest.\n\nThe opening lines of the Ode run thus:\u2014\n\n \u201cIo son venuto al punto della rota,\n Che l\u2019orizzonte, quando il Sol si corca,\n Ci parturisce il geminato cielo;\n E la stella d\u2019amor ci sta rimota\n Per lo raggio lucente, che la \u2019nforca\n S\u00ec di traverso, che le si fa velo;\n E quel pianeta che conforta il gelo\n Si mostra tutto a noi per lo grand\u2019 arco,\n Nel qual ciascun de\u2019 sette fa poca ombra.\u201d[231]\n\n[231]\n \u201cI to that point in the great wheel have come,\n Wherein the horizon, when the sun doth set,\n Brings forth the twin-starred heaven to our sight;\n And Love\u2019s fair star away from us doth roam,\n Through the bright rays obliquely on it met\n In such wise that they veil its tender light;\n That planet which makes keen the cold of night\n Shows himself to us in the circle great,\n Where each star of the seven casts little shade.\u201d\n (_Plumptre_).\n------------------------------------------------------------------------\n\nIt is astonishing that Giuliani should so completely miss the point of\nthe \u201ctwinned sky,\u201d that he substitutes \u201cingemmato\u201d for \u201cgeminato,\u201d and\nreads\u2014\n\n \u201c ... la rota,\n Ch\u2019 all orizzonte, quando il Sol si corca,\n Ci parturisce l\u2019ingemmato cielo.\u201d[232]\n\n------------------------------------------------------------------------\n[232] \u201cThe Wheel which, when the sun sets, brings forth for us on the\nhorizon the jewelled sky.\u201d\n------------------------------------------------------------------------\n\nHe understands the hour of evening to be meant, when the Wheel of\nDay and Night brings a jewelled, _i.e._ starry sky on the horizon as\nthe sun sets. But it is not only on the horizon that stars appear at\nsunset; and the mention of Gemini to indicate the time of year is\nthoroughly characteristic of Dante. The Wheel is the revolving year\nwhich has carried the sun into Sagittarius.\n\nAngelitti remarks that the whole description was literally true for\nDecember 1296, since Venus was then in conjunction with the sun, and\nSaturn in Cancer;[233] and as this poem is a complaint of the hardness\nof his lady, to whom the poet is nevertheless wholly devoted, it may\nwell have been written in that time when the lady Philosophy refused to\nsmile upon her lover.[234]\n\n------------------------------------------------------------------------\n[233] _Sulla Data del Viaggio Dantesco_ p. 90, note.\n\n[234] Comparing _Conv._ II. ii. 12, xiii. 49-52, and IV. i. 60-62, we\nlearn that in August 1293 (_vide infra_, p. 314), Dante first became\nacquainted with the Lady Philosophy; that in the early part of 1296 he\nwas completely under her spell; and that some time afterwards she for a\nwhile estranged herself from him.\n------------------------------------------------------------------------\n\nFurther on in the same poem the effects of the sun in spring, when he\nis in the sign of Aries, are alluded to as \u201cthe virtue of Aries\u201d:\u2014\n\n \u201cPassato hanno lor termine le fronde,\n Che trasse fuor la virt\u00f9 d\u2019Ariete,\n Per adornare il mondo, e morta \u00e8 l\u2019 erba.\u201d[235]\n\n------------------------------------------------------------------------\n[235]\n \u201cScattered and faded now is all the foliage\n Which had burst forth, beneath the power of Aries,\n To beautify the world, the grass is withered.\u201d _Canz._ xv. 40-42.\n------------------------------------------------------------------------\n\nContrast with this the passage in the _Paradiso_ where \u201cnocturnal\nAries\u201d is used as a synonym for autumn.\n\n \u201cQuesta primavera sempiterna\n Che notturno Ariete non dispoglia.\u201d[236]\n\n------------------------------------------------------------------------\n[236]\n \u201cThis everlasting spring\n Nocturnal Aries never can despoil.\u201d\n _Par._ xxviii. 116-117.\n------------------------------------------------------------------------\n\nFor although Aries may be seen during some part of the night in the\ngreater part of the year, it is most emphatically a noctural sign when\nit rises as the sun sets, and remains above the horizon until he rises;\nthis happens when the sun is in the opposite sign of Libra, which he\nenters at the autumnal equinox.\n\nA rather curious passage in the _Paradiso_ is incomprehensible unless\nwe think of the sun\u2019s path in the zodiac, and realize that Dante is\ncomparing the brightness of the spirit of St. John in an indirect way\nwith the brightness of the sun.\n\n \u201cPoscia tra esse un lume si schiar\u00ec,\n S\u00ec che, se il Cancro avesse un tal cristallo,\n L\u2019inverno avrebbe un mese d\u2019un sol d\u00ec.\u201d[237]\n\n------------------------------------------------------------------------\n[237]\n \u201cThereafterward a light among them brightened\n So, that if Cancer one such crystal had\n Winter would have a month of one sole day.\u201d\n _Par._ xxv. 100-102. (_Longfellow_).\n------------------------------------------------------------------------\n\nIf a light as dazzling as this spirit were to shine forth in Cancer,\nthere would be perpetual day for a whole month in winter. For when the\nsun entered Capricornus, which he does in December, he would be exactly\nopposite, so that as one light set the other would rise, and there\nwould be no darkness until the sun passed into another sign.\n\nTo many similar instances the diagram (p. 276) will be found to supply\na key, and some we shall have occasion to notice presently in another\nconnection.\n\n\n3. THE STARS.\n\nIf our poet did not love moonlight, there is no doubt that starlight\nwas very dear to him. Never are stars spoken of as cold, or placed in\nantithesis to the sun. Rather are they classed together, as in the\npathetic letter, written when he heard of the possibility that the\nFlorentines might receive him again if he would consent to return as a\ndisgraced but pardoned criminal. If this is the only path to Florence,\nnever will he re-enter the beloved city. \u201cWhat then?\u201d he cries. \u201cCan he\nnot see the mirrors of the sun and of the stars, wherever he may be?\ncan he not meditate on precious truths under any sky?\u201d[238]\n\n------------------------------------------------------------------------\n[238] _Ep._ ix. 46-49.\n------------------------------------------------------------------------\n\nHe describes the Inferno as bereft of stars as well as of sun;[239]\nhe hopes to escape those dark abysses to see the beautiful stars\nagain,[240] and the terror of the sounds of weeping and crying is\nheightened indescribably by the simple words:\u2014\u201crisonavan per l\u2019aer\nsenza stelle.\u201d[241] When he does at length come forth to see \u201cle cose\nbelle che porta il ciel\u201d[242] how eagerly he gazes, not only at Venus,\nbut at the new stars in the south! how his \u201cgreedy eyes\u201d[243] seek\nthe same region as soon as dusk begins to fall! and how radiantly the\nstars look down upon him on that last night on the rocky slopes of the\nMountain, near the summit![244]\n\n------------------------------------------------------------------------\n[239] _Inf._ iii. 23.\n\n[240] _Inf._ xvi. 82, 83.\n\n[241] \u201cResounded through the air without a star.\u201d _Inf._ iii. 23.\n\n[242] \u201cThe fair things that heaven holds.\u201d _Inf._ xxxiv. 137, 138.\n\n[243] _Purg._ viii. 85.\n\n[244] _Purg._ xxvii. 89, 90.\n------------------------------------------------------------------------\n\nThis is all allegorical, no doubt, but it is because of Dante\u2019s\nfeeling for the real \u201cbelle stelle\u201d[245] that he uses them as symbols\nof truth and holiness, and concludes each Cantica of the _Divine\nComedy_ with their name:\u2014\n\n------------------------------------------------------------------------\n[245] \u201cBeautiful stars,\u201d _Inf._ xvi. 83.\n\n \u201cE quindi uscimmo a riveder le stelle.\u201d[246]\n \u201cPuro e disposto a salire alle stelle.\u201d[247]\n \u201cL\u2019Amor che move il sole e l\u2019altre stelle.\u201d[248]\n\n[246] \u201cThence issuing we beheld again the stars.\u201d\n\n[247] \u201cPure and disposed to mount unto the stars.\u201d\n\n[248] \u201cThe Love that moves the sun and the other stars.\u201d\n------------------------------------------------------------------------\n\nHere \u201cstelle\u201d has the wider meaning of the French \u201castres,\u201d for which\nwe have no equivalent in English except the clumsy \u201cheavenly bodies;\u201d\nbut most of Dante\u2019s hundred references are to stars in the more special\nsense, and often to particular stars or constellations. Over eighty\noccur in the _Divine Comedy_.\n\nStars are jewels, torches, flames, immortal nymphs adorning every\nregion of the sky.[249] Heaven is made beautiful by their light, and\nthe joy of the angels is expressed in their shining, as mortal joy\nshines forth in human eyes.[250] If the spirits in the fourth heaven\nare described as glowing suns,[251] the \u201csplendours\u201d that descend upon\nthe golden ladder in the seventh, make Dante think that all the stars\nin the sky are gathered together there.[252]\n\n------------------------------------------------------------------------\n[249] _Purg._ ix. 4; _Purg._ viii. 89; _Purg._ i. 25; _Par._ xxiii. 26.\n\n[250] _Par._ ii. 130, 142-144.\n\n[251] _Par._ x. 76.\n\n[252] _Par._ xxi. 28-33.\n------------------------------------------------------------------------\n\nThe eyes of Beatrice shone brighter than stars;[253] light comes as\nfrom many stars in reading the sacred books;[254] faith gleams like a\nstar in the sky;[255] and truth appears in a mind cleared of falsehood\nand error like the radiance of stars in a sky which has been wholly\nswept of cloud and mist by a north wind.\n\n------------------------------------------------------------------------\n[253] _Inf._ ii. 55.\n\n[254] _Par._ xxv. 70. See also _Conv._ II. xvi. 4-12, where the\nwritings of Bo\u00ebthius and Cicero, and all instructive books, are called\nstars full of light.\n\n[255] _Par._ xxiv. 147.\n\n \u201cCome rimane splendido e sereno\n L\u2019emisperio dell\u2019 aer, quando soffia\n Borea da quella guancia ond\u2019 \u00e8 pi\u00f9 leno,\n Perch\u00e8 si purga e risolve la roffia\n Che pria turbava, s\u00ec che il ciel ne ride\n Con le bellezze d\u2019ogni sua paroffia:\n Cos\u00ec fec\u2019 io, poi che mi provvide\n La Donna mia del suo risponder chiaro,\n E come stella in cielo il ver si vide.\u201d[256]\n\n[256]\n \u201cEven as remaineth splendid and serene\n The hemisphere of air, when Boreas\n Is blowing from that cheek where he is mildest,\n Because is purified and resolved the wrack\n That erst disturbed it, till the welkin laughs\n With all the beauties of its pageantry:\n Thus did I likewise, after that my Lady\n Had me provided with her clear response,\n And like a star in heaven the truth was seen.\u201d\n _Par._ xxviii. 79-87. (_Longfellow_).\n------------------------------------------------------------------------\n\nStars, as well as the sun, are used as symbols for the objects of\nDante\u2019s deepest reverence; for the Blessed Virgin is called \u201cla viva\nstella,\u201d[257] and the Final Vision in which the redeemed find their\nultimate bliss is a Trinal Light seen as a single star:\u2014\n\n------------------------------------------------------------------------\n[257] \u201cThe shining star.\u201d _Par._ xxiii. 92.\n\n \u201cO trina Luce, che in unica stella\n Scintillando a lor vista s\u00ec gli appaga,\n Guarda quaggi\u00f9 alla nostra procella.\u201d[258]\n\n[258]\n \u201cO Trinal Light, that in a single star\n Sparkling upon their sight so satisfies them,\n Look down upon our tempest here below!\u201d\n _Par._ xxxi. 28-30. (_Longfellow_).\n------------------------------------------------------------------------\n\nThe diurnal motion of the stars is referred to many times. As Dante\nwatched the mystical procession in the Earthly Paradise, and saw one\ngroup follow in the footsteps of another across the flowers and the\ngrass, he thought of the stately procession of stars which we see here\nby night, star following star across the sky.[259] Their movement marks\nfor him the passage of time, as we see in the first sonnet of the _Vita\nNuova_:\u2014\n\n------------------------------------------------------------------------\n[259] _Purg._ xxix. 91.\n\n \u201cGi\u00e0 eran quasi ch\u2019 atterzate l\u2019 ore\n Del tempo che ogni stella \u00e8 piu lucente.\u201d[260]\n\n[260]\n \u201cOf those long hours wherein the stars above\n Wake and keep watch, the third was almost nought.\u201d\n _V. N._ iii. 81, 82. (_Rossetti_).\n------------------------------------------------------------------------\n\nand in the _Inferno_, where Virgil hastens Dante, saying that all\nthe stars are sinking which were rising when he started on his long\njourney.[261]\n\n------------------------------------------------------------------------\n[261] _Inf._ vii. 98, 99.\n------------------------------------------------------------------------\n\nThe motion of those stars which neither rise nor set, but are always\nseen circling round the pole, is clearly described. In the heaven\nof the sun, spirits gather round Dante and Beatrice, and circle\nround them, \u201cCome stelle vicine ai fermi poli;\u201d[262] and the motion\nof the stars near the pole is said to be slow, like the part of a\nwheel which is near the axle.[263] We may compare these descriptions\nwith the statement of Alfraganus:\u2014\u201cE\u00e6 stell\u00e6 (_i.e._ the northern\ncircumpolar) vertuntur omnes circa idem punctum. Et quei ex iis\npuncto huic est vicinior, minorem conficit circulum: motusque ejus\napp\u00e2ret lentior.\u201d[264] Dante assumes that his readers understand this\nmotion when he describes himself as seeing unknown stars near the\nSouth Pole. The Mount of Purgatory is supposed to be situated in the\nsouthern hemisphere, and at his first arrival, before dawn, he turns\nto the right, after looking at Venus in the east, therefore to the\nsouth, and sees near the pole four stars so brilliant that the whole\nsky seems to rejoice in their radiance, and he pities the \u201cwidowed\u201d\nnorthern hemisphere because they are invisible there.[265] In the\nevening, as soon as it begins to grow dark, although he is engaged\nin an interesting discourse with a friend with whom he had exchanged\nwarm greetings, he looks eagerly once more towards the pole (note the\nintensity expressed by the repeated \u201cpure\u201d)\u2014\n\n------------------------------------------------------------------------\n[262]\n\n \u201cLike unto stars neighbouring the stedfast poles.\u201d\n _Par._ x. 78.\n\n[263] _Purg._ viii, 86, 87.\n\n[264] \u201cThese stars all revolve round the same point, and the nearer a\nstar is to this point, the smaller is the circle that it makes, and the\nslower its motion appears.\u201d _El. Ast._ cap. ii.\n\n[265] _Purg._ i. 22-27.\n\n \u201cGli occhi miei ghiotti andavan pure al cielo,\n Pur l\u00e0 dove le stelle son pi\u00f9 tarde,\n S\u00ec come rota pi\u00f9 presso allo stelo.\u201d[266]\n\n[266]\n \u201cMy insatiate eyes\n Meanwhile to heaven had travelled, even there\n Where the bright stars are slowest, as a wheel\n Nearest the axle.\u201d\n _Purg._ viii. 85-87. (_Carey_).\n\nHe now sees three bright stars which make this pole glow with light,\nand Virgil says that the stars he saw in the morning are low, while\nthose now visible have risen higher to take their place.\n\n \u201cEd egli a me: Le quattro chiare stelle\n Che vedevi staman son di l\u00e0 basse,\n E queste son salite ov\u2019 eran quelle.\u201d[267]\n\n[267]\n \u201cAnd he to me: The four resplendent stars\n Thou sawest this morning are down yonder low,\n And these have mounted up to where those were.\u201d\n _Purg._ viii. 91-93. (_Longfellow_).\n------------------------------------------------------------------------\n\nThe diurnal movement of the starry heaven is also alluded to in the\n_Convivio_, and contrasted with that immensely slow movement which was\ndiscovered by Hipparchus, and is called by us Precession. The starry\nheaven, says Dante, displays one of its poles to us, and keeps the\nother hidden; and in like manner it displays only one movement to us,\nand keeps the other almost hidden. By the first, it revolves once in\nevery day from east to west; the other is nearly insensible, being only\none degree in a hundred years, and it is from west to east.[268] This\nis the value of precession as given by Alfraganus, following Ptolemy.\n\n------------------------------------------------------------------------\n[268] _Conv._ II. xv. 10-14, and 96-104.\n------------------------------------------------------------------------\n\nIt was this stupendous and mysterious cycle which was used by Dante\nto measure the age of Beatrice, though for his own he used (as we\nsaw) the ordinary measure of the sun\u2019s period. When he first saw \u201cla\ngloriosa donna\u201d[269] she had only been in this life so long that the\nstarry heaven had moved towards the east one-twelfth part of a degree.\nTherefore, she was one-twelfth of a hundred years old, or 8 years 4\nmonths, \u201cso that it was near the beginning of her ninth year that she\nappeared to me, and I saw her nearly at the end of my ninth.\u201d[270]\n\n------------------------------------------------------------------------\n[269] \u201cThe glorious Lady.\u201d\n\n[270] _V. N._ ii. 9-15.\n------------------------------------------------------------------------\n\nDante tells us how many stars had been counted by \u201cthe sages of Egypt,\u201d\nby whom he means Ptolemy and the other Alexandrians: he did not know\nthat the star catalogue of the _Almagest_ was originally made by\nHipparchus of Rhodes.\n\n \u201cDico ch\u2019 il cielo stellato ci mostra molto stelle;\n ch\u00e8, secondoch\u00e8 li savi d\u2019Egitto hanno veduto,\n infino all\u2019ultima stella che appare loro in\n meridie, mille ventidue corpora di stelle pongono,\n di cui io parlo.\u201d[271]\n\n------------------------------------------------------------------------\n[271]\n \u201cI say that the starry heaven displays a multitude\n of stars to us, for as the Sages of Egypt have\n perceived, including the last star which appears\n to them in the south, they reckon one thousand\n and twenty-two starry bodies, of which I am now\n speaking.\u201d\n _Conv._ II. xv. 18-22. (_Jackson_).\n------------------------------------------------------------------------\n\nIt will be noted that he carefully avoids saying that this is the\nnumber of all the stars visible from the whole earth. Had he, like\nRistoro, run away with the idea that a blank space on the globe meant\na blank in the sky, his night sky seen from Purgatory would have been\nstrangely bare and dull! Yet both writers used the same text-book.\nDante is here following Alfraganus closely, for he had written in his\nnineteenth chapter:\u2014\n\n \u201cSciendum itaque sapientes inivisse mensuram\n stellarum fixarum omnium, quoad instrumentis\n observari e\u00e6 potuerunt, extremam usque meridiei\n partem, in tertio climate ipsis conspicuam....\n Stell\u00e6 universae quarum agi mensura potuit sunt\n mille viginti du\u00e6.\u201d[272]\n\n------------------------------------------------------------------------\n[272] \u201cYou are to know that the Sages measured the places of all the\nfixed stars as accurately as possible with their instruments, as far\nsouth as they could see in the third climate.... The number of all the\nstars which he was able to measure is one thousand and twenty-two.\u201d\n------------------------------------------------------------------------\n\nBoth in the _Qu\u00e6stio_ and the _Paradiso_ Dante notes how stars differ,\nnot only in their brightness or \u201cmagnitude,\u201d but also in the quality of\ntheir light, by which he probably means their colour:\u2014\n\n \u201cVidemus in eo [_sc._ c\u0153lum stellatum] differentiam\n in magnitudine stellarum et in luce.\u201d[273]\n\n------------------------------------------------------------------------\n[273] \u201cWe see in it (the starry heaven) a difference in the magnitude\nof the stars and in their light.\u201d _Qu._ xxi. 19-21.\n\n \u201cLumi, li quali nel quale e nel quanto\n Notar si posson di diversi volti.\u201d[274]\n\n[274]\n \u201cLights many the eighth sphere displays to you\n Which in their quality and quantity\n May noted be of aspects different.\u201d\n _Par._ ii. 65-66. (_Longfellow_).\n------------------------------------------------------------------------\n\nIt seems as if it were the beauty and the movement of the starry sky\nas a whole which appealed to Dante, rather than the distinguishing of\nspecial stars and constellations. Those which he mentions are almost\nall either in the zodiac, and used to denote the hour, the season, or\nthe position of one of the seven planets; or else they are near one of\nthe poles and illustrate the circumpolar motion.\n\nAll the zodiacal constellations are mentioned except Virgo and\nSagittarius. Besides the ordinary names of \u201cAriete,\u201d \u201cLibra,\u201d etc.,\nAries is called \u201cil Montone;\u201d[275] Gemini \u201cil segno che segue il\nTauro,\u201d \u201cgli eterni Gemelli,\u201d and \u201cil bel nido di Leda,\u201d[276] in\nreference to the mother of Castor and Pollux, its two brightest\nstars; Libra is \u201cle Bilance\u201d;[277] Scorpio \u201cil freddo animale\u201d;[278]\nCapricornus is \u201cil Capra del ciel\u201d;[279] and Pisces \u201cla celeste\nLasca.\u201d[280]\n\n------------------------------------------------------------------------\n[275] \u201cThe Ram.\u201d _Purg._ viii. 134; _Par._ xxix. 2.\n\n[276] \u201cThe sign which follows Taurus,\u201d _Par._ xxii. 110, 111; \u201cThe\neternal Twins,\u201d xxii. 152; \u201cThe fair nest of Leda,\u201d xxvii. 98.\n\n[277] \u201cThe Balance.\u201d _Purg._ ii. 5.\n\n[278] \u201cThe cold creature.\u201d _Purg._ ix. 5.\n\n[279] \u201cThe Goat of the sky.\u201d _Par._ xxvii. 69.\n\n[280] \u201cThe celestial Carp.\u201d _Purg._ xxxii. 54.\n------------------------------------------------------------------------\n\nIn one place Castor and Pollux are mentioned, but merely as a synonym\nfor the whole constellation of Gemini.[281] \u201cIl petto del Leone\nardente\u201d[282] is perhaps Cor Leonis, the Heart of the Lion, for this is\nthe name given to Regulus by both Ptolemy and Alfraganus. The \u201cMaggior\nFortuna\u201d[283] of _Purg._ xix. 4, is a group of stars belonging to the\ntwo constellations of Aquarius and Pisces, in which the geomancers, who\ntold fortunes by means of certain points traced at random, thought they\nsaw a special series of these points,-:::..\n\n------------------------------------------------------------------------\n[281] _Purg._ iv. 61.\n\n[282] \u201cThe burning Lion\u2019s breast.\u201d _Par._ xxi. 14.\n\n[283] \u201cGreater Fortune.\u201d\n------------------------------------------------------------------------\n\nIt is generally agreed that the \u201cgemme\u201d of _Purg._ ix. 4, \u201cposte in\nfigura del freddo animale, Che con la coda percote la gente,\u201d[284] are\nsome stars of Scorpio which were shining on the eastern horizon just\nbefore the moon rose on the first night in the Island of Purgatory.\n\n------------------------------------------------------------------------\n[284]\n \u201cGems ... set in the shape of that cold animal\n Which with its tail doth smite amain the nations.\u201d\n (_Longfellow_).\n------------------------------------------------------------------------\n\nThe zodiacal constellations in general are spoken of as \u201call the\nlights of his [the sun\u2019s] path:\u201d \u201cTutti i lumi della sua strada.\u201d\n(_Par._ xxvi. 121, 122).\n\nThe pole star is described as the point of the axle round which the\nfirst sphere revolves.[285] The first sphere (or wheel, as it is\ncalled, with reference to its circling motion) is here the Primum\nMobile, which was thought to cause the diurnal motion. This unique\nposition gains for the pole star the name of \u201cthe star,\u201d as for\ninstance in _Conv._ III. v. 84, 85, where Dante says that a man\nstanding at the north pole would have \u201cla stella\u201d directly over his\nhead. And in Paradise he hears a voice among the spirits which makes\nhim turn in its direction as the needle turns to the star\u2014\n\n------------------------------------------------------------------------\n[285] _Par._ xiii. 11, 12.\n\n \u201cVoce, che l\u2019ago alla stella\n Parer mi fece in volgermi al suo dove.\u201d[286]\n\n[286]\n \u201cA voice,\n That made me seem like needle to the star,\n In turning to its whereabout.\u201d\n _Par._ xii. 29, 30. (_Carey_).\n------------------------------------------------------------------------\n\nThis property of the magnet was known in Dante\u2019s day, as well as its\npower of attracting iron, though only the latter had been known to\nPtolemy and the classical world. Whether the discovery came from China,\nwhere it is said that some form of compass has been used since the\nsecond century A.D., or whether it had been discovered independently\nby Arab or Italian navigators, we do not know: but scholars and poets\nin the twelfth and early thirteenth centuries write of the \u201cugly brown\nstone\u201d used by sailors to make an instrument that cannot lie. For a\nneedle, rubbed by it and run through a straw, when floated on water\nturns so surely to \u201cthe star\u201d that one need never doubt its guidance.\nThus writes Guyot, the poet of Languedoc, about 1200:\u2014\n\n \u201cUn art font qui mentir ne puet,\n Par la vertu de la manete,\n Une pierre laide et brunete,\n Ou le fers volentiers se joint,\n Ont: si esgardent le droit point,\n Puis c\u2019une aiguile i ont touchie,\n Et en un festu l\u2019ont couchie,\n En l\u2019eve la metent sanz plus,\n\n * * * * *\n\n Puis se torne la pointe toute\n Contre l\u2019estoile si sanz doute,\n Que ja nas hom n\u2019en doutera.\u201d\n\nAnd thus Ristoro:\u2014\n\n \u201cL\u2019angola, che guidi li marinari, ch\u00e8 per la virtu\n del cielo \u00e8 tratta e rivolta alla stella la quale \u00e8\n chiamata tramontana.\u201d[287]\n\n------------------------------------------------------------------------\n[287] \u201cThe needle which guides mariners, for by the virtue of the\nheavens it is attracted and turned towards that star which is called\nthe North Star.\u201d _Composizione del Mondo_, Bk. VII. part iv. ch. 2.\n------------------------------------------------------------------------\n\nAlbertus Magnus speaks of it in the same way, as something well known\nto mariners.\n\nIt seems strange to us how Dante and his contemporaries failed to see\nthe importance of this discovery; Brunetto Latini, when the ugly stone\nwas shown to him on his visit to Roger Bacon at Oxford, even professing\nto regard it as a mere toy, of no practical use. Dante discusses the\nnumber of the stars known to Ptolemy, and describes the last mad voyage\nof Ulysses, who saw all the stars of the other pole, while ours sank\nlow on the ocean floor;[288] but he does not seem to guess that the new\ntoy would make possible even longer voyages than these, and that in\ntime the blank in his celestial globe would be filled.\n\n------------------------------------------------------------------------\n[288] _Inf._ xxvi. 127-129.\n------------------------------------------------------------------------\n\nYet even in his own life-time plucky little Genoa fitted out two\ngalleys which ventured through the forbidden Straits, with intent to\ncircumnavigate Africa and find a new route to India. And meanwhile,\ntravelling by old overland or coasting routes, Italian missionary\nmonks, and Italian traders, were visiting southern countries and\ndescribing southern skies. Friar Giovanni de Monte Corvino, who was\nin South India with Nicolo of Pistoia, writes home in 1291, telling\nof his disappointment that he had never been able to see \u201cthe other\npole star\u201d (l\u2019altra tramontana), though he saw new stars moving round\nand evidently near to it, close to the southern horizon. A few years\nlater Marco Polo the Venetian was dictating the story of his travels to\na Pisan in Genoa: he had been further south than the missionaries, for\nin a certain island (probably Sumatra) he had seen the south pole \u201ca\nspear\u2019s length\u201d above the horizon; and in the land of Zinzi (Zanzibar?)\nhe had seen a marvellous star as big as a sack (which was evidently the\nGreater Magellanic Cloud). This he drew a picture of with his own hand.\n\nDante\u2019s silence, and probable incredulity, regarding these experiences\nof his own countrymen and contemporaries is characteristic of his\nage; for scholars were too eager to explore the precious classical\nlore lately recovered from oblivion, to realize that they were on the\nthreshold of a new era in knowledge, of which these men were pioneers.\n\nIt is sometimes thought, however, that Dante made use of contemporary\nobservations of southern skies in his description of the stars he\nfeigned himself to have seen when the Wain disappeared under his\nnorthern horizon.[289] Quite correctly, he does not place any single\nbright star to mark the south pole; his two constellations, one of four\nbright stars seen above the pole in the morning,[290] one of three\nwhich takes its place after sunset,[291] are these real or fictitious?\n\n------------------------------------------------------------------------\n[289] _Purg._ i. 30.\n\n[290] _Purg._ i. 26.\n\n[291] _Purg._ viii. 89.\n------------------------------------------------------------------------\n\nIt is a fact that there are four bright stars in the form of a cross,\nlying between 56\u00b0 and 63\u00b0 south: are these Dante\u2019s \u201cquattro chiare\nstelle,\u201d \u201cquattro luci sante?\u201d[292] They were not recognized as a\nseparate constellation until the beginning of the sixteenth century,\nwhen Amerigo Vespucci described them in his letters about his southern\nvoyages, and the Florentine Andrea Corsali wrote about the marvellous\nCross which was so beautiful that in his opinion no other constellation\nin the sky was worthy to be compared with it. This, he believed, was\nthe very cross of which Dante had spoken in a prophecy.\n\n------------------------------------------------------------------------\n[292] \u201cFour bright stars, four sacred lights.\u201d\n------------------------------------------------------------------------\n\nEven among Dante\u2019s most enthusiastic admirers, I suppose none will be\nfound to-day to support this view; but many think that he must have\nheard of the Cross from travellers. True, these stars are visible\nduring at least part of the year in all places south of 34\u00b0 north, and\ntherefore in North Africa, and they had been catalogued by Ptolemy as\npart of the Centaur, so that no astronomer could take them to be a\nnewly-found constellation, but might not some unscientific traveller\nlike Marco Polo have brought a vague report of their position?\n\n[Illustration: MAP OF STARS VISIBLE BEFORE DAWN IN PURGATORY. _To face\np. 295_]\n\nTo this we might reply that Dante never says his four stars were in\nthe form of a Cross; that there had to be four to represent the four\nPagan virtues, the other constellation of three representing the three\nChristian virtues (compare the group of four handmaidens who sing, \u201cNoi\nsiam qui ninfe, e nel ciel siamo stelle,\u201d[293] and are followed by a\ngroup of three);[294] and that this other constellation was certainly\nimaginary, since there is no group of three bright stars anywhere near\nthe south pole.\n\n------------------------------------------------------------------------\n[293]\n \u201cWe are nymphs here, and in heaven we are stars.\u201d\n _Purg._ xxxi. 104-106.\n\n[294] _Purg._ xxxi. 111.\n------------------------------------------------------------------------\n\nBut the fact is that conjectures and arguments are unnecessary, since\nDante has expressly said that his four stars had never been seen before\nby anyone except the first people\u2014\u201cnon viste mai fuor che alla prima\ngente,\u201d (_Purg._ i. 24)\u2014that is, our first parents, in that Eden of his\nimagining which was in the southern hemisphere, and on the island where\nhe was then standing in his vision.\n\nAs a matter of curiosity I have included a map showing what stars\nwould have been really visible to Dante at the supposed latitude of\nPurgatory, when Pisces was on the eastern horizon, as described in\n_Purg._ i. It will be seen that the Southern Cross is low, and would\nhave been hidden behind the Mountain of Purgatory at five o\u2019clock in\nthe morning.[295]\n\n------------------------------------------------------------------------\n[295] Antonelli thinks the four stars were \u03b1 and \u03b2 Crucis, \u03b1 and \u03b2\nCentauri, all of which had been mentioned by Ptolemy, and all lie\nnear the circle which marks the limit of circumpolar stars in the\nsupposed latitude of Purgatory (32\u00b0 south). The three stars he says\nwere \u03b6 Navis, Canopus, and Achernar:\u2014Antonelli, _Accenni alle Dottrine\nAstronomiche nella Divina Commedia_.\n------------------------------------------------------------------------\n\nAmong northern constellations, Ursa Major is frequently spoken of by\nDante, under different names, but always with reference to its high\nnorthern latitude. As the Wain, \u201cil Carro,\u201d it is said to be lying\nin the north-west when Pisces is on the eastern horizon, and to have\ndisappeared from view in the southern hemisphere.[296] The wain-pole\nor shaft is pictured as sweeping round in the diurnal revolution,\nbut always remaining above our horizon day and night, throughout its\nturning:\n\n------------------------------------------------------------------------\n[296] _Inf._ xi. 113, 114; _Purg._ i. 30.\n\n \u201cQuel Carro, a cui il seno\n Basta del nostro cielo e notte e giorno,\n S\u00ec ch\u2019 al volger del temo non vien meno.\u201d[297]\n\n[297]\n \u201cThe Wain, that in the bosom of our sky\n Spins ever on its axle, night and day.\u201d\n _Par._ xiii. 7-9. (_Carey_).\n------------------------------------------------------------------------\n\nThe same idea is expressed in the Midwinter Ode, where the\nconstellation is called the Seven Frosty Stars, never lost to sight in\nEurope:\u2014\n\n \u201cFuggito \u00e8 ogni augel che \u2019l caldo segue\n Dal paese d\u2019Europa, che non perde\n Le sette stelle gelide unquemai.\u201d[298]\n\n------------------------------------------------------------------------\n[298]\n \u201cFled is every bird that seeks the warmth,\n From European lands which never lose\n The seven cold stars.\u201d\n _Canz._ xv. 27-29.\n------------------------------------------------------------------------\n\nThis is a reminiscence of some lines of Bo\u00ebthius quoted by Dante in\n_De Monarchia_, in which the northern nations are described as under\nthe sway of the \u201cseptem gelidi triones.\u201d[299] The Septem Triones, the\nSeven Ploughing Oxen, was one of the Latin names for Ursa Major, whence\ncomes \u201cseptentrional\u201d for North. This name also is used by Dante in\n_Purg._ xxx. 1, where the Seven Candlesticks of the mystic procession\nseen in the Garden of Eden are likened to these seven stars, and are\nnamed the Septentrion of the First Heaven (the Empyrean). This divine\nSeptentrion was guiding the Procession, as the starry Septentrion of a\nlower heaven guides the mariner into port:\n\n------------------------------------------------------------------------\n[299]\n \u201cSeven cold oxen.\u201d\n _De Mon._ II. ix. 96.\n\n \u201cfaceva l\u00ec ciascuno accorto\n Di suo dover, come il pi\u00f9 basso face\n Qual timon gira per venire a porto.\u201d[300]\n\n[300]\n \u201cTo duty there\n Each one convoying, as that lower doth\n The steersman to his port.\u201d\n _Purg._ xxx. 4-6. (_Carey_).\n------------------------------------------------------------------------\n\nLike the seven stars, also, the heavenly Septentrion is said\nfiguratively to know neither setting nor rising, but unlike them it\nknows no cloud except of sin.[301] Because it is spoken of as guiding\nmariners, some commentators have taken the above to refer rather to\nSeptentrio Minor (Ursa Minor), which also has seven chief stars, and\nis a better guide because nearer the Pole, as Thales taught; but the\ncomparatively faint stars of the Little Bear would not be so apt a\ncomparison with the celestial lights.\n\n------------------------------------------------------------------------\n[301] _Purg._ xxx. 1-3.\n------------------------------------------------------------------------\n\nBy the name of the Bears, both Ursa Major and Minor are referred to as\nguides at sea in _Par._ ii. 9. In the strange new seas on which Dante\nwarns his readers he is about to enter, Minerva will blow a favouring\nwind, Apollo will steer the barque, and the nine Muses will guide his\ncourse by the Bears. They are also spoken of together in _Purg._ iv.\n65, to indicate the northern part of the sky.\n\nA fifth name for Ursa Major is derived from the fable (known to Dante\nprobably from Ovid\u2019s _Metamorphoses_) of the nymph Helice, who was\nturned into a she-bear by Juno, and was hunted by her own son, Orcas.\nJupiter transformed them into Ursa Major and Bo\u00f6tes.\n\n \u201cSe i barbari, venendo di tal plaga\n Che ciascun giorno d\u2019Elice si copra,\n Rotante col suo figlio ond\u2019 ell\u2019 \u00e8 vaga,\n Vedendo Rome e l\u2019 ardua sua opra,\n Stupefaciensi....\u201d[302]\n\n------------------------------------------------------------------------\n[302]\n \u201cIf the barbarians coming from some region\n That every day by Helice is covered,\n Revolving with her son whom she delights in,\n Beholding Rome and all her noble works\n Were wonder-struck....\u201d\n _Par._ xxxi. 31-35. (_Longfellow_).\n------------------------------------------------------------------------\n\nHere we have the same idea as of the Wain wheeling round but never\nsetting, with the addition of a neighbouring constellation describing a\ncircle in the same time.\n\nThe Barbarians who lived in a region always dominated by Ursa Major,\nand came to marvel at the mighty buildings of ancient Rome, are\nprobably the races of northern Europe in general; and this reminds\nus again of the lines of Bo\u00ebthius quoted above, for it is among the\npeoples ruled by Rome that he mentions \u201cquos premunt septem gelidi\ntriones.\u201d[303] If, however, Dante meant a country where the seven stars\npass exactly overhead, the barbarians must have inhabited Scotland, or\nsouthern Scandinavia, or central Russia. If he means that Bo\u00f6tes also\nremained always above the horizon, they must have come from within the\nArctic Circle, but this is not likely.\n\n------------------------------------------------------------------------\n[303] \u201cThose under the sway of the seven cold oxen.\u201d\n------------------------------------------------------------------------\n\n[Illustration: Fig. 42. Ursa Minor as a Horn. _Par._ xiii. 10.]\n\nIn one of the passages just quoted other constellations and stars are\nmentioned together with Ursa Major. In _Par._ xii. Dante has compared\nthe two circles of spirits which surround Beatrice and himself to a\ndouble rainbow, and to two garlands of immortal roses. In the next\ncanto he finds a new simile: in imagination he takes some of the\nbrightest and most familiar stars from our sky, and makes of them two\nnew constellations in the form of two crowns. The stars are these:\nfifteen from different parts of the sky, which are so brilliant that\nthey shine through air dense enough to quench lesser orbs; the Wain,\nwhich never sets in our sky; and the mouth of the horn whose tip is\nthe axis on which the Primum Mobile revolves. That is to say, as we\nhave before remarked, Dante takes the fifteen first-magnitude stars and\nthe stars instanced by Alfraganus as of second magnitude. Ursa Minor\nis aptly compared to a horn, the wide mouth of which is formed by its\ntwo bright stars Beta and Gamma,[304] while the narrow end is Alpha,\nthe Pole Star. These twenty-four bright stars we must then imagine to\ngroup themselves into two constellations like that into which Ariadne,\nthe daughter of Minos, was changed when she died; this is Corona\nBorealis or the Northern Crown, otherwise called Ariadne\u2019s Crown,\nwhich suggests a circle, though it is not a perfect one. Dante uses the\nword \u201csegni\u201d for any constellations, a custom we find in Ristoro also,\nalthough the modern usage is to restrict \u201csigns\u201d to mean only divisions\nof the zodiac.\n\n------------------------------------------------------------------------\n[304] I do not know whether this comparison originated with Dante, but\nit was well known to Spanish sailors two centuries later. In the _Arte\nof Navigation_ which was \u201cEnglished out of the Spanyshe,\u201d by Richard\nEden in 1561, Beta and Gamma of Ursa Minor are referred to as \u201ctwo\nstarres called the Guardians, or the mouth of the horne.\u201d\n------------------------------------------------------------------------\n\nThe star-like spirits, thus grouped into a surpassingly brilliant\ndouble constellation, begin to sing their ineffable heavenly song, and\nto circle round the centre where Dante stands, in a marvellous dance,\nwhose swiftness, when compared with anything known on earth, is as the\nmovement of that swift heaven which carries with it all the rest, when\ncompared with the flowing of the sluggish river Chiana.[305]\n\n------------------------------------------------------------------------\n[305] _Par._ xiii. 1-28.\n------------------------------------------------------------------------\n\nThis passage helps us to understand expressions which often strike\none as very strange, describing the circling movements of the spirits\nin Paradise. For the likeness to stars is clear throughout. Their\nbrightness is an expression of their happiness,[306] and increases in\neach succeeding heaven. Only in the lowest can Dante see the forms and\nfeatures of Piccarda and the other blessed spirits; in the next they\nclothe themselves in light, and although at first the radiant eyes of\nJustinian are seen, the first words addressed to him cause him to shine\nmore brilliantly than before, and as the sun conceals himself by his\nown light, so the spirit conceals himself by the splendour which grows\nwith his joy.[307] In the third heaven the spirits shine in the star\nof Venus like sparks seen in flame;[308] in the fourth they are called\nsuns, and surpass the sun in brilliancy;[309] in the fifth they are\ncompared with the Galaxy[310] and with shooting stars,[311] in the\nseventh and eighth with stars[312] and with spheres of light, turning\non fixed poles and flaming like comets.[313]\n\n------------------------------------------------------------------------\n[306] _Par._ viii. 52, 53.\n\n[307] _Par._ v. 136, 137.\n\n[308] _Par._ viii. 16.\n\n[309] _Par._ x. 76, 40-42.\n\n[310] _Par._ xiv. 97-101.\n\n[311] _Par._ xv. 13, 14.\n\n[312] _Par._ xxi. 32, 33; xxiii. 26, 27.\n\n[313] _Par._ xxii 23; xxiv. 11, 12.\n------------------------------------------------------------------------\n\nIn like manner the swiftness of their motion increases in proportion\nto the clearness with which each beholds eternal truth.[314] The\nalmost incredible speed with which Dante himself soars from sphere to\nsphere, and with which the spirits move\u2014whether in coming towards him,\nimpelled by Divine charity, in returning to the heaven of heavens,\nor in circling with one another in mystic dance\u2014is frequently dwelt\nupon, and illustrated by many striking similes. The dance is always a\ncircling or wheeling movement (\u201cil giro,\u201d \u201cla rota,\u201d _Par._ viii. 20\nand 26; ix. 65). And besides this, individual spirits turn with a rapid\nmotion, remaining on the same spot. Descending the celestial Ladder in\nthe heaven of Saturn, step by step, they revolve:\u2014\n\n------------------------------------------------------------------------\n[314] _Par._ viii. 20, 21; and xxviii. 100-102.\n\n \u201cVid\u2019 io pi\u00f9 fiamelle\n Di grado in grado scendere e girarsi,\n Ed ogni giro le facea pi\u00f9 belle.\u201d[315]\n\n[315]\n \u201cSaw I many little flames\n From step to step descending and revolving,\n And every revolution made them fairer.\u201d\n _Par._ xxi. 136-138. (_Longfellow_).\n\nCompare 80, 81 and 39; and _Par._ xxiv. 10, 11.\n------------------------------------------------------------------------\n\nNow these two things, their light and their movements, were all the\nfacts concerning the stars which medi\u00e6val astronomers could observe;\nand the movements were thought to be in circles and inconceivably\nrapid. Motion in circles, and especially the movement of rotation\non an axis, remaining in the same place, had been said by Aristotle\nto be the most noble form of motion, and the fittest for celestial\nbodies. Therefore, when Dante represents the redeemed and the angels\nas expressing their bliss by radiance and marvellously rapid motion\nin circles, he makes them resemble the heavenly spheres and stars\namong which they manifest themselves to him. The motions are directly\ncompared with those of stars in the passage already quoted:\u2014\n\n \u201cPoi, s\u00ec cantando, quegli ardenti soli\n Si fur girati intorno a noi tre volte,\n Come stelle vicine ai fermi poli.\u201d[316]\n\n------------------------------------------------------------------------\n[316]\n \u201cAs soon as singing thus those burning Suns\n Had round about us whirled themselves three times,\n Like unto stars neighbouring the steadfast poles.\u201d\n _Par._ x. 76-78. (_Longfellow_).\n------------------------------------------------------------------------\n\nRemembering this significance of circular motion we shall feel a little\nless strange the similes of a mill and a top applied to the spirits of\nParadise.[317]\n\nA third way in which the spirits express their joy is by the sweetness\nof their song,[318] and here also they resemble the heavenly bodies,\nwhich make sweet music as they circle. This doctrine of Pythagoras was\nvery popular throughout the Middle Ages.\n\n------------------------------------------------------------------------\n[317] _Par._ xxi. 80, 81; xii. 3; xviii. 41, 42.\n\n[318] _Par._ xxiv. 22-24, x. 73, and many others.\n------------------------------------------------------------------------\n\n\n4. THE GALAXY.\n\nThe Galaxy or Milky Way is twice referred to in the _Divine Comedy_. In\n_Inf._ xvii. 106-108, it is in connection with the myth of Phaeton, who\nbeing allowed by his father Jove to drive the chariot of the sun for\none day, lost control of his chargers, and going all astray, burned the\nsky in a part which still shows signs of this catastrophe, _i.e._ the\nMilky Way.\n\n \u201cQuando Fet\u00f2n abbandon\u00f2 li freni,\n Per che il ciel, come pare ancor, si cosse.\u201d[319]\n\n------------------------------------------------------------------------\n[319]\n \u201cWhat time abandoned Pha\u00ebton the reins,\n Whereby the heavens, as still appears, were scorched.\u201d\n _Inf._ xvii. 107-108. (_Longfellow_).\n------------------------------------------------------------------------\n\nThis of course is only a poetical myth. But in the _Paradiso_, in three\nlines the appearance, colour, and approximate position of the Galaxy\nare described, and allusion is made to the difference of opinions\nbetween learned men with regard to the puzzling question of its\nnature. Dante is in the heaven of Mars. He sees the soldier saints,\nstar-like and fiery red, some larger and some less, thronging thick\nin two great bands, which, crossing one another in the depths of the\nplanet, form a marvellous Crucifix. The crowded lights make him think\nof the Galaxy, with its multitudinous points of light, differing in\nbrightness, although that is white, and lies in a great circle between\nthe celestial poles.\n\n \u201cCome, distinta da minori e maggi\n Lumi, biancheggia tra i poli del mondo\n Galassia s\u00ec che fa dubbiar ben saggi,\n S\u00ec costellati facean nel profondo\n Marte quei rai il venerabil segno\n Che fan giunture di quadranti in tondo.\u201d[320]\n\n------------------------------------------------------------------------\n[320]\n \u201cEven as, distinct with less and greater lights,\n Glimmers between the two poles of the world\n The Galaxy that maketh wise men doubt,\n Thus constellated in the depths of Mars\n Those rays described the venerable sign\n That quadrants joining in a circle make.\u201d\n _Par._ xiv. 97-102. (_Longfellow_).\n------------------------------------------------------------------------\n\nIf we now turn to the fifteenth chapter of Treatise II. of the\n_Convivio_, we shall find the Phaeton myth and the various theories\nabout the Milky Way set forth in due order, and shall learn which of\nthese Dante considered to be true.\n\nHe is comparing the two sciences of Metaphysics and Physics with the\nHeaven of the Fixed Stars, and takes the opportunity to tell us some\nof the most important facts known about it. Here he calls the Galaxy\na circle:\u2014\u201cLa Galassia, cio\u00e8 quello bianco cerchio che il vulgo\nchiama la Via de Santo Jacopo.\u201d[321] This popular name perhaps arose\nthrough a confusion of Galaxy and Galicia, where was a famous shrine\nof St. James, and hence came the belief in Italy that the _Galassia_\nwas a sign by night to guide pilgrims on their way to this shrine at\nCompostella in _Galizia_.\n\n------------------------------------------------------------------------\n[321] \u201cThe Galaxy, that is, the white circle commonly called St.\nJames\u2019s Way.\u201d\n------------------------------------------------------------------------\n\nDante proceeds as follows with his comparison:\u2014\n\n \u201cE per la Galassia, ha questo cielo grande\n similitudine colla Metafisica. Perch\u00e8 \u00e8 da sapere\n che di quella Galassia li filosofi hanno avuto\n diverse opinioni. Ch\u00e8 li Pittagorici dissero che \u2019l\n sole alcuna fiata err\u00f2 nella sua via, e, passando\n per altre parti non convenienti al suo fervore,\n arse il luogo, per lo quale pass\u00f2; e rimasevi\n quell\u2019 apparenza dell\u2019 arsura. E credo che\n si mossero dalla favola di Fetonte, la quale\n narra Ovidio nel principio del secondo di\n _Metamorfoseos_. Altri dissero (siccome fu\n Anassagora e Democrito) che ci\u00f2 era lume del sole\n ripercosso in quella parte. E queste opinioni\n con ragioni dimostrative riprovarono. Quello che\n Aristotile si dicesse di ci\u00f2, non si pu\u00f2 bene\n sapere, perch\u00e8 la sua sentenza non si trova cotale\n nell\u2019 una traslazione come nell\u2019 altra. E credo\n che fosse l\u2019errore de\u2019 traslatori; che nella\n Nuova par dicere che ci\u00f2 sia uno raunamento di\n vapori sotto le stelle di quelle parte, che sempre\n traggono quelli; e questa non pare avere ragione\n vera. Nella Vecchia dice, che la Galassia non \u00e8\n altro che multitudine di stelle fisse in quella\n parte, tanto picciole che distinguere di quaggi\u00f9\n non le potemo, ma di loro apparisce quello albore\n il quale noi chiamiamo Galassia. [E puote essere\n che il cielo in quella parte \u00e8 pi\u00f9 spesso, e\n per\u00f2 ritiene e ripresenta quello lume] e questa\n opinione pare avere, con Aristotile, Avicenna e\n Tolommeo. Onde conciossiacosach\u00e8 la Galassia sia\n uno effetto di quelle stelle le quali non potemo\n vedere, se non per lo effetto loro intendiamo\n quelle cose, e la Metafisica tratta delle prime\n sustanze, le quali noi non potemo simigliantemente\n intendere se non per li loro effetti; manifesto \u00e8\n che \u2019l cielo stellato ha grande similitudine colla\n Metafisica.\u201d[322]\n\n------------------------------------------------------------------------\n[322]\n \u201cAnd in the Galaxy this heaven has a close\n resemblance to Metaphysics. Wherefore it must be\n known that the Philosophers have had different\n opinions about this Galaxy. For the Pythagoreans\n affirmed that the sun at one time wandered in its\n course, and in passing through other regions not\n suited to sustain its heat, set on fire the place\n through which it passed; and so these traces of the\n conflagration remain there. And I believe that they\n were influenced by the fable of Pha\u00ebton, which Ovid\n tells at the beginning of the second book of the\n _Metamorphoses_. Others (as for instance Anaxagoras\n and Democritus) said that the Galaxy was the light\n of the sun reflected in that region. And these\n opinions they confirmed by demonstrative reasons.\n What Aristotle may have said about it cannot be\n accurately known, because the two translations give\n different accounts of his opinion. And I think that\n any mistake may have been due to the translators,\n for in the _New Translation_ he is made to say\n that the Galaxy is a congregation, under the stars\n of this part of the heaven, of the vapours which\n are always being attracted by them; and this\n opinion does not appear to be right. In the _Old\n Translation_ he says that the Galaxy is nothing but\n a multitude of fixed stars in that region, stars\n so small that they are not separately visible from\n our earth, but the appearance of whiteness which\n we call the Galaxy is due to them. [And it may be\n that the heaven in that part is more dense, and\n therefore retains and reproduces that light] and\n this opinion Avicenna and Ptolemy appear to share\n with Aristotle. Therefore, since the Galaxy is an\n effect of those stars which cannot be perceived\n except so far as we apprehend these things by\n their effect, and since Metaphysics treats of\n primal substances which in the same way we cannot\n apprehend except by their effects, it is plain that\n there is a close resemblance between the starry\n heaven and Metaphysics.\u201d\n _Conv._ II. xv. 44-86. (_Jackson_).\n------------------------------------------------------------------------\n\nThis characteristic passage is interesting for several reasons. It\nillustrates the medi\u00e6val fondness for allegory, the reluctance to\nbelieve that Aristotle could ever be wrong, and the interest in ancient\nGreek speculations, in all of which Dante expresses the feelings of his\nage: and it brings vividly before us the methods and the difficulties\nof medi\u00e6val authors. For Dante is repeating from Albertus Magnus\nall these ancient speculations: the officious copyist who altered\nAristotle\u2019s words, the fact that Aristotle could only be read in\nLatin, and the variety of translations, were all everyday obstacles\nto study; and Dante\u2019s own book has suffered from one of them in this\nvery passage. The words placed between brackets are evidently an\ninterpolation (as Mr. Wicksteed observes in the \u201cTemple\u201d _Convivio_):\nwithout them the passage goes on smoothly and logically to its end.\nOn the assumption that the Galaxy is composed of a multitude of small\nstars, but not that the sky is denser in that part, the parallel with\nMetaphysics holds good.\n\nDante therefore held the true opinion about the Milky Way, but he was\nmistaken in thinking that he had the support of Aristotle. It was the\n\u201cNew Translation\u201d (made by Aquinas from the Greek) which gave his\nopinion correctly; in the \u201cOld\u201d (made by Michael Scot from the Arabic)\nhis statement had been apparently changed without comment into one\nwhich seems to Dante\u2014and also to us\u2014to represent the truth about the\nGalaxy.\n\n\n5. THE PLANETS.\n\nAll the planets which were known before the days of the telescope are\nmentioned by Dante several times. Each has its peculiar beauty, but \u201cla\nlucentissima stella di Venere\u201d[323] is brighter and more beautiful than\nany other. He speaks of \u201cla chiarezza del suo aspetto, ch \u2019\u00e8 soavissima\na vedere pi\u00f9 che altra stella.\u201d[324]\n\n------------------------------------------------------------------------\n[323] \u201cThat most brilliant star, Venus.\u201d _Conv._ II. iv. 88.\n\n[324] \u201cThe brightness of her appearance, which is more lovely to behold\nthan that of any other star.\u201d _Conv._ II. xiv. 112, 113.\n------------------------------------------------------------------------\n\nNo reader of the _Purgatorio_ can ever forget that matchless morning on\nwhich Dante, escaping at last from the murky gloom of the _Inferno_,\nsees the sky once more, pure blue even to its furthest limits, and the\nplanet of love shining in the east.\n\n \u201cDolce color d\u2019oriental zaffiro,\n Che s\u2019accoglieva nel sereno aspetto\n Dell\u2019 aer, puro infino al primo giro,\n Agli occhi miei ricominci\u00f2 diletto,\n Tosto ch\u2019 i\u2019 uscii fuor dell\u2019 aura morta,\n Che m\u2019avea contristati gli occhi e il petto,\n Lo bel pianeta che ad amar conforta\n Faceva rider tutto l\u2019oriente,\n Velando i Pesci ch\u2019erano in sua scorta.\u201d[325]\n\n\n------------------------------------------------------------------------\n[325]\n \u201cSweet colour of oriental sapphire,\n Which was gathering in the serene aspect\n Of the sky, pure even to the first circle,\n To my eyes restored delight,\n So soon as I had come forth from that dead air,\n Which had troubled eyes and breast.\n The fair planet that inspires love\n Was making all the orient smile,\n Veiling the Fishes which were in her train.\u201d\n\nAlternative rendering of the first three lines:\u2014\n\n \u201cSweet colour of oriental sapphire,\n Which was diffused over the tranquil scene,\n From mid-heaven even to the first circle.\u201d\n _Purg._ i. 13-21.\n------------------------------------------------------------------------\n\nStrange to say, the beginning of the above beautiful passage which\nconveys so direct and vivid an impression of blue sky and pure air,\npresents some difficulties when one comes to translate it word by\nword, especially as the texts offer more than one reading. By some\ncommentators the \u201cprimo giro\u201d[326] has been understood to mean the\nsphere of the moon,[327] or even the highest sphere (the Primum\nMobile); but this is certainly inadmissible, as Dante supposed the\natmosphere to reach only as far as the sphere of Fire, which came\nbetween it and the moon. The prime circle is here evidently the\nhorizon, the fundamental circle of observers, the First Circle of the\nastrologers, from which they reckoned all the rest. It is here that the\nsky usually becomes pale and misty, however blue and clear it may be\nabove. The colour was gathering and deepening,[328] especially in the\neast, where Dante was looking, as dawn began to appear in a perfectly\ncloudless sky; for during the darkness of the night it would have\nappeared almost black.\n\n------------------------------------------------------------------------\n[326] First, or prime, circle.\n\n[327] _Conv._, II. iv. 1-3.\n\n[328] Literally, \u201cwas assembling,\u201d or \u201cwas being collected.\u201d\n------------------------------------------------------------------------\n\nDr. Moore thinks the authority better for a different reading, viz.\n\u201cDal mezzo\u201d[329] instead of \u201cDell\u2019 aer.\u201d[330] In this case, we must\ntake \u201cmezzo puro\u201d to mean mid-heaven, that is the zenith, \u201cpuro\u201d being\nused as a noun, and meaning a cloudless sky (like \u201csereno\u201d in _Purg._\nv. 38); and \u201cil sereno aspetto\u201d must mean \u201cthe quiet scene.\u201d\n\n------------------------------------------------------------------------\n[329] \u201cFrom the middle.\u201d\n\n[330] \u201cOf the air.\u201d\n------------------------------------------------------------------------\n\nVenus appears again in the _Purgatorio_, shining upon the Mountain from\nthe east before sunrise; and this time she is called Cytherea, after\nthe island near which she was fabled to have risen from the sea, and in\nwhich she received a special worship.\n\n \u201cDell\u2019 oriente ... raggi\u00f2 nel monte Citerea,\n Che di foco d\u2019amor par sempre ardente.\u201d[331]\n\n------------------------------------------------------------------------\n[331] \u201cFrom the east there shone upon the Mountain Cytherea, who in the\nflame of love seems to be always burning.\u201d _Purg._ xxvii. 94-96.\n------------------------------------------------------------------------\n\nThe position of Venus in her course through the zodiac is indicated\nin the previous passage by the expression \u201cvelando i Pesci.\u201d[332] The\noscillating motion, by which she appears first on the morning and then\non the evening side of the sun is referred to several times. In prose\nDante speaks of her two apparitions, the morning and the evening: \u201cla\nsua apparenza, or da mane, or da sera;\u201d[333] in poetry, he describes\nher as wooing the sun, first following and then facing him:\u2014\n\n------------------------------------------------------------------------\n[332] \u201cVeiling the Fishes\u201d (the zodiacal constellation).\n\n[333] \u201cHer appearance, now in the morning, and now in the evening.\u201d\n_Conv._ II. xiv. 114, 115.\n------------------------------------------------------------------------\n\n \u201cla stella\n Che il sol vagheggia or da coppa or da ciglio.\u201d[334]\n\n------------------------------------------------------------------------\n[334]\n \u201cThe star\n That woos the sun, now following, now in front.\u201d\n _Par._ viii. 11-12. (_Longfellow_).\n------------------------------------------------------------------------\n\nMercury and Venus (called rather oddly after their mothers), are said\nboth to move closely round the sun:\u2014\n\n ... \u201cvidi com\u2019 si move\n Circa e vicino a lui Maia e Dione.\u201d[335]\n\n------------------------------------------------------------------------\n[335]\n \u201cI saw how move themselves,\n Around and near him, Maia and Dione.\u201d\n _Par._ xxii. 143-144.\n------------------------------------------------------------------------\n\n\u201cQuel bel pianeta di Mercuro\u201d[336] keeps closest, for he is more\nhidden than any other in the rays of the sun. Here again the fact is\nexpressed in simple prose in the _Convivio_:\u2014\n\n------------------------------------------------------------------------\n[336]\n \u201cThat fair planet, Mercury.\u201d\n _Son._ xxviii. 9.\n------------------------------------------------------------------------\n\n \u201cMercurio ... pi\u00f9 va velata de\u2019 raggi del sole che\n null\u2019 altra stella.\u201d[337]\n\n------------------------------------------------------------------------\n[337] \u201cMercury ... as it moves is more veiled by the rays of the sun\nthan any other star.\u201d _Conv._ II. xiv. 99-100.\n------------------------------------------------------------------------\n\nwhich explains (if necessary) the more poetical language of the\n_Paradiso_:\u2014\n\n \u201cLa spera,\n Che si vela ai mortal con altrui raggi.\u201d[338]\n\n------------------------------------------------------------------------\n[338]\n ... \u201cThe sphere\n That veils itself from men in alien rays.\u201d\n _Par._ v. 128, 129.\n------------------------------------------------------------------------\n\nIn the same way we may compare the descriptions of Mars in the\n_Paradiso_ with a statement in the _Convivio_:\u2014\n\n \u201cQuesto fuoco,\u201d[339] and \u201cl\u2019affocato riso della\n stella,\u201d[340] and \u201cMarte rosseggia,\u201d[341] with\n\n------------------------------------------------------------------------\n[339] \u201cThis Fire.\u201d _Par._ xvi. 38.\n\n[340] \u201cThe burning smile of the star.\u201d _Par._ xiv. 86.\n\n[341] \u201cMars shows red.\u201d _Purg._ ii. 14.\n------------------------------------------------------------------------\n\n \u201cEsso Marte ... il suo calore \u00e8 simile a quello del\n fuoco; ... esso appare affocato di colore.\u201d[342]\n\n------------------------------------------------------------------------\n[342]\n \u201cThis Mars ... his heat is like the heat of a fire ...\n his colour is as if he were on fire.\u201d\n _Conv._ II. xiv. 162-165.\n------------------------------------------------------------------------\n\nThe famous occultation of Mars by the moon, seen by Aristotle, is\nquoted by Dante in _Conv._ II. iii. 59-65.\n\nJupiter is the \u201cdolce stella\u201d[343] and the \u201cgiovial facella.\u201d[344] He\nis silvery white, the whitest of all the stars:\u2014\u201cIntra tutte le stelle\nbianca si mostra, quasi argentata.\u201d[345]\n\n------------------------------------------------------------------------\n[343] \u201cSweet star.\u201d _Par._ xviii. 115.\n\n[344] \u201cThe torch of Jove.\u201d _Par._ xviii. 70.\n\n[345] \u201cAmongst all the stars it shows white, as if silvered over.\u201d\n_Conv._ II. xiv. 202-204.\n------------------------------------------------------------------------\n\nTherefore when Dante saw the planet filled with brilliant spirits,\nhe says: \u201cGiove pareva argento l\u00ec d\u2019 oro distinto.\u201d[346] Comparisons\nbetween the colours of Jupiter and Mars are made in _Par._ xviii.\n64-69, and xxvii. 13-15.\n\n------------------------------------------------------------------------\n[346]\n \u201cJupiter\n Seemed to be silver there with gold inlaid.\u201d\n _Par._ xviii. 95-96. (_Longfellow_).\n------------------------------------------------------------------------\n\nFinally Saturn is the slowest and the most distant of all the planets.\nThese two characteristics are thus described in the _Convivio_:\u2014\n\n \u201cL\u2019una si \u00e8 la tardezza del suo movimento per li\n dodici segni; ch\u00e8 ventinove anni e pi\u00f9, secondo le\n scritture degli astrologi, vuole di tempo lo suo\n cerchio: l\u2019altra si \u00e8 che esso \u00e8 alto sopra tutti\n gli altri pianeti.\u201d[347]\n\n------------------------------------------------------------------------\n[347] \u201cOne is the slowness of its movement through the twelve signs;\nfor twenty-nine years and more, according to the writings of the\nastrologers, are required for its revolution: the other is that it is\nhigh above all other planets.\u201d _Conv._ II. xiv. 226-231.\n------------------------------------------------------------------------\n\nIn the _Paradiso_ Saturn is called a Mirror,[348] a Crystal,[349] a\nsplendour;[350] his circling motion is alluded to, and his position at\nthe time in the zodiac:\u2014\n\n------------------------------------------------------------------------\n[348] _Par._ xxi. 18.\n\n[349] _Par._ xxi. 25.\n\n[350] _Par._ xxi. 13.\n------------------------------------------------------------------------\n\n \u201cCerchiando il mondo.\u201d[351]\n \u201cSotto il petto del Leone ardente.\u201d[352]\n\n------------------------------------------------------------------------\n[351] \u201cCircling the world.\u201d _Par._ xxi. 26.\n\n[352] \u201cBeneath the burning Lion\u2019s breast.\u201d _Par._ xxi. 14.\n------------------------------------------------------------------------\n\nSome of the most beautiful similes in the _Divine Comedy_ are drawn\nfrom the planets. The angel-pilot of Purgatory, when first seen far\noff over the sea, is likened to the planet Mars, glowing red through\nmorning mists, low in the west above the ocean floor;[353] and the\nangel that welcomes the poet to the second circle on the Mountain is\nbeautiful as the Morning Star.\n\n------------------------------------------------------------------------\n[353] _Purg._ ii. 13-15.\n \u201cA noi venia la creatura bella,\n Bianco vestita, e nella faccia quale\n Par tremolando mattutina stella.\u201d[354]\n\n[354]\n \u201cTowards us came the being beautiful,\n Vested in white, and in his countenance\n Such as appears the tremulous morning star.\u201d\n _Purg._ xii. 88-90. (_Longfellow_).\n------------------------------------------------------------------------\n\nAlthough any of the planets when rising just before the sun may be\ncalled a morning star, Venus is probably intended here, as also where\nSt. Bernard, in his devotion to the Virgin, is compared with the\nMorning Star which takes its beauty from the sun:\u2014\n\n \u201cColui ch\u2019abbelliva di Maria,\n Come del sole stella mattutina.\u201d[355]\n\n------------------------------------------------------------------------\n[355] \u201cHe who drew beauty from Mary, as the Morning Star does from the\nSun.\u201d _Par._ xxxii. 107, 108.\n------------------------------------------------------------------------\n\nAll the seven planets (that is, including sun and moon), are\noccasionally mentioned together, \u201ctutti e sette,\u201d[356] and their\nmovement in the ecliptic is referred to in _Par._ x, 14: \u201cL\u2019obbliquo\ncerchio che i pianeti porta.\u201d[357] In the 14th and 15th chapters of\nthe second treatise of the _Convivio_, already so often quoted, Dante\ndraws an elaborate comparison between the seven planets and the seven\nsciences of the Trivium and Quadrivium. The moon is Grammar, Mercury\nDialectic, Venus Rhetoric, the Sun Arithmetic, Mars Music, Jupiter\nGeometry, and Saturn Astrology. The reasons given for the latter are\nthe slow movement and the height (_i.e._ distance from Earth) of\nSaturn, which Dante compares with the length of the time taken in\nlearning astronomy, and the loftiness of its subject.\n\n------------------------------------------------------------------------\n[356] \u201cAll the seven.\u201d _Son._ xxviii. 14, and _Par._ xxii. 148.\n\n[357] \u201cThe oblique circle which carries the planets.\u201d\n------------------------------------------------------------------------\n\nIn the same way the star sphere is said to resemble Physics and\nMetaphysics, the Primum Mobile Ethics, and the Empyrean Theology. The\nargument is very fanciful, but just what would appeal to readers of\nDante\u2019s day, who loved to find allegories everywhere; and it gives him\nan opportunity of instructing them very simply in his beloved science.\n\nHe sometimes uses the planetary periods as divisions of time (as Plato\nsaid they should be used), for computing earthly events, and in him\nthis does not seem affectation, as it would with almost anyone else. It\nseems quite natural that Cacciaguida, when speaking in the heaven of\nMars, and answering a question regarding the date of his birth, should\ncount the time not by solar but by Martian years, saying that from\nthe beginning of the Christian Era to the day of his birth, Mars had\nreturned to his Lion (the constellation of Leo) five hundred and eighty\ntimes.[358] The length of the Martian year according to Alfraganus is\n1 Persian year, 10 months, and 22 days nearly. The Persian year (as\nhe tells us in the first chapter of the _Elementa_) consists of 12\nmonths of 30 days each plus 5 extra days, making 365 days exactly (not\n365\u00bc days like the Roman), so the Martian year is 687 days (the modern\nestimate is 686\u00b79). 687 days\u00a0\u00d7\u00a0580 gives us 1091 a.d. as the date of\nCacciaguida\u2019s birth. This is consistent with the date of his death, for\nhe had just told Dante that he fell in the Crusade to which he followed\nthe Emperor Conrad, and we know that this was fought in the year 1147.\n\nSome commentators think that Dante did not intend the Martian year\nto be taken so precisely, but only as approximately two solar years,\nsince he gave it thus in _Conv._ II. xv. 145. But there he specially\nstates that he is quoting an approximate figure only (\u201cuno anno\nquasi\u201d[359] is half the period of Mars) whereas in the _Paradiso_ it\nis used to fix a date. Since by taking 580\u00a0\u00d7\u00a02 years we get 1160, an\nimpossible date of birth for a man who died in 1147, the only way to\nsupport this theory that Dante was speaking loosely here is to adopt\nanother reading of the passage, and substitute \u201ctre\u201d for \u201ctrenta.\u201d[360]\nThen 553 (instead\u00a0of\u00a0580)\u00a0\u00d7\u00a02 years would give the date 1106; but the\nreading is not supported by good authority.\n\n------------------------------------------------------------------------\n[358] _Par._ xvi. 34-39.\n\n[359] \u201cAbout a year.\u201d\n\n[360] \u201cThree,\u201d for \u201cthirty.\u201d\n------------------------------------------------------------------------\n\nThe period of Venus is used with equal appropriateness when Dante is\nrelating how love for the Gentil Donna found a way to his heart, coming\non the rays of Venus,[361] the star of love.\n\n \u201cLa stella di Venere due fiate ere rivolta in\n quello suo cerchio che la fa parere serotina e\n mattutina, secondo i due diversi tempi, appresso\n lo transpassamento di quella Beatrice beata, che\n vive in cielo con gli angioli e in terra colla mia\n anima, quando quella Gentil Donna, di cui feci\n menzione nella fine della _Vita Nuova_, apparve\n primamente accompagnata d\u2019Amore agli occhi miei, e\n prese alcuno luogo nella mia mente.\u201d[362]\n\n------------------------------------------------------------------------\n[361] _Conv._ II. vii. 88, 89.\n\n[362] \u201cThe star of Venus had twice revolved in that circle of hers\nwhich makes her appear as evening and morning star, according to her\ntwo seasons, since the translation of that holy Beatrice who lives in\nheaven with the angels and on earth in my soul, when that Gentle Lady,\nof whom I made mention at the end of the \u2018New Life,\u2019 appeared first\nbefore my eyes, escorted by Love, and took some place in my mind.\u201d\n_Conv._ II. ii. 1-12.\n------------------------------------------------------------------------\n\nVenus runs through her changes, appearing first as Evening and then\nas Morning star, in 584 days; and, as the reader will remember,\nthis movement was ascribed by Ptolemy to her epicycle (\u201cquello suo\ncerchio,\u201d \u201cthat circle of hers\u201d). Dante would find 584 days given for\nit in his Alfraganus.[363] Twice 584 is 1168 days, or three years and a\nlittle more than 2 months. Therefore, since we know from _V. N._ xxx.\nthat Beatrice died in June 1290, Dante wishes to say that he first saw\nthe Lady of Pity in August 1293.\n\n------------------------------------------------------------------------\n[363] \u201cVenus [ambitum epicycli peragit] anno Persico 1, mensibus 7,\net diebus prope 9,\u201d that is, the period of Venus on her epicycle is\n365\u00a0+\u00a0210\u00a0+\u00a09\u00a0=\u00a0584\u00a0days nearly, according to Alfraganus. The modern\nmean value is also 584 days.\n------------------------------------------------------------------------\n\nThe period has been taken by some modern commentators to refer to the\n225 days in which Venus revolves round the sun, but this period has no\nplace in the Ptolemaic system. We cannot here discuss Dante\u2019s allegory\nof the Gentle Lady and Philosophy, but in this passage he has stated\nwithout ambiguity or uncertainty the date of her first appearance.[364]\n\n------------------------------------------------------------------------\n[364] See Lubin\u2019s _Dante e gli Astronomi Italiani_. The period of 225\ndays may be easily deduced from Ptolemy\u2019s system, for it is the time in\nwhich the epicycle of Venus would make an absolute revolution round its\ncentre, the diameter becoming parallel to its former position. But the\nGreeks invariably reckoned the period as the time in which it revolved\nrelatively to Earth, that is 584 days.\n------------------------------------------------------------------------\n\n\n6. ECLIPSES.\n\nWe find solar eclipses mentioned six times in Dante\u2019s works. As in all\nold records, there is no allusion to the features which chiefly strike\nmodern astronomers\u2014the pearly corona, and the blood-red prominences\nstanding out like flames round the black disc. The terror of the sudden\ndarkness, even when foreseen, seems to have absorbed all attention,\nand only the appearance of stars in the daytime and the frightened\nbehaviour of animals was noted by Ristoro, and by others until quite\nmodern times.\n\nIn his letter to the Cardinals of Italy, Dante speaks of the shameful\nand grievous removal of the Papacy from Rome to Avignon as an eclipse\nof the sun.[365] In his dream of the death of Beatrice, he sees the sun\nso darkened that the stars appear, to his great terror:\u2014\n\n------------------------------------------------------------------------\n[365] _Ep._ viii. 158, 159.\n\n \u201cPoi mi parve vedere appoco appoco\n Turbar lo Sole ed apparir la stella.\u201d[366]\n\n[366]\n \u201cThe while, little by little, as I thought,\n The sun ceased, and the stars began to gather.\u201d\n _V. N._ xxiii. 176, 177. (_Rossetti_).\n\nSee also the prose description just before, lines 35-37.\n------------------------------------------------------------------------\n\nHe also refers to the disputed idea that the darkness at the time of\nthe Crucifixion was caused by an eclipse of the sun,[367] and to the\nfigurative eclipse which then took place in heaven.[368]\n\n------------------------------------------------------------------------\n[367] _Par._ xxix. 97-102.\n\n[368] _Par._ xxvii. 35, 36.\n------------------------------------------------------------------------\n\nIf he had ever seen one in reality, it would have made more impression\nupon him, and we should surely have found it referred to several times\nand vividly described. The only suggestion of a personal experience is\nwhere he temporarily loses the power of sight by gazing too fixedly\nupon the spirit of St. John; and he compares this to a man who looks so\nintently at the sun, just before an eclipse, that he becomes incapable\nof seeing it at the critical moment.[369] This incident may have been\ntold him by an observer of the total eclipse of June 1239, which was\nvisible in Italy, and seems to be the one described by Ristoro.\n\nLastly, he mentions the discovery that the moon comes between us and\nthe sun, which we have learned from eclipses, as an example of the\nproper method of reasoning: for we must first ask whether a thing is,\nand afterwards why it is. Thus man\u2019s wonder leads him to knowledge.[370]\n\n------------------------------------------------------------------------\n[369] _Par._ xxv. 118-121.\n\n[370] _Qu._ xx. 3-5, 26-29.\n------------------------------------------------------------------------\n\nThe eclipsed moon is only once mentioned, viz. in _De Mon._ III. iv.\n140-142, where she is described as not wholly dark. With his usual\nindifference to her Dante fails to note the often extraordinary beauty\nof her colouring when the eclipse is total.\n\n\n7. COMETS AND METEORS.\n\nThe connection between these two classes of heavenly bodies seems to be\nreal, though its exact nature is still a mystery. In old days little\nor no distinction was drawn between them, so that it is sometimes\ndifficult to know whether a writer is describing a large meteor, or a\ncomet, or a shower of falling stars.\n\nDante only mentions comets once, very briefly, when he describes\nspirits in Paradise as \u201cfiammando forte a guisa di comete.\u201d[371] He\nsays nothing of the magnificent comet described by Ristoro, which\nrose at three o\u2019clock in the morning, huge as a mountain, and with\ngreat rays like a mane; but travelling always towards the south grew\ngradually fainter, and disappeared after 60 days. Yet it was seen in\nTuscany shortly before Dante\u2019s birth, and it was thought to herald the\ndeath of the Pope (Urban IV. in 1264) and the terrible war in which\nfirst Manfred and afterwards Conradin were slain. These events are\nfamiliar to every reader of the _Divine Comedy_,[372] but there is\nnever any mention of the comet.\n\n------------------------------------------------------------------------\n[371] \u201cBlazing brilliantly like comets.\u201d _Par._ xxiv. 12.\n\n[372] _Inf._ xxviii. 16-17; _Purg._ iii. 112-132.\n------------------------------------------------------------------------\n\nNor does he describe in any detail the fiery cross which was seen in\nthe sky above Florence \u201cin the beginning of her destruction,\u201d which\ndoes not mean, as one might think, the legendary sack of the city\nby Totila, but the treacherous entry of Charles of Valois, \u201cTotila\nsecundus,\u201d[373] in November 1301. This portent was of course considered\nas of ill omen for the Republic, and although Dante was still absent\non his embassy to Rome, and cannot have seen it himself, it is rather\nremarkable that he says so little about it. It is described by an\neye-witness, \u201cIo, che chiaramente la viddi\u201d[374] as a red cross which\nappeared in the evening over the Priors\u2019 Palace; the vertical arm\nseemed to be 20 ells long, the transverse one a little shorter, and\nit remained visible for as long as it would take a horse to gallop\ntwo furlongs. Villani the historian describes it as like a comet with\nan immense trail, as of smoke, behind it. Dante merely mentions it,\ntogether with the ball of fire seen by Seneca at the death of Augustus,\nwhich, judging by Seneca\u2019s own words, was also a large meteor, for\nhe describes it as flashing into sight and moving very rapidly,\ndisappearing as it moved.[375]\n\n------------------------------------------------------------------------\n[373] _V. E._ II. vi. 48.\n\n[374] \u201cI, who saw it clearly.\u201d\n\n[375] _Naturales Qu\u00e6stiones_, Bk. I.\n------------------------------------------------------------------------\n\nDante calls meteors \u201ckindled vapours,\u201d[376] in accordance with the\ndoctrines of Aristotle, but the popular idea of them is shown by his\nobservation that they might be taken for stars in motion, only that\nno star vanishes from its place, and they are only seen for a short\ntime.[377] Ristoro d\u2019Arezzo had already alluded to this fallacy:\u2014\n\n------------------------------------------------------------------------\n[376] _Conv._ II. xiv. 168-171, and _Purg._ v. 37.\n\n[377] _Par._ xv. 16-18.\n \u201cAlquanti non savi credono ch\u2019elle sieno stelle,\n che caggino del cielo e vengano meno.\u201d[378]\n\n[378] \u201cSome ignorant people think that they are stars which fall from\nheaven and vanish.\u201d _Comp. del Mondo_, VII. v.\n------------------------------------------------------------------------\n\nHe gives the same reason as Dante for disbelieving this, and Seneca had\nexpressed it more forcibly, saying that if true there would be no more\nstars in the sky, for some meteors are seen every night.\n\nAlbertus Magnus, who seems to have had a genius for mistaking his\nauthorities, quotes Alfraganus as stating that shooting stars are most\nfrequent in evening twilight, though nothing of the kind is said in the\n_Elementa._ Dante perhaps accepted the statement, though it is by no\nmeans necessarily implied in his \u201cdi prima notte:\u201d[379] moreover there\nis some authority for the alternative reading of \u201cmezza notte.\u201d[380]\nWherever the idea originated, its sole foundation must have been the\ncircumstance that more persons are awake in the early than in the late\nhours of the night: the fact is that more meteorites are captured by\nthe morning side of the earth, which is turned in the direction towards\nwhich she is moving in her orbit.\n\n------------------------------------------------------------------------\n[379] \u201cEarly in the night.\u201d\n\n[380] \u201cMidnight.\u201d _Purg._ v. 38.\n------------------------------------------------------------------------\n\nShooting stars were necessarily familiar to a lover of starry skies,\nand Dante has given us an exquisite description of the suddenness with\nwhich they startle quiet eyes, while their brilliancy and swiftness of\nflight provides him with two beautiful similes.\n\nIn the first he compares them, and also flashes of summer lightning,\nwith messenger spirits in Purgatory hastening to bring their friends to\nhim:\u2014\n\n \u201cVapori accesi non vid\u2019 io s\u00ec tosto\n Di prima notte mai fender sereno,\n N\u00e8, sol calando, nuvole d\u2019agosto,\n Che color non tornasser suso in meno,\n E giunti l\u00e0, con gli altri a noi dier volta.\u201d[381]\n\n------------------------------------------------------------------------\n[381]\n \u201cVapours enkindled saw I ne\u2019er so swiftly\n At early nightfall cleave the air serene,\n Nor, at the set of sun, the clouds of August,\n But upward they returned in briefer time,\n And on arriving with the others, wheeled\n Towards us.\u201d\n _Purg._ v. 37-41. (_Longfellow_).\n\n(By \u201cvapours that cleave the clouds of August,\u201d flashes of lightning\nwithout thunder are meant. Aristotle believed both these and meteorites\nto be ignited vapours).\n------------------------------------------------------------------------\n\nThe second illustrates the brightness and beauty, as well as the\nmovement, of the star-like spirits in Mars:\u2014\n\n \u201cQuale per li seren tranquilli e puri\n Discorre ad ora ad or subito foco,\n Movendo gli occhi che stavan sicuri,\n E pare stella che tramuti loco,\n Se non che dalla parte ond\u2019 ei s\u2019 accende\n Nulla sen perde, ed esso dura poco ...\u201d[382]\n\n------------------------------------------------------------------------\n[382]\n \u201cAs through the pure and tranquil evening air\n There shoots from time to time a sudden fire,\n Moving the eyes that steadfast were before,\n And seems to be a star that changeth place,\n Except that in the place where it is kindled\n Nothing is missed, and this endureth little.\u201d\n _Par._ xv. 13-18. (_Longfellow_).\n------------------------------------------------------------------------\n\n\n8. THE SUN\u2019S PATH IN THE SKY SEEN FROM DIFFERENT PARTS OF THE EARTH.\n\nWe have now seen how familiar Dante was with the aspects of the skies\nabove his head. His writings show also that he had pictured clearly\nto himself what they must be in other parts of the world\u2014in regions\nfar east or west, in the southern hemisphere, at the equator, and at\neither pole. Science could not tell him all that he would have liked to\nknow about the stars, so that although he can speak of regions where\nUrsa Major passes overhead, and where it sinks out of sight below\nthe horizon, he has to fall back upon his imagination and invent new\nconstellations for the southern hemisphere.\n\nBut astronomy could tell him, and his habit of accurate thought,\nas well as his imagination, helped him to grasp how the sun would\nappear at any latitude on the earth, and what would be the results on\nthe length of day and night, and on the seasons. A very interesting\nlittle disquisition on this subject is found in the _Convivio_, in\nillustration of some lines in one of his Odes, which speak of the sun\ncircling the whole world. In order to understand this completely, Dante\nsays, we must know exactly in what way the sun circles the world. The\nchief point to bear in mind while reading his description is that the\nsun, besides the simple daily motion in a circle, has a constant slow\nmotion north or south, and therefore his path in the sky, as we see it\nday after day, is really spiral.\n\nThe passage is much too long to quote in full, but if the reader will\nfollow me, taking his _Convivio_ and opening it at chapter v. of\nTreatise III. and beginning at line 66, I will give a r\u00e9sum\u00e9 which will\nform a running commentary on the text, and an explanation of any points\nwhich may not at once be clear.\n\nWe see the sky, says Dante, continually revolving round Earth as\ncentre; and it has two fixed poles of revolution\u2014the northern, which is\nvisible to nearly all the land not covered by sea, and the southern,\nwhich is hidden from nearly all of it. And the circle which is\nequi-distant from these two poles [the celestial equator] is that part\nof the sky in which we see the sun when he is in Aries and in Libra.\n\nNow if a stone could be dropped from this pole of ours [the northern],\nit would fall far away yonder in the ocean just where, if a man were\nstanding, he would always have the Pole Star exactly overhead. [\u201cLa\nstella\u201d[383] is the Pole Star, see p. 291]. And I believe (Dante says)\nthat from Rome to the north pole, in a direct line, is a distance\nof about 2,700 miles. To fix our ideas, let us imagine that at this\nspot there is a city called _Maria_, and let us imagine another city,\ncalled _Lucia_, at the spot exactly opposite, where a stone would\nfall if dropped from the other pole. And I believe that from Rome\nsouthwards to this second place would be a distance of about 7500\nmiles. Thus the distance between the two cities, in whatever direction\nthe measuring cord be stretched, would be 10,200 miles, that is, half\nthe circumference of the globe,[384] and the inhabitants of _Maria_\nwould have their feet opposite the feet of those of _Lucia_. [If any\ntwo spots on a sphere are exactly antipodal, but in no other case, the\ndistance may be measured in an infinity of directions, and always come\nout the same.]\n\n------------------------------------------------------------------------\n[383] \u201cThe star.\u201d\n\n[384] As this is the value given by Alfraganus, we must here understand\nArabian miles. The distances from Rome to the north and south pole are\ntherefore probably equal to 3500 to 9750 English miles, and both are a\nlittle too large, because the half circumference of Earth is too large.\nThe proportion is about right, however, for Rome is nearly three times\nas far from the south pole as the north, her latitude being 42\u00b0 N.\nAlfraganus placed her in the fifth climate, at the northern boundary of\nwhich he said the pole was elevated 43\u00bd\u00b0.\n------------------------------------------------------------------------\n\nLastly, let us imagine a circle on the globe, which will be at equal\ndistances everywhere from _Maria_ and _Lucia_ [the equator]. According\nto the opinions of the astrologers, if I understand them aright,\nand according to what is said by Albertus Magnus and by Lucan, this\ncircle would divide the dry land from the ocean there in the south,\napproximately along the extremity of the First Climate, where amongst\nothers live the Garamantes, who go almost always naked, to whom Cato\nwent when fleeing from C\u00e6sar.\n\n\u201cApproximately,\u201d because the southern extremity of the First Climate,\naccording to Alfraganus, lay a little north of the equator, although\nland extended, and was sparsely inhabited, as far the equator (see p.\n186).\n\nDante speaks again of these extra-climatal races in _De Mon._ I. xiv.\n43-51, where he contrasts the Scythians who live beyond the seventh\nclimate, and therefore endure extreme inequality of days and nights,\nand suffer almost intolerable cold, with the Garamantes who live under\nthe equator, where days and nights are always equal, and the heat\nis so intense that they can scarcely bear any clothing. Since \u201cthe\nastrologers who determine the climates\u201d[385] had fixed their northern\nlimit at 50\u00bd\u00b0, nearly the whole of Britain also lay, like barbarous\nScythia, in this scarcely habitable region of long nights and bitter\ncold!\n\n------------------------------------------------------------------------\n[385] _Qu._ xix. 36.\n------------------------------------------------------------------------\n\nWhen we have marked these three places on the globe, _i.e._ the two\npoles and the equator, it is easy (Dante goes on) to see how the sun\ncircles. I say then, that the heaven of the sun turns from west to\neast, not directly against the diurnal movement\u2014that is, the movement\nwhich produces day and night\u2014but obliquely against it, and so that its\nmiddle circle, which is similarly between its two poles, and on which\nis the body of the sun [_i.e._ the ecliptic], cuts in two opposite\npoints the circle of the two first poles [the equator], that is, at the\nbeginning of Aries and the beginning of Libra; it diverges from that\ncircle in two arcs, one north and the other south. The highest points\nof these arcs are equally distant from the first circle in either\ndirection, being 23 degrees and a little more; and the one summit is at\nthe beginning of Cancer, and the other at the beginning of Capricorn.\n\nTherefore, when the sun is in the beginning of Aries, travelling in\nthe mid-circle of the first poles [the equator], _Maria_ will see this\nsun circling the world, low down on the ground, or on the sea, like\na mill-stone only half of which is seen, and day after day he will\nbe seen to rise, like the screw of a press, until he has performed\nabout ninety revolutions, or a little more. When these revolutions are\naccomplished, he will be as high in the sky above _Maria_ as he stands\nin the sky of the Garamantes at middle-tierce at the time of equal days\nand nights.[386]\n\n------------------------------------------------------------------------\n[386] Adopting the reading of Dr. Moore: \u201cnella mezza terra, alla mezza\nterza,\u201d that is, \u201cat the equator at middle-tierce.\u201d See _Studies in\nDante_ III. 107, 108.\n------------------------------------------------------------------------\n\n[From _Conv._ IV. xxiii. and III. vi., where Dante explains the use\nof temporal hours, we learn that mid-tierce on the day of the equinox\nis an hour and a half after sunrise, or 7.30 A.M. Since the sun moves\nthrough 360 degrees divided by 24, that is 15 degrees, in an hour,\nand his motion is vertical in equatorial countries at the equinox,\nit would bring him in 1\u00bd hours to 22\u00bd degrees above the horizon. His\ngreatest height above the horizon at the pole is only one degree more\nthan this, for it is obviously equal to the greatest distance between\nthe equator and the ecliptic, _i.e._ 23\u00bd degrees, since at the pole the\nequator coincides with the horizon. This gives a good idea, therefore,\nof the appearance of the sun in the sky to the people at _Maria_, and\nis a striking illustration of the difference between the polar sun and\nthe equatorial. For at the time mentioned, the sun has only a quarter\nthe height which it will attain at noon, when it will pass through the\nzenith of the Garamantes; yet this is the highest position in which the\ninhabitants of _Maria_ can ever see it].\n\nIf a man stood upright in _Maria_, and kept turning his face to the\nsun, he would see it move to his right [as we do].\n\nAfter reaching his greatest height in the sky, the sun would begin to\ndescend again, in the same spiral way like a screw turning, for another\nninety revolutions or so, until once more he was circling down on the\nhorizon, only half his body visible.\n\nThen he would be lost to sight altogether, and would begin to be seen\nin _Lucia_, where he would rise and descend in just the same way as in\n_Maria_. But if a man faced the sun in _Lucia_, he would see it moving\nto his left [as one does in Australia where it goes north at noon].\n\n[Illustration: Fig. 43. The Sun at the Equinox, seen from the poles and\nthe equator. _Conv._ III. v.\n\n(Maria, Lucia, imaginary cities at the North and South poles).]\n\nWe see, then, that these places have one day in the year which is six\nmonths long, and one night of equal length, and when it is day with\none, it is night with the other.\n\nNow on the circle on the globe where the Garamantes live [the equator],\nthe sun when in Aries goes exactly overhead, not circling horizontally\nlike a mill-stone, but vertically like a wheel, and exactly half of\nthis wheel is visible above the horizon.\n\nAfter this, the sun is seen to depart and go towards _Maria_ for about\n91 days; then in about the same time it returns, and enters Libra; then\nit goes towards _Lucia_ for about 91 days, and in the same period\nreturns. And this place, which circles the entire globe, always has\nequal day and night, on whichever side of it the sun is; and twice in\nthe year it has a very hot summer, and twice a mild winter.\n\nThe regions which are between the two imaginary cities and the\nmid-circle, see the sun in different ways, according to their distance\nfrom these places, but the details, our author says, he will leave to\nthe ingenious reader,\n\n \u201cSiccome omai, per quello che detto \u00e8, puote vedere\n chi ha nobile ingegno, al quale \u00e8 bello un poco di\n fatica lasciare.\u201d[387]\n\n------------------------------------------------------------------------\n[387] \u201cFor now, after what has already been said, the rest may be\nunderstood by whomsoever has a noble mind, to which it is well to leave\na little labour.\u201d (_Cf. Par._ x. 22-25).\n------------------------------------------------------------------------\n\nHe draws attention to the interesting fact, which follows from the\nabove, that in the course of a year (when the heaven of the sun has\nmade a complete revolution and returned to the same place), every\npart of this globe on which we live has received an equal amount of\ndaylight. And the essay ends in an apostrophe which recalls the reproof\nof Virgil to those who will not look up to the skies:[388]\n\n \u201cO ineffabile Sapienza che a cos\u00ec ordinasti, quanto\n \u00e8 povera la nostra mente a Te comprendere! E voi,\n a cui utilit\u00e0 e diletto io scrivo, in quanta\n cecit\u00e0 vivete, non levando gli occhi suso a queste\n cose, tenendoli fissi nel fango della vostra\n stoltezza.\u201d[389]\n\n------------------------------------------------------------------------\n[388] _Purg._ xiv. 148-151.\n\n[389] \u201cO unspeakable Wisdom who hast thus ordained, how poor is our\nintellect to understand Thee! And you, for whose benefit and pleasure\nI am writing, in what blindness you live, not lifting up your eyes to\nthese things, but keeping them fixed on the slough of your folly.\u201d\n------------------------------------------------------------------------\n\nIt is interesting to compare this passage with the parallel passages\nin Alfraganus and Ristoro. The astronomer is concise and clear; the\nmonk is diffuse and apt to repeat himself; the poet is quaintly\npicturesque. Both the Italians evidently draw the main facts from\nthe Arab, and all use the illustration of a mill-stone to explain\nthe horizontal motion of the heavens at the pole: here are the three\ncorresponding passages:\u2014\n\n \u201cCoelumque mol\u00e6 trusatilis instar gyrum\n vertitur.\u201d[390]\n\n \u201cL\u00ec si volgera il cielo attorno con tutte le sue\n stelle, in modo di macina.\u201d[391]\n\n \u201cConviene che _Maria_ veggia ... esso sole \u2018girare\n il mondo\u2019 ... come una mola.\u201d[392]\n\n------------------------------------------------------------------------\n[390] \u201cAnd the sky revolves like a mill-stone.\u201d _El. Ast._ ch. vii.\n\n[391] \u201cThere the sky will revolve, with all its stars, mill-stone\n fashion.\u201d _Comp. del Mondo._ I. xxiii.\n\n[392] \u201cIt follows that _Maria_ must see this sun \u2018circling the world\u2019\nlike a mill.\u201d _Conv._ III. v. 142-147.\n------------------------------------------------------------------------\n\nDante alone uses the figure of a wheel to illustrate the vertical\nmotion at the equator; he perhaps takes from Ristoro the idea of\nthe spiral. For the latter describes the path of the sun as a \u201cvia\ntortuosa, la quale i savi chiamano spira;\u201d[393] but he explains it as\nlike a string wound round a stick, Dante like the screw of a press.\nDante is dealing only with the sun, and does not enter into details\nabout the visibility of the zodiacal signs like the other two authors;\nbut on the other hand he goes south to the other pole, which apparently\ndoes not interest the others, perhaps because the southern hemisphere\nwas thought to be uninhabited. But the poet has added life to his\ndescription by supposing both poles inhabited, placing there his\nimaginary, mysteriously-named cities of \u201cMaria\u201d and \u201cLucia.\u201d On the\nequator, where Ristoro has the mythical city of Arym, whose wise and\nprosperous citizens enjoy a perfect climate, Dante, relying more on the\nclassics, lets his barbarous Garamantes run about naked most of the\nyear, under the fierce equatorial sun.\n\nNeedless to say, his little homily in conclusion is all his own;\nit is more interesting to find that he alone mentions the opposite\nmovements of the Sun, to right and left respectively in the north and\nsouth hemispheres,[394] and the fact that every part of the earth\nreceives the same amount of sunlight in a year. This may have been\nsuggested by someone else, but one would like to think he arrived at it\nindependently, when thinking over the facts.\n\n------------------------------------------------------------------------\n[393] \u201cA winding path, which the learned call a spiral.\u201d\n\n[394] \u201cLucan, who was well known to Dante, had observed that shadows\ncast by the sun in the southern hemisphere travel to the right instead\nof to the left, and fall southwards when with us they fall to the\nnorth.\u201d Moore, _Studies in Dante_ i. p. 239.\n------------------------------------------------------------------------\n\nIn the light of this treatise, which describes so truthfully the path\nof the sun, and its effect on the seasons in different latitudes, we\nmay explain two rather puzzling passages in the _Divine Comedy_.\n\nOne is at the beginning of the tenth canto of the _Paradiso_, where\nDante wishes his readers to realize the position of the sun when he\nentered it with Beatrice, and the great importance of this position.\n\u201cLift your eyes with me, reader,\u201d he says, \u201cto that place in the lofty\nheavens where the one motion meets the other, and see how the oblique\ncircle which carries the planets branches off from that point.\u201d The\nreader is now familiar with the \u201ctwo chief motions,\u201d and knows that one\nis the diurnal, from east to west, the other the planetary periodical\nmotions in the opposite direction; they meet at the equinoxes, where\nthe ecliptic cuts the equator. It is the spring equinox which Dante is\nspeaking of, for a little further on he says that the sun, situated\nin the place above-mentioned, was circling in those spirals which\nbring him to us earlier every day (lines 31-33). Now if the path\nof the planets were not thus oblique, he continues, much virtue in\nheaven would be lost, and almost every earthly power dead. Even if the\nobliquity were merely less or more, the universal order of both heaven\nand earth would suffer greatly. But why this should be so he leaves his\nreaders to think out for themselves, having a greater matter in hand\nwhich demands all his attention.\n\nIt is easy to see that if the sun always moved in the equator, without\ndeparting from it either north or south, he would rise every day to\nthe same height in the sky, and there would be no change of seasons\nanywhere on the earth; he would always be overhead at noon to Dante\u2019s\nGaramantes, living on the equator, and always just on the horizon, day\nand night, to the people of \u201cMaria\u201d and \u201cLucia\u201d at the Poles. If the\necliptic made a greater angle with the equator the seasons would be\nmore marked, and the sun would rise higher in summer in high latitudes.\nIf the angle were less, the reverse would be the case. Moreover if sun\nand moon and all the planets followed the same track, they would be\nconstantly eclipsing one another.\n\nBut if we would understand the full meaning of\u2014\n\n \u201cSe la strada lor non fosse torta,\n Mota virt\u00f9 nel ciel sarebbe in vano,\n E quasi ogni potenza quaggi\u00f9 morta.\u201d[395]\n\n------------------------------------------------------------------------\n[395]\n \u201cIf their pathway were not thus inflected,\n Much virtue in the heavens would be in vain,\n And almost every power below here dead.\u201d\n _Par._ x. 16-18. (_Longfellow_).\n------------------------------------------------------------------------\n\nwe must turn to thirteenth-century Ristoro of Arezzo, who has set forth\nin detail the results which he believed would follow from a change in\nthe ecliptic. If all the seven planets moved in the same narrow path,\nthere would be much less variety in their \u201caspects,\u201d and therefore\nin their influences upon the earth; and in the frequent eclipses one\nwould prevent the other from looking at the earth (\u201cimpedimenterebbe\nl\u2019uno l\u2019altro a guardare la terra\u201d), and so hinder its action. And\nsince it is the northward movement of the sun which causes our plants\nto blossom, and later to bear fruit, if there were no such motion we\nshould see no renewal of life. He argues further that if the obliquity\nof the ecliptic were greater, countries in high latitudes would have\ntoo severe a winter to be inhabited; while if it were less, the summer\nthere would not be warm enough for the ripening of harvests; therefore\nin whichever way it differed from the actual value, a smaller part of\nthe earth would be habitable.\n\n \u201cOr ti riman, lettor, sopra il tuo banco,\n Dietro pensando a ci\u00f2!\u201d[396]\n\n------------------------------------------------------------------------\n[396]\n \u201cAnd now remain, reader, on your bench, thinking over this!\u201d\n _Par._ x. 22, 23.\n------------------------------------------------------------------------\n\nHow much of this was in Dante\u2019s mind it is hardly possible to say,\nbut it is evident that the \u201cvia tortuosa\u201d of the seven planets, and\nits effects on the earth, was a favourite subject for thought in his\ntime.[397]\n\n------------------------------------------------------------------------\n[397] Thus Petrarch: \u201cLe stelle vaghe e lor viaggio torto.\u201d (\u201cThe\nwandering stars and their winding way.\u201d) _Sonetto de Morte di Madonna\nLaura._\n------------------------------------------------------------------------\n\nBut the most famous passage relating to the sun\u2019s path and its aspect\nin strange latitudes is _Purg._ iv. 52-84.\n\nHere Dante is able at once to understand the startling appearance\nof the sun travelling to his left instead of his right, as seen on\nthe first morning in Purgatory, for he grasps the full meaning of\nVirgil\u2019s explanation, and caps it, in a way which seems astonishingly\nquick-witted to unastronomical readers!\n\nThe two poets had begun to climb the mountain just at sunrise, and sat\ndown to rest on a ledge at about half-past nine, looking east. Dante\nat first looked down at the shore, whence he had so painfully climbed,\nthen raised his eyes to the sun, and was amazed to find that its rays\nstruck him on the left shoulder.\n\nVirgil, seeing his astonishment, explains why the sun is going north\ninstead of south as it climbs the sky. The sun is now in Aries, and\ntherefore on the equator, as we know from several passages, but Virgil\nbegins by saying that if it were in Gemini [a more northerly sign] and\nkept to its ancient path, Dante would see it travelling still further\nnorthwards in its daily course. \u201cIf Castor and Pollux [stars in Gemini]\nwere in company with that Mirror [the sun] which carries his light up\nand down [_i.e._ goes north and south alternately], you would see the\nglowing zodiac [that part in which the sun is] revolving still closer\nto the Bears.\u201d Gemini is literally nearer to the constellations of the\nBears than Aries, but this is not the sense of Virgil\u2019s statement: he\nmeans merely to indicate the north in general (see Ptolemy, p. 157).\n\u201cTo understand why the sun goes north,\u201d Virgil says, \u201cyou must know\nthat this mountain and Zion [Jerusalem] are so situated on the earth\nthat one is precisely antipodal to the other; and so, the sun\u2019s path\nbeing between them, when he is viewed in one direction from Jerusalem,\nhe is viewed in the opposite direction from Purgatory. If you turn from\nthe east to your right to see him from Jerusalem, you must turn to your\nleft in Purgatory.\u201d Virgil speaks of the sun\u2019s path or the ecliptic as\nthe path which Pha\u00ebton was not able to keep, and he describes the two\nantipodal places as having one and the same horizon but two entirely\ndifferent hemispheres.\n\n\u201cCertainly,\u201d replies Dante, \u201cI have never seen anything so clearly as\nI now perceive what at first puzzled me. For the middle circle of the\ncelestial motion,[398] which is called the equator in a certain art\n[astronomy], and which always remains between the sun and winter, [the\nsun crosses it departing from us in either hemisphere at the autumnal\nequinox], here lies to the north of us, for the reason you have given\n[namely, that we are in the southern hemisphere], whilst the Hebrews\n[inhabitants of Jerusalem] see it towards the hot region [the south].\u201d\n\nObserve that the expression used of the equator \u201cche sempre riman\ntra il sole e il verno,\u201d[399] distinctly suggests the reversed\nseasons in the southern and northern hemispheres, so that Dante has\nno intention, as Dr. Moore suggests, of assuming by a poetic licence\nthat it is spring in Purgatory as well as in Italy.[400] It is autumn\nin the southern hemisphere, but this need not distress us: the holy\nMountain knows no inclement weather,[401] and in the Garden of Eden\non its summit spring flowers and autumn fruits eternally flourish\ntogether.[402]\n\nAn allusion is made to a tropical summer in \u201cla terra che perde\nombra.\u201d[403] Tropical Africa is intended, where the sun at certain\ntimes passes directly overhead, and therefore casts no shadows, as the\nAlexandrian astronomers had observed (see p. 117).\n\n------------------------------------------------------------------------\n[398] _Cf. Conv._ III. v. 76, 191.\n\n[399]\n \u201cWhich always remains between the sun and the winter.\u201d\n _Purg._ iv. 81.\n\n[400] _Studies in Dante_ iii. p. 166.\n\n[401] _Purg._ xxi. 46-48; _Purg._ xix. 38.\n\n[402] _Purg._ xxviii. 143.\n\n[403] \u201cThe land where shadows are lost.\u201d _Purg._ xxx. 89.\n------------------------------------------------------------------------\n\nDid Dante believe that no land exists anywhere in the southern\nhemisphere? There are some indications that he thought it possible to\npush the limits of the habitable earth a little beyond the equatorial\nboundary of Alfraganus. There would be no heresy in lengthening the\nsouthward extremities of Africa or Asia, because all that the Church\nforbade was to plant another land in the south, separated from us\nby a vast ocean or impassable torrid zone, and to people it with\ninhabitants, who could not therefore be descendants of Adam or have the\nGospel preached to them. Nor would there be any inconsistency with the\npoet\u2019s own description of our hemisphere as that covered by \u201cla gran\nsecca,\u201d[404] or with the voyage of Ulysses, on which he saw no land but\nthe Mountain of Purgatory; for he sailed south-west, not due south, and\nthe \u201cmondo senza gente\u201d[405] was \u201cdiretro al Sol.\u201d[406]\n\n------------------------------------------------------------------------\n[404] \u201cThe great dry land.\u201d _Inf._ xxxiv. 113.\n\n[405] \u201cThe unpeopled world.\u201d _Inf._ xxvi. 117.\n\n[406] \u201cBehind the sun.\u201d _Ibid._\n------------------------------------------------------------------------\n\nThe indications are as follows:\u2014\n\n(1) The passage quoted above, where it is said that the equator\n\u201cdivides the uncovered land from the ocean\u201d[407] is ambiguous in the\noriginal, and might mean \u201cdivides the land uncovered by Ocean.\u201d\n\n------------------------------------------------------------------------\n[407] _Conv._ III. v. 117, 118.\n------------------------------------------------------------------------\n\n(2) Shortly before, he has distinctly admitted that there is some land\nin the southern hemisphere, by saying that the north celestial pole is\nvisible to _nearly all_ the land not covered by sea, and the south is\nhidden from _nearly all_ of it. The first is true in any case, since\nthough the pole is theoretically visible as far as the equator, it is\noften hidden by mist or rising land on the northern horizon; but unless\nthe second \u201cnearly\u201d has been added by a (somewhat natural) mistake of a\ncopyist, it can only apply to lands in the southern hemisphere.[408]\n\n------------------------------------------------------------------------\n[408] Refraction makes the pole visible a little before one reaches the\nequator, but such refinements need not be considered in dealing with a\npopular work like the _Convivio_.\n------------------------------------------------------------------------\n\n(3) There is a stanza in _Canzone XV._ which suggests that Dante\nbelieved Ethiopia to be on the south side of the equator. Classical\nand medi\u00e6val cosmographers had very vague ideas about the extent and\nposition of this country. Dante describes a wind raised in its deserts\nby the sun, which _now_ is heating it (implying the time of summer?);\nbut the same wind, crossing the sea to Europe, darkens all _this_\nhemisphere, bringing clouds which fall in snow.\n\n \u201cLevasi della rena d\u2019Etiopia\n Un vento pellegrin, che l\u2019 aer turba,\n Per la spera del sol, ch\u2019 or la riscalda,\n E passa il mare, onde n\u2019adduce copia\n Di nebbia tal, che s\u2019 altro non la sturba\n Questo emisperio chiude tutto, e salda;\n E poi si solve, e cade in bianca falda\n Di fredda neve, ed in noiosa pioggia.\u201d[409]\n\n------------------------------------------------------------------------\n[409]\n \u201cThere riseth up from Ethiopia\u2019s sands\n A wind from far-off clime which rends the air,\n Through the sun\u2019s orb that heats it with its ray.\n The sea it crosses; thence, o\u2019er all the lands\n Such clouds it brings that but for wind more fair\n O\u2019er all our hemisphere \u2019twould hold its sway;\n And then it breaks and falls in whitest spray\n Of frozen snow and pestilential showers.\u201d\n _Canz._ xv. 14-21. (_Plumptre_).\n------------------------------------------------------------------------\n\nHowever, it may be said that \u201cor la riscalda\u201d[410] means merely\nthat it is always hot in the tropics, even when we have winter, and\nthat \u201cquesto emisperio\u201d[411] cannot possibly mean the whole of the\nterrestrial northern hemisphere from equator to pole, but simply\ndescribes the appearance of the hemispherical sky,[412] completely\ncovered with cloud.\n\nThese doubtful passages are not strong enough to set against the\nexplicit statement in the _Qu\u00e6stio_ that the habitable earth extends\nfrom the equator to the Arctic circle and no further.[413] Letters and\nreports from missionaries and traders, none of them scientific, did not\nshake Dante\u2019s faith in the limits laid down by Ptolemy and Alfraganus.\nHis geography was utterly wrong, but his astronomy was right; and\ntherefore, although he had no idea of what he would see on our globe in\nuntravelled latitudes, he knew exactly, and has described vividly, what\nhe would see in the sunny sky.\n\n------------------------------------------------------------------------\n[410] \u201cNow heats it.\u201d\n\n[411] \u201cThis hemisphere.\u201d\n\n[412] Just as in _Par._ xxviii. 80.\n\n[413] _Qu._ xix. 53-57, and repeated in xxi. 36-40.\n------------------------------------------------------------------------\n\n\n9. CELESTIAL PHENOMENA AND TIME.\n\nThe foregoing quotations have shown how well Dante understood\nthe changing appearances of the celestial phenomena as viewed\nfrom different latitudes: it now remains to be seen what were his\nconceptions of longitude.\n\nA difference in longitude between two places makes no difference in the\nstars, nor in the apparent paths of the heavenly bodies, but they come\nto the meridian sooner in the more easterly place; and as it is the\nmeridian passage of the sun which determines local time, this will vary\nin exact proportion to the distance east. When it is early morning in\nEngland, it is noon in Burmah, and evening in Fiji. As Alfraganus had\nobserved (following Ptolemy), a celestial phenomenon such as a lunar\neclipse, which is caused by an actual darkening of the moon\u2019s surface\nwhen immersed in Earth\u2019s shadow, is visible in every place where the\nmoon is above the horizon, though the local hour differs.\n\nIt is otherwise with a total solar eclipse, for this is only visible\nfrom the very small portion of Earth on which the moon\u2019s shadow falls\nas she passes between us and the sun (see fig. 44); and as this shadow\nmoves on, owing to her own motion and the diurnal revolution combined,\nthe eclipse becomes visible successively from different parts of\nthe earth. Dante realized this when he quoted the argument of some\ntheologians that the miraculous three hours\u2019 darkness described in\nthe Gospels could not have been caused by an eclipse of the sun, as\nAquinas and others had suggested, because it was visible all over the\nearth at the same absolute time, that is, during the Crucifixion.[414]\nSome said, he tells us, that the moon went back and placed herself\nbetween us and the sun (for the moon at Passover time was always full,\nand therefore opposite the sun), so that the sun\u2019s light should not\ncome down (to us on the earth); others, that the sun hid itself, for\na corresponding eclipse was seen by Spaniards and Indians as well as\nJews.[415] Spaniards and Indians were supposed to live at the extreme\nwestern and eastern limits of the habitable earth: they were 180\u00b0 in\nlongitude, or 12 hours in time, apart, and Jerusalem was midway between\nthem. Therefore the sun would be visible to all, though only just\nrising in India and just setting in Spain;[416] but it could not have\nbeen an eclipse that darkened it to all at the same time.\n\n------------------------------------------------------------------------\n[414] _Luke_ xxiii. 44.\n\n[415] _Par._ xxix. 97-102.\n\n[416] Dante believed the death of Christ to have taken place when it\nwas noon in Jerusalem. _Conv._ IV. xxiii. 105-106.\n------------------------------------------------------------------------\n\n[Illustration: Fig. 44. Lunar and Solar Eclipses.]\n\nThis passage shows that Dante was entirely orthodox and conservative\nin his geography, as far as longitude was concerned, and confirms us\nin the conclusion that he was so also with regard to latitude, and was\nnot likely to accept contemporary evidence about lands south of the\nequator, or stars unknown to Ptolemy. In the _Divine Comedy_ there are\nseveral passages which refer to the same system, as for instance where\nNight is described as covering the whole region from \u201cthe Shore\u201d to\nMorocco,[417] or where the time is stated to be noon on the Ganges,\nsunrise at Jerusalem, and midnight in Spain.[418] And in the _Qu\u00e6stio\nde Aqua et Terra_ the system is thus clearly explained:\u2014\n\n \u201cAs all these agree in believing [the naturalists,\n the astrologers, and the cosmographers], this\n habitable earth extends in longitude from Gades,\n which lies on the western boundaries of Hercules,\n as far as the mouths of the Ganges, as Orosius\n writes.[419] That longitude is such that at the\n equinox the sun is setting upon those who are at\n one of these boundaries, while it is rising upon\n those who are at the other, as astrologers have\n discovered by eclipses of the moon. Therefore the\n aforesaid boundaries must be 180 degrees distant in\n longitude, which is half the distance of the whole\n circumference.\u201d[420]\n\n------------------------------------------------------------------------\n[417] _Purg._ iv. 137-139.\n\n[418] _Purg._ xxvii. 1-5.\n\n[419] Orosius says: \u201cEurop\u00e6 in Hispania occidentalis oceanus termino\nest, maxime ubi apud Gades insulas Herculis column\u00e6 visuntur.... Asia\nad mediam frontem orientis habet in oceano Eoo ostia fluminis Gangis.\u201d\n\n[420] _Qu._ xix. 38-52.\n------------------------------------------------------------------------\n\nGades is not the city of Cadiz, but two islands (the \u201cGades Insul\u00e6\u201d of\nOrosius), on which Hercules was said to have set up his Pillars, as a\nsign that no one should venture further; and they were thought to lie\nin the mouth of what we call the Straits of Gibraltar:[421]\u2014\n\n------------------------------------------------------------------------\n[421] Moore, _Studies in Dante_ iii. p. 124.\n------------------------------------------------------------------------\n\n \u201cquella foce stretta,\n Ov\u2019 Ercule segn\u00f2 li suoi riguardi,\n Accioch\u00e8 l\u2019uom pi\u00f9 oltre non si metta.\u201d[422]\n\n------------------------------------------------------------------------\n[422]\n \u201cThe strait pass, where Hercules ordained\n The boundaries not to be o\u2019erstepped by man.\u201d\n _Inf._ xxvi. 107-109. (_Carey_).\n------------------------------------------------------------------------\n\nThrough these Ulysses sailed, never to return.[423]\n\n------------------------------------------------------------------------\n[423] _Inf._ xxvi. 106-142.\n------------------------------------------------------------------------\n\nIt is difficult to believe that a lunar eclipse had ever been observed\nsimultaneously, and the local time compared, on the Ganges and at\nGibraltar, as the above quotation from the _Qu\u00e6stio_ declares: and if\nit had been, the astrologers, the cosmographers, and the naturalists\nwould have found out that they were greatly mistaken, for the distance\nis little more than half what they thought. All that Ptolemy had said\nwas that this was the right method for calculating longitudes, and he\ngave as an example an eclipse which had been seen at Arbela at the\nfifth hour and at Carthage at the second hour.[424] It was, in fact, an\nexcellent method, and the only one before the day of chronographs and\ntelegraphs; and it seems to have been assumed that Ptolemy\u2019s guess of\n180\u00b0 for the extent in longitude of the inhabited earth was based upon\nit.\n\n------------------------------------------------------------------------\n[424] _Ptolemy\u2019s Geography_, Bk. I.\n------------------------------------------------------------------------\n\nThen this 180\u00b0 was considered, in the Middle Ages, as divided into two\nequal parts, the western half containing Europe and Africa, the eastern\ncontaining Asia. On the western front of Asia lay Jerusalem, thus\nholding the central position in the inhabited earth which was thought\nto be her right, on the authority of certain Scripture texts, as we\nsaw.[425] This gave the Mediterranean a length of 90\u00b0, which of course\nis vastly too great. Even Ptolemy had only estimated it at 62\u00b0, and the\nAlfonsine Tables made it 52\u00b0, while the true distance is only about 42\u00b0.\n\n------------------------------------------------------------------------\n[425] See p. 176.\n------------------------------------------------------------------------\n\nLatitude, however, was much more easily measured than longitude, for\nit was only necessary to take the height of the pole star above the\nhorizon with an astrolabe; and the latitude of Jerusalem is really\njust about midway between the supposed limits of the habitable earth,\nthe equator and arctic circle, for it is nearly 32\u00b0 north.\n\nSome daring spirits ventured to suggest that the dry land stretched\nmuch further round the globe than was commonly supposed, so that one\nmight sail from Spain to Asia in quite a short time, and they sheltered\nthemselves behind the great names of Aristotle, Seneca, Pliny, and\nEsdras.[426] Albertus Magnus quotes Aristotle to this effect, although\nin another part of the same book (his _De C\u00e6lo et Mundo_), he repeats\nthe usual phrase about the habitable Earth being all contained within\none of the northern quadrants of earth. Roger Bacon expresses himself\nmore boldly, and it is possible that he was impressed by the long\njourney of the Franciscan friar Rubruquis, on his mission to Central\nAsia, from St. Louis of France to the Emperor of the Mongols. Besides\nrelating the story of this journey, Bacon speaks of men who were known\nto live in tropical Taprobane (Ceylon), and if there, why not also\nsouth of Capricorn? There may be delightful countries there, since it\nis the better and nobler part of the world, as Aristotle and Averro\u00ebs\ntaught.\n\nMoreover, Dante\u2019s own countryman, the learned Pietro d\u2019Abano,\nmaintained that there are habitable lands on, and even beyond the\nequator, and did not hesitate to quote conversations with Marco Polo\nas evidence, although this \u201cmost extensive traveller and most diligent\nenquirer\u201d was accounted a romancer by most of his contemporaries. Had\nnot Messer Marco told him that in islands south of the equator he had\nseen not only great rams with coarse stiff wool like the bristles of\npigs, but human beings?[427]\n\n------------------------------------------------------------------------\n[426] _Esdras_ II. vi. 42.\n\n[427] Beazley, _Dawn of Geography_ iii. 28, 29.\n------------------------------------------------------------------------\n\nRoger Bacon was banished from Oxford on a charge of heresy and\nwitchcraft: Pietro d\u2019Abano escaped the Inquisition by dying, in 1316.\nMen such as these belonged to the new age that was coming, the age\nthat would throw away the old lesson-books, and begin to discover for\nitself\u2014and they suffered in consequence. Dante belonged heart and soul\nto his own era, and clung passionately to its ideals and traditions.\nFor him the Ganges still flowed into the all-surrounding ocean on\nthe east coast of Asia, 90 degrees from Jerusalem, as Orosius had\npictured it, and there is not the faintest echo in his writings of the\nvoyages of his countrymen, Corvino and his bishops, or Polo and his\ncompanions,[428] between \u201cGreater India\u201d and \u201cZayton\u201d (Amoy harbour),\nalthough they surely must have recognized, when they praised the great\nrivers of China, that these flowed into a sea many days\u2019 journey\nbeyond that into which the Ganges rolled its waters. Nor is there, on\nthe other hand, any hint of the monstrous races with which Dark-Age\nsuperstition had peopled the remote regions of the earth, although\nthey were regularly represented on the maps of that time. It is true\nthat the \u201cportolani,\u201d or handy charts, of which the earliest known\ndate from Dante\u2019s life-time, showed none of these things, but depicted\nthe coast-lands of the Mediterranean and Black Seas with marvellous\naccuracy: but they were only for pilots and merchant captains, and\nhad nothing to do with scholars. The maps Dante would see were hung\non church or monastery walls, or illustrated learned books; and the\nmappe-monde of Cardinal Heinrich of Mainz may be taken as typical of\nthem all. It much resembles our great Hereford Map of the World, and\nwas probably copied from the same original design.\n\n------------------------------------------------------------------------\n[428] Corvino and Marco Polo made the voyage in the same year, 1292,\nbut in reverse directions.\n------------------------------------------------------------------------\n\nIt is two hundred years older than Dante, but so stationary was\ngeography throughout the Middle Ages that it might have been executed\nin his day, or, except for a few details, several centuries earlier.\n\nMedi\u00e6val maps are as fascinating as a fairy tale, which indeed they\nmuch resemble. The shape is conventional, and not supposed to represent\nthe true shape of the habitable earth; it is sometimes circular,\nsometimes quadrilateral, occasionally oval, as in the present instance.\nThe east is here, as usual, at the top, and there we see the Paradise\nof Adam and Eve, and close beside it, to the north, the River Ganges,\nflowing into the great ocean which surrounds all the land. At the\nopposite or western extremity are the Pillars of Hercules, which two\nangels appear to be guarding. In the centre, but not so exactly or\nconspicuously central as in some other maps, we find \u201cHierusalem.\u201d\nAlong the south is the long narrow continent of Africa, with the Atlas\nand Ethiopian mountains; and the Nile, rising far in the south-west,\nafter mysterious submergences and reappearances, finally flows into\nthe Mediterranean, past the pictured Pyramids, here strangely called\n(according to Dark-Age myth) the Barns of Joseph. In the north another\nAngel points to the country where dwell the Gog-Magogs, and not far\noff are the lands of the Hyperboreans, here described as untroubled\nby disease or discord, of the \u201cmost wicked\u201d Gryphons, and of the\nDog-headed folk, adjoining the Arctic Ocean.\n\nItaly is a very large country, roughly triangular, and in the\nMediterranean to the south lie Sicily, the whirlpool Charybdis, the\nrock Scylla, Sardinia, Corsica, and other islands. Rome is figured as a\nbattlemented city, about halfway between Jerusalem and the Pillars of\nHercules.\n\n[Illustration: MAP OF THE WORLD BY HEINRICH OF MAINZ, ABOUT A.D. 1110.\n\n_To face p. 344._\n\n_Reproduced by permission from Beazley\u2019s \u201cDawn of Modern Geography.\u201d_]\n\nThis is where Dante also places the imperial city, for in his system\nit is about 45\u00b0, or 3 hours, east of Gades and west of Jerusalem. He\ntells us in one place that it was vespers in Naples when the sun rose\nin Purgatory,[429] and in another that when it was vespers or three\no\u2019clock in the afternoon in Purgatory, it was midnight \u201chere\u201d[430]\nwhich may mean Florence or Italy in general; both these statements\nindicate a difference of nine hours or 135\u00b0 between Italy and\nPurgatory. Purgatory in the _Divine Comedy_ is exactly antipodal to\nJerusalem, and therefore twelve hours distant in time;[431] and for\nthe sake of his allegory Dante has so far departed from tradition as\nto place the Earthly Paradise here also.[432] These five places may\ntherefore be diagramatically represented thus:\u2014\n\n------------------------------------------------------------------------\n[429] _Purg._ iii. 25.\n\n[430] _Purg._ xv. 1-6.\n\n[431] _Purg._ iv. 68-71; xxvii. 1-5.\n\n[432] _Purg._ xxviii. 142. Opinions differed as to its exact site, and\nsome placed it in the ocean beyond the eastern limit of the habitable\nearth. In _V. E._ I. viii. 6-10, Dante says that the root of the human\nrace was planted in eastern lands, but this refers to Adam\u2019s home after\nthe expulsion from Paradise.\n------------------------------------------------------------------------\n\n +---------------------------------------------------------+\n EARLY <---------------- TIME ----------------------> LATE\n 12 hours 6hrs. 3hrs. 6hrs. 12 hours\n ---+----------+-------+----+---------+-----------+--------\n\n Purgatory Gades Italy Jerusalem Ganes Purgatory\n\n ---+----------+-------+----+---------+-----------+--------\n 180\u00b0 90\u00b0 45\u00b0 0\u00b0 90\u00b0 180\u00b0\n WEST <--------------- LONGITUDE --------------------> EAST\n +---------------------------------------------------------+\n\nWith this key, Dante\u2019s fondness for describing the time at one place by\nmentioning one of the others need be no stumbling-block, as it is to\nmany readers.\n\nThe fact is that though Dante had none of our opportunities for\nchanging time-reckoning by long journeys, nor for communicating with\nfriends at the other side of the world, who wake while we sleep, the\nmarvellous daily revolution of the skies had a fascination for him,\nand he delighted to picture a glorious sunrise taking place in one\ncountry while in another it was high noon, or the middle of the night.\nThus, the beautiful description of the stars fading in the growing\nlight of dawn, which we quoted above, is preceded by a picture of the\nsun glowing on the meridian some 6000 miles away (rather more than a\nquarter the circumference of the globe), while with us Earth\u2019s shadow\nhas sunk almost to a level plane.[433]\n\nAgain, Folco of Marseilles, when describing his birthplace, says that\nthe greatest of all the seas (the Mediterranean) except the ocean which\nencircles all the habitable earth, stretches so far against the sun\n(i.e. from west to east), that the line of sky which is on its horizon\nat one end is on its meridian at the other.[434] If the sun were\nseen just rising on the eastern horizon at Gades, it would be on the\nmeridian at Jerusalem and the time would there be noon.\n\n------------------------------------------------------------------------\n[433] _Par._ xxx. 1-3.\n\n[434] _Par._ ix. 82-87.\n------------------------------------------------------------------------\n\nDante\u2019s hours are always reckoned from sunrise, and they are the\n\u201ctemporary\u201d or Church hours. He defines both kinds in the _Convivio_.\nThe same lines of his Ode which provided him with a text whereon to\ndiscourse of the sun\u2019s movements, give him occasion to treat of the\ndivision of each day into hours, thus:\u2014\n\n \u201cI say that the sun, in circling round the world,\n _ne\u2019er beholdeth aught so noble as this lady_, from\n which it follows that she is, as the words affirm,\n the most noble of all the things on which the sun\n shines. And I say _in that hour_, etc. Wherefore\n we must know that the _hour_ is understood in\n two senses by astrologers. One sense is employed\n when they assign twenty-four hours to the day and\n night, that is, twelve to the day and twelve to the\n night, however long or short the day may be. And\n these hours become short or long in the day and in\n the night, according as the day and night wax and\n wane. And the Church uses hours in this sense when\n she speaks of Prime, Tierce, Sext, and None; and\n these are called temporal hours. The other sense is\n employed when, of the twenty-four hours alloted to\n the day and night, the day has sometimes fifteen\n and the night nine, and sometimes the night has\n sixteen and the day eight assigned to it, according\n as the day and the night wax and wane; and these\n are called equal hours. And at the equinox these\n latter are always one and the same with those which\n are called temporal; for it must needs be so when\n the day and the night are of the same length.\u201d[435]\n\nThe choice of these two examples of unequal days and nights seems to be\nanother instance of Dante\u2019s dependence upon Alfraganus, for in Chapter\nVIII. of the _Elementa Astronomica_ we read that the middle of the\nseventh climate (in which the inequality is greatest) has a longest day\nof 16 hours, and the middle of the fifth, of 15 hours; and in chapter\nIX. we find that Magna Roma is situated in the fifth climate.\n\nIn the fourth treatise of the _Convivio_, Dante returns to the same\nsubject, and enters into further detail about Church hours and\ndivisions of the day.[436] Our lives, like the arch of heaven which is\nalways above us, consist of a rise and a decline, with a culminating\npoint, and this point he fixes as normally reached at a man\u2019s 35th\nyear, as Ristoro had also done.[437] In the same way the day rises and\ndeclines, and culminates at the sixth hour; and it is the most noble\nhour of the day and the most virtuous (in the old Latin sense of virtue\nas strength, efficacy).\n\n------------------------------------------------------------------------\n[435] _Conv._ III. vi. 7-32.\n\n[436] _Conv._ IV. xxiii. 50 to end.\n\n[437] _Comp. del Mondo_, I. xxii.\n \u201cLa sesta ora, cio\u00e8 il mezzo del d\u00ec, \u00e8 la pi\u00f9\n nobile di tutto il d\u00ec, e la pi\u00f9 vertuosa.\u201d[438]\n\n[438] \u201cThe sixth hour, that is, the middle of the day, is the most\nnoble of all the day, and the most virtuous.\u201d\n------------------------------------------------------------------------\n\nThis means the whole of the sixth hour (as we should say, from 11 to\n12 o\u2019clock): the beginning of the seventh hour is the exact moment of\nnoon, after which the day begins to decline. It was for this reason,\nDante believes, that Christ chose to die during the sixth hour,[439]\nand during his 34th year, for then the day and his human life were both\nat their culmination, and had not begun to decline.\n\n------------------------------------------------------------------------\n[439] _Luke_ xxiii. 44-46. Dante understands this to mean that death\ntook place at about the sixth hour, not the ninth.\n------------------------------------------------------------------------\n\nThere was some difference in the methods of reckoning the hours for\nChurch offices, but Dante tells in this same passage which of them he\nconsidered right, and he follows it consistently in his works. The\nChurch day was divided into four parts, viz.:\u2014\n\n At the equinox=\n Tierce, Sunrise to the end of the third hour 6 to 9 a.m.\n Sext, Fourth to end of sixth hour 9 a.m. to 12 noon\n Nones, Seventh to end of ninth 12 noon to 3 p.m.\n Vespers, Tenth hour to sunset 3 to 6 p.m.\n\nTwo of the Church offices were to be said at the beginning, and one at\nthe end, of these periods, as follows:\u2014\n\n Tierce, at the end _i.e._ 9 a.m. at the equinox.\n Nones, at the beginning _i.e._ 12 noon.\n Vespers, \u201d \u201d _i.e._ 3 p.m. at the equinox.\n\nThus sext is omitted altogether, and Dante says that the reason for\nthe arrangement is to approximate in every case to that hour which is\nthe noblest of the whole day, the sixth.\n\nMid-tierce was halfway through the period from sunrise to the end of\nthe third hour, that is, 7.30 a.m. at the time of the equinox; and\nmid-nones and mid-vespers were counted in the same way.\n\nAs an instance of reckoning hours by the sun, we may quote the reply of\nAdam when Dante desired to know how long time he had spent in Eden:\n\n \u201cDalla prim\u2019 ora a quella che seconda,\n Come il sol muta quadra, l\u2019ora sesta.\u201d[440]\n\n------------------------------------------------------------------------\n[440]\n \u201cFrom the first hour to that which cometh next\n (As the sun changes quarter) to the sixth.\u201d\n _Par._ xxvi. 141-142. (_Carey_).\n------------------------------------------------------------------------\n\nJust as the time of day may be told, if one is accustomed to watch the\nsun, by noting how much of the daily course has been run, so the time\nof day or night (according to her phase) may be told by the moon; only\nwith her we must take into consideration the rapid and variable motion\neastwards in the zodiac. Alfraganus says that her _mean_ daily motion\nin longitude is 13\u00b0 and nearly 11 minutes,[441] but that a small amount\nmust be added or subtracted every day in order to find her true motion.\nAs a clock, therefore, for use in daily life, she leaves much to be\ndesired. This daily motion makes her fall constantly behind the sun, so\nthat she loses time every day, and not even the same amount of time;\nfor though she crosses the meridian on an average 50\u00bd minutes later\neach day, the interval is sometimes only 38 minutes and sometimes as\nmuch as 66 minutes. And her times of setting and rising are even more\nvariable.\n\n------------------------------------------------------------------------\n[441] It is easily seen that this is correct, if we divide the 360\u00b0 of\nthe moon\u2019s path through the zodiac by the 27 days and eight hours in\nwhich she traverses it, and returns to the same star. Brunetto Latini\nsays \u201cLa lune s\u2019esloigne _dou Soleil_ chascun jor xiii degrez po s\u2019en\nfaut,\u201d but he is wrong, having apparently forgotten that the sun is\nalso moving in the same direction, at the average rate of nearly 1\u00b0\ndaily.\n------------------------------------------------------------------------\n\nThis is easily understood if we remember how much the sun\u2019s time\nof setting varies throughout the year, according to the part of the\nzodiac in which he is travelling, and consider that what the sun does\nin a year the moon does in a month. And in her case the effect is\nsometimes exaggerated, sometimes diminished, for her path in the zodiac\nis inclined to the sun\u2019s path; moreover, her greatest departure from\nit to north and south takes place in different parts of the zodiac at\ndifferent times. These facts were well known to Ptolemy and to medi\u00e6val\nastronomers, and everyone who watches the moon must have noticed how\nvariable are the intervals between one moonrise or one moonset and the\nnext.\n\nThe extent of variability also depends upon our latitude (just as with\nsunrises and sunsets); and in Florence the retardation in one day may\nsometimes be only twenty minutes, sometimes an hour and twenty minutes.\nThe difference would be less in Dante\u2019s Purgatory, since this was in\nlatitude 32\u00b0 south, and the intervals between moonset and moonset\nbecome less variable in length as we approach the equator, just as the\ndays become less unequal all the year round. Still, they would vary\na good deal, so we must conclude that Dante only means to indicate\nthe time quite roughly when he uses the moon as a clock. As a matter\nof fact, he seldom does so in the _Divine Comedy_ without giving us\nanother clue to the time as well.\n\nThese passages all belong to a most interesting series of time\nindications, which we may now proceed to examine.\n\n\n\n\n_VI. DANTE\u2019S JOURNEY THROUGH THE THREE REALMS: INDICATIONS OF TIME AND\nDIRECTION BY MEANS OF THE SKIES._\n\n\n1. TIME REFERENCES IN THE DIVINE COMEDY.\n\nThe plan of the universe through which Dante feigns himself to have\njourneyed is familiar to all readers of the _Divine Comedy_. Hell,\nas the Fathers taught, was a subterranean cavity, and Dante pictures\nit as an inverted cone, whose apex reaches the exact centre of Earth\nand therefore of the universe. It is situated vertically underneath\nJerusalem, the centre of the inhabited Earth. He departs from the\nFathers, however, in removing Purgatory from these dim regions, and\nplacing it on an island in the midst of the ocean of the uninhabited\nhemisphere, exactly at the antipodes of Jerusalem. On this island rises\na mountain whose immensely lofty summit reaches the upper regions of\nthe atmosphere, and upon the summit is the Eden of our first parents.\nThis original conception is an extraordinary gain, both from the\nartistic and the allegorical points of view; and it is in harmony\nwith the idea of Aristotle, and of many medi\u00e6val writers, that the\nsouthern hemisphere was the \u201cnobler\u201d part of Earth. Here, then, man was\npermitted to dwell before the Fall, and hither come repentant souls,\nsaved from Hell, but not yet pure enough to enter Heaven. Paradise\nconsists of all the spheres of medi\u00e6val astronomy, and the poet\nrises from one to another until he finally reaches the all-embracing\nEmpyrean, where his vision ends.\n\nNowhere does he describe this scheme in full, but it was evidently\nclear in his own mind, and by following him step by step in his journey\nit is easily reconstructed, and is represented in the accompanying\ndiagram.\n\nIn the same way he never states how long a time he spent on this\nvisionary journey, yet this also he had definitely determined, and in\neach Cantica he refers once to the period of time alloted to each realm.\n\nIn the last Circle but one of the Inferno, he is warned by Virgil\nthat the time allowed is drawing to a close;[442] in the last but one\nof the Purgatorio Virgil urges him to make the best use of the time\nappointed;[443] and in the Paradiso, just before the final vision, St.\nBernard tells him that the time of his trance is nearly over.[444]\n\n------------------------------------------------------------------------\n[442] _Inf._ xxix. 11.\n\n[443] _Purg._ xxiii. 5, 6.\n\n[444] _Par._ xxxii. 139.\n------------------------------------------------------------------------\n\nIn the first Canto, which is introductory to the whole _Commedia_,\nhe mentions the time at which he assumes that his vision began. It\nwas \u201cnel mezzo del cammin di nostra vita,\u201d[445] which may mean simply\nthat he was middle-aged, or comparing it with the passage in the\n_Convivio_ quoted earlier (see p. 347), we may suppose it to mean\nthat he was exactly in his 35th year. The season was spring\u2014\u201cla dolce\nstagione,\u201d[446] and when night was over the sun rose among those stars\nwhich were with him at the Creation, which was believed to have taken\nplace at the vernal equinox some sixty-five centuries before.\n\n------------------------------------------------------------------------\n[445] \u201cMidway in the journey of our life.\u201d _Inf._ i. 1.\n\n[446] \u201cThe sweet season.\u201d _Inf._ i. 43.\n\n \u201cIl Sol montava su con quelle stelle\n Ch\u2019 eran con lui quando l\u2019Amor Divino\n Mosse da prima quelle cose belle.\u201d[447]\n\n[447]\n \u201cAloft the sun ascended with those stars\n That with him rose when Love Divine first moved\n Those its fair works.\u201d\n _Inf._ i. 38-40. (_Carey_).\n------------------------------------------------------------------------\n\n[Illustration: Fig. 45. The Universe of Dante.]\n\nThe expression \u201cquelle stelle,\u201d[448] however, shows us that Dante\ndoes not intend to be pedantically accurate, which would indeed be\ninartistic in a poem. He speaks several times of the supposed slow\nmotion of the star sphere,[449] and although he never mentions its\neffect in shifting the place of the equinox continually among the\nstars, we can hardly imagine that he failed to understand this. He knew\nquite well, therefore, that the stars which accompanied the sun in\nthat first springtime of the world could not be the same stars which\nrose with him now. But astronomers had agreed to call the part of the\nsky which contains the vernal equinox by its old name, and it would be\nexceedingly tiresome if he were to distinguish, every time he mentioned\nthem, between the zodiacal constellations and the zodiacal signs; there\nshall be no occasion, therefore, to stop and consider which he means,\nand no ambiguity: he assumes once for all that they always have been\nand always are identical, that the \u201cfirst point of Aries\u201d or vernal\nequinox is now and always at the beginning of the constellation Aries.\nTo this assumption he is consistent throughout.\n\n------------------------------------------------------------------------\n[448] \u201cThose stars.\u201d\n\n[449] _Purg._ xi. 108; _Conv._ II. xv. 12-14.\n------------------------------------------------------------------------\n\nAnother important point to notice is that, since it is the time of\nthe equinox, there is no difference between \u201ctemporary\u201d and \u201cequal\u201d\nhours.[450] Days and nights are of equal length; sunrise and sunset\nare nearly at 6 a.m. and 6 p.m., according to our modern method\nof reckoning.[451] In this way also, and without any sacrifice of\nastronomical accuracy, the poet has simplified his time references for\nhis readers.\n\n------------------------------------------------------------------------\n[450] _Conv._ III. vi. 28-30.\n\n[451] On the day of the spring equinox the sun rises and sets a few\nminutes after six o\u2019clock, because we set our clocks not by the real\nsun but the more convenient \u201cmean sun.\u201d\n------------------------------------------------------------------------\n\nWe must observe, however, that the day is as uncertain as the year;\nfor, although it is certainly near the equinox, \u201cquelle stelle\u201d may\nmean exactly the first point of Aries or only the constellation Aries\nin general. From this Canto alone, therefore, we cannot be sure of the\nexact date.\n\nFrom other allusions of various kinds, scattered throughout the\n_Divine Comedy_, we gather that Dante did intend a definite date to be\nunderstood, but unfortunately the data by which he means to fix it are\nthemselves so ambiguous that commentators differ as to the day, the\nmonth, and the year. The question has so direct a bearing on Dante\u2019s\nastronomy that we cannot shirk it; but for the present, leaving it\naside, let us deal merely with the hour, which is distinctly stated\nfrom the first, and indicated in a number of passages so clearly that\nreaders with an elementary knowledge of the apparent movements of the\nheavenly bodies can find little difficulty in following Virgil and\nDante through their journey, seeing exactly how many days it required,\nand frequently at what hour of day or night they were in a particular\nspot. If my readers are not now in possession of this elementary\nknowledge, this book has been written in vain.\n\nI give below a list of all the hour-indications, astronomical and\nothers, for the sake of clearness and completeness; but I omit for the\npresent those that indicate only the date, and merely call the days\nthe first, second, etc. These passages, though they are only to be\nunderstood in a popular sense, prove quite as clearly as the elaborate\nastronomical explanations in the _Convivio_ how deep an interest\nDante always took in astronomy; and a study of them shows that he had\ncarefully considered the positions of the heavenly bodies and their\nmovements during the progress of the action in his poem.\n\n TIME REFERENCES IN THE DIVINE COMEDY\n\n Night. In the Forest. Moon full\n (see below, _Inf._ xx. 127-129, and _Purg._ xxiii. 118-121).\n\n \u201cLa notte ch\u2019 i\u2019 passai.\u201d\n _Inf._ i. 21.\n \u201cThe night that I had spent.\u201d\n ----------------------------------------------------------------\n 1st day. Just before sunrise.\n At the foot of the Hill.\n\n \u201cMa poi ch\u2019 io fui al pi\u00e8 d\u2019un colle giunto,\n . . . . .\n Guardai in alto, e vidi le sue spalle\n Vestite gi\u00e0 de\u2019 raggi del pianeta\n Che mena dritto altrui per ogni calle.\u201d\n _Inf._ i. 13-18.\n\n \u201cBut after I had reached a mountain\u2019s foot,\n . . . . . .\n Upward I looked, and I beheld its shoulders\n Vested already with that planet\u2019s rays\n Which leadeth others right by every road.\u201d\n ----------------------------------------------------------------\n Sunrise 6 a.m.[452]\n Climbing the Hill.\n\n \u201cTempo era dal principio del mattino,\n E il sol montava su con quelle stelle\n Ch\u2019eran con lui quando l\u2019 Amor divino\n Mosse da prima quelle cose belle.\u201d\n _Inf._ i. 37-40.\n\n \u201cThe time was the beginning of the morning,\n And up the sun was mounting with those stars\n That with him were, what time the Love Divine\n At first in motion set those beautous things.\u201d\n\n------------------------------------------------------------------------\n[452] The clock-hours in this column are not to be regarded as if taken\nfrom a railway time-table! Sunrise is at 6 a.m. within a few minutes\nonly, for the reasons above stated, viz.: our clocks are regulated by\nthe \u201cmean\u201d sun, and it is not necessarily the exact day of the equinox\nwhen the vision begins.\n------------------------------------------------------------------------\n\n Evening twilight.\n At the Gate of Hell.\n\n \u201cLo giorno se n\u2019andava, e l\u2019 aer bruno....\u201d\n _Inf._ ii. 1.\n\n \u201cDay was departing, and the brown air....\u201d\n ----------------------------------------------------------------\n Midnight.\n Crossing the fourth circle.\n\n \u201cGi\u00e0 ogni stella cade, che saliva\n Quando mi mossi.\u201d\n _Inf._ vii. 98, 99.\n\n \u201cAlready sinks each star that was ascending\n When I set out.\u201d\n ----------------------------------------------------------------\n 2nd day. About 2 hrs. before sunrise (4 a.m.)\n On the edge of the cliff, preparing to descend to the 7th\n circle.\n\n \u201cI Pesci guizzan su per l\u2019 orizzonta,\n E il Carro tutto sovra il Coro giace.\u201d\n _Inf._ xi. 113, 114.\n\n \u201cQuivering are the Fishes on the horizon,\n And the Wain wholly over Caurus lies.\u201d\n ----------------------------------------------------------------\n (Dante refers to the previous day.)\n In the 7th circle.\n\n \u201cMi smarri\u2019 in una valle.\n . . . . .\n Pur ier mattina le volsi le spalle.\u201d\n _Inf._ xv. 50-52.\n\n \u201cI lost me in a valley.\n . . . . .\n But yestermorn I turned my back upon it.\u201d\n ----------------------------------------------------------------\n After sunrise, between 6 and 7 a.m.\n Leaving the 4th Pit of Circle VIII.\n (Virgil reminds Dante of the night before last, spent in the\n Forest.)\n\n \u201cGi\u00e0 tiene il confine\n D\u2019 ambedue gli emisperi e tocca l\u2019 onda\n Sotto Sibilia Caino e le spine;\n E gi\u00e0 iernotte fu la luna tonda;\n Ben ten dee ricordar, ch\u00e8 non ti nocque\n Alcuna volta per la selva fonda.\u201d\n _Inf._ xx. 124-129.\n\n \u201c... Already holds the confines\n Of both the hemispheres, and under Seville\n Touches the ocean-wave, Cain and the thorns;\n And yesternight the moon was round already;\n Thou shouldst remember well: it did not harm thee\n From time to time within the forest deep.\u201d\n ----------------------------------------------------------------\n 7 a.m.\n On the bridge over the 5th Pit.\n\n \u201cIer, pi\u00f9 oltre cinq\u2019 ore che quest\u2019 otta,\n Mille dugento con sessanta sei\n Anni compi\u00e8 che qui la via fu rotta.\u201d\n _Inf._ xxi. 112-114.\n\n \u201cYesterday, five hours later than this hour,\n One thousand and two hundred sixty-six\n Years were complete that here the way was broken.\u201d\n ----------------------------------------------------------------\n About 1 p.m.\n Leaving the 9th Pit.\n\n \u201cE gi\u00e0 la Luna \u00e8 sotto nostri piedi,\n Lo tempo \u00e8 poco omai che n\u2019\u00e8 concesso.\u201d\n _Inf._ xxix. 10, 11.\n\n \u201cAnd now the moon is underneath our feet.\n Henceforth the time allotted us is brief.\u201d\n ----------------------------------------------------------------\n Nightfall.\n At the bottom of the world.\n\n \u201cLa notte risurge; ed oramai\n \u00c8 da partir, ch\u00e8 tutto avem veduto.\u201d\n _Inf._ xxxiv. 68, 69.\n\n \u201cNight is reascending, and \u2019tis time\n That we depart, for we have seen the whole.\u201d\n ----------------------------------------------------------------\n 3rd day. (no night intervening) 7.30 a.m.\n In the new hemisphere\n\n \u201cGi\u00e0 il sole a mezza terza riede.\u201d\n _Inf._ xxxiv. 96.\n\n \u201cAnd now the sun to middle-tierce returns.\u201d\n ----------------------------------------------------------------\n 4th day. About an hour before sunrise (5 a.m.).\n On the island of Purgatory.\n\n \u201cE quindi uscimmo a riveder le stelle.\u201d\n _Inf._ xxxiv. 139.\n\n \u201cThence we came forth to see again the stars.\u201d\n\n \u201cLo bel pianeta che ad amar conforta\n Faceva tutto rider l\u2019 oriente,\n Velando i Pesci ch\u2019 erano in sua scorta.\u201d\n _Purg._ i. 19-21.\n\n \u201cThe beauteous planet that to love incites\n Was making all the orient to laugh,\n Veiling the Fishes that were in her escort.\u201d\n ----------------------------------------------------------------\n Dawn.\n\n \u201cLo sol vi mostrer\u00e0, che surge omai.\u201d\n _Purg._ i. 107.\n\n \u201cThe sun, which now is rising, will direct you.\u201d\n\n \u201cL\u2019 alba vinceva l\u2019 ora mattutina.\u201d\n _Purg._ i. 115.\n\n \u201cThe dawn was vanquishing the matin hour.\u201d\n ----------------------------------------------------------------\n Sun just below east horizon.\n On the Shore of the Island.\n\n \u201cGi\u00e0 era il sole all\u2019 orizzonte giunto\n Lo cui meridian cerchio coperchia\n Jerusalem col suo pi\u00f9 alto punto;\n E la notte, che opposita a lui cerchia,\n Uscia di Gange fuor con le bilance\n Che le caggion di man quando soperchia;\n Si che le bianche e le vermilie guance,\n L\u00e0 dove io era, della bella Aurora,\n Per troppa etate divenivan rance.\u201d\n _Purg._ ii. 1-9.\n\n \u201cAlready had the sun the horizon reached\n Whose circle of meridian covers o\u2019er\n Jerusalem with its most lofty point;\n And night, that opposite to him revolves,\n Was issuing forth from Ganges, with the scales\n That fall from out her hand when she exceedeth;\n So that the white and the vermilion cheeks\n Of beautiful Aurora, where I was,\n By too great age were changing into orange.\u201d\n ----------------------------------------------------------------\n Sun risen.\n\n \u201cDa tutte parti saettava il giorno\n Lo sol, ch\u2019avea con le saette conte\n Di mezzo il ciel cacciato il Capricorno.\u201d\n _Purg._ ii. 55-57.\n\n \u201cOn every side was darting forth the day\n The sun, who had with his resplendent shafts\n From the mid-heaven chased forth the Capricorn.\u201d\n ----------------------------------------------------------------\n Soon after sunrise.\n Walking westward, towards the Mountain of Purgatory.\n\n \u201cLo sol che retro fiammeggiava roggio.\u201d\n _Purg._ iii. 16.\n\n \u201cThe sun that in our rear was flaming red.\u201d\n ----------------------------------------------------------------\n Shortly after 6 a.m. (3 p.m. in Italy).\n\n \u201cVespero \u00e8 gi\u00e0 col\u00e0 dov\u2019 \u00e8 sepolto\n Lo corpo dentro al quale io facea ombra.\u201d\n _Purg._ iii. 25, 26.\n\n \u201c\u2019Tis vespers there already where is buried\n The body within which I cast a shadow.\u201d\n ----------------------------------------------------------------\n About 9.30 a.m.\n At the foot of the Mountain.\n\n \u201cBen cinquanta gradi salito era\n Lo sole.\u201d\n _Purg._ iv. 15, 16.\n\n \u201cFifty full degrees uprisen was\n The sun.\u201d\n ----------------------------------------------------------------\n Midday.\n On a ledge of the Mountain (Anti-purgatory).\n\n \u201cVedi ch\u2019\u00e8 tocco\n Meridian dal sole, e dalla riva.\n Copre la notte gi\u00e0 col pi\u00e8 Morrocco.\u201d\n _Purg._ iv. 137-139.\n\n \u201cSee, the sun has touched\n Meridian, and from the shore the night\n Covers already with her foot Morocco.\u201d\n ----------------------------------------------------------------\n Afternoon.\n Climbing the eastern slope of the Mountain.\n\n \u201cVedi omai che il poggio l\u2019 ombra getta.\n . . . . .\n Prima che sii lass\u00f9 tornar vedrai\n Colui che gi\u00e0 si copre della costa,\n S\u00ec che i suoi raggi tu romper non fai.\u201d\n _Purg._ vi. 51-57.\n\n \u201cSee, e\u2019en now the hill a shadow casts.\n . . . . .\n Ere thou art up there, thou shalt see return\n Him, who now hides himself behind the hill,\n So that thou dost not interrupt his rays.\u201d\n ----------------------------------------------------------------\n Evening.\n\n \u201cVedi gi\u00e0 come dichina il giorno.\u201d\n _Purg._ vii. 43.\n\n \u201cSee already how the day declines.\u201d\n ----------------------------------------------------------------\n Sunset (6 p.m.).\n In the Flowery Valley, on the Mountain-side.\n\n \u201cEra gi\u00e0 l\u2019ora che volge il disio\n Ai naviganti e intenerisce il core,\n Lo di ch\u2019han detto ai dolci amici addio;\n E che lo nuovo peregrin d\u2019 amore\n Punge, se ode squilla di lontano\n Che paia il giorno pianger che si more.\u201d\n _Purg._ viii. 1-6.\n\n \u201c\u2019Twas on the hour that turneth back desire\n In those who sail the sea, and melts the heart,\n The day they\u2019ve said to their sweet friends farewell;\n And the new pilgrim penetrates with love,\n If he doth hear from far away a bell\n That seemeth to deplore the dying day.\u201d\n ----------------------------------------------------------------\n Evening twilight.\n\n \u201cTempo era gi\u00e0 che l\u2019 aer s\u2019annerava.\u201d\n _Purg._ viii. 49.\n\n \u201cAlready now the air was growing dark.\u201d\n ----------------------------------------------------------------\n (Dante refers to the morning of the same day.)\n\n \u201cPer entro il lochi tristi\n Venni stamane.\u201d\n _Purg._ viii. 58, 59.\n\n \u201cThrough the dismal places\n I came this morn.\u201d\n ----------------------------------------------------------------\n Early night: about 7 p.m.\n\n \u201cLe quattro chiare stelle\n Che vedevi staman, son di l\u00e0 basse,\n E queste son salite ov\u2019 eran quelle.\u201d\n _Purg._ viii. 91-93.\n\n \u201cThe four resplendent stars\n Thou sawest this morning are down yonder low,\n And these have mounted up to where those were.\u201d\n ----------------------------------------------------------------\n Shortly before moonrise, between 8 and 9 p.m.\n\n \u201cLa concubina di Titone antico\n Gi\u00e0 s\u2019imbiancava al balco d\u2019oriente,\n Fuor delle braccia del suo dolce amico;\n Di gemme la sua fronte era lucente,\n Poste in figura del freddo animale\n Che con la coda percote la gente;\n E la notte de\u2019 passi con che sale\n Fatti avea due nel loco ov\u2019 eravamo,\n E il terzo gi\u00e0 chinava in giuso l\u2019 ale.\u201d\n _Purg._ ix. 1-9.\n\n \u201cThe concubine of old Tithonus now\n Gleamed white upon the eastern balcony,\n Forth from the arms of her sweet paramour;\n With gems her forehead all relucent was,\n Set in the shape of that cold animal\n Which with its tail doth smite amain the people;\n And of the steps with which she mounts the Night\n Had taken two in that place where we were,\n And now the third was bending down its wings.\u201d\n ----------------------------------------------------------------\n 5th day. Dawn.\n At the Gate of Purgatory.\n\n \u201cNell\u2019 ora che comincia i tristi lai\n La rondinella presso alla mattina.\u201d\n _Purg._ ix. 13, 14.\n\n \u201cJust at the hour when her sad lay begins\n The little swallow, near unto the morning.\u201d\n\n (See also ix. 52 \u201cnell\u2019 alba che precede al giorno,\u201d\n and ix. 59 \u201ccome il di fu chiaro.\u201d)\n\n (See also \u201cAt dawn, which doth precede the day.\u201d\n and \u201cAs day grew bright\u201d).\n ----------------------------------------------------------------\n More than 2 hours after sunrise (after 8 a.m.).\n\n \u201cIl sole er\u2019 alto gi\u00e0 pi\u00f9 che due ore.\u201c\n _Purg._ ix. 44.\n\n \u201cAnd now the sun was more than two hours high.\u201d\n ----------------------------------------------------------------\n About 9.30 a.m.\n On the 1st Cornice of the Mountain.\n\n \u201cPria lo scemo della luna\n Rigiunse al letto suo per r\u00edcorcarsi,\n Che noi fossimo fuori di quella cruna.\u201d\n _Purg._ x. 14-16.\n\n \u201cSooner had the moon\u2019s decreasing disc\n Regained its bed to sink again to rest.\n Than we were forth out of that needle\u2019s eye.\u201d\n ----------------------------------------------------------------\n 12 noon.\n Ascent to the 2nd Cornice.\n\n \u201cPi\u00f9 era gi\u00e0 per noi del monte volto,\n E del cammin del sole assai pi\u00f9 speso\n Che non stimava l\u2019animo non sciolto.\n . . . . .\n ... Vedi che torna\n Dal servigio del d\u00ec l\u2019ancella sesta.\u201d\n _Purg._ xii. 73-81.\n\n \u201cMore of the mount by us was now encompassed,\n And far more spent the circuit of the sun,\n Than had the mind preoccupied imagined.\n . . . . .\n ... Lo, returning is\n From service of the day the sixth handmaiden.\u201d\n ----------------------------------------------------------------\n 3 p.m. (midnight in Italy).\n Ascent to the 3rd Cornice.\n\n \u201cQuanto tra l\u2018ultimar dell\u2019 ora terza\n E il principio del d\u00ec par della spera\n Che sempre a guisa di fanciullo scherza,\n Tanto pareva gi\u00e0 in ver la sera\n Essere al sol del suo corso rimaso;\n Vespero l\u00e0, e qui mezza notte era.\n E i raggi ne ferian per mezzo il naso,\n Perch\u00e8 per noi girato era si il monte,\n Che gi\u00e0 dritti andavamo in ver l\u2019occaso.\u201d\n _Purg._ xv. 1-9.\n\n \u201cAs much as \u2019twixt the close of the third hour\n And dawn of day appeareth of that sphere\n Which aye in fashion of a child is playing,\n So much, it now appeared, towards the night\n Was of his course remaining to the sun;\n There it was evening, and \u2019twas midnight here.\n And the rays smote the middle of our faces,\n Because by us the mount was so encircled,\n That straight towards the west we now were going.\u201d\n ----------------------------------------------------------------\n Evening.\n On the 3rd Cornice.\n\n \u201cNoi andavam per lo vespero, attenti\n Oltre, quanto potean gli occhi allungarsi\n Contra i raggi serotini e lucenti.\u201c\n _Purg._ xv. 139-141.\n\n \u201cWe passed along athwart the twilight, peering\n Forward, as far as ever eye could stretch\n Against the sunbeams serotine and lucent.\u201d\n ----------------------------------------------------------------\n Sunset at sea-level, 6 p.m.\n\n \u201cIo rividi\n Lo sole in pria, che gi\u00e0 nel corcare era.\u201d\n _Purg_ xvii. 8, 9.\n\n \u201cI saw again\n The sun at first, that was already setting.\u201d\n ----------------------------------------------------------------\n\n On the 3rd Cornice.\n\n \u201cI raggi, morti gi\u00e0, nei bassi lidi.\u201c\n _Purg._ xvii. 12.\n\n \u201cRays already dead on the low shores.\u201d\n ----------------------------------------------------------------\n\n Ascent to the 4th Cornice.\n\n \u201cProcacciam di salir pria che s\u2019abbui.\u201d\n _Purg._ xvii. 62.\n\n \u201cLet us make haste to mount ere it grow dark.\u201d\n ----------------------------------------------------------------\n Sunset on the Mountain, shortly after 6 p.m.\n On the 4th Cornice.\n\n \u201cGi\u00e0 eran sopra noi tanto levati\n Gli ultimi raggi che la notte segue,\n Che le stelle apparivan da pi\u00f9 lati.\u201d\n _Purg._ xvii. 70-72.\n\n \u201cAlready over us were so uplifted\n The latest sunbeams which the night pursues,\n That upon many sides the stars appeared.\u201d\n ----------------------------------------------------------------\n Towards midnight.\n\n \u201cLa luna, quasi a mezza notte tarda,\n Facea le stelle a noi parer pi\u00f9 rade,\n Fatta com\u2019 un secchione che tutto arda;\n E correa contra il ciel per quelle strade\n Che il sole infiamma allor che quel da Roma\n Tra i Sardi e i Corsi il vede quando cade.\u201d\n _Purg._ xviii. 76-81.\n\n \u201cThe moon, belated almost unto midnight,[453]\n Now made the stars appear to us more rare,\n Formed like a bucket that is all ablaze;\n And counter to the heavens ran through those paths\n Which the sun sets aflame when he of Rome\n Sees it \u2019twixt Sardes and Corsicans go down.\u201d\n\n------------------------------------------------------------------------\n[453] Or \u201calmost at late midnight.\u201d\n------------------------------------------------------------------------\n\n 6th day. Nearly 2 hours before sunrise, about 4 a.m.\n On the 4th Cornice.\n\n \u201cNell\u2019 ora che non pu\u00f2 il calor diurno\n Intepidar pi\u00f9 il freddo della luna,\n Vinto da terra, o talor da Saturno;\n Quando i geomanti lor Maggior Fortuna\n Veggiono in oriente, innanzi all\u2019 alba,\n Surger per via che poco le sta bruno.\u201d\n _Purg._ xix. 1-6.\n\n \u201cIt was the hour when the diurnal heat\n No more can warm the coldness of the moon,\n Vanquished by Earth, or peradventure Saturn;\n When geomancers their Fortuna Major\n See in the orient, before the dawn,\n Rise by a path that long remains not dim.\u201d\n ----------------------------------------------------------------\n Early morning.\n Ascent to 5th Cornice.\n\n \u201cSu mi levai, e tutti eran gi\u00e0, pieni\n Dell\u2019 alto d\u00ec i giron del sacro monte,\n Ed andavam col sol nuovo alle reni.\u201d\n _Purg._ xix. 37-39.\n\n \u201cI rose, and full already of high day\n Were all the circles of the sacred mountain,\n And with the new sun at our back we went.\u201d\n ----------------------------------------------------------------\n About 10 a.m.\n On the 6th Cornice.\n\n \u201cE gi\u00e0 le quattro ancelle eran del giorno\n Rimase addietro, e la quinta era al temo,\n Drizzando pure in su l\u2019 ardente corno.\u201d\n _Purg._ xxii. 118-120.\n\n \u201cAnd four handmaidens of the day already\n Were left behind, and at the pole the fifth\n Was pointing upwards still its burning horn.\u201d\n\n (Dante refers to \u201cthe other day\u201d when he began the journey.)\n\n \u201cDi quella vita mi volse costui\n Che mi va innanzi, l\u2019 altr\u2019 ier, quando tonda\n Vi si mostr\u00f2 la suora di colui\u2014\n E il sol mostrai.\u201d\n _Purg._ xxiii. 118-121.\n\n \u201cOut of that life he turned me back who goes\n In front of me, some days agone, when round\n The sister of him yonder showed herself\u2014\n And to the sun I pointed.\u201d\n ----------------------------------------------------------------\n Between 2 and 4 p.m.\n Ascent to the 7th Cornice.\n\n \u201cIl sole avea lo cerchio di merigge\n Lasciato al Tauro, e la notte allo Scorpio.\u201d\n _Purg._ xxv. 2, 3.\n\n \u201cThe sun bad his meridian circle\n To Taurus left, and Night to Scorpio.\u201d\n ----------------------------------------------------------------\n Evening.\n On the 7th Cornice, west side of the Mountain.\n\n \u201cFeriami il sole sull\u2019 omero destro,\n Che gi\u00e0, raggiando, tutto l\u2019 occidente\n Mutava in bianco aspetto di cilestro.\u201d\n _Purg._ xxvi. 4-6.\n\n \u201cOn the right shoulder smote me now the sun,\n That, raying out, already the whole west\n Changed from its azure aspect into white.\u201d\n ----------------------------------------------------------------\n Sunset at sea-level, 6 p.m.\n About to cross the zone of fire.\n\n \u201cS\u00ec come quando i primi raggi vibra\n La dove il suo Fattore il sangue sparse,\n Cadendo Ibero sotto l\u2019 alta Libra,\n E l\u2019 onde in Gange da nona riarse,\n S\u00ec stava il sole; onde il giorno sen giva.\u201d\n _Purg._ xxvii. 1-5.\n\n \u201cAs when he vibrates forth his earliest rays\n In regions where his Maker shed his blood,\n The Ebro falling under lofty Libra,\n And waters in the Ganges burnt with noon,\n So stood the sun; hence was the day departing.\u201d\n ----------------------------------------------------------------\n Sun about to set on the mountain heights.\n At the foot of the last stairway.\n\n \u201cLo sol sen va, soggiunse, e vien la sera.\u201d\n _Purg._ xxvii. 61.\n\n \u201cThe sun departs, it added, and night cometh.\u201d\n ----------------------------------------------------------------\n Sun sets.\n Climbing the last stairway.\n\n \u201cIo toglieva i raggi\n Dinanzi a me del sol ch\u2019era gi\u00e0 basso.\n . . . . .\n Il sol corcar, per l\u2019 ombra che si spense\n Sentimmo.\u201d\n _Purg._ xxvii. 65-69.\n\n \u201cI cut off the rays\n Before me of the sun, that now was low.\n . . . . .\n By the vanished shadow the sun\u2019s setting\n Behind us we perceived.\u201d\n ----------------------------------------------------------------\n Night.\n On the last stairway.\n\n \u201cVedev\u2019 io le stelle.\u201d\n _Purg._ xxvii. 89.\n\n \u201cI beheld the stars.\u201d\n ----------------------------------------------------------------\n 7th day. About 4 a.m.\n\n \u201cNell\u2019 ora, credo, che dell\u2019 oriente\n Prima raggi\u00f2 nel monte Citerea.\u201d\n _Purg._ xxvii. 94, 95.\n\n \u201cIt was the hour, I think, when from the east\n First on the mountain Cytherea beamed.\u201d\n ----------------------------------------------------------------\n Dawn.\n\n \u201cE gi\u00e0 per gli splendori antelucani\n . . . . .\n Le tenebre fuggian da tutti i lati.\u201d\n _Purg._ xxvii. 109-112.\n\n \u201cAnd now before the antelucan splendours\n . . . . .\n The darkness fled away on every side.\u201d\n ----------------------------------------------------------------\n Early morning.\n In the Earthly Paradise.\n\n \u201cVedi l\u00e0 il sol che in fronte ti riluce.\u201d\n _Purg_. xxvii. 133.\n\n \u201cBehold the sun that shines upon thy forehead.\u201d\n\n \u201cL\u2019 \u00f4re prime.\u201d\n _Purg._ xxviii. 16.\n\n \u201cThe hours of prime.\u201d\n ----------------------------------------------------------------\n Midday.\n By the fountain of Euno\u00eb.\n\n \u201cTeneva il sole il cerchio di merigge.\u201d\n _Purg._ xxxiii. 104.\n\n \u201cThe sun was holding the meridian circle.\u201d\n\n Ascent to Paradise.\n\n \u201cFatto avea di l\u00e0 mane e di qua sera\n Tal foce quasi, e tutto era l\u00e0 bianco\n Quello emisperio, e l\u2019 altra parte nera.\u201d\n _Par._ i. 43-45.\n\n \u201cAlmost that passage had made morning there\n And evening here, and there was wholly white\n That hemisphere, and black the other part.\u201d\n ----------------------------------------------------------------\n 8th day.\n A lapse of 6 hrs. since entering the 8th heaven.\n (_Cf. Par._ xxii. 151-153).\n Sunset in Jerusalem (sunrise in Purgatory).\n In the eighth heaven among the stars of Gemini.\n\n \u201cDall\u2019 ora ch\u2019io avea guardato prima\n Io vidi mosso me per tutto l\u2019arco\n Che fa del mezzo al fine il primo clima;\n Si ch\u2019io vedea di l\u00e0 da Gade il varco\n Folle d\u2019Ulisse. e di qua presso il lito\n Nel qual si fece Europa dolce carco;\n E pi\u00f9 mi fora discoperto il sito\n Di questa Aiuola, ma il sol procedea\n Sotto i miei piedi un segno e pi\u00f9 partito.\u201d\n _Par._ xxvii. 79-87.\n\n \u201cSince the first time that I had downward looked\n I saw that I had moved through the whole arc\n Which the first climate makes from midst to end;\n So that I saw the mad track of Ulysses\n Past Gades, and this side well nigh[454] the shore\n Whereon became Europa a sweet burden;\n And of this threshing-floor the site to me\n Were more unveiled, but the sun was preceding\n Under my feet, a sign and more removed.\u201d\n\n------------------------------------------------------------------------\n[454] Or \u201cnigh me:\u201d \u201cpresso\u201d may mean either.\n------------------------------------------------------------------------\n\n\n2. THE INFERNO.\n\nUsing the above table as a guide, we may now see how Dante uses the\nmovements of the heavenly bodies both for time and direction, and we\nshall discover how long his journey takes.\n\nDante has spent a night in a dark forest. The moon was then full; but\nwe only learn this later, when Virgil reminds him of it, and he himself\nmentions it to Forese, when talking in the Purgatorio. At dawn he finds\nhimself at the foot of a hill on which are already shining the first\nrays of the morning sun\u2014the planet which leads all aright by every\npath. The sun rises: it is in Aries, consequently the moon, being full,\nmust be in Libra, and must have set as the sun rose, i.e. at about 6\na.m. Virgil appears, rescues the poet from three terrible beasts, and\nannounces that he has come to conduct him through Hell and Purgatory,\nand to lead him to Beatrice, who will guide him to Paradise.\n\nOn the evening of the same day, at twilight, the poets enter the\nInferno. This great subterranean cavity, shaped like an inverted cone\n(see fig. 45), is divided into nine circles, in which the different\nclasses of sinners are punished. In this blind world of eternal\ndarkness no star shines, and the sun is never once mentioned as\ntimegiver; when Virgil wishes to remind Dante that they must hasten, he\nrefers to the position of moon or stars, and the former is called \u201cLa\nDonna che qui regge.\u201d[455]\n\n------------------------------------------------------------------------\n[455] \u201cThe Lady who rules here.\u201d _Inf._ x. 80.\n------------------------------------------------------------------------\n\nAfter passing through four circles, Virgil says that every star is now\nsinking which was ascending when he started, indicating that it is\nnow six hours since they entered the Inferno, or soon after midnight.\nHe does not mean that all these stars are setting, but that they have\ncrossed the meridian, and are at some point of their descent towards\nthe west. Strictly speaking this does not apply to stars north of the\nequator, since they take more than six hours to reach the meridian,\nbeing above the horizon for more than twelve. Perhaps Virgil is\nthinking chiefly of the constellations of the zodiac.\n\nThe poets cross the fifth circle, enter the \u201cbasso Inferno\u201d[456] or\ncity of Dis, and on the edge of the precipice which borders the circle\nof the Heretics they sit while Virgil explains the system of the\nseveral circles. Then he expresses a wish to continue the journey, for\nthe Fishes (of the zodiac) are quivering on the horizon, and the Wain\nlies to the north-west. As it is the time of the Vernal Equinox, and\nthe sun is in Aries, Pisces is the zodiacal sign immediately preceding\nthe sun, and begins to rise about four in the morning. The part of Ursa\nMajor called the Wain is somewhat less than 180\u00b0 distant from Pisces;\nhence when the latter appears on the eastern horizon the former will be\nin the west (and of course always in the north). The \u201cCaurus\u201d of the\nLatins was the wind from the north-west.\n\n------------------------------------------------------------------------\n[456] \u201cLower Hell.\u201d _Inf._ viii. 75.\n------------------------------------------------------------------------\n\nThey descend a cliff over loose stones which roll under the\nunaccustomed weight of Dante\u2019s living feet. Virgil tells him that\nboth here and elsewhere in Hell the ancient rocks were riven by an\nearthquake which immediately preceded the triumphant descent of Christ\nafter His crucifixion. So mighty was the shock that he thought the\nuniverse was dissolving into chaos by the force of love, as Empedocles\nhad said must happen periodically. At the base of the cliff they cross\nthe river Phlegethon, then pass through the wood of the Harpies, and\nwalk along the stone banks of a conduit which afterwards falls with\nthunderous roar down a steep precipice. On the burning sand through\nwhich the conduit runs, Dante sees Brunetto Latini, and tells him that\nit was only yesterday that he escaped from the Forest. The monster\nGeryon carries them down the precipice, and they reach the ten Pits of\nMalebolge, which like so many moats surround the central Depth.\n\nWhen looking down upon the astrologers in the fourth Pit, Virgil again\nhastens Dante on, telling him that now Cain and the thorns\u2014by which\nhe means the moon, alluding to the legend[457]\u2014is on the boundary of\nthe two hemispheres, and already touching the waves below Seville.\nThe two hemispheres are those of the habitable earth whose centre is\nJerusalem, and the uninhabitable with Purgatory at its centre: the\nmoon, therefore, is just setting as seen from Jerusalem, and in the\nInferno the time is Jerusalem time. It is here that Virgil adds, \u201cAnd\nyesternight the moon was full:\u201d did we not know this, the fact that\nshe was setting would give no clue to the time. When full, she set as\nthe sun rose, that was at 6 a.m.; now, therefore, she is setting after\nsunrise, between six and seven in the morning;[458] and this is how\nVirgil tells Dante, without mentioning the sun, that a new day has\nbegun.\n\n------------------------------------------------------------------------\n[457] _Cf. Par._ ii. 48-51.\n\n[458] The retardation is not likely to be more than the average of 50\nminutes, and may be less, because the moon is in Libra, and therefore\ngoing south. This tends to diminish the interval between one moonset\nand the next in the northern hemisphere, just as the days get shorter\nwhen the sun goes south in autumn.\n------------------------------------------------------------------------\n\nThe poets accordingly hasten on to the bridge above the next Pit, the\nfifth, and here the demons treacherously mislead them by assuring them\nthat the next bridge directly on their way is broken down, but the\none to the left is standing. The anniversary of the catastrophe is\nprecisely determined by Malacoda, the chief demon of the band, as five\nhours later than the present hour on the preceding day. There can be no\ndoubt that he refers to the same earthquake as Virgil described when\ndescending the stony cliff, and all commentators are agreed to this.\nThe time now, therefore, is five hours before midday, _i.e._ 7 a.m.,\nsince it was at midday that Dante believed Christ to have died.[459]\n\n------------------------------------------------------------------------\n[459] Some think the interval between this reference and the last\nalmost too short, but the words do not indicate that Malacoda spoke on\nthe stroke of seven! and the moon may have set at about 6.30.\n------------------------------------------------------------------------\n\nThe scenes with the demons follow, the breathless escape into the next\nPit, of the Hypocrites, and the horrors of the Pit of the Thieves.\n\nThen for a short space, when the suffering and the murk of Hell is\nbecoming almost intolerable, we are suddenly lifted into the upper\nair by the narrative of Ulysses\u2014into the pure air and the vast spaces\nof the southern ocean, and we see once more the skies. We follow the\nadventurers to the regions beyond the sun, the world where no one\nlives; we see all the stars of the other pole, and the moon shines down\nupon us. Too soon comes the tragic end of the story, and the waters\nclose over the ship; the shade of Ulysses passes on, and we are once\nmore in the \u201cbuio d\u2019 inferno.\u201d[460]\n\n------------------------------------------------------------------------\n[460] \u201cDarkness of Hell.\u201d _Purg._ xvi. 1.\n------------------------------------------------------------------------\n\nAt the next Pit, that of the Schismatics, as Dante stands ready to weep\nfor pity on the bridge above it, Virgil reproaches him for delaying,\nfor little remains now of the time permitted for seeing the Inferno,\nand already the moon is beneath their feet. This is about an hour\nafter midday; for if the moon were full she would be just opposite the\nsun, hence under our feet when the sun is on the meridian, _i.e._ at\nnoon; but this is one day after Full Moon, and therefore she does not\nreach the position till about an hour later.\n\nThe tenth and last Pit is traversed, and when the giant Ant\u00e6us has\nlifted them down into the sorrowful pit towards which all the rest\nof Hell converges, the poets have nearly reached the centre of the\nearth. For they have been descending continually, finding a slight\nfall between each circle, and between the great divisions of different\nclasses of sin, three sharp steep falls\u2014the cliff descending to the\nRiver of blood and other circles of the violent, the precipice down\nwhich Geryon carried them to the Malebolge of Fraud, and the Dark Pit\nto the bottom of which Ant\u00e6us conveyed them, where in the Frozen Lake\ntreachery was punished. Last of all, at the very centre and bottom of\nthe whole \u201cdolorous kingdom\u201d of Lucifer, they see its King, and Virgil\nsays all has been seen, and it is time to depart, for Night is rising\nagain.\n\nThus we see that the journey through the Inferno has taken exactly the\ntime from one sunset to another, twenty-four hours.\n\nNow Virgil seizes the shaggy side of the fiend, while the monstrous\nwings are raised, and with Dante clinging to him climbs down the side,\nas far as the hip; here with difficulty and labour the master turns\nround, so that his head is where his feet were, and climbs up, panting,\nso that Dante thinks they are returning. But when the ascent has been\nmade, and both poets sit down to rest, Dante sees to his astonishment\nthat the frozen lake is gone, the head and wings of Lucifer are gone,\nthey are looking down upon him, and see only his legs which are\ndirected upwards! To add to Dante\u2019s bewilderment, Virgil now says,\n\u201cRise, for the way is long and the road is bad, and the sun has already\nreturned to middle-tierce,\u201d which, as we have seen, means at the\ntime of the equinox 7.30 in the morning. Night was just beginning in\nthe dreadful place they have so recently left, but now for the first\ntime Virgil mentions the sun as giving them the time, and it is early\nmorning.\n\nThe explanation is that the point which they passed with so great an\neffort is the exact centre of the world; they are now on its further\nside, and above them is the other hemisphere, where all is ocean save\nthe island of Purgatory. Virgil explains how it was through the fall\nof Lucifer from Heaven that all the land except Purgatory is in one\nhemisphere, and that there is a cavity through which they may now climb\nto the opposite hemisphere. When Lucifer fell, all the land which then\nexisted in the unknown hemisphere fled for fear of him, sinking under\nthe sea, and then escaping round the globe settled in the inhabited\nhemisphere. It may be, he adds, that then the earth in the interior\nfled away from him upwards to form land in this hemisphere (Purgatory)\nand thus an empty space is left here. Up this, which is the same length\nas the tunnel of the Inferno, they climb, guided through the darkness\nby the sound of a little brook which has worn its winding way down\nthe rock. On this route there is nothing to detain them, for they are\nalone in the darkness, but it presumably takes much longer to ascend\nthan it did to descend, for climbing without a pause it takes about\ntwenty-three hours (from the centre) to reach that round hole in the\nrocks through which at last they once more see the stars, just before\nthe dawn of a new day.\n\n\n3. PURGATORY.\n\nLeaving Earth\u2019s centre at sunset by Jerusalem time, sunrise by\nPurgatory time, the poets emerge next morning by starlight when the\nmorning star is making all the orient smile. Henceforth Dante does not\nneed to be told how moon or stars are standing in the sky: he has but\nto look up, and see the sun and sometimes the moon by day, the stars\nand sometimes the moon by night. The Inferno was like one long dark\nnight, Paradise will be one brilliant day; in Purgatory the sun rises\nfour times and sets three times, before Dante reaches the summit, and\nthence rises to Paradise with Beatrice.\n\n\u201cLo bel pianeta che ad amar conforta\u201d[461] is of course Venus: if there\nwere any doubt about this, the words used concerning the dawn of the\nlast morning on the Mountain would solve it, for there \u201cCytherea\u201d is\nspoken of as shining in the east on the mountain. She is in Pisces,\nthe sign which rises about two hours before Aries, or 4 a.m. at this\nseason, and as the stars are still clearly visible, it is about 5 a.m.\nThe poets have evidently come up from the subterranean passage facing\neast, for they see Venus first, then Dante turns to his right (south)\nand sees the four brilliant stars near the south pole, then turning\ntowards the north pole he sees that the Wain has disappeared beneath\nthe horizon, and close beside him he finds Cato, on whose face the\nFour Stars are shining. Cato tells them that the sun, which is about\nto rise, will be their guide to reach the Mountain, and as they first\ngo down to the shore, following his instructions, daylight begins to\nappear.\n\n------------------------------------------------------------------------\n[461] \u201cThe fair planet which kindles love.\u201d\n------------------------------------------------------------------------\n\nWhile they are still on the shore the sun reaches the point just below\nthe horizon, for he is described as just touching the western horizon\nof the other hemisphere, whose zenith is above Jerusalem, and night is\njust rising on the eastern horizon of that hemisphere. Where the poets\nare the rose colour in the east is turning to orange, just before the\nsun rises. It rises over their horizon while they are watching a light\nfar over the sea, which with almost incredible rapidity draws near,\nbecomes visible as a vessel, touches land, the spirits disembark, and\nthe celestial pilot \u201csen g\u00ec, come venne, veloce.\u201d[462] The sun has now\ndriven Capricorn from the mid sky with his bright beams, that is, the\nstars have become invisible in bright daylight, and fig. 46 shows that\nwhen Aries rises over the eastern horizon Capricorn will be overhead.\nBut the sun is still very low, so swift was the coming of the spirits,\nfor Dante\u2019s shadow is not yet visible to them: it is by his breathing\nthat they perceive he is a living man. It is only after the meeting\nwith Casella, and the dispersal of the spirits by Cato, that the sun,\nstill red with sunrise tints, makes Dante\u2019s shadow fall in front of him\nas the poets are walking westward towards the mountain. He is alarmed\nnot to see Virgil\u2019s shadow on the ground beside it, and is told that\nthe body within which Virgil once had cast a shadow lies buried in a\ncountry where it is now the time of vespers. That is, in Italy it is\nthree o\u2019clock in the afternoon: hence in Purgatory, where they now are,\nit is six in the morning.\n\n------------------------------------------------------------------------\n[462] \u201cDeparted, as he came, swiftly.\u201d\n------------------------------------------------------------------------\n\n[Illustration: Fig. 46. The Signs of the Zodiac as seen at sunrise\nfrom the Mountain of Purgatory at the autumnal equinox there (the\n_vernal_ equinox in the Northern Hemisphere). _Purg._ ii. 55.\n\n At 6 a.m. Aries is just rising, Libra the opposite\n constellation is just setting, while Capricornus\n has just reached the meridian. The signs follow one\n another in their diurnal course over the sky in the\n direction shown by the arrows, circling parallel to\n the celestial equator.]\n\nAt the foot of the mountain they are joined by a band of spirits, and\nwalking very slowly with them, conversing with Manfred, so much time\npasses that to Dante\u2019s surprise, when they reach the place where the\nascent is to be made (still on the eastern side), the sun has travelled\nfully fifty degrees since rising. As the sun passes over 360\u00b0 in 24\nhours, this indicates about 3\u00bd hours after sunrise, or 9.30 a.m.[463]\nThe climb to the first ledge is slow and very arduous, for as Virgil\nexplains, the lower slopes are the most difficult, since the act of\nclimbing becomes more and more easy as the ascent is made. Resting on\na ledge, they look back and at the sun, and note how it has travelled\nnorth, so that it now strikes their left shoulders; and after a\nconversation with Belacqua Virgil begins to mount again, saying that\nit is noon. The other hemisphere consequently is all in darkness, from\nGanges (\u201cla riva\u201d[464]) to Morocco.\n\n------------------------------------------------------------------------\n[463] If the meaning is that the sun is now 50\u00b0 _above the horizon_,\nthis would indicate a later hour, nearing midday, for the sun does not\nrise vertically in this latitude, and reaches only 58\u00b0 at noon at the\ntime of the equinox. But the first explanation is the more probable.\n\n[464] \u201cThe shore.\u201d\n------------------------------------------------------------------------\n\nOther spirits have been met and spoken with, and they are still\nclimbing when evening comes, and Dante, thinking he is to reach the\nsummit of the mountain and see Beatrice that day, entreats Virgil to\nhasten. \u201cSee,\u201d he says, \u201chow the mountain now casts a shadow.\u201d For\nthe sun has travelled round to the west, and the poets, still on its\neastern side, are in deep shadow: this explains how, when they meet\nSordello, he does not recognize that Dante is a living man, as all the\nspirits until now have done. But Virgil assures him that the way is\nlonger than he knows: before they reach the summit, the sun, now hidden\nbehind the mountain and not causing Dante to cast any shadow, will\nreturn again to the east.\n\n[Illustration: Fig. 47. Northern slope of the Mountain of Purgatory,\nup which Dante climbed. Being in the southern hemisphere, this was the\nsunny side, and he followed the sun\u2019s course, from east through north\nto west.]\n\nImmediately after this, they meet with Sordello, who tells them that\nit is impossible to climb even one step on the mountain after sunset,\nand leads them to a flowery valley, in which to rest for the night.\nThe spirits in the valley sing the evening hymn while the sun sets;\nand it begins to grow dark while Dante is talking with judge Nino,\nexplaining whence he came that morning. As soon as the stars become\nvisible, his eyes seek the southern pole, and fix themselves on three\nbrilliant stars which have taken the place of that constellation of\nfour which he saw some fourteen hours before. The latter have travelled\nto the south-west, and are hidden behind the mountain, and the new\nconstellation is above the pole towards the east.\n\nNight has risen two steps and part of a third in this place when\nDante falls asleep, and the most natural meaning of this is that it\nis somewhat more than two hours after sunset, or after 8 o\u2019clock, in\nPurgatory. The moon has not yet risen, since she is like a clock which\nloses on an average 50 minutes every day.\n\nSince the first morning in the Forest, when she was exactly 12\nhours behind the sun and set at six o\u2019clock, three whole days have\nelapsed,[465] and if she has lost 3 times 50 minutes, or 2\u00bd hours, she\nwill rise 14\u00bd hours after the sun rises, that is 2\u00bd hours after sunset,\nor at about 8.30. As the retardation varies much, let us say simply\nthat she rises to-night between eight and nine o\u2019clock. She has also\nmoved among the stars, about 13 degrees each day, and as 3\u00a0\u00d7\u00a013\u00a0=\u00a039,\nand there are 30\u00b0 in a zodiacal sign, she has passed out of Libra and\nis in Scorpio. Libra begins to rise at 6 p.m., and Scorpio at a little\nbefore 8, therefore part of Scorpio is now above the horizon.[466]\nThis, then, is the meaning of the first two stanzas of Canto ix.: the\nmistress of Tithonus is the aurora before moonrise (the solar aurora\nbeing his wedded wife, according to classical mythology), and this\npale aurora is showing white in her balcony of the eastern sky, while\non her forehead shine the stars of Scorpio, the cold creature with the\nstinging tail.\n\n------------------------------------------------------------------------\n[465] See table on p. 361.\n\n[466] \u201cWe must not assume, as some commentators have done, that the\nsigns rise at equal intervals of two hours, although each circles the\nstar sphere in 24 hours. See fig. 46, where the dotted line shows how\n_e.g._ Cancer, circling parallel with the celestial equator, will rise\nat a point considerably north of east, and having had to traverse more\nthan 90 degrees since Aries rose due east, will not rise until about 7\nhours later, _i.e._ 1 p.m. Conversely Scorpio, following Libra, will\nrise south of east, and a little _less_ than 2 hours later. The moon\u2019s\nretardation, therefore, is less in this part of the zodiac than it\nwould otherwise be, and the hour is probably nearer eight than nine.\u201d\n------------------------------------------------------------------------\n\nThis curious passage has been otherwise interpreted by some\ncommentators, and Scartazzini calls it \u201coscuro al superlativo,\u201d[467] a\nriddle which still waits its \u0152dipus. According to him, \u201cTitone\u201d should\nbe read \u201cTitan,\u201d the sun-god, and his mistress is Tethys the ocean,\nwhich is now shining not under his rays (\u201cfuor delle braccia del suo\ndolce amico\u201d[468]) but under the rays of the rising moon. This seems\nfar-fetched, and the reading doubtful. In any case, it would indicate\nthe same hour and the same phenomenon (moonrise).\n\n------------------------------------------------------------------------\n[467] \u201cSuperlatively obscure.\u201d\n\n[468] \u201cOut of the arms of her lover.\u201d\n------------------------------------------------------------------------\n\nOthers think that the solar aurora is intended, and explain the \u201cfreddo\nanimale\u201d[469] as Pisces, and the \u201csteps\u201d as the watches of the night.\nBut why a terrible tail should be ascribed to a fish is not clear, nor\nis it easy to see how the third step with which Night ascends could\nbe the hour of dawn. Night, which circles opposite to the sun, surely\nreaches the culminating point and begins to descend at midnight, just\nas midday is \u201cil colmo del d\u00ec.\u201d[470] Moreover, the third watch would\nbring us at latest to a little before 3 a.m. To make the \u201csteps\u201d signs\nof the zodiac is no better; for if Libra, Scorpio, and Sagittarius have\nrisen, it is midnight; what then can be shining in the east? and on\nwhose forehead are the stars of Scorpio glittering?\n\nOn the other hand, all accords well if we accept the first\ninterpretation\u2014the light of the moon just about to rise whitening\nthe eastern sky, some brilliant stars of Scorpio shining there, and\nDante falling asleep at the third hour of the night, wearied after his\nsleepless nights, and the hardest day\u2019s climb that he will have. We\nneed not grudge him his long sleep of nearly twelve hours, as those do\nwho take this passage to indicate midnight or early morning.[471]\n\n------------------------------------------------------------------------\n[469] \u201cCold creature.\u201d\n\n[470] \u201cThe climax of the day.\u201d\n\n[471] See Moore, _Studies in Dante_ iii. pp. 75-84, for a detailed\ndiscussion of this passage. Several commentators have held that lines 1\nto 6 describe the dawn of day _elsewhere_; and it is true that it would\nbe nearly 6 a.m. and Pisces would be on the horizon in Italy when the\nhour was nearly 9 p.m. in Purgatory.\n------------------------------------------------------------------------\n\nWhen Dante wakes the sun has already been up for more than two hours,\nbut a dream which had come to him in the early dawn, at the time when\nthe swallow begins to twitter, has had its counterpart in the truth,\nthat the lady Lucia came at that time and carried him up the mountain\nside, leaving him outside the Gate of Purgatory when the day was bright.\n\nWhen this Gate has been passed through, a narrow chasm between the\nrocks has to be climbed, and the passage is so difficult that it is at\nleast an hour before the poets emerge on the open space of the First\nCornice. For the waning moon has already set, and as she has lost\nanother half hour or so during the night, the time of her setting this\nmorning was about 9 a.m.\n\nWhen Dante next notices the position of the sun, which he is too intent\nto do for some time, they have travelled some distance along the First\nCornice, with its outer edge on their right, and the sixth handmaid\nis returning from the service of the day, that is, the sixth hour is\nended: it is midday, and they have spent nearly three hours here,\nlooking at the rock sculptures and conversing with the spirits.\n\nThe ascent to the Second Cornice is made with marvellously little\nfatigue, as Virgil had promised. There they at first find no one to\ndirect them, so Virgil looks at the sun, and turns westward towards\nit, taking it as their guide, and they walk for about a mile before\nencountering any spirits in this circle.\n\nThe stairway to the next Cornice is reached at the time of vespers,\nthat is, 3 p.m.; and Dante describes the position of the sun by saying\nthat the portion of sky which it still had to traverse before evening\nwas equal to the portion which is brought into view between the\nbeginning of the day and the end of the third hour, that is, it was\nthree hours before sunset; and he compares this ceaseless motion of the\nsky, which according to the Ptolemaic system caused the motion of the\nsun, to an ever-playing child. We need not particularly enquire whether\nhe is thinking of the heaven of the sun, or the Primum Mobile: it may\nbe either, but is most likely simply the diurnal movement in general,\nmade strikingly evident by the sun. The sun\u2019s rays now strike their\nfaces, for they have so far circled the mountain that they are walking\ntowards the west; \u201cVespero l\u00e0\u201d[472] means in Purgatory, and \u201cqui\u201d[473]\nis Italy, where it is midnight now.\n\n------------------------------------------------------------------------\n[472] \u201cVespers there.\u201d\n\n[473] \u201cHere.\u201d\n------------------------------------------------------------------------\n\nThe sun is low when they reach the third Cornice, and when they emerge\nfrom the dense cloudy fog which here envelopes the spirits, Dante\ngradually sees the ball of the sun as when mists clear away, and he\nsees that it is just about to set. In fact the low shores at the foot\nof the mountain are already in shadow. Virgil urges that they make the\nascent to the next Circle before darkness comes, and, as each ascent is\neasier than the last, they are able just to reach the summit before the\nsun is quite gone. Here Dante sees the stars begin to appear, while he\nis wondering at the strange law which robs him of power to proceed (as\nSordello had warned them) after the sun has set.\n\nThey employ this time of forced inaction by talking of the sins which\nare punished in the several Circles, until all Dante\u2019s questions are\nanswered, and he is beginning to fall asleep. It is at this moment that\nhe first mentions the moon: she is glowing, shaped like a bucket in her\npresent phase, and the stars are paled by her light. She is \u201cbelated\nalmost till midnight,\u201d if the epithet \u201ctarda\u201d belongs to her; if it\napplies to \u201cmezza notte,\u201d then it is almost late midnight when she is\nseen paling the stars. She ought to have risen about ten o\u2019clock, but\nDante does not speak of her rising, so this may mean simply that it was\nmoonlight and starlight at the time of which he is about to speak, viz.\nnearly the late hour of midnight; or else that since he is now on the\nnorthern slope of the mountain, and the moon is in a southern sign, she\ndid not become visible to him till towards midnight. In any case, the\n\u201cquasi\u201d shows that he is only giving us a rough idea of the time.\n\nBut in what sign was she? Her position in the zodiac is described in a\npeculiarly round-about fashion. Dante says that her course _against the\nsky_, that is, her monthly motion which is contrary to the diurnal,\nhad taken her to that part of her track in which the sun is when from\nRome he is seen to set between Sardinia and Corsica. The straits\nbetween these islands lie west and a little south of Rome, therefore\nthe sun sets in that direction when he is going south after passing the\nautumnal equinox in Libra, and this is just what the moon is doing now.\n(The sun passes the same point again when coming north, before entering\nAries at the spring equinox, but Dante has either forgotten this, or\nconsiders it obvious that the first position is meant here).\n\nThis is probably all that he means to convey, and if we ask for more\nexact information, it is almost impossible to tell what degree or even\nwhat sign in the zodiac he intends us to understand; for as the straits\nare nearly two hundred miles from Rome they are quite invisible thence,\nand we do not know what he thought was their precise direction. The\nmedi\u00e6val commentator Benvenuto da Imola says that the position intended\nis in Scorpio; the moderns usually say Sagittarius, but without\nexplaining how they draw this conclusion. Benvenuto\u2019s is probably\nsimply the position which he thought the moon ought to have in order to\nagree with what Dante says about her, just as he states that Venus was\nin Pisces in March 1300, although this was not the case at all, as we\nshall presently see.\n\nA calculation based on the difference in latitude between Rome and the\nStraits shows that they are only about 9\u00b0 south of west, and that the\nsun, when setting in this direction is about 6\u00b0 south of the equator:\nthis is the case 15 days after the equinox, which in the beginning\nof the fourteenth century fell on September 14. Therefore the date\nat which the sun was seen from Rome setting in the direction between\nSardinia and Corsica was the 29th of September, and its position in the\nzodiac was then the middle of the sign Libra. (Owing to precession,\nit would be in the _constellation_ Virgo, but we have seen that Dante\nignores precession in these references.)\n\nBut the moon ought now, on this second night in Purgatory, to\nhave reached at least the last degrees of Scorpio, since on the\nprevious night she rose when the first part was already above the\nhorizon. Dante has therefore made a flagrant mistake with his moon,\nrunning her back into Libra again, and falsifying all his previous\ndescriptions\u2014_if_ he knew as much about geography as we do now. But it\nis only necessary to glance at the map of Henry of Mainz to see that\nsuch a supposition would be grotesque. The portolan maps did indeed\nshow the relative positions of Rome, Sardinia, and Corsica, with\nremarkable accuracy;[474] but as we have already said, it is not in\nthe least likely that Dante had ever seen one of these sailing charts.\nIt was on the classics, and especially on Orosius, that he relied\nfor his geography,[475] and the suggestion of Dr. Moore seems most\nplausible, that he was here thinking of the Spaniard\u2019s description of\nSardinia:\u2014\u201cHabet _ab oriente et borea_ Tyrrenicum mare quod spectat ad\nportum urbis Romae.\u201d[476] This implies that Sardinia lay south-west of\nRome, in a direction such as the sun might have had when setting in\nNovember, in Scorpio or Sagittarius.\n\n------------------------------------------------------------------------\n[474] See for instance the \u201cCarte Pisane,\u201c and the Central\nMediterranean map of Vesconte, dating from about 1300 and 1311\nrespectively, in Beazley\u2019s _Dawn of Geography_, iii. Latitudes and\nlongitudes are not given, but from certain centres lines radiate to all\npoints of the compass, like great spiders\u2019 webs.\n\n[475] _De Mon._ II. iii. 87-90. etc.\n\n[476] \u201cIt is bounded _on the east and north_ by the Tyrrhenian sea,\nwhich lies towards the port of Rome,\u201d Moore, _Studies in Dante_ iii. p.\n72.\n------------------------------------------------------------------------\n\nOr possibly, when the poet was in Rome in 1301, he may have been\nwatching a sunset in the second week in November, and may have been\ntold, among other pieces of misinformation which are so readily given\nto visitors to great cities, that he was looking towards the straits\nwhich separate Sardinia from Corsica. We can imagine his replying, or\nthinking: \u201cThen the sun sets behind them when he has nearly finished\nhis course in Scorpio, and is about to yoke his steeds under another\nstar!\u201d[477]\n\n------------------------------------------------------------------------\n[477] _Purg._ xxxii. 56, 57.\n------------------------------------------------------------------------\n\nIt is while the moon is shining on this Cornice that the spirits who\npurge their sins on it appear, rushing past in haste. Then at last\nDante sleeps, and dreams again in the cold moonlit dawn when Aquarius\nand Pisces are on the horizon (see p. 290).\n\nThe mountain is full of daylight when Virgil wakes him, and the\nnewly-risen sun shines behind them as they continue their journey, for\nthey had reached the north point of the circle, and are walking now\ndue west. They mount almost immediately to the Fifth Cornice, where\npresently they are startled by a violent trembling of the mountain\nfollowed by a mighty shout of \u201cGloria in excelsis\u201d from all the\nspirits. Statius joins them, and from him they learn that this was\nno earthquake, for since passing the gate of Purgatory they are in\na region too lofty for such disturbances to be felt, or for rain or\nsnow or dew to fall; the mountain trembles, and the shout of praise\nfollows, when a soul rises, purified and ready to ascend to Paradise.\nWith Statius they climb to the Sixth Cornice, and then, looking round,\nthey see that the fifth handmaid of the sun\u2019s chariot is directing\nits upward course, that is, it is the fifth hour, or between 10 and 11\na.m. As usual, they walk on with the outer edge of the circle on their\nright. It is here that we are reminded, as once in the Inferno, that\nonly a certain time is allowed, for while Dante is looking eagerly at\nthe first mysterious tree Virgil gently urges him onward:\u2014\n\n \u201cLo pi\u00f9 che padre mi dicea, Figliuole,\n Vienne oramai, ch\u00e8 il tempo che c\u2019 \u00e8 imposto\n Pi\u00f9 utilmente compartir si vuole.\u201d[478]\n\n------------------------------------------------------------------------\n[478]\n \u201cMy more than father said unto me, Son,\n Come now, because the time that is ordained us\n More usefully should be apportioned out.\u201d\n _Purg._ xxiii. 4-6. (_Longfellow_).\n------------------------------------------------------------------------\n\nIt is here also that Dante informs his old friend Forese Donati and\nother spirits, who are all astonished at the sight of his shadow, that\nhe is a living man who was rescued by Virgil some days ago, when the\nsister of the sun was round (referring of course to the full moon in\nthe forest), and he points to the sun. Now a curious question arises:\nDante was in sunshine in the early morning; he is in sunshine now, and\nhas been walking all morning in the same direction in which the sun was\nmoving; how is it then that Statius did not notice his shadow, but had\nto be told that he was not a spirit?[479] If the Mountain had been a\nsmall hill, it would have been quite easy to walk so large a part of\na circle round it, in a short time, that the poets would have been in\nshadow until the sun caught them up again when they lingered talking\non the Sixth Cornice; but the Mountain was so large that a whole\nday\u2019s walking only brought them a quarter of the way round, _i.e._\nfrom the east side to the north, and it was evidently a distance of\nmany miles.[480] It is difficult to believe that Dante has forgotten,\nbecause he is so careful throughout to mention the surprise of the\nspirits except when his shadow could not be seen for one reason or\nanother. It is true that in the latitude of Purgatory (32\u00b0 south, as\nthat of Jerusalem is 32\u00b0 north), the sun rises rather steeply, which\nmakes it easier to get into the shade in the early morning while\ncircling a mountain.[481] On the other hand a simpler solution offers\nitself in the text. Statius approaches Dante and Virgil from behind,\nand they only stop and turn their faces to him for a few moments while\nVirgil returns his greeting, then walk on quickly while Statius makes\nhis surprised reply: \u201cWhat! if you are spirits....\u201d If he has not yet\nquite overtaken them he cannot see Dante\u2019s shadow, which Dante himself\nis screening from view as it falls in front of him, the morning sun\nbeing still at his back, and Virgil explains at once that his companion\nis a living man.\n\n------------------------------------------------------------------------\n[479] _Purg._ xxi. 20-27.\n\n[480] _Purg._ xiii. 22-23.\n\n[481] On an Astronomical Point in Dante\u2019s _Purgatorio_, by P. H.\nCowell, F.R.A.S., _The Observatory_, December 1906.\n------------------------------------------------------------------------\n\nIn spite of their haste, the three poets remain about four hours in\nthis sixth Cornice; and when they reach the ascent to the next it\nwas indeed time to climb without any delay, for the sun had left the\nmeridian to the sign which follows Aries, viz. Taurus, and Night, \u201cche\nopposita a lui cerchia,\u201d[482] had left the meridian of the opposite\nhemisphere to Scorpio. Aries at the time of the equinox begins to\ncross the meridian at midday, Taurus at two o\u2019clock, and Gemini at\nfour[483]: therefore it is now between two and four in the afternoon.\nThe three poets hasten therefore (Statius still accompanying Virgil\nand Dante), like men who pause for nothing on their way, whatever the\nroad be like; and a question Dante is longing to ask with regard to\nthe form of purgation last seen is put and answered as they follow one\nanother up the narrow stair; as soon as they reach the top, they turn\nto the right, as usual, without hesitation or delay. As Dante walks\ncautiously between the outer edge of this Cornice and the fire which\nbursts forth from the inner wall of rock, all the blue of the western\nsky is already changing into ash-white, and he has come so far round\nthe Mountain that the evening rays strike his right shoulder. With\none of the many touches which show Dante\u2019s close observation and his\nvivid realization of the scene he is describing, he says here that his\nshadow falling on the flame makes it appear a deeper red, and this is\nobserved by the spirits. When they reach the spot where, on the further\nside of the flames, the chanting Angel guides them across to the last\nascent, the sun is very near to its setting. Its burning noonday beams\nare shining on the waves of Ganges, its first morning beams quiver over\nJerusalem, and Spain lying under Libra is wrapped in midnight gloom;\nhence it is beginning to set at sea-level in Purgatory. High on the\nMountain it still shines, but when the poets have crossed the flames,\nthe voice of the Angel persuades them to hasten their steps before the\ndarkness comes. The stair mounts through the rock on the west side of\nthe Mountain so that the low sun casts Dante\u2019s shadow in front of him\nas he climbs. And he has only climbed a few steps when they are all\naware that the sun has completely set because the shadow disappears.\nBefore the colour has all faded from the west, and the whole vast range\nof the horizon seen from this height has become one uniform tint, each\nof the three makes a bed of one step, and between the high and narrow\nenclosing rocky walls Dante sees the stars come out, much brighter and\nmuch larger than he has ever seen them before. No moonlight dims them,\nfor moonrise will be late to-night, long after Dante has fallen asleep.\n\n------------------------------------------------------------------------\n[482] \u201cThat circles opposite to him.\u201d _Purg._ ii. 4.\n\n[483] The signs follow one another _on the meridian_ at intervals of\nexactly 2 hrs.\n------------------------------------------------------------------------\n\nOnce again, for the third and last time, he has a prophetic dream in\nthe early dawn; and if we compare these three parallel passages, we\nfind that each begins with the same words \u201cNell\u2019 ora.\u201d[484] The first\ntime the ideas connected with the time are wholly sorrowful, for it is\nsaid to be the hour when the swallow begins to twitter, perchance in\nmemory of her former woes\u2014alluding to the tragic tale of Procne and\nPhilomel. The second is a depressing time, for it is the cold hour\nwhen, the day\u2019s heat being all spent, the chilled earth cannot overcome\nthe influence of the cold planets such as the moon or Saturn, but there\nis a thought of hope in the stars of the Greater Fortune seen rising\nin the east, in a sky which is now scarcely dark to them. The third is\nall joy, for it is the hour when Cytherea (the planet Venus), burning\never in the fire of love, shines first upon the mountain. Dante\u2019s sleep\nflees from him as the shades of darkness flee on all sides, chased by\nthe brightness before sunrise; and when Virgil tells him that to-day he\nshall reach the goal of his desires, he speeds up the remaining steps\nof the stair, almost as if on wings.\n\n------------------------------------------------------------------------\n[484] \u201cAt the hour.\u201d\n------------------------------------------------------------------------\n\nThe poets arrived on the shores of Purgatory, as we saw, facing east,\nand now that they have attained the summit of the mountain, coming up\nthe western slope, they again face east, and the just risen sun shines\nin their faces. Dante walks towards it: a breeze fans his forehead and\ncauses all the trees to bend in the direction of the shadow thrown at\nsunrise by the Mountain (_i.e._ westwards), and the murmur of this\ngentle wind in the branches forms a bass to the treble of the singing\nbirds who are greeting the morning hours. For a few steps the stream of\nLethe stays his steps in this direction, but he soon reaches a bend,\nand once more \u201ca levante mi rendei.\u201d[485] The symbolical procession\nwhich accompanies Beatrice comes towards him from the east, and after\nhe has crossed the river Lethe and joined the procession beside the Car\nin which Beatrice is throned, all turn to the sun, which by this time\nmust have travelled some distance towards the north. After the vision\nof the disasters which befell the holy Car, and after Beatrice has\nspoken with Dante again, they reach the fountain whence Eunoe flows,\nand now the sun is on the meridian and it is noon, though (as Dante\nreminds us) different places have different meridians, so that it is\nnot noon everywhere else. He is bathed in the holy waters, and thus,\nall having been accomplished for which he has visited these regions, he\nis \u201cpuro e disposto a salire alle stelle.\u201d[486]\n\n------------------------------------------------------------------------\n[485] \u201cI turned to the east.\u201d\n\n[486] \u201cPure and ready to rise to the stars.\u201d _Purg._ last line.\n\nHell was entered at twilight, Purgatory at dawn, the ascent to Paradise\nis made at noon, \u201cil colmo del d\u00ec.\u201d[487] The time spent in Purgatory is\nthree days and the morning of a fourth, which is the seventh from the\nbeginning of the vision.\n\n[487] \u201cThe climax of the day.\u201d\n------------------------------------------------------------------------\n\n\n4. PARADISE.\n\nThat the time of ascent to the spheres was noon is again stated in\nthe opening Canto of the _Paradiso_, where Dante says that the sun\nhad brought morning there (Purgatory) and evening here (the inhabited\nhemisphere), and that now the whole of that hemisphere was bright while\nthe whole of this was dark.[488] The sun is therefore now due north.\nWhile Beatrice stood beside the waters of Eunoe, after walking towards\nthe sun, it had moved to her left, so she now turns in that direction\nto gaze upon it.[489] She, like Virgil, takes as her guide that sun\nwhich Dante has said is the fittest symbol of God, and it is through\nthe power of this heavenly light that he is raised from earth. Compare\n\n[488] It has been suggested to read the line _Par._ i. 44. \u201cTal foce; e\nquasi tutto l\u00e0 era bianco,\u201d transferring the \u201cquasi\u201d (almost) so that\nthe meaning should be \u201calmost was wholly white that hemisphere,\u201d and\nto interpret that it is now morning of the day following the events\nin the last Canto of the _Purgatorio_. But if so, Dante would have\nspent a whole night in the Earthly Paradise without mentioning it, or\nexplaining this long delay after he had become \u201cpure and ready to rise\nto the stars.\u201d (For the meaning of \u201cfoce,\u201d the \u201cpassage,\u201d see later, p.\n400).\n\n------------------------------------------------------------------------\n[489] _Par._ i. 46, 47.\n \u201cAmor che il ciel governi\n ... _col tuo lume_ mi levasti.\u201d[490]\n\n[490]\n \u201cLove that rules the heavens,\n _with thy light_ Thou didst raise me.\u201d\n _Par._ i. 74, 75.\n------------------------------------------------------------------------\n\nHe is not conscious of any effort, or even movement, but is astonished\nby a great light and strange music, and learns that he is in the sphere\nof fire and listening to the harmony of the spheres. His soul, freed\nfrom all that bound it to earth, is soaring towards its natural goal,\nas fire mounts up and rivers run down.\n\nThe upward gaze to the sun or to the skies, and its power to raise\nthem, is again described in _Par._ i. 142: Beatrice \u201crivolse inver lo\ncielo il viso,\u201d[491] and in ii. 22, \u201cBeatrice in suso ed io in lei\nguardava.\u201d[492] Thus they rise to the First Heaven, of the moon. In\nanswer to an eager question of Dante\u2019s about the markings of the moon,\nBeatrice is led to discourse on the spheres and their movers. Spirits\nappear, and Dante learns that although all the redeemed dwell in the\nEmpyrean, those of different degrees of blessedness will manifest\nthemselves to him in each sphere. After explaining this and other\nthings, Beatrice once more\n\n------------------------------------------------------------------------\n[491] \u201cTurned her eyes again towards heaven.\u201d\n\n[492] \u201cBeatrice gazed upwards, and I at her.\u201d\n\n \u201csi rivolse tutta disiante\n A quelle parte ove il mondo \u00e8 pi\u00f9 vivo,\u201d[493]\n\n[493]\n \u201cTurned again with yearning\n to that part where the world is most living.\u201d\n _Par._ v. 86, 87.\n------------------------------------------------------------------------\n\nand swift as an arrow that strikes its mark before the cord has ceased\nto quiver, they ascend to the Second Heaven, of Mercury. To understand\nthe above lines we must remember that the sun, as Dante told us in the\nintroductory Canto,[494] is at the equinox, or near it, and therefore\non the equator; also that the equator of a sphere, where motion is\nquickest, is its most living part.[495] Beatrice is therefore looking\nagain at the sun. Some understand \u201cquella parte\u201d[496] to refer directly\nto the sun, \u201cquegli ch\u2019 \u00e8 padre d\u2019ogni mortal vita,\u201d[497] some to the\nequinoctial point;[498] others think that the east is meant; others the\nEmpyrean, in which is the true life of all the Universe.\n\n------------------------------------------------------------------------\n[494] _Inf._ i. 38-40.\n\n[495] _Conv._ II. iv. 52-62.\n\n[496] \u201cThat part.\u201d\n\n[497] \u201cHe who is father of all mortal life.\u201d _Par._ xxii. 116; see also\n_De Mon._ I. ix. 6, 7.\n\n[498] See _Par._ x. 7-21.\n------------------------------------------------------------------------\n\nEqually swiftly and unconsciously, Dante ascends to the successive\nheavens of Venus, the sun, Mars, Jupiter, and Saturn, finding himself\nalways in the planet which occupies each sphere. Mounting the\nmysterious golden ladder which is set up in Saturn, with a rapidity\ninconceivable on earth, the poet finds himself in the Heaven of Stars,\nin the constellation of Gemini. Now that he is so near the final\nblessedness his eyes are clear and keen, and that his heart may be\nfilled with joy Beatrice bids him look down and see how much of the\nuniverse is already beneath his feet. There lie the seven spheres, and\nthere is the little globe of Earth, so small that, like Scipio, he\nsmiles at its paltry appearance; there is the moon, showing him the\nface turned away from Earth, which has no dark markings: there is the\nsun, at which for once he is able to gaze; and near it circle Mercury\nand Venus; the temperate Jupiter moves between his father Saturn and\nhis son Mars; with a new power of vision Dante can grasp all their\nsizes and distances and the various speeds of their movements; and\nthe poor little disc of the earth, small and round as a threshing\nfloor,[499] about which we quarrel so fiercely, is all visible to him\nat a glance, its highest hills and its lowest river-valleys running\ndown to the sea. He turns away his eyes to look into the beautiful eyes\nof his guide. She is standing, erect, intent, watching eagerly for that\nglorious Procession, whose coming is making a growing brightness in the\nsky.\n\n[499] Longfellow says:\u2014\u201cLooking down from the terrace of Monte Cassino\nupon the circular threshing-floor of stone in a farm lying below, I\nfirst felt the aptness of Dante\u2019s phrase. This very scene may have\nsuggested it to him.\u201d\n\n \u201cLa donna mia si stava eretta\n Ed attenta, rivolta inver la plaga\n Sotto la quale il sol mostra men fretta.\u201d[500]\n\n------------------------------------------------------------------------\n[500]\n \u201cSo my lady stood, erect\n and intent, turned towards that place\n under which the sun shows least haste.\u201d\n _Par._ xxiii. 10-12.\n------------------------------------------------------------------------\n\nNo other intimation is given as to the direction from which the\nProcession comes. The sun\u2019s daily motion appears slowest on the\nmeridian, as Dante remarked in _Purg._ xxxiii. 103, 104, because he\nis scarcely changing his position with regard to the horizon; or in\nthe south (where we in this hemisphere see him when on the meridian);\nhe shows least haste to leave us in the long summer days, near the\nsolstice. If the Procession descends from the heaven of heavens to show\nitself here symbolically to Dante, as we know that the spirits in other\nheavens did,[501] then Beatrice was gazing upwards, and the meridian\nmay be meant, particularly that part of it which passes directly\noverhead. If the Procession came from the east, like the Procession in\nEden,[502] the summer solstice in Cancer is meant, which lies east of\nGemini. It is difficult to see any special meaning in its coming from\nthe south, for although some commentators say that this suggests the\nconsummate glory of the midday sun, the same idea is conveyed by the\nmeridian. A constellation like Cancer perhaps corresponds better than a\ncircle like the meridian with the expression \u201cplaga,\u201d[503] and the idea\nof the east makes more perfect the beautiful simile which the poet has\njust drawn between the little bird on the spray beside its nest waiting\nfor the sun to rise, and Beatrice watching for the advent of Him who is\nlikened to a sun among the starry company of His saints.[504]\n\n------------------------------------------------------------------------\n[501] See _Par._ iv. 34-39.\n\n[502] _Purg._ xxix. 12 and 34.\n\n[503] \u201cRegion.\u201d\n\n[504] _Par._ xxiii. 29, 30.\n\n------------------------------------------------------------------------\n\n[Illustration: Fig. 48. Dante\u2019s first view of Earth from the Stars.\n_Par._ xxii. (see p. 397).]\n\nWhen this glorious company has at length vanished, she bids him look\ndown once more, this time that he may realise how he has been revolving\nwith the spheres, the little earth lying immoveable at his feet. He\nlooks down, and notes what parts of Earth are lighted by the sun, and\nwhat parts are wrapped in darkness, for now he is able to see what\nhe had often imagined, the shadow of night sweeping westward over\nthe globe. The Atlantic Ocean, where Ulysses sailed beyond Gades, is\nall in daylight, and so is the Mediterranean, but the sun is setting\nover Jerusalem, for he says that its position prevents him from\nseeing beyond the coast whence Europa was carried (_i.e._ Ph\u0153nicia or\nPalestine). It must therefore be midday at Gades, and the sun is on\nthe meridian there; it is \u201ca sign and more,\u201d or something between 30\u00b0\nand 60\u00b0, advanced to the west beyond the meridian over which Dante\nstands.\n\nHe does not define his own position more exactly than this, but we may\nconjecture that he was 45\u00b0 (a sign and a half) east of the sun, since\nthis would be the meridian of Rome, and there would be a peculiar\nfitness in such a position at such a moment, when he has just received\na message of warning and prophecy from St. Peter to bear to this\ncity.[505]\n\n------------------------------------------------------------------------\n[505] _Par._ xxvii. 64-66.\n------------------------------------------------------------------------\n\n[Illustration: Fig. 49. The view six hours later. _Par._ xxvii.]\n\nFig. 49 shows these positions of Dante and the sun, and the consequent\nlimits of his vision. Jerusalem is \u201cnear,\u201d in comparison with the much\nmore distant sunlit space of ocean in the opposite direction. We place\nthe sun in the middle of Aries, because we shall see presently (when\ndiscussing the date) that this is its most probable position, and\nDante in the first degree of Gemini because this is 45\u00b0 east of the\nsun, and also because the fact that he is above Earth\u2019s \u201cfirst climate\u201d\nsuggests that he is in the beginning of this sign. For the northern\nlimit of the first climate was 20\u00bd\u00b0, according to Alfraganus, and the\necliptic in the sign of Gemini rises gradually from 20\u00b0 north of the\nequator to 23\u00bd\u00b0 at its end, where it adjoins Cancer.\n\nSince the time when he looked down before, he sees that he has revolved\nover an arc equal to half the climate, that is 90\u00b0, for the climates\nonly extended over the habitable earth, which was 180\u00b0 in longitude.\nHis former position, then, must have been 90\u00b0 further east, halfway\nbetween Jerusalem and Ganges; and it was then noon at Jerusalem, while\nall the ocean east of Ganges lay in the black darkness of night. Fig.\n48 shows this position.\n\nIn this interpretation of a difficult passage, the meaning given to\nthe first lines seems a little forced; but if we take them in the more\nnatural sense that Dante had moved from above the centre to the end\nof the climate, that is, from the meridian of Jerusalem to Gades, we\nare met by a difficulty in the following lines. For to say that he is\nstanding over Gades, and in the same breath that the sun is more than\n30\u00b0 further to the west, means that it is setting more than 30\u00b0 west\nof Jerusalem: he cannot therefore possibly see Jerusalem, nor is it\n\u201cnear\u201d him. It does not help us to take \u201cpresso\u201d in its alternative\nmeaning, and say that he could see \u201cnearly as far as\u201d Jerusalem, for\nhowever little more than 30\u00b0 \u201ca sign and more\u201d may mean, it brings the\n\u201cterminator\u201d (as astronomers call the dividing line between light and\ndarkness on a planet) a long way from Jerusalem and much nearer Italy,\naccording to Dante\u2019s reckoning of distances in the Mediterranean. This\nis shown on fig. 50, where the data are made as favourable as possible,\nby putting the sun at the very end of Aries.\n\nOn the whole, it is easier to accept a round-about expression in\nthe first lines than an inaccurate one later. The former is quite\ncharacteristic of Dante, and we have already met some like it in\nthe _Divina Commedia_ in descriptions of the positions of heavenly\nbodies.[506]\n\n------------------------------------------------------------------------\n[506] Compare _Purg._ xv. 1-5, where the course the sun still has to\nrun between vespers and sunset is described as equal to the space\nbetween the third hour and sunrise.\n------------------------------------------------------------------------\n\nLooking back to the earlier position, as described in Canto xxii., we\nfind no light thrown on the question; for here he does not mention any\nparticular place as visible, nor say where the terminator lay. His\nwords are:\u2014\n\n \u201cL\u2019aiuola che ci fa tanto feroci,\n Volgendom\u2019 io con gli eterni Gemelli,\n Tutta m\u2019apparve dai colli alle foci.\u201d[507]\n\n------------------------------------------------------------------------\n[507]\n \u201cThe threshing-floor that maketh us so proud,\n To me revolving with the eternal Twins,\n Was all apparent made from hill to harbour.\u201d\n _Par._ xxii. 151-3. (_Longfellow_).\n------------------------------------------------------------------------\n\nThis seems to express simply a bird\u2019s eye view of Earth, as it lay\nstretched out like a map below the observer.\n\nIt is, however, often taken to mean that the whole habitable earth was\nvisible. This could never be unless the sun, as well as Dante, was over\nthe meridian of Jerusalem, which is obviously impossible while one is\nin Aries and the other in Gemini; and as he refers back to the first\npassage from the second he cannot have forgotten this.[508]\n\n------------------------------------------------------------------------\n[508] Della Valle boldly assumes that they _were_ over the same\nmeridian, by a poetical licence, although at the same time the sun was\nin a different sign. Dante only mentions the latter fact, he thinks, in\norder to show that he was a few degrees north of the sun (Gemini being\nmore northerly than Aries); therefore he could see over the edge, as\nit were, of the sun-lighted hemisphere of Earth. This is desperately\nsubtle.\n------------------------------------------------------------------------\n\nIt is, however, the only way in which the passages can be reconciled\nwith his further assumption, shared by some other commentators, that\nDante, in his flight through the spheres, simply ascended without any\nmovement in longitude except that he was carried round by the daily\nrevolution of the spheres. All the planets, therefore, were ranged one\nabove the other, in the sign of Gemini, and it was always noon on the\nearth below his feet, since that was the hour at which he ascended from\nthe Earthly Paradise, and his movement was the same as the sun\u2019s. (Here\nDella Valle is inconsistent, however, for he maintains that the ascent\nwas made in the early morning.) But this is a very artificial conceit,\nand not indicated by Dante. He implies that Beatrice, in leading him\nto each sphere, chose the part of it which he was to enter (see _Par._\nxxvii. 102), and he tells us that Saturn was in Leo, Venus in Pisces,\nand the sun in Aries.\n\n[Illustration: Fig. 50. An impossible interpretation of _Par._ xxvii.]\n\nA book which aims at explaining Dante\u2019s _Paradiso_ to young people[509]\nsuggests an original way of reconciling the two passages, for the\nauthor gravely asserts that the sun was at first below Dante\u2019s feet in\nGemini, but that by the time he looked down again it had moved a good\ndistance onward, and was then in the sign of Taurus! According to this,\na whole month must have elapsed, and time had gone backwards, from May\nto April!\n\n------------------------------------------------------------------------\n[509] _Il Paradiso di Dante dichiarato ai giovani_, by Angelo de\nGubernatis.\n------------------------------------------------------------------------\n\nA suggestion much more worthy of attention is that of Professor\nRizzacasa d\u2019Orsogna, who thinks the key is to be found in the line,\n\u201cVolgendom\u2019 io con gli eterni Gemelli.\u201d This, he suggests, is in\nanticipation of the second passage, for although Dante could not see\nthe whole habitable earth at any one time, his change of position, as\nhe revolved with the Twins, enabled him to do so in the course of time\nwhich elapsed between his two views. A comparison of figures 48 and 49\nwill make this clear.\n\nOne more suggestion may perhaps be made, though it is rather a\nhazardous one. \u201cDai colli alle foci\u201d[510] may mean from the Apennine\nHills to the mouths of Ganges. This would be decisive for the\ncorrectness of the explanation illustrated by our diagram. (See fig.\n48).\n\n------------------------------------------------------------------------\n[510] \u201cFrom the hills to the river-mouths.\u201d\n------------------------------------------------------------------------\n\nIn any case, the points which Dante specially wishes us to understand\nare clear and simple: at the first glance he was struck by the\ninsignificance of the Earth; at the second, he became conscious that\nhe was moving with the spheres, having passed over 90\u00b0 of arc, or a\nquarter of the diurnal revolution, and he saw that it was now sunset at\nJerusalem.\n\nHe next ascends to the Primum Mobile, though he cannot tell us to which\npart of it Beatrice chose to lead him, since it is perfectly uniform\nthroughout. Beatrice explains that this most swift and living sphere,\nalthough it contains no star by which its motion is made visible,\ncauses the (diurnal) motion of all the lower spheres; and thus it is\nlike a flower-pot in which are hidden the roots of Time, while in\nthe others we see the leaves. Here he sees the nine hierarchies of\nangels who direct the nine moving spheres; and finally he soars to the\nEmpyrean, where Beatrice returns to her seat among the blessed spirits\nwho form the Celestial Rose, and St. Bernard encourages him to lift his\neyes to \u201cL\u2019Amor che move il sole e l\u2019 altre stelle.\u201d[511] This is the\nend and consummation of the Vision.\n\n------------------------------------------------------------------------\n[511] \u201cLove which moves the sun and the other stars.\u201d _Par._ last line.\n------------------------------------------------------------------------\n\nThe reader will have observed that although there are several\nindications of direction in Dante\u2019s journey through Paradise, all\nreferring to the heavenly bodies, there are no time references after he\nhas left Earth and entered the regions of eternity, except the passage\ndiscussed above, which indicates a period of six hours spent in the\neighth heaven, since 90\u00b0 of the diurnal revolution correspond with six\nhours of time. But it tells us also that at the close of this period\nthe sun was setting over Jerusalem: consequently another morning was\ndawning in Purgatory. Eighteen hours have passed, therefore, since\nDante left the Earthly Paradise at noon; and he rises to the Primum\nMobile and thence to the Empyrean on the eighth day of his Vision.\n\nThe whole Vision, therefore, occupied an octave, or eight days.\n\n\n5. POSITIONS OF SUN, MOON, AND PLANETS AMONG THE STARS DURING DANTE\u2019S\nVISION.\n\nThe allusions to sun, moon, and stars in the _Divine Comedy_, when\nthus brought together, are seen to follow one another according to a\nregular scheme, and they form a very good guide by which to time Dante\non his journey. There is a little inaccuracy in one passage about the\nstars, and the moon is ambiguous once, but quite explicable. Taking\nthe allusions in a simple popular sense, as he seems to intend us to\ndo, assuming that the signs and the constellations of the zodiac are\nidentical, and that the moon, which at first is opposite the sun,\ntraverses about 13\u00b0 in the zodiac daily, and loses about an hour of\ntime more or less, there is very little difficulty in following him. It\nis quite enough to know that the sun is somewhere in Aries throughout,\nand that the moon is therefore in Libra at the beginning.\n\n[Illustration: Fig. 51. The rising sun at the Spring Equinox.]\n\nBut if we wish to know a little more accurately the positions of sun\nand moon among the stars, we must carefully compare the passages\nbearing on this question. Commentators differ so much that while some\nthink the sun\u2019s annual motion is ignored, and it is assumed to be at\nthe equinox all the time, others maintain that it was at the equinox\non the first day and moved on through Aries at the rate of about one\ndegree a day (as it should do, since there are 365 days in a year and\n360\u00b0 in the circumference of the sphere);[512] while others again say\nthat it was merely somewhere in Aries from the beginning.\n\n------------------------------------------------------------------------\n[512] Alfraganus, as we saw, gives the daily movement of the sun\neastward in the zodiac as about 59 minutes of arc. (A degree contains\n60 minutes).\n------------------------------------------------------------------------\n\nWhat are the actual indications of its position? No one questions that\nit was in Aries throughout the Vision, for this is often indicated,\nsometimes directly, as in _Inf._ i. 38-40, sometimes by mentioning\nTaurus as the sign following the sun,[513] or Pisces as the sign\npreceding.[514]\n\n------------------------------------------------------------------------\n[513] _Purg._ xxv. 2, 3.\n\n[514] _Inf._ xi. 113; _Purg._ i. 21, xix. 4-6.\n------------------------------------------------------------------------\n\nThere are four detailed descriptions:\u2014\n\n(1) On the first morning, the sun rose among those stars which were\nwith him at the Creation.[515] As we have seen, this may mean merely\nsome point in Aries, or the first point of Aries, at which the sun was\nthought to have been placed when created.\n\n------------------------------------------------------------------------\n[515] _Inf._ i. 38-40.\n------------------------------------------------------------------------\n\n(2) On the seventh day it rose near a point where three crosses are\nformed by the intersection of four circles.[516] One naturally thinks\nof the horizon as one of these circles; the equator and ecliptic, whose\nintersection define the equinox, suggest themselves as two more; the\nfourth is doubtless the colure which passes through the equinoctial\npoints and the poles, although curiously enough this is not mentioned\nby Ptolemy or Alfraganus, who only speak of the solstitial colure. Fig.\n51 shows how the horizon makes a cross with each of the other three\nwhen the equinox is upon it. The sun is at the point of intersection\nwhen rising with the equinox, and it was _near_ there when it rose\nthis morning\u2014\u201cquasi.\u201d It was therefore near, but not exactly at the\nequinox, and we know that it was the vernal, not the autumnal equinox,\nfrom the many allusions to Aries.\n\n------------------------------------------------------------------------\n[516] _Par._ i. 38, 39.\n------------------------------------------------------------------------\n\n(3) When Dante rises to the sun (on the same day) he directs our\nattention once more to this point where \u201cthe one motion strikes the\nother,\u201d that is, where the ecliptic\u2014the oblique circle which bears the\nplanets\u2014branches off from the equator, and he reminds us of the supreme\nimportance of this divergence. The sun, he says, was in this place. He\ndoes not mean at the exact point of intersection, or this passage would\nbe in flat contradiction to the last: \u201cquella parte\u201d[517] is no more\nprecise than \u201cquelle stelle,\u201d[518] and means only this part of the sky,\nor the constellation of Aries. The words which follow not only specify\nthat it was the spring equinox, but suggest that the sun had already\ntraversed several of those spirals which bring him to us earlier each\nmorning, _i.e._ it was several days after the equinox.[519]\n\n------------------------------------------------------------------------\n[517] \u201cThat part.\u201d\n\n[518] \u201cThose stars.\u201d\n\n[519] _Par._ x. 7-33.\n------------------------------------------------------------------------\n\n(4) On the same day the sun was \u201cone sign and more\u201d removed from some\npoint in Gemini.[520] This is very vague, but at least the sun cannot\nnow have been at the first point of Aries, or it would have been two\nwhole signs from even the first degree of Gemini.\n\n------------------------------------------------------------------------\n[520] _Par._ xxvii. 86, 87.\n------------------------------------------------------------------------\n\nIt seems, then, that we cannot possibly agree that the sun was at the\nequinox throughout the poem. It is clear that it was past the equinox\ntowards the end; but from these four passages we cannot be sure whether\nit was there on the first morning, or whether it moved through some\nundefined part of Aries during the Vision.\n\nOne consideration gives us some help, however. We know from _Inf._\nxxi. 112-114 that the first day was either March 25, which was believed\nin the Middle Ages to be the true anniversary of the Crucifixion, or\nGood Friday, which was kept by the Church as such. March 25 is four\ndays after the date which the Church still kept as the day of the\nEquinox (March 21), and 13 days after the true equinox, which at this\ntime fell on March 12. Good Friday also almost inevitably must fall\nafter the equinox, since Easter follows the full moon which follows\nthe equinox. It is true that some of Dante\u2019s readers may still have\nregarded the old traditional date of March 25 as the true day of the\nequinox, and possibly it was to suit all shades of knowledge that he\nleft the sun\u2019s position vague; but he himself certainly knew better,\nand probably had March 12 in his mind. Then those who held to March 25\nmight consider the sun as exactly at the equinox on the first day of\nthe Vision, but all better-informed readers and Dante himself must have\nregarded it as somewhat past this point. If we take it that, _e.g._,\nit was a week past the equinox, the sun was in about 7\u00b0 of Aries, and\nthis position agrees with the four crucial passages mentioned above.\nThe stress laid on the equinox seems to demand that the sun should be\nat least as near it as this on the first day; and a week later it would\nhave reached the middle of Aries, which is the position we assigned to\nit from a discussion of _Par._ xxvii. 86, 87.\n\nThis also agrees well with the course of the moon in the zodiac, which\nmust depend upon the sun\u2019s. We have seen that she was opposite the\nsun on the first morning, that her light paled the first-risen stars\nof Scorpio while she was yet beneath the eastern horizon three days\nlater, and that she was proceeding south on the following night. If\nthe sun was in the 7th degree of Aries on the first morning, the moon\nmust have been in the 7th degree of Libra; her mean daily motion of 13\u00b0\nwould bring her to the 16th degree of Scorpio three days later and to\nthe last degree on the day following; so even if we allow a deviation\nof a few degrees from the average, she was just where she should have\nbeen on each occasion. We have assumed for convenience that she became\nfull and was opposite the sun just as she set on the first morning, but\nthis may have happened at any time during the previous night (in the\nForest): Dante has not specified the hour, and it is of no consequence,\nsince the indications of time by the moon must necessarily be vague.\n\nThe time of sunrise will still differ little from 6 o\u2019clock, a week\nafter the equinox. In London it is a quarter of an hour earlier, but\nthe difference is less in Italy, and still less in the latitude of\nJerusalem.\n\nBesides the sun and moon, two of the planets are mentioned as in a\nparticular place among the stars.\n\nVenus, before sunrise on the fourth morning, is seen among the stars of\nPisces;[521] and she is also mentioned as a morning star before sunrise\non the seventh day.[522]\n\nSaturn is in Leo. \u201cIl petto del Leone\u201d[523] may mean the western part\nof the Lion, the part which first rises and contains the head and\nbreast, or it may refer to the star Regulus, which is called by Ptolemy\nand Alfraganus \u201cCor Leonis.\u201d[524] \u201cSotto il petto\u201d[525] may mean the\nposition of the planet as seen projected in the sky or a map, that\nis, a little south of this part of the constellation; more probably,\nperhaps, Dante is thinking of the supposed position of Saturn\u2019s sphere\n_below_ that of the stars.[526]\n\n------------------------------------------------------------------------\n[521] _Purg._ i. 21.\n\n[522] _Purg._ xxvii. 95.\n\n[523] \u201cThe Lion\u2019s breast.\u201d _Par._ xxi. 14.\n\n[524] \u201cThe Lion\u2019s Heart.\u201d\n\n[525] \u201cBeneath the breast.\u201d\n\n[526] _Cf. _Purg._ xxxii. 56, 57, where the sun is spoken of as under\nanother star.\n------------------------------------------------------------------------\n\nMars is spoken of as having returned to his own Lion a number of\ntimes: \u201cal suo Leon ... venne,\u201d[527] but this does not necessarily\nimply that he was in that constellation at the time.\n\nMercury and Jupiter are not noted as seen anywhere in the sky, nor does\nDante say in what constellation they were when he entered them with\nBeatrice.\n\nThere are a number of pitfalls into which Dante might have stumbled,\nwith this disposition of the skies, and the change to the southern\nhemisphere; and that he has avoided all is as clear a proof of his\nfamiliarity with astronomical phenomena as the positive evidence of his\ntruthful, consistent descriptions. For instance, he might very well\nhave represented the cold planet Saturn as actually aiding the cold\nmoon in driving away the heat of the day during the night, in _Purg._\nxix. 1-3, instead of only saying \u201ctalor da Saturno;\u201d[528] but if so,\nthis would have been inconsistent with the position of Saturn in Leo,\nsince Leo was below the horizon when dawn was drawing near and Pisces\nwas rising. Again, we have already mentioned that he evidently did not\nforget that it was autumn in the southern hemisphere. He never suggests\nthat it was spring in Purgatory, and in the passage quoted above, where\nhe describes sunrise at the March equinox, saying that the sun then\nmoves \u201ccon miglior corso e con migliore stella,\u201d[529] this happiest\neffect on the world is restricted to \u201cmortals,\u201d who as he thought all\ndwelt in the northern hemisphere, \u201csurge ai mortali.\u201d[530] I do not\nmean that the expression was used for this reason, but it is an example\nof how instinctively he avoided mistakes into which any other author\nwould almost certainly have fallen.\n\n------------------------------------------------------------------------\n[527] \u201cTo his Lion has come.\u201d _Par._ xvi. 37, 38.\n\n[528] \u201cSometimes by Saturn.\u201d\n\n[529] \u201cWith a better course and better star.\u201d _Par._ i. 40.\n\n[530] \u201cRises upon mortals.\u201d _Par._ i. 37.\n------------------------------------------------------------------------\n\n\n6. THE ASSUMED DATE OF THE VISION.\n\nEven among Dante enthusiasts there must be many who are astonished\nat the warmth of the controversy concerning the assumed date of his\nVision. To know whether he feigned himself to have entered the Inferno\nwith Virgil in March or in April, in the year 1300 or in 1301, really\ndoes not help us to appreciate the music of his verse nor the depth\nof his thought; yet a wealth of learning and research has been poured\nout upon this problem, and some commentators seem ready to defend\ntheir opinions with their lives, if that would avail to convince their\nreaders!\n\nThe date is indeed intimately connected with the narrative of the\n_Divine Comedy_, since there are constant allusions to current events.\nBy choosing a year earlier than the time at which he was writing, Dante\nis able not only to tell the spirits what is passing on the earth they\nhave left, but to endow them with the power of prophesying to him\nevents which are to come.[531] The peculiar interest of the problem for\nus just now is that astronomy has been called in to solve it. We have\nseen that the positions and movements of the heavenly bodies are all\nconsistent with one another in his poem, but it is interesting to ask\nwhether they are merely a consistent fiction or whether they correspond\nwith facts. Did Dante arrange his moon and planets according to his\nfeeling for scenery and the convenience of his time references, or did\nhe take the positions as they really were at some particular date? If\nso, the full moon, Venus a morning star in Pisces, and Saturn in Leo,\nall together near a spring equinox, ought to help to fix that date.\n\nThe year which is almost universally accepted, by the oldest as well\nas the most modern commentators, is 1300, chiefly on the authority of\n_Inf._ xxi. 112-114. Here Malacoda says that yesterday (the day of\nDante\u2019s entering the Inferno) it was 1266 years since the earthquake\nwhich accompanied the Crucifixion (see p. 370). Adding to this the 34\nyears which Dante has told us he believed to have elapsed between the\nNativity and the Crucifixion,[532] we get 1266\u00a0+\u00a034\u00a0=\u00a01300. And the day\nis either the Church Festival commemorating the Crucifixion, _i.e._\nGood Friday, which in 1300 fell on April 8, or March 25, which was\nbelieved to be the actual anniversary.\n\n------------------------------------------------------------------------\n[531] _Inf._ x. 100-105.\n\n[532] _Conv._ IV. xxiii. 96-98.\n------------------------------------------------------------------------\n\nIf this is the right interpretation of the passage, we may say at once\nthat Dante\u2019s astronomical data are imaginary, for the moon was not full\non the night preceding either of these dates, but on March 5, and April\n4: Saturn was indeed in Leo, but Venus was so near the Sun as to be\ninvisible in March, and began to appear as an evening star in Taurus on\nabout the 9th of April.\n\nThese positions were all carefully calculated by Prof. Angelitti, who\nis a professional astronomer as well as a Dante scholar; and he made\nthe thrilling discovery that the positions agree wonderfully well for\nthe year 1301! In this year the moon was full on the early morning of\nthe 25th of March; Venus entered Pisces three days later, and was a\nmorning star, near her greatest elongation west, and very brilliant;\nSaturn was not only still in Leo but was just three degrees west of\nRegulus; and Mars was also in Leo.\n\nIf the anniversary of the Crucifixion means Good Friday, the day would\nbe March 31 in 1301, and the moon would be wrong, but March 25 has some\nclaims to be considered the more probable date. A fixed calendar date\nis more appropriate to use for calculating an exact number of years\nthan a changing festival, which might rather be regarded as an \u201cideal\ndate.\u201d[533] Moreover, March 25 is suggested by the allusion to the\nCreation in the opening Canto; this day was also the traditional date\nfor the spring equinox,[534] and it was one of the most important days\nin the year to Florentines, being their New Year\u2019s Day as well as Lady\nDay.\n\n------------------------------------------------------------------------\n[533] Moore, _Studies in Dante_ iii. p. 146.\n\n[534] See p. 177.\n------------------------------------------------------------------------\n\nWe know that the idea of writing his great work was in Dante\u2019s mind\neven when he wrote the last words of the _Vita Nuova_,[535] and we need\nonly suppose that he was thinking of it when he looked at the sky on\nthe evening before Lady Day in 1301, that he saw the full moon, and\nthe two bright planets Mars and Saturn making a striking asterism with\nRegulus; also that in the early dawn about the same time he rejoiced in\nthe sight of Venus veiling the Fishes in the east.\n\n------------------------------------------------------------------------\n[535] _V. N._ xliii. 1-11.\n------------------------------------------------------------------------\n\nBut is this attractive theory admissible? Can we take Dante\u2019s words\nelsewhere as referring to the year 1301?\n\nTake first the one passage in which he explicitly states the day and\nyear, the words of Malacoda quoted above. This is usually taken to\nindicate the year 1300, as shown above (p. 410), but it is easy to\ninterpret it another way\u2014thus: 1300 years had been completed since the\nNativity on the day Dante entered the Inferno. Now the year 1 is not\none year after the Nativity, but the year of the Nativity itself; hence\nthe year 2 is one year after, the year 3 two years after, ... the year\n1300 is 1299 years after, and the year 1301 is 1300 years after. The\nyear 1300 was completed on March 25,[536] and the date then changed,\naccording to Florentine usage, to 1301. (It had already been called\n1301 for three months, according to Roman usage, so fortunately for us,\nthere is no disagreement between the two calendars from this part of\nthe year).\n\n------------------------------------------------------------------------\n[536] Exactly at midday, moreover, according to one system then in\nvogue, though it seems to have been more usual to begin the day at\nsunrise.\n------------------------------------------------------------------------\n\nIt must also be noted that in several old MSS., considered\nauthoritative by some of the very early commentators, the passage\nreads:\u2014\u201cMille dugent _\u2019uno_ con sessanta sei.\u201d[537] Although it is\nimpossible to believe that Dante wrote such a faulty line, this shows\nthat some early copyist felt a difficulty either in accepting the\ndate 1300 or in understanding how Dante arrived at it by Malacoda\u2019s\ncomputations. This passage, therefore, is inconclusive for 1300 or 1301.\n\n------------------------------------------------------------------------\n[537] \u201cA thousand two hundred _and one_, added to sixty-six.\u201d\n------------------------------------------------------------------------\n\nThen there is the first line of the _Divina Commedia_ \u201cNel mezzo del\ncammin di nostra vita,\u201d[538] which is usually taken to mean that\nDante was in his 35th year, since in _Conv._ IV. xxiv. 30, 31, and\nxxiii, 88-94, he says that in normal natures the \u201cpunto sommo,\u201d the\n\u201ccolmo,\u201d[539] of the Arch of Life is reached at this age. But is it to\nbe taken as indicating a precise year? If so, it points to one which\nhas never been suggested for the Vision, so far as I know, for in\nanother passage of the _Convivio_ he says when speaking of his exile,\nthat he had lived in Florence \u201cfino al colmo della mia vita,\u201d[540]\nand we know that the year of his exile was 1302. But if we look again\nat the discussion concerning the arch of human life, we find that the\nwhole period of \u201cgioventute,\u201d[541] which is from the 25th to the 45th\nyear \u201cveramente \u00e8 colmo della nostra vita\u201d[542] (_Conv._ IV. xxiv.\n22, 23). If, nevertheless, it is said that the \u201cmezzo del cammin di\nnostra vita\u201d means Dante\u2019s 35th year, we must know the date of his\nbirth with certainty before we can deduce the year at which he had\nreached this age. And this is not quite easy. This very line is used\nindifferently to show that he was born in 1265 because the date of\nthe Vision was 1300, or that the date was 1300 because he was born in\n1265! No registers of births or baptisms were kept in those days. Most\nof the old biographers give 1265 for the date, but not all, and some\nof those who do betray ignorance or confusion in the matter: Boccaccio\nsays the year 1265, when Urban the Fourth was Pope, yet Urban we know\ndied in 1264; Lionardo Bruni says \u201c1265, a little after the return to\nFlorence of the Guelfs, who had been in exile by reason of the defeat\nof Montaperti,\u201d but this return was in September 1266! Dante himself\nsays that his ancestors shared in this exile,[543] and as he also often\nrefers to the fact that he was born in Florence,[544] it is difficult\nto see how that could have been in 1265.\n\n------------------------------------------------------------------------\n[538] \u201cMidway in the journey of our life.\u201d\n\n[539] \u201cThe highest point,\u201d the \u201csummit.\u201d\n\n[540] \u201cUntil the summit of my life.\u201d _Conv._ I. iii. 24, 25.\n\n[541] \u201cYouth.\u201d\n\n[542] \u201cIs in truth the summit of our life.\u201d\n\n[543] Farinata alludes to the two Guelf banishments of 1248 and 1260.\n_Inf._ x. 42-50.\n\n[544] _Conv._ I. iii. 22-24; _Inf._ xxiii. 94, 95, etc.\n------------------------------------------------------------------------\n\nAgain, he says that there was a difference of less than 8 months\nbetween the age of Beatrice and himself (she was 8 years 4 months old\nwhen he was nearly nine),[545] that she died in June 1290,[546] and was\nthen on the threshold of her \u201csecond age,\u201d[547] that is in her 24th\nyear, or 23 years old. This gives 1267 for the year of her birth, and\nhe must have been born in the same or the preceeding year. Historical\ndocuments show that Dante spoke in the Council of the Hundred in 1295,\nand Brunetto Latini says no man could hold office in Florence under\nthirty years of age; but Brunetto wrote in exile in France and died in\n1290, and in a translation from his original French into Italian the\nage has been altered to 25, so it is possible that the age had been\nlowered before 1295.[548] There remains the story told by Boccaccio,\nthat a Ser Piero di Messer Giardino (a notary whose name occurs in\nlegal documents of the time), heard from Dante himself shortly before\nhis death that he had been 56 years old in the preceding May. The date\nof his death is unanimously given as 1321, so this story, if we may\naccept it as authentic, is one clear piece of evidence that Dante was\nborn in 1265.\n\n------------------------------------------------------------------------\n[545] _V. N._ ii. 1-15.\n\n[546] _V. N._ xxx. 4-13.\n\n[547] _Purg._ xxx. 124, 125; _Cf. Conv._ IV. xxiv. 11-13.\n\n[548] Imbriani: _Quando nacque Dante?_ and _Che Dante\nprobabilissimamente nacque nei MCCCLXVII_.\n------------------------------------------------------------------------\n\nOn the whole, we must say that it is doubtful whether the \u201cmezzo del\ncammin\u201d means Dante\u2019s 35th year, and if it does, we are not certain\nthat he reached that age in 1300.\n\nAnother passage which is often quoted as clearly indicating the year\nof the Jubilee, 1300, for the assumed date of the Vision is Casella\u2019s\nexplanation of his late arrival in Purgatory.[549] Dante is surprised\nto witness this arrival, knowing that it is some time since his\nfriend\u2019s death; and Casella replies that the Angel of the Passage had\nrefused many times to bring him, until three months ago, when every one\nwho wished to come had been graciously received. This is believed to\nrefer to the Bull of Pope Boniface published at Christmas 1299, that is\njust three months before March 1300. But this Bull gave no indulgence\nto the dead; it was in favour of those who performed certain spiritual\nexercises in the churches of Rome during the Jubilee year. On the other\nhand, there was a Bull published just a year later, which was for the\nbenefit of departed souls: it extended the indulgences to those who\nhad died on their way to Rome, or before the spiritual exercises were\ncompleted there. We do not know when Casella died, but if it was some\ntime in 1300, with his purpose of gaining the indulgence unfulfilled,\nthe Angel\u2019s refusal at first, and acceptance afterwards\u2014after December\n1300\u2014and his arrival in Purgatory in March 1301, would be explained.\nThe fact that his arrival was still three months after the Bull, and\nthat all without exception were welcomed by the Angel, are difficulties\nwhich apply to both interpretations. But perhaps that just given is a\nlittle too clever. It is most natural to consider the Indulgence as the\nfamous one of 1300, and to understand that in the Jubilee year the way\nof salvation was made easier for all souls, living or dead.[550]\n\n------------------------------------------------------------------------\n[549] _Purg._ ii. 91-103.\n------------------------------------------------------------------------\n\n[550] For this point and a full discussion of the date, especially\nfrom the astronomical data, see Angelitti\u2019s _Sulla Data del Viaggio\nDantesco_, and _Sull\u2019 anno della Visione Dantesca_, and Moore\u2019s \u201cThe\nDate assumed by Dante for the Vision of the \u2018Divina Commedia,\u2019\u201d\n_Studies in Dante_ III.\n\nIf however these, and many other passages quoted in the controversy,\nare unconvincing, the same cannot be said of Cunizza\u2019s \u201cQuesto\ncentesim\u2019 anno.\u201d[551] Prof. Angelitti\u2019s suggestion that she was\nreckoning by the Easter year, which was used in some parts of France\nand Italy, so that the date was still 1300 for her, though for most\nItalians it was 1301, is too ingenious; and it is hard to believe that\nshe means \u201cthis century year\u201d applying it to 1301. Though this might\nbe correct, it is clear that 1300 was regarded as the century year,\nbecause the words \u201ccentesimo anno\u201d occur in the Bull of Boniface VIII.\nwith reference to the year 1300. This then speaks strongly and clearly\nagainst our astronomical theory of 1301.\n\n------------------------------------------------------------------------\n[551] \u201cThis hundredth year.\u201d _Par._ ix. 40.\n------------------------------------------------------------------------\n\nThe historical events alluded to in the _Divine Comedy_ are so often\nof unknown date to us, that few of them help as much as might be\nexpected. Judge Nino\u2019s widow remarried on June 24, 1300, and as he\nspeaks of her as having already put off her widow\u2019s weeds,[552] this\nmight indicate that we are in 1301, but it is not conclusive, since\nthey would probably be discarded three months before she was actually\nthe wife of another. On the other hand, Can Grande della Scala, who is\nsaid in a fourteenth century chronicle to have been born on March 9,\n1291, is described as only nine years old.[553] Dante might possibly\nhave been mistaken by a year in the date of his birth, but he cannot\nhave been ignorant of the death of his friend Guido Cavalcanti. The cry\nof anguish from Guido\u2019s father will be remembered by all readers of the\n_Inferno_, after Dante has spoken of his friend in the past tense:\u2014\n\n------------------------------------------------------------------------\n[552] _Purg._ viii. 74.\n\n[553] _Par._ xvii. 80, 81.\n \u201cDi subito drizzato grid\u00f2: Come,\n Dicesti _egli ebbe_? Non viv\u2019 egli ancora?\n Non fiere gli occhi suoi lo dolce lome?\u201d[554]\n\n[554]\n \u201cUp starting suddenly he cried out: How\n Saidst thou? \u2018_he had_?\u2019 Is he not still alive?\n Does not the sweet light strike upon his eyes?\u201d\n _Inf._ x. 67-69.\n------------------------------------------------------------------------\n\nAnd as Dante hesitates a little, Cavalcante sinks back into his tomb\nof punishment, and does not reappear. Before Dante leaves the place,\nfeeling compunction, he charges Farinata to tell the father that his\nson is still among the living, and that the sinister hesitation was\ndue to another cause than he thought. Now it is beyond dispute that\nGuido died in August 1300, for he was buried in the cemetery of St.\nReparata in Florence on August 29, 1300, according to official records\nstill extant;[555] and Dante had a share in banishing him amongst other\nexiles to the unhealthy place where he contracted the illness of which\nhe died. The year 1300, in which Dante held the official position\nwhich obliged him to do this, was burned into his mind, as we see in\nhis letter, mentioned by Lionardo Bruni, in which he says that all his\nmisfortunes sprang from the time of his priorate.\n\n------------------------------------------------------------------------\n[555] Toynbee\u2019s _Dante Dictionary_, under \u201cCavalcanti.\u201d\n------------------------------------------------------------------------\n\nHow then can we believe that he here imagines himself speaking in the\nspring of 1301, unless we assume that Cavalcanti had really guessed the\ntrue cause of his hesitation, and that what Dante said afterwards was a\nkindly lie? Is this in character with his uncompromising, even ruthless\nstraightforwardness? Unless therefore some really satisfactory way of\nescape can be found from this incident and the \u201ccentesim\u2019 anno\u201d I fear\nwe must reluctantly abandon the theory of 1301, championed so skilfully\nby Angelitti and others, and must agree with the majority that Dante\nmeans us to understand the year 1300.\n\nThe early commentators seem to have taken for granted that Dante was\ncorrect in his astronomical data, without taking any particular trouble\nto verify them. Jacopo della Lana in commenting _Par._ xxi. 14 says\nthat in 1300 in the month of March Saturn was in Leo, and was in the\n8th degree of that sign; and in order that we should know what was the\ndisposition of the whole sky at that time he further informs us that\nJupiter was in Aries in the 24th degree, and Mars in Pisces in the\n11th degree, that the sun was near the beginning of Aries, and Venus\nin Pisces (these two are evidently taken simply from Dante). Mercury\nwas in Virgo (with the sun in Aries! in this case Mercury would have\nbeen visible nearly the whole night), and the moon in \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0. Here\nthere is said to be a blank in all the MSS. The moon was too much for\nDella Lana, whether the difficulty was in finding her position or in\nreconciling it with that given by Dante. The Ottimo and Benvenuto da\nImola copy Della Lana with little change, both giving the positions\nof Saturn, Jupiter, and Mars in degree and sign, but the sun only as\nnear the beginning of Aries, Venus in Pisces, and Mercury in Virgo.\n(It is astonishing that neither should have noticed this gross error.)\nBenvenuto boldly adds that the moon was in Libra, doubtless because\nDante\u2019s description so required it at the beginning of his poem.\n\nNor do these early commentators seem to feel any difficulty about the\ndate on which the Vision began. From _Inf._ i. 38-40 they generally\nconclude that it was the day of the equinox, which they say vaguely\nfell in the middle of March \u201cmezzo Marzo,\u201d and from _Inf._ xxi. 112-114\nall except Boccaccio (who interprets March 25) take it to be Good\nFriday.[556] No discrepancy seems to have been felt here: they merely\nremark that in 1300 Easter fell in March, and more than two hundred\nyears passed before anyone pointed out that this was wrong.\n\n------------------------------------------------------------------------\n[556] Moore, _Studies in Dante_ III. p. 146.\n------------------------------------------------------------------------\n\nAt last a work appeared in 1554, called \u201c_Del Sito, Forma, et Misure\ndello Inferno di Dante_,\u201d in which the author, Giambullari, remarked\nthat according to astronomical calculations the Paschal Moon was not\nfull on the night between Thursday and Good Friday in 1300, but on the\nmorning of April 5th. This excited a good deal of interest, and many\ntheories have since been put forth to reconcile Dante\u2019s astronomical\ndata with the facts of the year 1300.\n\nDr. Moore thinks the date of entering the Inferno was Good Friday,\nApril 8, 1300, but that Dante uses instead of the real moon the\necclesiastical moon, which, as we know, is a conventional body\nrevolving according to Meton\u2019s cycle, and sometimes appearing on tables\nas full two or three days before or after the real Full Moon. Dr. Moore\nfinds that this ecclesiastical moon, was full on April 7, 1300.[557]\nBut would Dante trouble about the ecclesiastical moon, and would his\nreaders know anything about it? Its only use was for determining\nEaster, and this was done for the people by the Church. The real moon\nwas extremely important for astrologers, for whose benefit Tables and\nAlmanachs were chiefly drawn up; the real moon was useful to everyone\nas light-giver and time recorder. It is surely inconceivable that a\nFlorentine who wished to arrange a midnight festival, or to start on a\nnight-journey, would consult a calendar to find out on what date the\n_ecclesiastical_ moon would be full! And the ecclesiastical moon does\nnot alter the position of Venus.\n\n------------------------------------------------------------------------\n[557] \u201cThe Astronomy of Dante,\u201d in _Studies_ III., and _Time References\nin the Divina Commedia_.\n------------------------------------------------------------------------\n\nAccording to another suggestion, Dante followed a tradition as to the\nposition of all the \u201cseven planets\u201d at the Creation, and for this\nreason not only was his sun in Aries, but the moon full and opposite,\nand Venus in Pisces. Venus is said to have this position in a picture\nof the Creation in a Church at San Gemignano.[558] Compare also\nMilton\u2019s moon at her creation:\u2014\n\n------------------------------------------------------------------------\n[558] Note on _Purg._ i. 19-21 in the \u201cTemple\u201d edition of Dante.\n\n \u201c ... Less bright the moon,\n But opposite in levelled west, was set,\n His mirror, with full face borrowing her light\n From him.\u201d[559]\n\n[559] _Par. Lost_ vii. 375-378.\n------------------------------------------------------------------------\n\nOr again, it is sometimes held that the day and all the celestial\npositions are ideal. Dante means us to understand that the first day\nof his Vision was Good Friday, but without troubling as to what day it\nfell on in 1300; the equinox and the full moon are naturally connected\nwith Good Friday, since they determine Easter; Venus is connected with\nthe idea of dawn, and when the Sun is in Aries the morning star may\nwell be in Pisces.\n\nEither of these views might be correct, and no one will dispute a\npoet\u2019s right to arrange his skies as he thinks fit, if he is consistent\nwith them, as Dante was. But how did these positions, if they are\npurely imaginary, come to coincide exactly with the real positions of\n1301?\n\nIf we examine the positions of 1301, and accept nothing that is\ndoubtful in Dante\u2019s own words, what does the coincidence amount to?\nSaturn was near Regulus, but he was also in the forepart of Leo in\n1300, and we are not sure that Dante means more than this; Mars was in\nLeo, but we are not sure that Dante wanted him there;[560] the moon\nwas full on the morning of March 25, but we are not sure whether Dante\nmeans March 25 or Good Friday. Venus was a morning star in Pisces, and\nthis till very lately was the one astronomical fact incontestably in\nfavour of 1301 and against 1300.\n\n------------------------------------------------------------------------\n[560] See p. 407.\n------------------------------------------------------------------------\n\nBut in 1908 there was printed in Florence, for the first time, a\nmedi\u00e6val Almanach, which suggests so simple an explanation of this\nmost striking coincidence that it seems to leave nothing more to be\nsaid for the 1301 hypothesis. This Almanach, which has been published\nunder a title which perhaps takes things a little too much for\ngranted\u2014_Almanach Dantis Aligherii_\u2014was compiled by a learned Jew,\nJacob ben Machir ben Tibbon, who was born in Marseilles about 1236,\nand died at the beginning of the fourteenth century. Using the Toledan\nTables, he constructed this so-called perpetual almanach, which gives\nthe positions of sun, moon, and planets, at intervals of a few days for\nwhole cycles of years. Each has a cycle of a different length, that\nof Venus for instance being 8 years, as on the Babylonian tablets of\nephemerides; and at the end of each cycle nearly the same positions\ncome over again. It was written in Hebrew, and translated into Latin\nby an unknown author, and must have been popular, since there were\nan immense number of Latin MSS. in the fourteenth century. In the\noriginal, all the cycles begin in 1301, but in the Latin they begin in\n1300, _except the cycles of Venus and the sun, which begin in 1301_.\nYet 1301 is not written over the first column for Venus, but merely 1,\nor nothing at all, or even in some copies 1300, and in both the Hebrew\nand Latin prefaces the beginning of all the cycles is stated to be\n1300.[561]\n\n------------------------------------------------------------------------\n[561] Preface to _Almanach Dantis Aligherii_, Boffito and Melzi d\u2019\nEril.\n------------------------------------------------------------------------\n\nIf, therefore, Dante looked up the position of Venus in this almanac,\nhe would very naturally take the 1301 positions for 1300, and he would\nfind that Venus was in Aquarius throughout March, until the 27th, when\nshe passed into the sign of Pisces, and therefore was a morning star\nduring the whole month and also in April. And he would find that Saturn\nwas in the 7th and 8th degrees of Leo in March and April 1300 (which\nwas very nearly correct).[562]\n\n------------------------------------------------------------------------\n[562] It is important to observe that this suits the description of\nthe \u201cLion\u2019s breast\u201d better than the 20th and 21st degrees (Almanach\npositions for 1301), if Dante, as usual in the _Divina Commedia_,\nidentifies the constellation with the sign.\n------------------------------------------------------------------------\n\nIt appears then that while certain expressions used in the _Divine\nComedy_ prove clearly that 1301 is not the year assumed as the date of\nthe Vision, the astronomical argument in favour of it is not strong\nenough to be convincing, especially in the light of this recent\ndiscovery.\n\nGranting that 1300 was the year, what was the day? Probably not March\n25, for the early commentators, excepting only Boccaccio in one\npassage, are all in favour of Good Friday, and Dante might see in the\nAlmanac that the moon was not full on that date. But neither was she\nfull on the actual date of Good Friday, which fell on April 8 in 1300;\nmoreover the sun was then so far advanced in Aries that seven days\nlater, when Dante describes it as a little past the equinox, it would\nreally have been in Taurus. The third and only possibility is to accept\nthe theory that his moon and his day were ideal; that is, he simply\nassumed Good Friday and a full moon to occur together soon after the\nequinox, with which both are so intimately associated. The date of\nEaster is not given in the old almanac, and we have seen that the early\ncommentators who knew that the equinox fell in \u201cmezzo Marzo\u201d[563] were\ncontent to accept Easter as falling in that month also. We must not\nforget the convenience of an equinox and a full moon for simplifying\nthe time references also.\n\n------------------------------------------------------------------------\n[563] The middle of March.\n------------------------------------------------------------------------\n\nWe conclude, then, that the year chosen by Dante was 1300 (as has been\nmost generally believed), and the day Good Friday, which he assumes\nto have fallen about a week after the equinox, and at a time of full\nmoon. Saturn in his poem, and also in fact, was in Leo; Venus was not\nactually a morning star, nor in Pisces, but he may have been led to\nassign this position to her through an error in a contemporary almanac.\n\nI must confess to a great feeling of disappointment in coming to the\nconclusion that Prof. Angelitti\u2019s enticing theory must be rejected, but\na careful study of Dante\u2019s own words, and Prof. Boffito\u2019s discovery\nof the \u201cAlmanach perpetuum ad annum 1300 inchoatum\u201d seem to leave no\nother choice. Last April,[564] when helping to photograph Halley\u2019s\nComet in beautiful early dawns, this problem was much in my mind. Venus\nonce more had the Fishes in her train, and oddly enough Good Friday\nhad fallen on March 25! I could not help wishing that these things had\nhappened in 1300 as well as in 1910!\n\n------------------------------------------------------------------------\n[564] This was written in 1910.\n------------------------------------------------------------------------\n\nIf in spite of all arguments to the contrary, any readers are convinced\nthat Dante\u2019s celestial positions were taken from the real skies, it\nremains to them to imagine that he saw them in March of 1301 and wove\nthem into the narrative of his poem, although for some reason he\nadopted another date.\n\nThe following tables (pp. 425-26) summarize the foregoing pages. It\nwill be noted with what appropriate symbolism Dante enters Hell on the\nevening of Good Friday, spends that night and the whole of Saturday in\nthe depths, and rises out of them on Easter Day before the dawn.\n\nFor although he reaches Earth\u2019s centre on Saturday evening by Jerusalem\ntime, the change of hemisphere there makes his time suddenly go back\ntwelve hours, so that it is again Saturday morning, and he spends the\nday and night of Saturday (Purgatory time) in climbing to Earth\u2019s\nsurface.\n\nDAYS OF THE VISION AND POSITIONS OF THE SUN, MOON, AND PLANETS.\n\n _Dante\u2019s |Jerusalem|Purgatory| Positions of Sun,_|\n _Journey. | Time. | Time. | Moon and Planets | References._\n | | | _in Zodiac._ |\n ----------+---------+---------+-------------------+-----------------\n | Night | |Moon full in Libra,|_Inf._ xx. 127.\n | | | about 7th degree |\n |Day I. | |Sun in Aries, |_Inf._ i. 38-40.\n Forest |Good | | about 7th degree |\n |Friday | | |\n |(1300) | | |\n ----------+---------+---------+-------------------+-----------------\n | Night | | |\n Inferno |Day II. | | |\n |Saturday | | |\n ----------+---------+---------+-------------------+-----------------\n |Night |Day III. | |\n | |Saturday | |\n Earth\u2019s | Day | in | |\n Interior |(Sunday) |Purgatory| |\n | Easter | Night | |\n | Day | | |\n | |Day IV. | Venus in Pisces |_Purg._ i. 19-21.\n | |(Sund.) | at dawn |\n | |Easter | |\n | | Day | |\n | | in | |\n | |Purgatory| |\n | | | |\n | | Night |Moon in the middle |_Purg._ ix. 1-6.\n | | | of Scorpio |\n ----------+---------+---------+-------------------+-----------------\n | |Day V. | |\n | |(Mond.) | |\n | | Night |Moon at end of |\n | | | Scorpio or |\n Purgatory | | | beginning of |_Purg._\n | | | Sagittarius | xviii. 79-81.\n | |Day VI. | |\n | |(Tues.) | |\n | | Night | |\n ----------+---------+---------+-------------------+-----------------\n Earthly | |Day VII. |Sun in the middle |_Par._ i. 37-44;\n Paradise,| |(Wed.) | of Aries | x. 7-33;\n planetary| | |Saturn in Leo | xxvii. 86,87.\n & stellar| | | |\n spheres | | | |\n ----------+---------+---------+-------------------+-----------------\n Primum | |Day VIII.| |_Par._ xxi.\n Mobile | |(Thur.) | | 13-15.\n and | | | |\n Empyrean | | | |\n\n\n\n\nSummary.\n\n\n _Arguments for 1300 or 1301._\n _From Expressions and Incidents in the D.C._\n\n Malacoda. | Inconclusive: method of reckoning uncertain.\n _Inf._ xxi. 112-114.|\n |\n \u201cNel mezzo del | Inconclusive: a precise year possibly not\n cammin.\u201d | indicated, and date of Dante\u2019s birth not\n _Inf._ i. 1. | certainly known.\n |\n Casella. | Inconclusive: may refer to Bull of 1299,\n _Purg._ ii. 98-99. | but possibly of 1300.\n |\n Can Grande. | For 1300: Can Grande 9 years old in\n _Par._ xvii. 80, 81.| March 1300.\n |\n Cunizza. | For 1300: \u201cquesto centesim\u2019 anno\u201d can only\n _Par._ ix. 40. | mean 1300.\n |\n Nino\u2019s widow. | Inconclusive: might put off widow\u2019s weeds\n _Purg._ viii. 74. | before re-marriage.\n |\n Guido Cavalcanti. | For 1300: Guido, Dante\u2019s intimate friend,\n _Inf._ x. 111. | died in August 1300.\n\n\nThe Astronomical Data.\n\n (_True Equinox, March 12. Ecclesiastical, March 21.\n Traditional, March 25_).\n\n _In D.C. | On Good Friday, 1300. | On March 25, 1301._\n | |\n SUN near |Day assumed to fall soon after|Date of traditional\n EQUINOX. | equinox (actually April 8.) | equinox (13 days\n | | after true\n | | equinox).\n | |\n MOON full on |Assumed full, since Easter |Full.\n first day. | associated with equinox and |\n | full moon. (Actually full |\n | March 5, and April 4.) |\n | |\n VENUS in Pisces |Supposed in Pisces from error |Entered Pisces\n on 4th day. | in contemporary almanac, | March 27.\n | confounding 1301 with 1300. |\n | |\n SATURN \u201con the |In forepart of Leo, |In Leo, 21st degree\n Lion\u2019s breast.\u201d| 8th degree of the sign. | of the sign,\n | | close to Regulus.\n | |\n MARS possibly |Not near Leo. |In Leo.\n intended to be | |\n in Leo. | |\n\nEarly commentators understand Good Friday, not March 25.\n\n\n_VII. THEORETICAL AND SPECULATIVE ASTRONOMY._\n\n \u201cThou shalt learn the burning nature of the pure\n clear sun, thou shalt hear the wandering nature\n of the round-eyed moon, and thou shalt learn of\n the surrounding heaven, whence it arose, and how\n Necessity guiding it compelled it to hold fast the\n bounds of the stars.\u201d\n _Parmenides._\n\n\n1. THE SPHERES.\n\nDante\u2019s astronomical phenomena, though they are just the same that are\nfamiliar (or ought to be familiar) to us, have led us into some strange\nby-ways, because they are so intimately connected with his works of\nimagination. His astronomical theories, by which these phenomena were\nexplained, will also take us into paths which are now seldom trodden\nby astronomers or others, because medi\u00e6val astronomy was mingled with\nmagic, with metaphysics, and with religion, in a way which seems very\nstrange to us.\n\nThe second treatise of the _Convivio_ has for its text the Ode which\nis quoted in _Paradiso_ viii. 37, \u201cVoi che intendendo il terzo ciel\nmovete.\u201d[565] When speaking of the literal meaning of this Ode, Dante\ntakes the occasion to discourse on the system of astronomy which he\nhad learned, and describes how all the apparent movements of the\nheavens are explained by postulating the existence of spheres and\nepicycles, entering with special detail into the system of Venus, the\nthird heaven; and later on, when expounding the allegorical meaning of\nthe Ode, he draws an elaborate comparison between the spheres and the\ndifferent branches of science and philosophy, in which he incidentally\ngives his readers a good deal of information about the heavens.\n\n------------------------------------------------------------------------\n[565]\n \u201cOh ye whose intellectual ministry\n Moves the third heaven.\u201d\n (_Carey_).\n------------------------------------------------------------------------\n\nFrom this interesting treatise, therefore, as well as from many\nscattered passages in all his works, we learn what Dante thought\nwere the real movements of the heavenly bodies, their dimensions,\ntheir nature, and the forces which move them; and it forms a valuable\ncommentary on the _Paradiso_, in reading which he supposes us to\nunderstand the elements of the Ptolemaic system, and the ideas of the\nphilosophers and the Fathers of the Church concerning the organization\nof the Universe.\n\nOf these ultimate truths concerning the heavens, Dante says, very\nlittle can be known, but the little which is within the reach of human\nreason, gives more delight (as Aristotle says) than the abundance\nand the certainty of other things easier to be understood.[566] This\nthought finds an echo in the _Paradiso_, where the poet reminds us of\nthe beautiful order to be found throughout the universe, and invites us\nto contemplate the skill of the architect as shown in the movements of\nthe planets.[567]\n\n------------------------------------------------------------------------\n[566] _Conv._ II. iii. 8-14.\n\n[567] _Par._ x. 1-12.\n------------------------------------------------------------------------\n\nDante knew that great men in ancient days had speculated on the\npossibility that it was Earth, and not the skies, that moved in the\ndiurnal period, but the balance of authority was against them, and they\nhad been confuted by the Master of those who KNOW,[568] that glorious\nphilosopher to whom Nature most fully revealed her secrets,[569]\nAristotle. In Treatise III. of the _Convivio_ he gives a clear and\nconcise account of the theory of Philolaus, and of what he understood\nto be the theory of Plato.[570] In the former he seems to have been\nstruck with the deduction that, if Fire were at the centre of the\nUniverse, the real motion of fire on Earth, which to us appears always\nto ascend, would in reality be a descent towards its own place at the\ncentre.\n\n------------------------------------------------------------------------\n[568] _Inf._ iv. 131.\n\n[569] _Conv._ III. v. 54-56.\n\n[570] _Conv._ III. v. 29-52. See Part I. of this book _Pythagoras and\nhis Followers_, and _Plato_, for a description of their astronomical\nsystems.\n------------------------------------------------------------------------\n\nBoth these hypotheses he had evidently learned from Aristotle\u2019s _De\nC\u00e6lo_,[571] and when thus presented they seem entirely fanciful; so\nalthough Dante had reverence for both Pythagoras and Plato it is not\nsurprising that he rejected the systems of both. He adds that it is\nnot his intention to recount here the arguments by which Aristotle\nconfutes them and establishes the truth: it is enough for his readers\nto know, on so great an authority, that the earth is fixed, and does\nnot revolve, and is at the centre of the World.\n\nDante has to confess reluctantly that Aristotle made two mistakes in\nhis astronomy: he said that there were only eight spheres, those of the\nseven planets, and that of the stars, \u201ce che di fuori da esso non fosse\naltro alcuno;\u201d[572] also he placed the heaven of the sun immediately\nabove that of the moon, that is to say second in order, counting from\nEarth outward. Aristotle\u2019s loyal admirer hastens to add that these\nserious mistakes \u201cquesta sua sentenza cos\u00ec erronea\u201d[573] are explicable\nand excusable because, as Aristotle himself shows in the _Metaphysics_,\nwhen he treated of astrology he was merely following the opinions of\nothers. That is to say, he took his facts from others, and they cannot\nall be depended upon, but his philosophical deductions are his own, and\nare never in error. In the above question of the possible movements\nof Earth, we saw (pp. 101-2) that Aristotle\u2019s arguments were almost\nentirely drawn from metaphysics.\n\n------------------------------------------------------------------------\n[571] See Part I. \u201cAristotle.\u201d\n\n[572] \u201cAnd that outside the latter there was no other.\u201d _Conv._ II.\niii. 24, 25.\n\n[573] \u201cThis entirely mistaken opinion of his.\u201d _Ibid._ 28.\n------------------------------------------------------------------------\n\nThere have been many opinions regarding the number and the positions\nof the spheres, Dante says, but the truth about them has at length\nbeen found. The scheme which he expounds is that of Ptolemy, modified\nby the Arabs and adapted to the doctrines of the Church by Christian\nwriters. In the _Vita Nuova_ he almost seems to imply that the nine\nmoving spheres form an article of faith. \u201cSecondo Tolommeo e secondo la\nCristiana verit\u00e0, nove siano li cieli che si muovono.\u201d[574]\n\n------------------------------------------------------------------------\n[574] \u201cAccording to Ptolemy and according to Christian Truth, nine is\nthe number of the moving heavens.\u201d _V. N._ xxx. 16-18.\n------------------------------------------------------------------------\n\nQuoting from Albertus Magnus, or Averro\u00ebs, he apparently credits\nPtolemy with the discovery of precession, for he says that it was\nPtolemy who added a ninth sphere to the eight of Aristotle, because\nhe perceived that otherwise the outer sphere would have a double\nmovement, and so he felt obliged to assume a sphere beyond the\nstar sphere which should have only the one simple motion of the diurnal\neast to west revolution. The period of this revolution (the sidereal\nday) Dante gives as 23 hours and \u00b9\u2074/\u2081\u2085ths of an hour, \u201cgrossamente\nassegnando,\u201d[575] _i.e._ 23 hours 56 minutes, which is the correct\nvalue ignoring the 4 seconds. We know that it was not Ptolemy in fact\nwho thought it necessary to add a ninth sphere; he was not sufficiently\ninterested in spheres, since to him they were only mathematical\nabstractions: but the Arabs of Baghdad noted that he had added another\n_movement_, the discovery of Hipparchus; and they, accepting the\nspheres as material instruments of celestial motions, felt obliged to\nassume the existence of the Primum Mobile or 9th sphere.\n\nThat Dante should believe the spheres to exist as actual entities was\ninevitable, for his principal authorities, Greek, Arab, and Christian,\nall taught this. And there is abundant evidence that he did think\nof them thus. He calls them bodies:\u2014\u201comnia corpora,\u201d[576] \u201cquesti\ncorpi grandi,\u201d[577] \u201ccerchi corporai,\u201d[578] \u201cil maggior corpo,\u201d[579]\netc. They are transparent, one sphere not obstructing the light from\nanother;[580] and composed of \u00e6ther, \u201cquesto etera tondo.\u201d[581] They\nhave a certain thickness, and would be visible if near enough, for\nDante speaks of the inner margin of the Primum Mobile, and says that it\nwas too far above him for him to have seen it yet, when he was in the\nStar Sphere.[582]\n\n------------------------------------------------------------------------\n[575] \u201cRoughly speaking.\u201d _Conv._ II. iii. 36-48.\n\n[576] \u201cAll bodies.\u201d _Ep._ x. 445.\n\n[577] \u201cThese vast bodies.\u201d _Par._ viii. 99.\n\n[578] \u201cMaterial circles\u201d (here compared with the Angels, who are purely\nspiritual). _Par._ xxviii. 64.\n\n[579] \u201cThe greatest body.\u201d _Par._ xxx. 39.\n\n[580] _Purg._ iii. 29, 30.\n\n[581] \u201cThis rounded ether.\u201d _Par._ xxii. 132.\n\n[582] _Par._ xxiii. 112-117.\n------------------------------------------------------------------------\n\nHe gives the order of the eight heavens as in Ptolemy, and adds the\nninth, which is only perceived by the diurnal movement of which it\nis the cause; and it is called by many the Crystalline, that is, the\ndiaphanous or completely transparent Heaven.[583] The order of these\nspheres has been discovered by observation and reasoning, with the use\nof the principles of Perspective, Arithmetic, and Geometry. Dante gives\nas an instance the experience of Aristotle, who with his own eyes saw\nthe moon pass below Mars, and so hide it for some time; and he mentions\nalso how in eclipses it is evident that the moon is below the sun\n(_i.e._ nearer to us).[584]\n\nTo these nine spheres of the astronomers, the Catholic Church, \u201cwhich\ncannot lie,\u201d adds a tenth, the Empyrean Heaven, which means the heaven\nof flame or light, and is the abode of the blessed spirits and of God\nHimself.[585] And here Dante is able to give himself the pleasure of\nadding that Aristotle seems to have been of this opinion also; \u201cEd anco\nAristotile pare ci\u00f2 sentire, a chi bene lo intende, nel primo _Di Cielo\ne Mondo_.\u201d[586] He is no doubt alluding to what Aristotle says about\nthe existence beyond the finite universe.[587] The whole passage is\nthus translated in the \u201cTemple\u201d Dante:[588] \u201cNor is there any change\nof any of those things which are ranged above the outmost rotation,\nbut they are unchangeable and passionless, enjoying the superlative\nexistence, and passing in absolute self-sufficiency their eternal life.\u201d\n\n------------------------------------------------------------------------\n[586] \u201cAnd Aristotle also, to one who rightly understands him, seems to\nmean the same thing, in his first book of _The Heaven and the Earth_.\u201d\n_Conv._ II. iv. 32-34.\n\n[583] _Conv._ II. iv. 1-13.\n\n[584] _Conv._ II. iii. 52-65.\n\n[585] _Conv._ II. iv. 13-16, 30-32. See also _Ep._ x. 448-452.\n\n[587] See p. 97.\n\n[588] _The Convivio of Dante_, \u201cTemple\u201d Edition, note on II. iv.\n------------------------------------------------------------------------\n\nThe ninth sphere rotates on two poles, which are absolutely fixed,\n\u201cfermi e fissi e non mutabile, secondo alcuno rispetto,\u201d[589] the eight\nwithin it have each two poles which are only relatively fixed (for they\nmove with the movement of the Primum Mobile), and every sphere has an\nequator, every point on which is equally distant from the two poles of\nrotation, as anyone may see who will turn round an apple, or any other\nspherical thing. Any point on the equator moves more quickly than any\nother point on the sphere, and each part moves more quickly the nearer\nit is to the equator, more slowly as it is far from it and nearer to\nthe pole, since all the circling is done in the same time, and some\nparts have a greater, and some a less distance to go, according to\ntheir distance from the equator. Dante adds that the nearer any part of\na heaven is to its equator, the nobler it is compared with its poles,\nfor it has more movement, and more actuality, more life, and more form,\nand it touches more of the heaven just above, and in consequence is\nmore noble.[590]\n\n------------------------------------------------------------------------\n[589] \u201cFirm and fixed and not moveable, from any point of view.\u201d\n_Conv._ II. iv. 50, 51.\n\n[590] _Conv._ II. iv. 68-75.\n------------------------------------------------------------------------\n\nBesides these ten heavens there are others which, strictly speaking,\nshould be included in the number: these are the little spheres which\nare called \u201cepicycles\u201d by astronomers, and they also have equators and\npoles of rotation, and are fixed on the large spheres, or heavens.\nDante does not enter into any particulars about these, but only\nmentions (as belonging specially to the subject in hand) that the\nbrilliant star of Venus is carried \u201con the back\u201d of an epicycle, which\nis itself fixed on the back of the third Heaven.[591] The apparent\nmovement of Venus is therefore compounded of no less than four\nmovements: that of her epicycle, of her whole heaven (the \u201cdeferent\u201d\nDante does not name, probably as introducing too technical a word),\nof the west to east motion of the star sphere (precession), and the\ndiurnal. The epicycle of Venus is also called in this treatise, as\nwe have already seen, \u201cquello suo cerchio che la fa parere serotina\ne mattutina, secondo i due diversi tempi,\u201d[592] and the \u201cterzo\nepiciclo\u201d[593] is referred to in _Par._ viii. 3.\n\n------------------------------------------------------------------------\n[591] _Conv._ II. iv. 78-104.\n\n[592] \u201cThat circle of hers which makes her appear as evening and\nmorning star, according to the two different periods.\u201d _Conv._ II. ii.\n3-5.\n\n[593] \u201cThird epicycle.\u201d\n------------------------------------------------------------------------\n\nA little further on in the same treatise, Dante tells us the periods\nin which all these nine spheres revolve. It is an interesting passage,\nand illustrates the poet\u2019s vivid way of bringing home to his own mind\nand those of his readers the effects of the different celestial\nmotions.[594] The ninth sphere, which is the Crystalline or Primum\nMobile, causes by its daily revolution the daily revolution of all the\nother spheres, which are within it; it is, as Beatrice says, \u201ccostui,\nche tutto quanto rape l\u2019altro universo seco.\u201d[595] Therefore if we\nimagine it possible for the motion of this Crystalline Heaven to cease,\nwhat will be the effect on the motions of the other heavens? Obviously\ntheir diurnal movement from east to west will cease, and we shall only\nsee them revolving, each in its own period, from west to east. There\nwill be no alternation of day and night, or rather, there will be one\nlong day of six months, and one long night of the same length, in\nany given place all over the earth. In the same way the moon will be\ninvisible for half the month; and all the planets will be invisible\nto us for half their periods; and as Dante believed only the known\nhemisphere of Earth to be inhabited, he could say that during one half\nof each period no one would see the planet at all. He enumerates the\nhalf period in each case, as follows:\u2014\n\n------------------------------------------------------------------------\n[594] _Conv._ II. xv. 132-155.\n\n[595] \u201cThat one which sweeps the whole of the rest of the universe\nalong with it.\u201d _Par._ xxviii. 70, 71.\n------------------------------------------------------------------------\n\n _Half Period Whole Period given by Alfraganus_\n \u201c_Planets._\u201d (_approximate_) (_El. Ast. ch. xvii._)\n _given by Dante. Years Months Days_\n\n Saturn 14\u00bd years 29 5 8\n Jupiter 6 \u201d 11 10 14\u00bd about.\n Mars about a year 1 10 22 nearly.\n Sun 182 days, 14 hrs. ... 365\u00bc nearly.\n {about the same\n Venus { as the sun. ... \u201d\n Mercury \u201d \u201d ... ... \u201d\n Moon 14\u00bd days ... (nearly) 27, 7\u00be hrs.\n (Paris edition, 29 days, 12\u00be hrs.)\n\nIf we compare these with the zodiacal periods given by Alfraganus,\nwe see that Dante has taken those of Saturn, Jupiter, and Mars at the\nnearest whole number of years and halved them, but with the sun he\nseems to have used that more exact value with which we have already\nseen that he was acquainted. For to divide the 365\u00bc days of Alfraganus\nby 2 would have given him exactly 182 days 15 hours; but dividing 365\ndays 5 hours, and neglecting minutes gives 182 days 14 hours. The\nlarge oscillations of Venus and Mercury would make their periods of\nvisibility very irregular, but the mean period would be, as Dante says,\nabout the same as that of the sun. He has made a slip with the moon,\nfor of course it is her sidereal period of 27 days 7\u00be hours which he\nshould have taken, giving a half period of less than 14 days, whereas\nhe has evidently taken the mean synodic period of 29 days 12\u00be hours,\nand ignored the hours. All the printed editions of Alfraganus give the\nsidereal period in this passage, except the Paris edition of 1546; but\nthat gives the synodic,[596] so it doubtless appeared on some medi\u00e6val\nMSS. Dante must have had the misfortune to possess or consult one of\nthese.\n\n------------------------------------------------------------------------\n[596] Toynbee, \u201cDante\u2019s Obligations to Alfraganus in _Vita Nuova_ and\n_Convivio_,\u201d in _Romania_ xxiv. 95.\n------------------------------------------------------------------------\n\nAs for the stars, one third of their sphere would not yet have been\nseen. This is not difficult to understand if we remember what the\nmovement of the star sphere was supposed to be, and how long it was\nsince man had first begun to look upon it, according to Dante\u2019s\nchronology. The movement which makes the equinoctial point shift its\nplace among the stars was thought to be a movement of revolution of\nthe whole star sphere, and its rate to be one degree in a century;\nthe age of the world, we learn from _Par._ xxvi. 118-123, was over\nsixty centuries when Dante wrote. For Adam said that he had spent 930\nyears on Earth and 4302 in the Limbo, so that Dante evidently counted\n5232 years from the Creation to the Crucifixion, that is (5232-33 =)\n5199 to the beginning of our era at the birth of Christ, which is the\ndate given by Orosius; adding 1300 years to this, we find that the age\nof the world in Dante\u2019s day was more than 6000 years. Therefore the\nstar sphere had revolved, since the beginning of the world, through\nmore than 60 degrees.\n\nThe first inhabitants of this earth saw half the starry sky or 180\u00b0,\nand since then it had revolved through 60\u00b0, which together is equal\nto 240\u00b0; therefore there would still remain 120\u00b0, or one third of a\nrevolution, to be made to complete the whole 360\u00b0, and bring every\npart of the star sphere into view. Just before this passage Dante\nhad expressed the same idea in another way. This movement proper to\nthe star sphere, he says, will never have an end, for the end of\na revolution is to return to the same point; and this heaven will\nnever do so, for since the beginning of the world it has turned\nthrough a little more than the sixth part of its whole revolution\n(60\u00b0\u00a0=\u00a0\u215b\u00a0of\u00a0360\u00b0), and we are already in the last age of the world, and\nindeed are awaiting the consummation of the celestial motion.[597]\n\n------------------------------------------------------------------------\n[597] _Conv._ II. xv. 108-118.\n------------------------------------------------------------------------\n\nIf the premises be granted, the conclusions are correct. As regards\nsun, moon, and planets, they are correct even from the point of view of\nmodern knowledge. For if the diurnal motion (that is Earth\u2019s rotation)\nwere to cease, while her other motions, and those of the rest of the\nsolar system remained as at present, her motion round the sun would\ncause it to rise and set once in a year, and the appearance of moon and\nplanets also would be as described. The vastly distant stars would have\nno appreciable motion, save that caused by precession, for if the earth\nrevolved round the sun without turning on her axis, the same stars\nwould always remain on the meridian at any given place. Precession,\nhowever, would not have the result which Dante supposed. He considered\nit to be a rotation of the star sphere, but we know that it is merely\na nodding. Hence at any given place a star at the pole would describe,\nin the course of centuries, a small circle in the sky, and those at the\nequator would move in short lines first north and then south, while\nstars between would move in ellipses which become narrower as they\napproach the equator. All round the horizon, therefore, there would be\nslight very slow changes, bringing a few fresh stars into view, and\ncausing others to disappear. The whole amount of the sky actually seen\nwould vary but little, even if the world should last much longer than\nDante expected.\n\nDante evidently took his value of precession from Alfraganus, for he\nwas one of the few Arab astronomers who accepted Ptolemy\u2019s erroneous\nfigure.\n\nIn the _Paradiso_, as the poet mounts with Beatrice from sphere to\nsphere he mentions the number of each one in its order. The moon is \u201cla\nprima stella,\u201d[598] Mercury \u201cil secondo regno,\u201d[599] Venus \u201cil terzo\nciel,\u201d[600] the spirits met in the sun are \u201cla quarta famiglia,\u201d[601]\nMars is \u201cquesta quinta soglia,\u201d[602] and \u201cpi\u00f9 levato\u201d[603] than\nthe last heaven, Jupiter is the \u201cstella sesta,\u201d[604] Saturn \u201cil\nsettimo splendore.\u201d[605] The starry heaven is alluded to as \u201cla spera\nottava.\u201d[606] The Primum Mobile is \u201cil ciel velocissimo,\u201d[607] \u201cil\nmaggior corpo.\u201d[608] The Empyrean, \u201cil ciel ch\u2019 \u00e8 pura luce,\u201d[609] is\ncalled \u201cl\u2019ultima spera,\u201d[610] but this has no limits and no movement,\nand therefore no poles:\u2014\n\n------------------------------------------------------------------------\n[598] \u201cThe first star.\u201d _Par._ ii. 30.\n\n[599] \u201cThe second realm.\u201d _Par._ v. 93.\n\n[600] \u201cThe third heaven.\u201d _Par._ viii. 37.\n\n[601] \u201cThe fourth family.\u201d _Par._ x. 49.\n\n[602] \u201cThe fifth threshold.\u201d _Par._ xviii. 28.\n\n[603] \u201cMore lofty.\u201d _Par._ xiv. 85.\n\n[604] \u201cSixth star.\u201d _Par._ xviii. 68, 69.\n\n[605] \u201cThe seventh splendour.\u201d _Par._ xxi. 13.\n\n[606] \u201cThe eighth sphere.\u201d _Par._ ii. 64.\n\n[607] \u201cThe swiftest heaven.\u201d _Par._ xxvii. 99.\n\n[608] \u201cThe greatest body.\u201d _Par._ xxx. 39. Compare _V. N._ xlii. 47.\n\u201cOltre la spera che pi\u00f9 larga gira,\u201d (\u201cbeyond the sphere which has the\nlargest circle).\u201d\n\n[609] \u201cThe heaven of pure light.\u201d _Par._ xxx. 39.\n\n[610] \u201cThe last sphere.\u201d _Par._ xxii. 62.\n\n \u201c ... In quella sola\n E ogni parte l\u00e0 dove sempr\u2019 era;\n Perch\u00e8 non \u00e8 in loco, e non s\u2019impola.\u201d[611]\n\n[611]\n \u201c ... Within that one alone\n Is every part where it has always been;\n For it is not in space, nor turns on poles.\u201d\n _Par._ xxii. 65-67. (_Longfellow._)\n------------------------------------------------------------------------\n\nIn _Conv._ II. iv. 35-39 it is thus described:\u2014\n\n \u201cQuesto \u00e8 il sovrano edificio del mondo, nel quale\n tutto il mondo s\u2019inchiude; e di fuori dal quale\n nulla \u00e8; ed esso non \u00e8 in luogo, ma formato fu\n solo nella Prima Mente, la quale li Greci dicono\n Protonoe.\u201d[612]\n\n------------------------------------------------------------------------\n[612] \u201cThis is the sovereign edifice of the world, in which all the\nworld is enclosed, and beyond which is naught; and it exists not in\nspace, but received form only in the Primal Mind, which the Greeks call\nProtonoe.\u201d See also _Ep._ x. 442-447.\n------------------------------------------------------------------------\n\nWe must remember, however, that the spheres are sometimes counted in\nthe other direction, from the outermost to the innermost or lowest, and\ntherefore this \u201cultima spera\u201d[613] is elsewhere spoken of as \u201cil primo\ncielo,\u201d[614] \u201cil primo giro,\u201d[615] \u201cc\u0153lum primum.\u201d[616]\n\n------------------------------------------------------------------------\n[613] \u201cLast sphere.\u201d\n\n[614] \u201cThe first heaven.\u201d _Purg._ xxx. 1.\n\n[615] \u201cThe first circle.\u201d _Par._ iv. 34.\n\n[616] \u201cFirst heaven.\u201d _Qu._ iv. 7.\n------------------------------------------------------------------------\n\n\n2. THE SPHERES AND THE FOUR ELEMENTS.\n\nThe pure region of the spheres, \u201cil paese sincero,\u201d is immortal as the\nspirits themselves;[617] but below the lowest celestial sphere (\u201cla\ncelestial c\u2019ha men salita\u201d _Par._ iv. 39) all is mortal and transitory,\nas the Greeks and the Latin poets had said. This is expressed in the\nLetter to Can Grande, when Dante contrasts the spheres (c\u0153lum) and the\nelements, and says: \u201cillud incorruptibile, illa vero corruptibilia\nsunt.\u201d[618] It is also implied in Virgil\u2019s address to Beatrice:\n\n------------------------------------------------------------------------\n[617] _Par._ vii. 130-132 compared with 67, 68. See also _Par._ i. 64\nand 76.\n\n[618] _Ep._ x. 435-437.\n------------------------------------------------------------------------\n\n \u201cO donna di virt\u00f9, sola per cui\n L\u2019umana specie eccede ogni contento\n Da quel ciel che ha minor\u2019 li cerchi sui.\u201d[619]\n\n------------------------------------------------------------------------\n[619]\n \u201cO Lady of Virtue, thou alone through whom\n The human race exceedeth all contained\n Within the heaven that has the lesser circles.\u201d\n _Inf._ ii. 76-78. (_Longfellow_).\n------------------------------------------------------------------------\n\nIt is only through the spiritual teaching which Beatrice symbolizes\nthat the human race can rise above all that is comprised within the\nheaven of the smallest sphere. And it is taught by Beatrice herself\nwhen, in the heaven of Mercury, she discourses on the mysteries of the\ncreation and redemption. The angels, the souls of men, and the spheres,\nwere created directly by God, she says, and are therefore immortal,\nbut the elements, water, fire, air, earth, and all things that are\nformed out of them, also the souls or living principles of all animals\nand plants, were created through intermediate instruments and are\nmortal. These intermediate instruments are the heavenly bodies. Pure\nor inchoate matter was created at the beginning by God, and a power\ninfused into the stars to give it form.[620]\n\n------------------------------------------------------------------------\n[620] _Par._ vii. 124-143. Compare with Plato\u2019s account of the creation\nof living beings (Part I., _Plato_).\n------------------------------------------------------------------------\n\nDante follows the classics and agrees with his contemporaries in\narranging the four elements in four spheres, which are below the\ncelestial spheres. The sphere of Fire is immediately within that of the\nmoon, below this comes Air, then Water, and lastly the solid sphere of\nEarth. The contrast between Fire which constantly tends to rise towards\nthe moon, and Earth which sinks towards the centre of the universe, is\na favourite thought with him;[621] and lightning striking the earth\nis described as fleeing its proper place.[622] Aristotle seems to\nhave regarded the four elements as flowing into one another, so that\nthese lowly spheres beneath the moon were not sharply divided, but his\nmedi\u00e6val disciples, following the Greek idea to its logical conclusion,\nconceived them with boundaries as definite as those of the celestial\nspheres. \u201cExhalations\u201d could pass from one to another, but each\nparticle of every element tended always to revert to its own place,\nwhich was distinct from the others.\n\n------------------------------------------------------------------------\n[621] _Par._ i. 115, 117; _De Mon._ I. xv. 38-41; and III. vii. 30, 31,\netc.\n\n[622] _Par._ i. 92, 130-134.\n------------------------------------------------------------------------\n\nAnd here they encountered a serious difficulty. If the sphere of water\nis naturally higher than that of earth, how comes it that in one\nquarter of the globe land rises above the ocean? It was recognised as\nnecessary that this should happen in some part of the world, in order\nfor an opportunity to be given for the elements to combine and to form\nall those substances and all those living creatures, including man, for\nwhich this earth was prepared; it was also agreed that the celestial\nspheres were the agency by which the Creator had first chosen to \u201clet\nthe dry land appear,\u201d and by which it was maintained above the ocean;\nbut the exact nature of this force and the way in which it acted was a\nquestion sometimes discussed. Albertus Magnus was of opinion that the\nrays of the sun and the stars, which had more power in the temperate\nand tropic zones than in the arctic, had here dried up the ocean, and\nhe quotes Albumassar\u2019s statement that this proves the existence of land\non the southern side of the equator also. Ristoro, on the other hand,\nbelieved that the waters had been drawn up and rolled back from the\nhabitable earth, and he attributes the elevating force to the stars of\nthe north, bringing in his favourite theory that in this hemisphere\nthey are far more numerous, and the constellations, from their upright\nposition, are far more powerful than in the south.\n\nHe compares this lifting force of the stars to the attractive power\nof a magnet over iron, and argues that it must be the waters which\nare drawn away from the earth, not the earth which is lifted above\nthe water, because the starry influence in its downward course would\nmeet first the sphere of water, and moreover it is lighter and easier\nto move than Earth. He also thinks that the presence of springs\non mountain tops is to be explained by the fact that the ocean is\npreserved at a higher level, hence water percolating through the porous\nland, as through a sponge, is forced up to its utmost height.\n\nIt does not seem as if Dante had paid much attention to this problem\nwhen he was writing the _Convivio_, for although he calls the habitable\npart of the earth \u201cthe uncovered land,\u201d \u201cla terra discoperta\u201d (_Conv._\nIII. v. 73), he speaks of Earth and ocean as if they formed a globe\ntogether, \u201cQuesta terra ... col mare \u00e8 centro del cielo,\u201d[623] in the\nmanner of Alfraganus, \u201cInter sapientes convenit, terram un\u00e0 cum aqua\nglobosam esse.\u201d[624] But if we may believe that Dante is the author\nof the _Qu\u00e6stio de Aqua et Terra_\u2014a belief shared by many experts\u2014he\nbecame greatly interested in the problem later on. According to the\nintroduction and the final colophon, he attended a discussion on the\nsubject and joined in it himself, when in Mantua, and afterwards in\nVerona less than two years before his death he wrote and read in public\na Latin treatise in which his arguments and conclusions are set forth.\n\n------------------------------------------------------------------------\n[623] \u201cThis earth, together with the sea, is the centre of heaven.\u201d\n(_Conv._ III. v. 63-65.)\n\n[624] \u201cIt is agreed among learned men that earth and water together\nform a globe.\u201d (_El. Ast._ iii.).\n------------------------------------------------------------------------\n\nHe seems to have had in mind Ristoro\u2019s book, and while refuting some\nof the conclusions agrees with others. As a thirteenth century scholar\nhe admits, as a matter of course, that the centre of the earth is the\ncentre of the Universe and the goal towards which all heavy things\ntend; that earth as the heaviest element ought to be everywhere nearest\nthis centre, while water ought to occupy the nobler place above it,\nthat is, nearer to the most noble sphere of all which envelops all the\nothers (the Empyrean). He also reasons, in true Dantesque and true\nmedi\u00e6val fashion that there must be some place in the universe where\nall the elements may meet and mingle so that all potential forms of\nmatter may be realized; otherwise the Mover of heaven, in whom all\nthese forms (Plato\u2019s Ideas) actually exist, would fail to give complete\nexpression to his goodness, which is impossible.[625]\n\n------------------------------------------------------------------------\n[625] _Qu._ xviii. 28-54. This may be compared with _Par._ xxix. 13-18.\n------------------------------------------------------------------------\n\nThe author of the _Qu\u00e6stio_ denies, however, that this was accomplished\nby the removal of part of the sphere of water from the underlying\nearth. The ocean cannot have been drawn away and heaped up, he says,\nfor water would always flow down again, being fluid and naturally\nseeking its own level; nor can the sphere of water be eccentric to that\nof Earth so that the latter emerges from it in one part. The reason for\nthis is interesting since it implies a curious and apparently novel\ntheory of gravity. Aristotle\u2019s theory was that all heavy things tend\nby a natural law towards the centre of the universe, and therefore\nnecessarily range themselves in spheres round it; the writer might\ntherefore have made short work of Water\u2019s eccentric sphere by stating\nbriefly that it could not exist; instead of this, however, he suggests\na new law of gravity, apparently invented on the spur of the moment,\naccording to which everything which has weight tends towards the centre\nof its own circumference. If then earth and water had two separate\ncentres, they would fall naturally in different directions, or as he\nputs it \u201cto different _downs_.\u201d Yet we know that the law of gravity\nis the same for both, and therefore their spheres must be concentric.\nThe centre of the universe must be also the centre of the sea.[626] It\nhad apparently been urged (perhaps in the discussion at Mantua) that\nsince water follows the moon in the tides, its sphere may also imitate\nhers in being eccentric, but although Dante takes for granted that a\nconnection between moon and tides is proved (and indeed it had been\nnoted by the Greeks),[627] he replies that imitation in one particular\nneed not imply imitation in all. Again, if the sphere of earth emerged\nfrom the sphere of water in the way proposed, the outline of the\nemergent earth must be circular, instead of which it is that of a\nhalf-moon, or nearly so, its width from east to west being much greater\nthan its length from north to south.\n\n------------------------------------------------------------------------\n[626] _Qu._ xv. 10, 11.\n\n[627] See p. 134.\n------------------------------------------------------------------------\n\nDante has been blamed for assigning this shape to the emergent earth,\nbut the comparison of Earth\u2019s habitable quadrant with the illuminated\nquadrant of the moon is perfectly just, as we saw with Ristoro,[628]\nfrom whom Dante is perhaps quoting here. The qualifying \u201cvel\nquasi\u201d[629] is added because the truly habitable regions did not extend\nover the whole quadrant, but stopped short at the arctic circle.\n\n------------------------------------------------------------------------\n[628] See p. 247.\n\n[629] \u201cOr nearly.\u201d _Qu._ xix. 61-63.\n------------------------------------------------------------------------\n\nThe existence of springs on mountain tops is explained by the fact\nthat water rises thither not in the form of water but of vapour.\nAnother upholder of Ristoro\u2019s theory that Water was rolled away from\nEarth seems to have brought forward as evidence that sailors can see\ndistant land from the mast which is invisible from the deck, and that\ntherefore it evidently lies below the ocean; but this is confuted by\nthe true and well known explanation that it is the convex shape of\nthe sea which hides the distant land. Our author adds to his other\narguments, in the curiously casual way so characteristic of his age,\nthe ordinary observation which would be the first to occur to us, and\nquite sufficient in itself, viz. that instead of seeing a great wall of\nocean rising above our sea-coasts, we invariably see the coast rising\nabove the sea.\n\nHis own idea is that though the sphere of Water in general rises above\nEarth, in one part of the northern hemisphere Earth has been drawn up\nabove the ocean. Earth must be subject to an uplifting influence, as\nwell as to the downward drag of gravity, just as man is susceptible to\nthe influence of reason as well as to the sway of his lower passions.\nThis uplifting influence is not inherent in Earth herself, an upward\nimpulse would be contrary to her own nature; nor can it be in water, or\nair, or fire, since all these are homogeneous bodies, and their virtue\nis evenly distributed, so that they could not cause a local and partial\neffect. It must be therefore in one of the heavens, and it remains for\nus to enquire which.\n\nIt cannot be in the heaven of the moon, for in the moon herself resides\nwhatever influence comes from her sphere;[630] and she goes as far\nsouth of the equator as she does north: therefore she would raise land\nbeyond the equator as well as on this side, but this is not so.\n\n------------------------------------------------------------------------\n[630] Compare with _Conv._ II. vii. 88-100, where the poet says that\nthe influence from each sphere comes on the rays of the planet in that\nsphere, also _De Mon._ III. iv. 139, 140.\n------------------------------------------------------------------------\n\nThen follows a passage of which commentators can make nothing as it\nstands:\u2014\n\n \u201cNec valet dicere quod illa declinatio non\n potuit esse propter magis appropinquare terr\u00e6\n per excentricitatem; quia si h\u00e6c virtus elevandi\n fuisset in luna, (quum agentia propinquiora\n virtuosius operentur) magis elevasset ibi quam hic.\u201d[631]\n\n------------------------------------------------------------------------\n[631] \u201cNor does it avail anything to say that that declination could\nnot take place because of approaching nearer the earth through\neccentricity; for if this elevating virtue were in the moon, since\nagents act the more powerfully the nearer they are, she would elevate\nthere rather than here.\u201d _Qu._ xx. 65-71.\n------------------------------------------------------------------------\n\nMr. Wicksteed suggests reading \u201celevatio\u201d instead of \u201cdeclinatio,\u201d and\napparently deletes the \u201cnon,\u201d[632] and Dr. Moore seems to read the same\nway,[633] for both agree in interpreting as follows:\u2014the author is\nstating an argument that the elevation of land (in only one hemisphere)\nmight be due to the moon\u2019s coming nearer to Earth in one part of her\norbit, owing to its eccentricity; to which he replies that if that were\nthe cause the elevation would be greater in the south than here in the\nnorth, because the moon is nearer to the earth when she goes south.\n\n------------------------------------------------------------------------\n[632] Note on this passage in \u201cTemple\u201d Dante.\n\n[633] _Studies in Dante_, ii. p. 339.\n------------------------------------------------------------------------\n\nThis is supposed to imply a belief that the moon is always in\nperigee[634] when south of the equator, whereas the fact that her\nperigee revolves all round the zodiac was as well known to Ptolemy and\nAlfraganus as it is to modern astronomers. The interpretation therefore\nconvicts the author of the _Qu\u00e6stio_ of so serious and inexplicable a\nblunder that these commentators find themselves obliged to consider\nit as evidence either that it was not written by Dante, or that his\nknowledge of astronomy was much less extensive than has been supposed.\nIt is suggested that there may have been a popular fallacy in his time\nthat the moon was like the sun in this respect\u2014although to know that\nthe sun has a perigee, and that it is situated in the south, requires\nsome acquaintance with astronomy! However, Dr. Moore has searched\nAlfraganus and other works in vain to find a suggestion of this kind.\n\n------------------------------------------------------------------------\n[634] Nearest Earth.\n------------------------------------------------------------------------\n\n[Illustration: Fig. 52. The moon\u2019s epicycle and deferent.\n\n(The dotted line represents the southern half of the deferent).]\n\nYet an explanation and a source of this statement is not far to seek,\nand instead of proving ignorance it indicates that the author of the\n_Qu\u00e6stio_ knew his Alfraganus well. The passage is evidently slightly\ncorrupt, but the clue to its meaning lies in the word \u201ceccentricity.\u201d\nIn two other places of the _Qu\u00e6stio_ the moon\u2019s eccentric \u201corbis\u201d\nis alluded to,[635] but if we translate this as \u201corbit\u201d we shall\nbe introducing modern ideas which meant nothing to Dante or his\ncontemporaries. According to Alfraganus and Ptolemy the moon\u2019s orb\nor sphere[636] was eccentric, but this was not the main cause of her\nvarying distance from Earth. It was the revolution of her epicycle\nround its centre C, which caused her to move continually from apogee M\nto perigee P; and as the whole epicycle was meanwhile revolving on the\ndeferent round C, and these two periods were not quite equal, the moon\nwas as often in the perigee of her epicycle when it was south as when\nit was north. But besides this, the deferent, being eccentric to Earth,\nhad also a perigee and apogee; and Alfraganus says that _the perigee\nof the eccentric is always in the south_. \u201cSaturnus, Jupiter, atque\nMars eccentricorum suorum absidas summas et imas habent declinatas a\nzodiaco, illas ad boream, hasce ad austrum, secundum eandem semper\ndeflexus mensuram: _quedadmodum res in Luna obtinet_.\u201d[637]\n\n------------------------------------------------------------------------\n[635] _Qu._ vii. 4, 6, and xxiii. 52.\n\n[636] \u201cOrbis\u201d and \u201csph\u00e6ra\u201d are used indifferently by Alfraganus to\nindicate the celestial spheres: thus, in ch. xii. he says \u201c_Orbes_, qui\nstellarum omnes motus complectantur, numero esse octo,\u201d and on the next\npage, \u201cunamquamque harum _sph\u00e6rarum_ octo.\u201d\n\n[637] \u201cThe upper and lower apsides of the eccentrics of Saturn,\nJupiter, and Mars, have a certain declination from the zodiac, the\nformer to the north, the latter to the south, the amount always\nremaining constant: _and it is just the same with the moon_.\u201d _El.\nAst._ xviii. par. 6.\n------------------------------------------------------------------------\n\nThe upper and lower apsides are defined in chapter xii. as the\npositions of apogee and perigee respectively.[638]\n\nIn this quotation the word \u201cdeclinatas\u201d also supplies us with the\nmeaning of Dante\u2019s \u201cdeclinatio,\u201d which need not be changed for\n\u201celevatio.\u201d He is using it in the astronomical sense of position north\nor south, like Alfraganus and modern astronomers, and it refers here\nto the \u201cdeclinet\u201d of five lines earlier. \u201cLuna ... tantum _declinet_\nper zodiacum ab \u00e6quinoctiali _versus polum antarcticum_ quantum versus\narcticum.\u201d[639]\n\n------------------------------------------------------------------------\n[638] In the edition of Golius ch. vii. par. 5, the position of\ngreatest distance is called the perigee, of least the apogee, but this\nmistake is corrected in the next paragraph.\n\n[639] \u201cThe moon\u2019s declination in the zodiac from the equator towards\nthe south pole is as great as towards the north.\u201d _Qu._ xx. 61-63.\n------------------------------------------------------------------------\n\nIt is only necessary to delete \u201cquod\u201d and \u201cnon potuit,\u201d and the\nwhole passage becomes clear and, from the point of view of medi\u00e6val\nastronomy, correct. The author has shown that the moon cannot be\nsupposed to exert any preponderating influence in the northern\nhemisphere, because her declination south is equal to that in the\nnorth. Nor is it of any use, he adds, to say that this declination\n(south) results from her approaching the earth more nearly on her\neccentric orb (see diagram);[640] for (although this does imply an\nunequal influence) if the elevating influence came from the moon, it\nwould act more powerfully in the south than here in the north, since\nthe nearer an agent is the more powerfully it acts.\n\nHe goes on to say that the same reasoning rules out the planetary\nspheres, and here Alfraganus still supports him, for Saturn, Jupiter,\nand Mars are said to have the perigees of their eccentrics in the\nsouth, just like the moon, while those of Venus and Mercury are\ncontinually changing.[641]\n\n------------------------------------------------------------------------\n[640] The deferent was the equator of her orb or sphere.\n\n[641] Ristoro also defines apogee and perigee (\u201cauge\u201d and \u201copposito\nd\u2019auge\u201d) as effects of movements on an epicycle, and says that the\ndeferent is \u201cdeclined\u201d from the ecliptic (\u201cdeclinato della via del\nsole,\u201d) part being north and part south, but he does not say whether\nits perigee is north or south. _Comp. del Mondo._ I. xii. xiv., and\nIII. vii.\n------------------------------------------------------------------------\n\nAs for the Primum Mobile, or ninth sphere, it is uniform throughout,\nand consequently quite uniform in virtue, therefore there is no reason\nwhy it should elevate land here rather than elsewhere. Since, then,\nthere are no more moving bodies except the star sphere, or eighth\nheaven, it must be from this that the lifting power proceeds. And it\nis specially adapted to exercise such an influence since it contains\na number of stars, all of which have different \u201cvirtues.\u201d Without\nrepeating Ristoro\u2019s na\u00efve assertions about the greater number and the\nupright positions of the northern constellations, our author bids us\nremark that star differs from star, constellation from constellation,\nand that their influences are also diverse, so that those in the north\nhave different virtues from those in the south. The lifting virtue\nwhich raises the land must reside in those stars which are between\nthe equator and 67\u00b0 north, since those are above the habitable earth;\nbut we do not know the nature of the force they exercise, whether\nit attracts the land as a magnet attracts iron, or forces it up by\ngenerating underground vapours, such as have raised some mountains\n(Aristotle had said in his _Meteorologica_ that volcanic hills were\nformed by pent-up winds beneath them).\n\nAfter so elaborate a search for a power capable of raising land only\nin the north and not in the south, we naturally inquire why in the\neast and not in the west? But to this we only receive the reply that\nthere was not enough material to go round, and that we must not ask\npresumptuous questions. Let us seek to approach divine and immortal\nthings as nearly as is possible to human nature, but leave those which\nare too high for us.\n\nThis somewhat lengthy description of the contents of the _Qu\u00e6stio_ has\nbeen given because, even if it is not Dante\u2019s work, it illustrates\nwell the current ideas concerning the Cosmos, its form and forces. So\nmany of the ideas, however, and even the expressions find parallels in\nthe unquestioned writings of Dante, that the internal evidence for its\ngenuineness is strong.[642]\n\n------------------------------------------------------------------------\n[642] For a thorough discussion of this question see Moore\u2019s _Studies\nin Dante_ ii. pp. 303-374.\n------------------------------------------------------------------------\n\nIn his poems Dante is faithful to his own descriptions of the universe\nin prose, and in the visionary journey of the _Divine Comedy_ he\npasses successively through all the spheres which are enumerated in\nthe _Convivio_ and the _Qu\u00e6stio_. The central sphere of earth, the\nlowest of all the elements, \u201cil suggetto dei vostri elementi,\u201d[643]\nis completely traversed, from side to side, and on the further side\nis seen the vast sphere of ocean which envelopes three-quarters of\nthe earth. The Mountain which the poet has placed here (his only\ninnovation) rises out of the water towards the heavens higher than any\nother, \u201cinverso il ciel pi\u00f9 alto si dislaga,\u201d[644] and in climbing\nit he reaches that region in the sphere of air into which no cold\nexhalations can rise from earth or sea, neither the \u201csecco vapor\u201d[645]\nwhich causes wind and earthquake, nor the \u201cesalazion dell\u2019 aqua\u201d[646]\nfrom which are formed rain and hail, cloud and dew. Hot exhalations\nascend to the sphere of fire, there to become meteors or comets (see\np. 103); but the cold vapours rising as high as they can towards the\nsun which draws them up (\u201cretro il calor\u201d[647]), are unable to ascend\nbeyond the Gate of Purgatory.[648] Therefore Purgatory is exempt from\nall changes except those caused by that which heaven receives from\nitself into itself. This was ingeniously conjectured by Venturi to be\nlight, since there is change of day and night in Purgatory; but from\nthe context it seems clear that human souls are meant. Souls come forth\nfrom their Creator, whose special abode is the heaven of heavens,\nand return thither after purification. And it was the rising of the\npurified soul of Statius, ready to return to heaven, which had been the\ncause of that trembling of the Mountain of which he is here speaking.\n\n------------------------------------------------------------------------\n[643] \u201cThe foundation of your elements.\u201d _Par._ xxix. 51.\n\n[644] \u201cRises highest towards heaven out of the sea.\u201d _Purg._ iii. 15.\n\n[645] \u201cDry vapour.\u201d\n\n[646] \u201cExhalations from the water.\u201d\n\n[647] \u201cBehind [_i.e._ following] the heat.\u201d\n\n[648] _Purg._ xxviii. 97-99 and xxi. 52-53. The gate is meant by \u201ci tre\ngradi\u201d (\u201cthe three steps\u201d), and \u201cove si serra\u201d (\u201cwhere it is locked\u201d).\nSee _Purg._ ix. 76, 106-108.\n------------------------------------------------------------------------\n\nAfter learning this, Dante is surprised to find, on the summit of the\nMountain, that his brows are caressed by a gentle breeze which comes\nfrom the east and bends all the trees of the Forest in one direction.\nMatilda tells him that it is true no atmospheric changes are felt on\nthis Mountain, and it was for this that it was made to rise so high, so\nthat man in the Garden of Eden, on the top of the Mountain, should be\nuntroubled by the disturbances which occur lower down: what he feels\nnow is no fluctuating wind. On this lofty mountain, remote from any\nother land in the midst of the hemisphere of sea, he feels for the\nfirst time the revolution of the atmosphere uninterruptedly following\nthe movement of the celestial spheres.\n\nThe idea that Eden was on a lofty mountain, secure from stormy weather,\nand inaccessible to fallen man, was a familiar one with medi\u00e6val\nwriters: it was sometimes located on Adam\u2019s Peak in Ceylon, and Bede\nthought it might rise as high as the moon, but Albertus Magnus says\nthis was only meant figuratively. But the connection with Purgatory,\nand the thought that here the movement of the heavens might be felt as\na soft breeze, is, so far as I know, all Dante\u2019s own.\n\nIn all the _Divine Comedy_ there is no more beautiful allegory than\nthis. Man in the age of innocence, man to-day when purified from sin,\nis already partly in heaven, though he still walks the earth. And like\nmany another allegory of Dante\u2019s, it follows naturally from the science\nof his day. Aristotle had said that the upper air \u201cflows in a circle,\nbecause it is drawn along with the circulation of the Whole,\u201d and\nAquinas:\u2014\n\n \u201cThus the air which exceeds the greatest altitude\n of the mountains flows round, but the air which is\n contained within the altitude of the mountains is\n impeded from this flow by the immoveable parts of\n Earth.\u201d\n\n_Purg._ xxviii. 103-108 is almost a poetical paraphrase of this:\u2014\n\n \u201c ... In circuito tutto quanto\n L\u2019aer si volge con la prima volta,\n Se non gli \u00e8 rotto il cerchio d\u2019alcun canto:\n In questa altezza, che tutta \u00e8 disciolta\n Nell\u2019 aer vivo, tal moto percote\n E fa sonar la selva, perch \u2019\u00e8 folto.\u201d[649]\n\n------------------------------------------------------------------------\n[649]\n \u201c ... The universal atmosphere\n Turns in a circuit with the primal motion,\n Unless the circle is broken on some side:\n Upon this height, that all is disengaged\n In living ether, doth this motion strike,\n And make the forest sound, for it is dense.\u201d\n (_Longfellow_).\n------------------------------------------------------------------------\n\nThe whole body of the air, everywhere in the world, is turning with the\nFirst Revolution (the Primum Mobile), wherever it is not interrupted by\nany obstruction (of hills etc.); and as at this height the Mountain is\naltogether free and open to the pure air, this motion strikes the thick\nforest and makes it murmur.[650]\n\n------------------------------------------------------------------------\n[650] Scartazzini takes the passage as referring to Eden only, and\ninterprets that all the air _here_ is moving evenly and noiselessly\nunless it meets with any obstacle _such as this forest_, when a\nmurmuring sound results.\n------------------------------------------------------------------------\n\nFrom this region of pure air, Dante rises with Beatrice through the\nsphere of Fire, into which already in a dream he had been rapt, on the\nfirst night in Purgatory, by the Eagle with golden feathers, when the\nburning heat of the dream-fire roused him from his sleep.[651] Now he\nfeels no heat, but is amazed at the vast extent of light, greater than\nany river or lake ever seen on earth, and at the same moment he begins\nto hear the music of the eternal spheres,[652] for he is approaching\nthe heaven of the moon.\n\nIn each one he hears it until the seventh is reached, but here, in pity\nfor his mortal senses, which are not yet strong enough to bear so much\ndivine beauty, not only does Beatrice forbear to smile, but the sweet\nsymphonies of heaven are silent.[653]\n\n------------------------------------------------------------------------\n[651] _Purg._ ix. 30-33.\n\n[652] _Par._ i. 76-81.\n\n[653] _Par._ xxi. 58-63.\n------------------------------------------------------------------------\n\nDid Dante then, in spite of Aristotle, believe in the music of the\nspheres? Perhaps the fact that only the _Commedia_, of all his works,\nmakes mention of it indicates that he only thought of it as a poetical\nfiction, an allegory? Yet it was fully believed in by many in his day,\nalthough opinions varied greatly as to what note each planet sang. The\nfavourite idea among Greek and Latin writers seems to have been that\nthe notes made up a musical scale, the lowest sphere sounding forth the\nlowest note, and the star sphere its octave; but others thought that\nonly the seven planets took part in the harmony, corresponding with the\nseven strings of the lyre: the moon being at the shortest distance from\nEarth, was the shortest string and gave the highest note, Saturn was\nthe longest and gave the deepest.\n\nOur own Milton, when he prays, \u201cRing out, ye crystal spheres,\u201d bids the\nPrimum Mobile join in, as well as the star sphere:\n\n \u201cAnd with your nine-fold harmony\n Make up full concert to the angelic symphony.\u201d[654]\n\nAnd Shakespear lets every separate star swell the chorus:\n\n \u201cThere\u2019s not the smallest orb which thou beholdest\n But in his motion like an angel sings,\n Still quiring to the young-eyed cherubins.\u201d[655]\n\nIn the same spirit, but more literally perhaps than these, are we to\nunderstand the music of Dante\u2019s spheres, which accompanies the singing\nof the angels:\u2014\n\n \u201cIl cantar di quei che notan sempre\n Dietro alle note degli eterni giri.\u201d[656]\n\n------------------------------------------------------------------------\n[654] _Hymn on the Nativity._\n\n[655] _Merchant of Venice._\n\n[656]\n \u201cThe song of those who sing for ever\n After the music of the eternal spheres.\u201d\n _Purg._ xxx. 92, 93. (_Longfellow_).\n------------------------------------------------------------------------\n\n\n3. DIMENSIONS AND PHYSICAL NATURE OF THE UNIVERSE.\n\nWe have seen that Dante believed the circling of the nine moving\nspheres and their epicycles to be the immediate cause of the movements\nwhich he saw in stars and planets. If we ask what were his ideas with\nregard to their sizes and distances the question is easily answered.\n\nIt is a curious fact that although our ideas about the size of anything\nwe see depend upon the distance at which it appears to be, and no\none can say how far away the sun looks, most of us nevertheless have\na quite definite idea as to how large it looks, about the size of a\ndinner-plate, a cart-wheel, &c. Cleomedes, in the days of Augustus,\nquotes Lucretius and the Epicureans as believing that the sun is no\nlarger than it looks, _that is a foot in diameter_; and he rightly\nremarks, amongst other arguments to the contrary, that if it were\nonly that size it would be invisible unless nearer than the tops of\nthe mountains, yet we see islands and hills projected against it when\nrising, which shows that its distance is greater. Dante twice quotes\nthe same fallacy, as an instance of the folly of trusting to the\nimpression of our senses, when not corrected by reason, and he tells us\nwhat he believes the true size of the sun to be.\n\nIn _Conv._ IV.[657] he says:\u2014\n\n \u201cThus we know that to most people the sun appears\n to be a foot wide in diameter; and this is so\n utterly false that according to the investigation\n and discovery made by human reason with her\n attendant arts, the diameter of the sun\u2019s body is\n five times that of the earth\u2019s, and a half besides.\n For whereas the earth has a diameter of six\n thousand five hundred miles, the diameter of the\n sun, which when measured by sense-impressions seems\n to be a foot in extent, is thirty-five thousand,\n seven hundred and fifty miles.\u201d\n (See also _Ep._ x. 42-46).\n\nWhen speaking of the planet Venus he says she is \u201cfar off from\nus, being distant even when she is nearest to us one hundred and\nsixty-seven times the distance of the distance of the centre of\nthe earth from us, which is three thousand two hundred and fifty\nmiles.\u201d[658]\n\n------------------------------------------------------------------------\n[657] _Conv._ IV. viii. 51-64.\n\n[658] _Conv._ II. vii. 104-108.\n------------------------------------------------------------------------\n\nMercury is spoken of in the _Paradiso_ as a small star, \u201cQuesta\npicciola stella,\u201d[659] and in _Conv._ II.[660] Dante says:\u2014\u201cMercury is\nthe smallest star in the sky; for the length of its diameter is not\nmore than 232 miles, according to Alfraganus, who says that it is one\ntwenty-eighth of the diameter of the earth,[661] which is six thousand\nfive hundred miles.\u201d\n\n------------------------------------------------------------------------\n[659] \u201cThis small star.\u201d _Par._ vi. 112.\n\n[660] _Conv._ II. xiv. 92-98.\n\n[661] The Frankfort printed edition and some Latin MSS of Alfraganus\nagree with this: the edition of Golius gives \u00b9/\u2081\u2088.\n------------------------------------------------------------------------\n\nIt is only in the last passage that our poet quotes his authority,\nbut in the others also the diameter or the semi-diameter of the earth\nis used as the unit of measure, and it is the same as that given by\nAlfraganus; so are the sizes of Mercury and the Sun, and the least\ndistance of Venus is the value given by Alfraganus for the greatest\ndistance of Mercury, which he asserted to be equal. It seems quite\nclear, therefore, that the figures given in the tables on pp. 189-90\nrepresent Dante\u2019s belief as to the dimensions of the Universe. These\npassages also are another proof that Dante had not studied Ptolemy\u2019s\nown work, for Ptolemy had said that the distances of Venus and Mercury\ncould not be accurately known.[662]\n\n------------------------------------------------------------------------\n[662] _Almagest_, Bk. IX.\n------------------------------------------------------------------------\n\nWe do not expect exact measures of distance in Dante\u2019s descriptions of\nhis soaring flight through the spheres, but he so constantly speaks of\nthe marvellous speed with which he passes from star to star that we\nare not required to ignore the stupendous distances between. The one\nindication he does give us of the space which separates him from earth\nis full of poetry and symbolic meaning: I refer to Folco\u2019s words in the\nheaven of Venus:\u2014\n\n \u201cQuesto cielo, in cui l\u2019ombra s\u2019appunta\n Che il vostro mondo face\u201d ...[663]\n\n------------------------------------------------------------------------\n[663]\n \u201cThis heaven, where ends the shadowy cone\n Cast by your world.\u201d\n _Par._ ix. 118, 119. (_Longfellow_).\n------------------------------------------------------------------------\n\nThis is the last of the three heavens in which Dante has met spirits\nwhose lives did not reach the perfection of the saints in higher\nheavens, but were marred by broken vows, earthly ambition, earthly\nlove; and here he is reminded that he has not yet soared high enough\nto be beyond reach of the cone of shadow thrown by the earth. This is\nanother allegory resting on what was to the poet an astronomical fact.\nFor Earth\u2019s shadow was said by Ptolemy and Alfraganus to extend to 268\ntimes the distance of her semi-diameter, and the distance of Venus from\nEarth varied, according to Alfraganus, between 167 and 1120 times this\nunit, while the next planet, the sun, at his least distance was 1120\nunits distant (the same as Venus\u2019 greatest). Therefore the spheres of\nVenus and the two nearer planets Mercury and the Moon, were all within\nreach of Earth\u2019s shadow, but the sun and the rest were far beyond\nit.[664] Venus and Mercury themselves never could be actually touched\nby the shadow like the moon, however, because they keep too near the\nsun for Earth to interpose herself between them and the source of light.\n\n(Though the length of the shadow thrown by Earth is nearly accurate,\nsee pp. 191-92, the planets are a great deal further than Alfraganus\nsupposed; for the least distance of Venus is nearly 6000 times Earth\u2019s\nsemi-diameter, and the least distance of Mercury 12,000).\n\n------------------------------------------------------------------------\n[664] Rabbi Abraham ben Chija, in his _Sph\u00e6ra Mundi_, written about\n1100 A.D., says that Earth\u2019s shadow extends as far as the distance of\nMercury, not of Venus (Delambre, _Histoire de l\u2019astronomie ancienne_,\nand Dreyer, _Planetary Systems_); but this does not agree with the\nfigures given by Alfraganus.\n------------------------------------------------------------------------\n\nExcept for this we have only the passage in the _Paradiso_ already\nreferred to, where Dante, standing among the stars of Gemini, found\nthe sphere above him too distant to be seen, but turning his gaze\ndownwards was able to survey all the planets and the earth at the\ncentre of the World. He knew very well that at a distance from Earth\n20,000 times her own semi-diameter it would be impossible to see her as\na disc,[665] far less to distinguish oceans and continents, hills and\nriver-mouths. It would in fact be like looking at an object one foot in\ndiameter at a distance of two miles. But as we have before observed,\nhis power of vision here was more than human: at every step in this\nmarvellous journey it had grown clearer and stronger, and in the fourth\nheaven he had been able to look on spirits which shone in the sun more\nbrilliantly than the sun itself, although on earth no eye can look upon\nthe sun.[666]\n\nIn the Empyrean, distinctions of space, and impediments to vision\nvanished altogether.[667]\n\n------------------------------------------------------------------------\n[665] Her diameter would look no larger than the diameter of Saturn,\nas we see it when nearest to him; but like Saturn she would be visible\nas a bright point, because shining by reflected sunlight. Ancient and\nmedi\u00e6val astronomers never realized this, however, but thought of Earth\nas a dark body, receiving light but giving none.\n\n[666] _Conv._ II. xiv. 126, 127; _Par._ x. 40-42, 48.\n\n[667] _Par._ xxii. 67; xxxi. 19-24; xxx. 118-123.\n------------------------------------------------------------------------\n\nWith regard to the physical nature of the heavenly bodies, Dante and\nhis contemporaries had no means whatever of investigation, and could\nonly profess ignorance or accept one or other of the guesses of their\npredecessors. Some of the Greek philosophers, as we saw, guessed\nthat the planets were worlds somewhat like the earth, others thought\nthey were composed of fire or of air. But the general belief in the\nthirteenth century was that planets and spheres alike were composed\nof a kind of celestial matter, called by Aristotle and the Greeks\n\u201c\u00e6ther,\u201d by the Arabs \u201cal-acir,\u201d an immortal substance which had neither\nheaviness nor lightness, and was altogether distinct from any of the\nfour elements existing below the sphere of the moon. Beatrice speaks of\n\u201cthis sphered ether,\u201d \u201cquesto etera tondo.\u201d _Par._ xxii. 132.\n\nDante\u2019s description of this celestial substance when he first enters\nthe ethereal world is one of the finest instances of his faithfulness\nto the teachings of astronomy as he had learned it, combined with\npoetical imagination, and at the same time his power of using material\nfacts (as he conceived them) to present an allegory of the deepest\nreligious mysteries. If we merely listen to the magic of the words,\nan impression is conveyed of something mysteriously beautiful and\ndazzling, unlike anything known on earth; but if we look into the\nmeaning, we find that the globe of the moon has just those strange,\ncontrasting qualities, just the colour and the form which a sphere of\nether may be imagined to have. It is white and rounded like a pearl,\n\u201cpolished\u201d as Plato said of the universal orb, it is thick and shining,\nsoft as cloud but hard as diamond; and it offers no more resistance to\nDante as he enters into it than does water to a ray of light.[668]\n\nThen follows a discussion concerning the substance not only of the\nmoon but of all the heavenly bodies. On hearing that he has reached\nthe boundaries of the immortal world, and has entered \u201cla prima\nstella,\u201d[669] Dante eagerly enquires of Beatrice what are those dark\nmarkings in the body of this planet which are seen from Earth and have\ngiven rise to the fable of Cain. She smiles a little, and bids him tell\nher first what is his own opinion. He advances the theory which he had\ntaught in the _Convivio_, viz. that the parts of the moon which look\ndark to us are less dense than the rest, and therefore the rays of the\nsun when striking them are not stopped and reflected back to us; hence\nthe brightness is less than in other parts of her surface.\n\n \u201cL\u2019ombra ch\u2019 \u00e8 in essa, ... non \u00e8 altro che rarit\u00e0\n del suo corpo, alla quale non possono terminare\n i raggi del sole e ripercuotersi cos\u00ec come nell\u2019\n altre parti.\u201d[670]\n\n------------------------------------------------------------------------\n[668] _Par._ ii. 25-45.\n\n[669] \u201cThe first star.\u201d\n\n[670] \u201cThe shadow which is in her is nothing but rare parts of her\nsubstance, which cannot stop the rays of the sun and reflect them back\nlike the other parts.\u201d _Conv._ II. xiv. 72-76.\n------------------------------------------------------------------------\n\nThis explanation seems to have been first suggested by Averro\u00ebs, the\nArab philosopher and astronomer of Cordova, who was known in the Middle\nAges as \u201cThe Commentator,\u201d from his famous commentary of Aristotle.\nThe suggestion occurs in his _De Substantia Orbis_, and as it follows\na quotation from Aristotle (to the effect that the moon is more nearly\nrelated to Earth in her nature than to the stars), it was believed by\nmany to be originally due to Aristotle himself.\n\nThe strange circumstance that the moon alone, among all the heavenly\nbodies, appeared to have dark shadows on her bright face, had roused\nmuch curiosity already among the Greeks; and Plutarch, in his dialogue\n\u201cOn the Face in the Moon,\u201d mentions the different explanations\nsuggested in his day. Some thought that the polished surface of the\nmoon reflected, like a mirror, parts of the earth; the Stoics said that\nair was enclosed within her globe of fire and obscured it in certain\nplaces, but this view was rejected with contumely by Plutarch.\n\n \u201cIt is a slap in the face to the moon when they\n fill her with smuts and blacks, addressing her in\n one breath as Artemis and Athena, and in the very\n same describing a caked compound of murky air and\n charcoal fire, with no kindling or light of its\n own, a nondescript body smoking and charred like\n those thunderbolts which the poets address as\n lightless and sooty!\u201d[671]\n\n------------------------------------------------------------------------\n[671] Plutarch, _On the Face in the Moon_, translation by Prickard.\n------------------------------------------------------------------------\n\nThe third hypothesis, which was favoured by most of the speakers in the\ndialogue, was that the moon was not a star at all, but a kind of more\nbeautiful Earth; and it was even suggested that men might dwell on her\nwho thought their world the only place fit for human beings, looking\ndown with contemptuous pity on our Earth, as a sort of sediment and\nslime of the Universe, appearing through damps and mists and clouds, a\nplace \u201cunlighted, low, motionless,\u201d entirely incapable of supporting\nmoving breathing warm-blooded animals!\n\nThis was not a view which could possibly be held by medi\u00e6val\nChristians, and in a treatise on Aristotle\u2019s _De C\u0153lo_, attributed to\nAlbert of Saxony, we find others put forward. The author disproves\nthe old theory of a mirror-like moon reflecting parts of Earth, and\nalso another that the moon draws up cold vapours which are seen like\nclouds on her surface, and upon which she is nourished\u2014for how should\nan eternal heavenly body need nourishment?\u2014and finally he expounds the\ntheory of \u201cThe Commentator,\u201d with which he agrees. The markings are\nrare parts of the moon\u2019s substance, which cannot shine so brightly as\nthe denser parts, and this varied surface he compares with alabaster,\nin which \u201cthe dense and not translucent part is very white, while that\nwhich is translucent like glass is obscure and tends to blackness.\nAnd if,\u201d he adds, \u201cit is asked why the moon is thus dissimilar in her\nparts, the reply is that this is her nature.\u201d[672]\n\n------------------------------------------------------------------------\n[672] See Paget Toynbee, _Le Teorie Dantesche sulle Macchie della\nLuna_, in _Giornale Storico della Letteratura Italiana_, vol. xxvi. pp.\n156-161.\n------------------------------------------------------------------------\n\nThis theory was perhaps the most popular one with medi\u00e6val scholars,\nthough there was some difference of opinion as to whether the dense or\nthe rare parts of the moon were those that showed dark. Ristoro perhaps\nalludes to it, in the passage where he speaks of the moon\u2019s markings,\nbut in a very confused way, and the contrast of \u201cpolished\u201d and \u201crugged\u201d\nsurface is what he chiefly lays stress upon.\n\nAfter upholding this theory in the _Convivio_, Dante rejects it in the\n_Paradiso_: perhaps because it was more or less bound up with the idea\nthat the moon was partly of an earthy nature, and this was inconsistent\nwith the other theory of Aristotle, so popular among classical writers,\nthat all within and above the sphere of the moon was eternal and\nheavenly. He is evidently very anxious to convince us of the falsity\nof his old belief, for he is not content with a simple assertion, but\nlets Beatrice reason like a learned doctor, using arguments which would\nappeal to his readers, drawn now from experiments which might be used\nin a school, and now from the accepted astrological beliefs of the day.\n\nFirst she reminds him that the numerous stars scattered over the\nsurface of the eighth sphere differ in brightness, like the different\nparts of the moon\u2019s surface, but they differ in the quality (colour?)\nof their light, as well as the quantity, and we know that there are\nessential differences between them, because their \u201cvirtues\u201d are\ndifferent. It cannot be, therefore, that they differ simply in density\nor rarity of their substance.\n\nThen she shows that in no circumstances is the theory of varying\ndensity in different parts of the moon capable of explaining the\nobserved variety of brightness. For if the parts which look dark are\nless dense than others, either they must be so right through the\nplanet, or there must be an alternation of dense and rare matter in\nthose parts, like fat and lean in a material body, one behind the other\nlike pages in a book. (The double metaphor is characteristic of Dante.)\nNow if the first be true, the sunlight would shine through the moon\nis those parts, during an eclipse;[673] and if the second, the sun\u2019s\nrays must penetrate to the lower-lying denser part, and be reflected\nthence just as from the dense parts of the moon\u2019s surface. A possible\nobjection that in that case the reflecting surface would be further\naway, and therefore appear fainter, may be disproved by an experiment.\nTake two mirrors and place them at an equal distance from you; place\na third between them but further away, face the three mirrors, and\nplace a light behind you so that it may be reflected from them all: the\ndistant one will appear smaller, but no less bright than the two near\nones. This reasoning is perfectly sound.\n\nThen follows the explanation for which all this is a preparation. It\ninvolves an exposition of ultimate causes which we need not enter into\nhere: for the present we need only say that difference of brightness\nis not caused by differences of much or little of the same substance.\nThere are intrinsic differences between star and star, and between\ndifferent parts of the moon,[674] but all are manifestations of divine\nintelligence; just as the different members and faculties of a human\nbody are manifestations of a human soul.\n\n------------------------------------------------------------------------\n[673] Albert of Saxony notes this objection, but says the rarity is not\nsufficiently great to make these parts transparent.\n\n[674] This is in agreement with modern belief. Some parts of the moon\u2019s\nsurface reflect sunlight less well than others, and therefore look\ndark, just as a peaty soil looks darker than limestone.\n------------------------------------------------------------------------\n\nThe diversity of the celestial matter is also touched upon in the\n_Convivio_, where it is said that the epicycle of Venus is \u201cnot of\nthe same essence as that which carries it [the deferent or large\nsphere], although it is more nearly of one nature with it than with\nthe rest.\u201d[675] Differences of colour are indicated in the glowing\nmasses of the planets, which are entered by Dante and Beatrice.\nAs with the moon, they do not merely alight upon the surface, but\npenetrate the planetary ether. \u201cQuel ch\u2019 era _dentro_ al sol,\u201d[676]\n\u201cNel profondo Marte,\u201d[677] \u201cLa temprata stella sesta, che _dentro\na s\u00e8_ m\u2019avea ricolto.\u201d[678] Mercury is called a pearl\u2014\u201cla presente\nmargarita\u201d[679]\u2014while Mars is \u201cquesto fuoco,\u201d[680] and the astronomer\npoet says he knew the planet by its burning smile, for it seemed to him\neven more ruddy than its wont.\n\n------------------------------------------------------------------------\n[675] _Conv._ II. iv. 94-96.\n\n[676] \u201cThat which was _within_ the sun [_sc._ the spirits].\u201d _Par._ x.\n41.\n\n[677] \u201cIn the depths of Mars.\u201d _Par._ xiv. 100, 101.\n\n[678] \u201cThe temperate sixth star, which _within itself_ had received\nme.\u201d _Par._ xviii. 68, 69.\n\n[679] \u201cThe present pearl.\u201d _Par._ vi. 127.\n\n[680] \u201cThis fire.\u201d _Par._ xvi. 38.\n\n \u201cBen m\u2019 accors\u2019 io ch\u2019 io era pi\u00f9 levato,\n Per l\u2019affocato riso della stella,\n Che mi parea pi\u00f9 roggio che l\u2019usato.\u201d[681]\n\n[681]\n \u201cWell was I \u2019ware that I was more uplifted\n By the enkindled smiling of the star\n That seemed to me more ruddy than its wont.\u201d\n _Par._ xiv. 85-87. (_Longfellow_).\n------------------------------------------------------------------------\n\nAnd when, without being conscious of any movement, he found that the\nred light shining on Beatrice had turned to purest white, like a blush\nfading from a fair face, he knew that the sixth star (Jupiter) had\nreceived him within itself.\n\n \u201cE quale \u00e8 il trasmutare in picciol varco\n Di tempo, in bianca donna, quando il volto\n Suo si discarchi di vergogna il carco,\n Tal fu negli occhi miei, quando fui volto,\n Per lo candor della temprata stella\n Sesta, che dentro a s\u00e8 m\u2019avea ricolto.\u201d[682]\n\n------------------------------------------------------------------------\n[682]\n \u201cAnd such as is the change, in little lapse\n Of time, in a pale woman, when her face\n Is from the load of bashfulness unladen,\n Such was it in mine eyes, when I had turned,\n Caused by the whiteness of the temperate star,\n The sixth, which to itself had gathered me.\u201d\n _Par._ xviii. 64-69. (_Longfellow_).\n------------------------------------------------------------------------\n\nThis contrast between the colours of Jupiter and Mars is referred to\nmore than once. In _Par._ xxvii., the flaming spirit of St. Peter,\nflushed with righteous indignation, becomes brilliant as the planet\nJupiter, and red as Mars:\u2014\n\n \u201cE tal nella sembianza sua divenne,\n Qual diverrebbe Giove, s\u2019egli e Marte\n Fossero augelli, e cambiassersi penne.\u201d[683]\n\n------------------------------------------------------------------------\n[683]\n \u201cHe in semblance such became\n As Jove might be, if he and Mars were birds,\n And interchanged their plumes.\u201d\n _Par._ xxvii. 13-15. (_Carey_).\n------------------------------------------------------------------------\n\nAnd when Dante looks down upon the seven planets he sees\n\n \u201cil temperar di Giove\n Tra il padre e il figlio.\u201d[684]\n\n------------------------------------------------------------------------\n[684] \u201cThe temperate light of Jove, between his father and his son.\u201d\n_Par._ xxii. 145-146.\n------------------------------------------------------------------------\n\nTo understand which we must turn to the oft-quoted fourteenth chapter\nof the second treatise in the _Convivio_. Here we find that Jupiter\n\u201cmoves between two heavens\u201d which \u201care antagonistic to its excellent\ntemperateness, that is to say the heavens of Mars and that of\nSaturn,\u201d[685] and Dante quotes Ptolemy as saying that Jupiter is a star\nof temperate constitution, between the cold of Saturn and the heat of\nMars.\n\nIt seems that these ideas of cold and heat, as applied to the planets,\nwere taken literally, not merely as poetical descriptions of colour,\nnor of astrological significance; for Dante says explicitly in the same\nchapter of the _Convivio_ that Mars is hot like fire, that this is the\ncause of his colour,[686] and that he dries up and burns things.[687]\n\n------------------------------------------------------------------------\n[685] _Conv._ II. xiv. 196-198.\n\n[686] _Cf._ Ristoro, _Comp. del Mondo_, III. iii.\n\n[687] _Conv._ II. xiv. 161-165.\n------------------------------------------------------------------------\n\nSimilarly he appears to have believed that Saturn and the moon were\nliterally of a cold nature. \u201cQuel pianeta che conforta il gelo,\u201d[688]\nin _Canzone_ xv. is doubtless Saturn; and the chill of the hour before\ndawn is described as due not only to loss of heat by the earth but\nsometimes also to the influence of the cold moon or of Saturn.[689]\n\nBesides her shadowy markings, the moon had another peculiarity which\ndistinguished her from all other heavenly bodies, for she was the only\nplanet then known to vary in apparent size and shape \u201caccording to the\nway in which the sun looks upon her.\u201d[690] She was therefore a very\ndark body, though it was believed that she had some light of her own,\nand Dante argues in favour of this that she does not become totally\ninvisible during an eclipse.[691] This was a very natural conclusion:\nit would not readily occur to anyone that the reddish light of the\neclipsed moon is sunlight refracted (_i.e._ bent out of its direct\ncourse) in passing through the earth\u2019s atmosphere.\n\n------------------------------------------------------------------------\n[688] \u201cThe planet that strengthens the cold.\u201d _Canz._ xv. 7.\n\n[689] _Purg._ xix. 1-3.\n\n[690] _Conv._ II. xiv. 78, 79.\n\n[691] _De Mon._ III. iv. 140-142.\n------------------------------------------------------------------------\n\nThe sun, although the astrologers made him not very much larger than\nthe brightest fixed stars and the largest planets, was much brighter\nand hotter than any, and it was universally agreed that all obtained\ntheir light from him. Even if, like the Moon, they had some light of\ntheir own, and did not only reflect like mirrors, this inherent light\nhad originally come from the sun and was but absorbed sunlight.[692]\nWe meet constantly with this idea in Dante\u2019s works. In one of his Odes\nthe sun is said to \u201cdonar luce alle stelle;\u201d[693] in the _Convivio_ he\nsays, \u201cIl sole ... di sensibile luce s\u00e8 prima, e poi tutti i corpi\ncelestiali ed elementali allumina.\u201d[694] The Morning Star is described\nas deriving her beauty from the sun;[695] and after the sun has set he\nshines forth again in the light of all the stars.[696]\n\nSo also says Brunetto Latini, \u201cSans faille li solaus est fondemenz de\ntout\u00e8s lumieres et de toute chalor.\u201d\n\n------------------------------------------------------------------------\n[692] See quotations from Albertus Magnus and Roger Bacon in Moore\u2019s\n_Studies_, iii. p. 45, _note_.\n\n[693] \u201cBestow light on the stars.\u201d _Canz._ xix. 117.\n\n[694] \u201cThe sun illumines first himself and then all celestial and\nelemental bodies with visible light.\u201d _Conv._ III. xii. 54-56.\n\n[695] _Par._ xxxii. 107, 108.\n\n[696] _Par._ xx. 1-6; compare xxiii. 28-30.\n------------------------------------------------------------------------\n\n\n4. INFLUENCE OF THE SPHERES ON HUMAN AFFAIRS.\n\nIf we are to believe a fifteenth century biographer, we have so far\nomitted to mention Dante\u2019s greatest claim to be considered a proficient\nin astronomy. \u201cHe foretold,\u201d says Filelfo, \u201cmany of the calamities\nof Florence, the wars of Italy, and other political changes, all of\nwhich would have been impossible without an accurate knowledge of the\nmovements of the celestial bodies.\u201d\n\nFilelfo was a poet, and his authority for this surprising statement\ncan be no other than that on which, Dr. Moore says, he mainly depends,\nand which seldom or never fails him, \u201chis own most airy and lively\nimagination unembarrassed by any references to documents.\u201d[697] The\nprophecies of the _Divina Commedia_ are obviously written after the\nevents, and in no single instance are they supposed to have any\nconnection with the art of the astrologers. On the contrary, it is\nremarkable how very little we find in Dante\u2019s writings about the\nfate-predicting and character-reading which passed as the chief part of\nastronomy with the large majority of his contemporaries, and played a\nconsiderable part even in the scientific writings of his fellow authors.\n\n------------------------------------------------------------------------\n[697] Moore, _Dante and his early Biographers_, p. 95.\n------------------------------------------------------------------------\n\nNot that he disbelieved in the art: it would have been almost a miracle\nif he had. The astrologers in the fourth Bolgia were punished with\nother soothsayers not because they deceived credulous clients, but\nbecause they had desired to look too deeply into the future,[698] which\nwas impiety. For this reason the learned Michael Scot, the honoured\nof Popes, was there, as well as poor Asdente, and Guido Bonatti, and\nAruns who from his solitary cave had watched the stars, and prophesied\nthe victories of C\u00e6sar over Pompey.[699] This orthodox sentiment that\n\u201cjudicial astronomy,\u201d was apt to be a snare, and lead to practices\ncondemned by the Church, may have been one reason for Dante\u2019s avoidance\nof it; but we cannot read his works without feeling that it was the\nbeauty of the skies, and the keen desire to understand the structure of\nthe universe which inspired him to study astronomy, and that he had no\nsuperstitious fear of the heavenly bodies, no greedy wish to make use\nof his knowledge to pry into the future. There is no evidence that he\nwas acquainted with the details of astrology. The few allusions made\nin his works to special effects of certain stars or planets are only\nto those most familiarly known, and parallel instances might be found\nto many of them in modern poems. With this difference, however, that\nto-day they are figures of speech: with Dante they represented facts.\nVenus was to him in serious truth \u201cla stella d\u2019amor,\u201d[700] \u201clo bel\npianeta che ad amar conforta,\u201d[701] and exercised a real power over\nFolco[702] and Cunizza,[703] and his own heart.[704] He even tells\nus, in serious prose, that it is the planet and not the whole sphere,\nwhich is the source of this influence, and that it is borne to us upon\nher rays.[705] So also the moon has a special influence, which is\ncommunicated by her rays.[706]\n\n------------------------------------------------------------------------\n[698] _Inf._ xx. 38.\n\n[699] _Inf._ xx. 115-118, 46-51.\n\n[700] \u201cThe star of love.\u201d _Canz._ xv. 4.\n\n[701] \u201cThe fair planet which incites to love.\u201d _Purg._ i. 19.\n\n[702] _Par._ ix. 94-96.\n\n[703] _Par._ ix. 32, 33.\n\n[704] _Conv._ II. _Canz._ 1-6.\n\n[705] _Conv._ II. vii. 88-100.\n\n[706] _De Mon._ III. iv. 139, 140.\n------------------------------------------------------------------------\n\nTo the strong star of Mars the noble warlike nature of Can Grande was\npartly due;[707] Jupiter is a temperate star, not only in the purity\nof his colour, but his influence is felt where justice is worked on\nearth.[708] Saturn\u2019s influence is modified when he shines in Leo,[709]\nthe sun has special powers in Aries,[710] and to his presence in\nGemini at the time of Dante\u2019s birth the poet attributes his literary\ngift.[711] In _Inf._ xxvi. 23, he again suggests that his mental powers\nmay be due to the influence of a good star, and Brunetto Latini bids\nhim follow his star.[712]\n\nDante also quotes Albumassar, and Seneca, and the events of his own\nday, to show that those fiery vapours, meteorites, portend the death\nof kings and the downfall of states, adding that this is because they\nare effects of the sovereignty of Mars.[713] This passage explains why\nthe warrior Malaspina is called a vapour drawn by Mars from Valdimagra,\nwhich in the tempest of battle at Piceno shall suddenly split the\nclouds and deal death to the combatants.[714]\n\n------------------------------------------------------------------------\n[707] _Par._ xvii. 76-78.\n\n[708] _Par._ xviii. 115-117.\n\n[709] _Par._ xxi. 13-15.\n\n[710] _Par._ i. 40-42; _Canz._ xv. 41.\n\n[711] _Par._ xxii. 112-117. The Ottimo, commenting this passage, says\nthat Gemini \u201cis the house of Mercury, who signifies, according to the\nastrologers, literature, science, and learning. And in this direction\nit disposes those who are born when it is in the ascendant, and more\npowerfully if the sun is in it.\u201d\n\n[712] _Inf._ xv. 55.\n\n[713] _Conv._ II. xiv. 170-180.\n\n[714] _Inf._ xxiv. 145-150.\n------------------------------------------------------------------------\n\nThe results of the right disposition of sphere with sphere are spoken\nof in _Canz._ xix. 77-79; all the nine were in perfect accord when\nBeatrice, herself a nine or miracle of perfection, was to be born;[715]\nand every star rained its light and its virtue into her beautiful\neyes.[716] There is also a charming sonnet, in which the poet tells us\nhow all the seven planets influence his lady.\n\n------------------------------------------------------------------------\n[715] _V. N._ xxx. 22-24.\n\n[716] _Ball._ vi. 11, 12.\n\n \u201cDa quella luce che il suo corso gira\n Sempre al volere dell\u2019 empiree sarte,\n E stando regge tra Saturno e Marte,\n Secondo che l\u2019astrologo ne spira;\n Quella che in me col suo piacere aspira,\n D\u2019essa ritragge signorevol arte:\n E quei che dal ciel quarto non si parte\n Le d\u00e0 l\u2019effetto della mia desira.\n Ancor quel bel pianeta di Mercuro\n Di sua virtute sua loquela tinge,\n E \u2019l primo ciel di s\u00e8 gi\u00e0 non l\u2019\u00e8 duro.\n Colei, che \u2019l terzo ciel di s\u00e8 costringe\n Il cor le fa d\u2019ogni eloquenza puro;\n Cos\u00ec di tutti e sette si dipinge.\u201d[717]\n\n[717]\n \u201cFrom that bright star which moveth on its way\n For ever at the Empyrean\u2019s will,\n And between Mars and Saturn ruleth still,\n E\u2019en as the expert astrologer doth say,\n She who inspires me with her beauty\u2019s ray\n Doth subtle art of sovereignty distil;\n And he whose glory doth the fourth heaven fill\n Gives her the power my longing soul to sway.\n And that fair planet known as Mercury\n Colours her speech with all its virtue rare,\n And the first heaven its boon does not deny.\n She who the third heaven ruleth as her share\n Makes her heart full of utterance pure and free;\n So all the seven to perfect her agree.\u201d\n _Sonnet_ xxviii. (_Plumptre_).\n------------------------------------------------------------------------\n\nIn more serious vein is the discourse in _Par._ ii. on the different\nvirtues of the different stars;[718] and this should be compared\nwith passages in the _Qu\u00e6stio_ and the _Convivio_. \u201cSciendum quod\nlicet c\u0153lum stellatum habeat unitatem in substantia, habet tamen\nmultiplicitatem in virtute,\u201d[719] sounds like an echo of the words of\nBeatrice:\n\n------------------------------------------------------------------------\n[718] _Par._ ii. 64-72, 130 to end.\n\n[719] \u201cIt should be borne in mind that although the starry heaven has\nunity in substance it nevertheless has multiplicity in virtue.\u201d _Qu._\nxxi. 12-14.\n\n \u201cCos\u00ec l\u2019intelligenza sua bontate\n Multiplicata per le stelle spiega,\n Girando s\u00e8 sopra sua unitate.\u201d[720]\n\n[720]\n \u201c ... E\u2019en so\n The intellectual efficacy unfolds\n Its goodness multiplied throughout the stars,\n On its own unity revolving still.\u201d\n _Par._ ii. 136-138. (_Carey_).\n------------------------------------------------------------------------\n\nAnd when comparing Nobility with the star-spangled sky, our author says:\n\n \u201cTante sono le sue stelle che nel cielo si\n stendono, che certo non \u00e8 da maravigliare, se molti\n e diversi frutti fanno nella umana Nobilt\u00e0, _tante\n sono le nature e le potenze di quelle, in una\n sotto una semplice sustanza comprese e adunate_,\n nelle quali siccome in diversi rami fruttifica\n diversamente.\u201d[721]\n\n------------------------------------------------------------------------\n[721]\n \u201cSo many are the stars which spread themselves over\n her sky, that surely we cannot wonder if they make\n many and diverse fruits grow on human nobility, _so\n many are their natures and potencies, concentrated\n and united in one simple substance_; and on them\n as on diverse branches she bears fruit in diverse\n ways.\u201d\n _Conv._ IV. xix. 45-52. (_Jackson_).\n\n See also _Conv._ IV. xxi. 62-66.\n------------------------------------------------------------------------\n\nThe author goes on to say in the _Qu\u00e6stio_ that the many and diverse\nstars which we see in the eighth heaven were placed there in order that\nit might pour down diverse virtues, and that he who perceives this\nnot, let him know that he is outside the pale of philosophy.[722] In\nanother place he tells us that the nearer a star is to the mid-circle\nof the star sphere, the greater is its virtue:[723] he no doubt\nmeans, not the celestial equator, but the zodiac (or more exactly the\necliptic), since this was the mid-circle of the star sphere, parallel\nto which its slow revolution of 36,000 years was made. This would\nagree with the view of the astrologers, who paid more attention to the\nconstellations of the zodiac than to any others.\n\n------------------------------------------------------------------------\n[722] _Qu._ xxi. 17-19.\n\n[723] _Conv._ II. iv. 75-77.\n------------------------------------------------------------------------\n\nBut we may search all Dante\u2019s works in vain for any reference to the\n\u201chouses\u201d or \u201caspects\u201d of the planets, or for any information about the\nmasculine and feminine, mobile and stable, signs. All such things,\nwhich seemed to most writers of his day quite as important as the\nperiods of the planets or the positions of the signs, he entirely\nignores. Among the circumlocutions by which he describes the signs,\nsuch as \u201cthe fair nest of Leda,\u201d or \u201cthe sign that follows Taurus,\u201d\nwe never find \u201cthe house of Saturn,\u201d or \u201cthe sign in which Mars is\nmildest.\u201d Leo is called Mars\u2019 own Lion, probably because the \u201cleo\naudax et ferox\u201d of bestiaries agreed with the fiery colour and nature\nof Mars:[724] astrologically, his signs were Scorpio and Aries. It is\nquite astonishing that among all the characteristics of the planets\nand spheres mentioned in _Convivio_ II. chapters xiv. and xv., only\ntwo relate to astrology, namely, the temperate disposition of Jupiter\nbetween the hot Mars and cold Saturn, and the power of Mars to draw up\nthe hot vapours which become meteors and portend the deaths of kings.\nAll the rest\u2014the markings and phases of the moon, the small size and\nproximity to the sun of Mercury, the beauty of Venus and her appearance\nalternately as morning and evening star, the brilliance of the sun and\nhis capability of giving light to all the stars, the position of the\nsphere of Mars midway between those of the other planets, the purity\nof Jupiter\u2019s colour, the slow movement and distance of Saturn\u2014all\nthese are purely astronomical, to use the modern distinction. So also\nare the characters of the star sphere\u2014the thousand and twenty-two\nvisible stars, and the indistinguishable stars of the Galaxy, the pole\nwe see and the other which remains hidden, the conspicuously swift\ndiurnal movement and the almost imperceptible secular revolution of\n36,000 years. Of the Primum Mobile it is remarked that it controls the\nmovement of all the rest, and of the Empyrean that it is full of peace.\n\n------------------------------------------------------------------------\n[724] But see Tozer\u2019s _English Commentary on Dante\u2019s Divina Commedia_,\nnote on _Par._ xvi. 37. \u201cIn medi\u00e6val astrology Mars was one of the\nLords of the Lion.\u201d\n------------------------------------------------------------------------\n\nThe symbolism of the spheres assigned in Paradise to the different\nsaints is partly drawn from astrological ideas, for in Venus Dante\nmeets the lovers, in Mars the warriors, in Jupiter the just rulers. But\nthose who were not eternally faithful to their vows are in the moon\nbecause she has the lowest sphere,[725] the contemplative saints are\nin the highest planet, the theologians who enlightened the faithful\nare in the sun, and the ambitious are in the little planet which ever\nkeeps closest to the sun. The heaven of \u201cmany and diverse stars\u201d shows\nthe poet a host of saints, and the Primum Mobile, which controls the\nmovement of the other spheres, reveals to him the Angels who direct\nthem.\n\nIt seems, then, that Dante was not interested in technical astrology,\nand had never made a study of it; and I think we may adduce this\nadditional evidence that he had not learned astronomy in a university,\nor under Cecco d\u2019Ascoli. It is only necessary to look at the list of\nbooks prescribed at Bologna[726] to feel sure that Dante had not taken\na regular course there. The list, it is true, belongs to a somewhat\nlater time, but there is no reason to suppose that astrology became of\nmore importance in the late fourteenth century than at its beginning.\n\n------------------------------------------------------------------------\n[725] _Par._ iii. 55-57.\n\n[726] See p. 202.\n------------------------------------------------------------------------\n\nNevertheless, however little Dante may have cared for the details of\nastrology, we shall never understand all that the skies meant to him\nunless we realize that a general belief in their influence on man was\ndeeply rooted in his mind. For him it was a tremendous fact, and one\nwhich pervades his writings, that stars and spheres are the instruments\nof God\u2019s providence, and are ordained by the First Mover to mould the\ndestinies of Earth.[727] It is their movements which manifest His\nWill;[728] they are the hammers,[729] earth the metal, they are the\nseals,[730] and earth the wax.\n\n------------------------------------------------------------------------\n[727] _De Mon._ II. ii. 15-18, 25, 26, 36-38; III. ii. 30-32; xvi.\n91-101; _Ep._ v. 133-135; _Par._ ii. 121, viii. 97-99.\n\n[728] _Ep._ v. 124, 125.\n\n[729] _Par._ ii. 127, 128.\n\n[730] _Par._ ii. 130-132; xiii. 73-75; viii. 127, 128; i. 41, 42.\nRistoro of Arezzo uses the same expression, _Comp. del Mondo_, Bk. VII.\npart I. chapter 2.\n------------------------------------------------------------------------\n\nThree times the stars are invoked to bring justice and righteousness\non earth.[731] Through the spheres the elements were evolved out of\nthe first chaotic matter, and everything on earth took form; all life\nand motion is generated by them.[732] Man\u2019s soul is a direct creation\nby God, but the moving heavens play an important part in the formation\nof his material body, his mental faculties, and his disposition.[733]\nWere it not for the action of the spheres, children would be precisely\nlike their parents, their whole nature being governed by the law of\nheredity alone: it is the different influences of the skies that give\nthem different natures.[734] This, says Beatrice, is perhaps what Plato\nmeant when he said that souls came from different stars and returned\nthither: if his meaning was that the influences of the stars is so\ngreat that to them is due the praise or blame which we distribute to\nmen, there is some truth in the saying.[735]\n\n------------------------------------------------------------------------\n[731] _Purg._ vi. 100; xx. 13, 14; xxxiii. 40-45.\n\n[732] _Par._ vii. 133-141; xiii. 65, 66; _Conv._ III. xv. 159-161; II.\nxv. 152-154; IV. xxiii. 50-52.\n\n[733] _Conv._ II. xiv. 28-30; IV. ii. 58-61; _Par._ xxvi. 128, 129.\n\n[734] _Par._ viii. 127-135.\n\n[735] _Par._ iv. 49-60. See also _Ecl._ ii. 16, 17; and _Conv._ IV.\nxxi. 17-19, 25-27.\n------------------------------------------------------------------------\n\nSome truth only\u2014\u201calcun vero\u201d; for the stars are not independent\npowers, for good or evil, which men are unable to resist. This view is\nexpressly combated in _Purg._ xvi. 58-84. Dante has asked the spirit\nof the courtly Venetian Marco Lombardo why the world is so full of\nwickedness now, for some say it is the effect of the heavens, and\nothers seek an earthly cause. Marco groans at the blindness of men, who\naccuse heaven for the results of their own misdeeds: it is true that\nthe heavens influence our lower natures, our instincts, and desires;\nbut the soul is free, and can control them. This is in accordance\nwith the teaching of St. Augustine and Aquinas. In one passage of the\n_De Monarchia_, Dante goes even further than this, and asserts that\nthe influences of the spheres are only good, and that evil results\nfrom imperfections in the material on which these perfect instruments\nwork.[736]\n\n------------------------------------------------------------------------\n[736] _De Mon._ II. ii. 21-23; _Cf. Par._ xiii. 64-78.\n------------------------------------------------------------------------\n\nConceptions such as these give us a new idea of medi\u00e6val astrology.\nThey may be mistaken, but at least they are grand, and not unworthy of\na philosopher and a Christian.\n\n\n5. THE MOTIVE POWER.\n\nDante\u2019s ideas regarding the laws and origin of motion in the universe\nwere derived from Aristotelian metaphysics and Church doctrines. He\nbelieved that there were three kinds of motion proper to three kinds\nof bodies: _i.e._ heavy bodies tended towards the centre of the\nuniverse, which is also the centre of the earth; light bodies tended\nupwards to the region of fire just below the moon; and bodies of\nethereal substance\u2014the stars, planets, and spheres\u2014moved eternally in\ncircles round the centre. Thus Beatrice, when speaking of the instinct\nimplanted in all created things, which bears them through the great\nocean of being each to his destined haven, says:\u2014\n\n \u201cQuesti ne porta il foco inver la luna,\n . . . . .\n Questi la terra in s\u00e8 stringe ed aduna.\u201d[737]\n\n------------------------------------------------------------------------\n[737] \u201cThis carries fire towards the moon, this compresses and binds\nEarth together.\u201d _Par._ i. 115, 117. See also _De Mon._ III. vii. 30,\n31, and I. xv. 38-41; _Conv._ III. iii. 10-13; _Qu._ xviii. 11, 12, and\nmany others.\n------------------------------------------------------------------------\n\nAnd Virgil:\u2014\n\n \u201cIl foco movesi in altura,\n Per la sua forma, ch\u2019 \u00e8 nata a salire\n L\u00e0 dove pi\u00f9 in sua materia dura.\u201d[738]\n\n------------------------------------------------------------------------\n[738]\n \u201cThe fire doth upward move\n By its own form, which to ascend is born,\n Where longest in its matter it endures.\u201d\n _Purg._ xviii. 28-30. (_Longfellow_).\n------------------------------------------------------------------------\n\nThat is to say the form of a flame fits it to rise to that place\nwhere, being in its own element, it may last longer than on Earth.\nConversely, the centre of the earth is described as the bottom\nof the whole universe, and the point towards which all weights\nare attracted.[739] These opposite forces Dante calls gravity and\nlevity.[740]\n\n------------------------------------------------------------------------\n[739] _Inf._ xxxii. 8, and 74; xxxiv. 110, 111. See also _Par._ xxxiii.\n22, 23; _Inf._ ix. 28, 29; _Qu._ iii. 6-9, etc.\n\n[740] _De Mon._ I. xv. 46-48; _Qu._ xii. 39-42.\n------------------------------------------------------------------------\n\nThe most interesting illustration of this force of gravity is the\ndescription, in the last canto of the Inferno, of passing the centre\nof the earth, \u201cil punto al qual si traggon d\u2019ogni parte i pesi.\u201d[741]\nVirgil turned here \u201ccon fatica e con angoscia,\u201d[742] and bid Dante hold\nhim fast, \u201cansando com\u2019 uom lasso.\u201d[743] It was natural to suppose that\nthe force of gravity would increase as one neared the centre, though\nthe fact is that it decreases. In deep mines it is less than at the\nsurface of earth; and if we could go to much greater depths we should\nfind that we could stand in any position, and walk in any direction\nwith almost equal ease, till at the exact centre the sense of weight\nand of \u201cup\u201d and \u201cdown\u201d would vanish altogether. This is because it\nis the whole mass of the earth which attracts, and when we penetrate\nbeneath the surface the part above is no longer dragging us down, and\nits effect is annulled. But at the surface gravity acts as if the\nforce were all concentrated at the centre, and falling bodies increase\ntheir speed as they approach the surface: before the days of Newton,\ntherefore, it was thought that the whole of the attracting force was\nactually situated at the centre of the earth. Brunetto Latini speaks\nof gravity increasing as this point is approached, and Dante, like\nAristotle, calls it the goal of gravity.[744]\n\n------------------------------------------------------------------------\n[741] \u201cThe point towards which weights are drawn from every direction.\u201d\n_Inf._ xxxiv. 110-111.\n\n[742] \u201cLaboriously and painfully.\u201d _Inf._ xxxiv. 78.\n\n[743] \u201cPanting like a tired man.\u201d _Inf._ xxxiv. 83.\n\n[744] _Qu._ xvi. 54, 55.\n------------------------------------------------------------------------\n\nBetween the physical and the spiritual universe as conceived by\nDante, there is a very close correspondence. Souls burdened with the\nweight of sin fall towards the centre of the universe, sinking deeper\nthe heavier is their guilt, and at the bottom of the whole universe\nis the personification of all evil. Repentant souls, as they are\nfreed from their sins, rise higher and higher, and the ascent becomes\nalways easier, until at last they soar heavenward as naturally and\nspontaneously as flames of fire. In Paradise the motion of the pure\nspirits is inconceivably rapid, and their mystic dances expressive of\njoy are always in circles.\n\nMotion in circles was the only appropriate kind for the heavenly\nbodies,[745] but the actual force which originated and preserved their\nmotions was intelligence and will. When Dante sang, \u201cVoi che intendendo\nil terzo ciel movete,\u201d[746] he was not addressing beings created merely\nby his poet\u2019s imagination. His own commentary on the words shows\nus that they were as real to him as the planets themselves. He can\nknow nothing of them through the senses, yet is as certain of their\nexistence as one with closed eyes is of light.[747] These beings move\nthe spheres not through any material contact, but solely by the power\nof thought: they are immaterial immortal intelligences, commonly called\nAngels, and Dante identifies them with the Forms of Aristotle, the\nIdeas of Plato, and the gods and goddesses of the Pagans, \u201cavvegnach\u00e8\nnon cos\u00ec filosoficamente intendessero quelle come Plato.\u201d[748] As the\nhammer beats out forms in metal, and thus expresses what is in the\nmind of the smith, and as he works from the artist\u2019s design, so the\nmovements and \u201cvirtues\u201d of the sacred spheres mould earthly events, but\nthese movements and virtues are the expression of controlling angels,\nand they are carrying out the Will of the First Mover. And as the joy\nof a happy mortal shines out in the eyes, so the joy of the angels\nshines out in stars and planets.[749]\n\n------------------------------------------------------------------------\n[745] This is nowhere stated, but everywhere taken for granted, and\nin _Conv._ II. xiv. 211 the circle is said to be the most perfect of\nfigures.\n\n[746] \u201cOh ye whose intellectual ministry moves the third heaven.\u201d\n_Conv._ II. canzone; and _Par._ viii. 37.\n\n[747] _Conv._ II. v. 119-126.\n\n[748] \u201cAlthough they did not think of them as philosophically as\nPlato.\u201d _Conv._ II. v. 5-37, 94, 95; vi. 154-159.\n\n[749] _Par._ ii. 127-129, 142-144.\n------------------------------------------------------------------------\n\nThere were nine Orders in the angelic hierarchies, according to the\nteaching of the Church, the chief authority on this subject being\na book _De Celestia Hierarchia_, supposed to have been written by\nDionysius the Areopagite, a disciple of St. Paul, who had learned from\nthe apostle what he had seen when rapt to the third heaven. Aquinas\nassigns to one of these nine orders the guidance of stars and planets,\nand to others the rule over earthly affairs. But since the latter\nfollow the celestial motions, there was no need to separate the two\nfunctions, and Dante laid down in the _Convivio_ that a few Angels from\neach Order preside over the movements of each sphere. With Aristotle,\nhe agreed that there is one Intelligence for each movement, so that for\nVenus (for instance) there are three movers to direct respectively the\ncircling of the Epicycle, the Deferent, and the movement of Precession\nwhich every planet shares with the stars; but whether there is a fourth\nmover to guide the diurnal motion of Venus or if all the inner spheres\nare swept along by the motion of the Primum Mobile, he would not\npresume to decide.[750]\n\nWhen he wrote the _Paradiso_, he no longer thought that a few Angels\nwere set apart for this ministry: he implies that all the angels in\neach order united in the act of moving a whole heaven and perhaps he\nmeans to include the beatified human spirits as well.[751] He also\nslightly changes the correspondence between the angelic orders and\ntheir respective spheres.[752]\n\nSwiftness of motion in a sphere corresponds with fervour of adoration\nin the Movers: hence the highest and swiftest of the moving heavens,\nwhich is the Primum Mobile, is moved by the highest Order, the\nSeraphim: and the lowest and slowest, which is that of the moon, by the\nlowest order, the Angels.[753]\n\n------------------------------------------------------------------------\n[750] _Conv._ II. v. and vi.\n\n[751] _Par._ viii. 34-37.\n\n[752] _Cf. Par._ xxviii. 98 to end, with _Conv._ II. vi. 43-55,\n106-109.\n\n[753] _Par._ xxviii. 34-39, 64-75.\n------------------------------------------------------------------------\n\nAll these movements are a proof of the existence of a First Mover,\nHimself unmoved, as Aquinas had said, following Aristotle, and the\nfirst words of Dante\u2019s confession of faith in Paradise are an echo of\nthis:\u2014\n\n \u201cIo credo in uno Iddio,\n Solo ed eterno, che tutto il ciel muove,\n Non moto, con amore e con disio.\u201d[754]\n\n------------------------------------------------------------------------\n[754]\n \u201dIn one God I believe,\n Sole and eterne, who moveth all the heavens,\n With love and with desire, Himself unmoved.\u201d\n _Par._ xxiv. 130-132. (_Longfellow_).\n------------------------------------------------------------------------\n\nHere, as often elsewhere, Dante identifies the heavens with their\nMovers, and speaks as if the spheres themselves were moved by love and\nlonging. In the tenth heaven, or Empyrean, this longing was completely\nfulfilled, hence this heaven was for ever at rest.[755]\n\n------------------------------------------------------------------------\n[755] _Conv._ II. iv. 13-30; _Ep._ x. 442-452, and 472-488; _Par._ i.\n121-123.\n------------------------------------------------------------------------\n\n\n\n\n_VIII. MEDI\u00c6VAL AND MODERN VIEWS OF THE UNIVERSE._\n\n\nMEDI\u00c6VAL AND MODERN VIEWS OF THE UNIVERSE.\n\nLet us now gather into one picture the details of medi\u00e6val astronomy\nwhich Dante has taught us, and try to see the universe as it presented\nitself to men\u2019s minds in his days.\n\nMotionless, at the centre of all things, is the earth, a massive globe\n20,400 miles in circumference.[756] Only the northern part of one\nhemisphere is inhabited; the rest is covered by ocean. It is surrounded\nby air, into which rise the exhalations from land and sea which cause\nwinds, rain, etc. Above the height to which these rise, and above the\ntops of the highest mountains, the air sweeps uninterruptedly round the\nearth from east to west, sharing the movement of the skies. Above this\nagain is the region of pure fire: all fire on Earth\u2019s surface tends to\nrise into it, and hot dry vapours ascending here burst into flame, and\nare seen from Earth as shooting stars and comets.\n\n------------------------------------------------------------------------\n[756] Probably equal to 26,500 English statute miles.\n------------------------------------------------------------------------\n\nBounding the sphere of fire is the lowest of the celestial spheres,\nthat of the moon; and here we pass abruptly from the world of the\nfour elements, transitory, changing, to the celestial world, eternal,\nchangeless. Sphere rises above sphere, carrying moon and sun and\nplanets, until we reach the vast orb in which are set all the stars.\n\nAll these bodies are composed of a mysterious imponderable substance\ncalled \u00e6ther; all are perfectly spherical, and all their movements are\ncircular. The diurnal rotation which we see is caused by an outermost\nsphere which contains no star: it communicates its own motion to all\nthe spheres within it. The zodiacal motions of sun, moon, and planets,\nand the precession of the equinoxes, are caused by the proper motion of\neach sphere, rotating from west to east. The oscillating movements of\nthe five planets and the varying speed of the moon are caused by small\nrotating spheres called epicycles, on which planets and moon are fixed,\nthe epicycles in their turn being attached to the large spheres.\n\nThe distance from the earth to the nearest heavenly body, which is the\nmoon, is 64\u215b times the radius of the earth; the distance of the fixed\nstars, more than 20,000 times the radius of Earth.\n\nMercury, the smallest of the heavenly bodies, is only 232 miles in\ndiameter,[757] the moon and Venus are both rather more than a quarter\nthe size of the earth, Mars is a little larger than Earth; next in\norder of size come the stars, from the faintest visible increasing up\nto those of the second magnitude; Saturn and Jupiter are much larger\nthan Earth, and the fifteen brightest (first-magnitude) stars larger\nstill; the sun is the largest body in the whole universe, having a\ndiameter 5\u00bd times Earth\u2019s diameter. It is immensely bright and hot, is\nthe source of light to the whole universe, and on Earth is the chief\ngiver of light, heat, and life, and the chief measure of time.\n\n------------------------------------------------------------------------\n[757] 300 English statute miles.\n------------------------------------------------------------------------\n\nThe moon and stars are also useful in this way to Earth, and upon her\nare poured all the influences of the celestial spheres, the sun, moon,\nand planets: these are the instruments by which every event on Earth is\nbrought to pass.\n\nIt is their nature to move in circles, as it is Earth\u2019s nature to\nremain motionless at the centre of the universe; but all their motions\nare controlled by the wills of immortal angels, which are subject to\nthe Will of the First Mover.\n\nThe sensible universe is eternal, but it is finite and measurable, and\nof definite form,[758] being bounded by a sphere. Beyond this in every\ndirection is infinity.\n\n------------------------------------------------------------------------\n[758] _Conv._ IV. ix. 23-25.\n------------------------------------------------------------------------\n\nSuch was the medi\u00e6val conception of the Universe, as we gather from\nlearned medi\u00e6val books, and as we find it vividly pictured in Dante\u2019s\nglowing verse. How do we conceive it now?\n\nThe heavens are the same to our eyes as to Dante\u2019s. The blue dome of\nthe sky still arches over our heads, and in it we may see the stars\nshine out after the sun has set; we may see Venus making all the orient\nsmile at early dawn, and the light of the moon not yet risen paling the\nstars of Scorpio. We may also see with our bodily eyes what was only\nvisible to the keen eyes of Dante\u2019s mind, the rising sun travelling\nto our left, and the southern stars circling round the southern pole,\nwhile the stars of the north sink below the ocean floor.[759]\n\n------------------------------------------------------------------------\n[759] Compare with Dante\u2019s accurate descriptions a poem by Kipling in\n\u201cA School History of England\u201d:\u2014\n\n \u201cSouth and far south below the line\n Our Admiral leads us on.\n Above, _undreamed-of planets_ shine.\u201d (!)\n------------------------------------------------------------------------\n\nBut to one who knows anything of modern astronomy the ideas suggested\nare widely different. Most striking is the absence of that sharp\ncontrast between Earth and heaven which our forefathers felt. Earth\nis not to us small, dark, and inert, made of the basest material and\nsunk, like the dregs of the Universe, to its lowest depths. Earth is\na heavenly body, as the Pythagoreans rightly guessed, a beautiful big\nplanet, shining brightly by reflected sunlight and moving swiftly, like\nher sister-planets. To Venus she is the brightest star in the sky; to\nthe moon she shows a far larger disc than the moon shows to us, and\nmarkings more beautiful and wonderful, brilliant caps of snow at either\npole, oceans coloured blue-green, and continents varying in tint,\nwhenever the dazzling white clouds part to reveal her surface.\n\nEarth is the largest planet among her neighbours, Mercury, Venus, and\nMars; just as Jupiter is largest among the giant planets\u2014Saturn and the\nmore recently discovered Uranus and Neptune. In the gap between these\ntwo groups modern astronomers have discovered hundreds of tiny planets,\nto which Earth is a monster, for many are only a few miles in diameter.\nThe meteorites which shoot across our view, \u201cstartling quiet eyes,\u201d we\nstill regard as a kind of conflagration in our upper atmosphere, but\ninstead of vapours rising from Earth\u2019s surface we recognise them as\nvisitants from inter-planetary space, caught by Earth\u2019s great mass as\nthey pass too near, and flaming up with the heat caused by their sudden\nrush through the air. They exist in shoals of thousands and millions,\nsome small as pebbles, some like great rocks, but all belonging to\nour system and pursuing definite paths like planets. The same must be\nsaid of comets, which have just as little to do with a hypothetical\nfire-sphere round Earth, but travel in regular periods, some long,\nsome short; several small ones are seen every year, and occasionally a\ngreat splendour like Halley\u2019s draws near to us in its orbit, yet even\nthese seem to consist of very small quantities of matter. Other members\nof our celestial family are the moons of Mars, Jupiter, and the rest,\nof which more are still being discovered. The Earth-Moon system is,\nhowever, unique in that our satellite is much nearer our own size than\nthe proportionately tiny companions of other planets and the pair must\nlook like a beautiful \u201cdouble\u201d moving through the stars and continually\nrevolving round one another.\n\n[Illustration: Fig. 53. Comparative sizes of the Sun and his\nsatellites. _p. 490_]\n\nAll these bodies are made, not of a mysterious ether, but of something\njust as wonderful, beautiful, and incomprehensible\u2014the same stuff as\nEarth. Most probably all developed in long-past ages out of a nebula,\nor mass of gas which for some unknown reason was intensely hot. Small\nbodies, like the Moon and Mars, cooled off the most quickly, and have\nlost or are losing their air and their water; larger bodies, like\nJupiter, have still some heat, and are probably in a more or less fluid\ncondition. On the sun an inconceivable heat still rages; everything is\nin a gaseous state, and this globe which men used to think eternally\nchangeless is the scene of the fiercest turmoil; currents are always\nascending and descending, clouds of fire are flung up thousands of\nmiles high, and patches which look black compared with the surrounding\nsurface and indicate a mysterious commotion are constantly forming,\ndeveloping, and disappearing. The sun is enormously larger than Dante\nthought, larger than all the planets put together, large enough for\nour moon\u2019s whole orbit to fit comfortably inside. It is hot enough\nand brilliant enough to light all the planets: this, which was only\na guess of medi\u00e6val astronomers, we know as a fact to-day, and the\nplanets which are suitably placed show it to us, when seen in the\ntelescope; Venus, for instance, changing her phase \u201caccording as the\nsun looks upon her,\u201d exactly like the moon. And Earth must show similar\nphases as seen from Mars.\n\nFor Aristarchus was right: the sun is the centre of the planetary\nmovements, including those of the planet Earth.\n\nWe saw how Ptolemy\u2019s system hinted at this, in the significant\nconnection between each planet\u2019s movement and the movement of the\nsun; but a strong argument against it was that if Earth were really\nmoving round the sun we ought to see a yearly displacement in the\npositions of all the stars. Modern instruments have at last made it\npossible to perceive this displacement. About a hundred stars, our\nnearest neighbours, describe a very minute orbit in the sky, which in\nevery case is an exact reflection of the sun\u2019s apparent orbit round\nthe earth. Unless, therefore, we are going to provide all these stars,\nas well as the planets, with epicycles, which must all revolve in the\nsame period, in the same direction, and in parallel planes, we must\nconclude that the movement is really Earth\u2019s yearly movement round the\nsun. These miniature star-orbits also show us the stupendous distances\nwhich lie between Earth and the nearest stars, while by far the greater\nnumber are too remote to show any displacement at all.\n\nAristarchus and those other ancient astronomers were also right who\nthought that Earth was turning on her axis, and thus producing by her\nown motion the alternation of day and night, and the apparent circling\nof the stars. When we look now at stars hastening across the sky,\nthey no longer present themselves to our thought as fixed on a sphere\nwith a radius of 20,000 Earth-radii, which is revolving round us at a\ntremendous speed; we feel that we are looking into space at glowing\nglobes which are at various and almost inconceivable distances from\nus; also that all those we see, all those that Hipparchus numbered,\nare but an insignificant fraction of all those now known to exist.\nAll have their own real motions, as well as the apparent motions\nproduced by Earth, but these are in different directions, towards what\ngoal we cannot at present tell. Compared with them, Earth is indeed\ninsignificant, in size and also in brightness, for while she shines\nwith reflected light they glow as the sun does and are his peers.\n\nNevertheless, with them too we have a feeling of kinship, for analysis\nof their light shows that they too are made of earth-stuffs: they are\nnot eternal nor changeless, for very many vary constantly in their\nlight, and they are at different stages of development, some appearing\nvery young, while others are beginning to burn dim and low, and some\ncan only be inferred to exist, for they seem to be wholly dark.\n\nMore wonderful perhaps than anything else, we find that the force\nwhich binds the whole of our sun\u2019s family together is nothing strange\nand unknown, but the same familiar force of gravity, which the Greeks\nknew so well but thought only applicable to Earth. Its rule includes\nthe seemingly unruly comets and meteors, and it extends as far as our\nsearch can reach, to the uttermost star.\n\nThis sense of unity throughout the world, which is always growing\nstronger, is comforting. And we allow ourselves to wonder whether\nintelligent life has not developed elsewhere, as well as on this globe\nthat we inhabit. Perhaps each planet that attends our sun is fitted at\nsome period to be the abode of life: surely among the millions of stars\nmany must have attendant planets, and on some of them even now are\nliving, thinking, beings.\n\nDante\u2019s world was easier to think about than ours. Encompassed by an\ninfinity which gave the imagination free scope, the material universe\nwithin was neatly rounded off, as it were, complete, finished. Only\nin the central spot was any development taking place, and thither\nwere directed all effects of the circling spheres. Our universe is\nvague, vast, mysterious, without known limits or centre, offering\nproblem after problem to the thinker. Dante\u2019s marvellous moon-substance\nis simple compared with the baffling nature of our \u00e6ther; Dante\u2019s\nAngel-Movers are intelligible compared with the amazing mystery of\nuniversal gravitation.\n\nYet when we lift our eyes from earth to heaven, we share the feeling\nof our medi\u00e6val forefathers, of the ancient Greeks, of the earliest\nmen whenever and wherever they became men. The unerring courses of\nthe stars speak to us, \u201cthe unperturbed to the perturbed,\u201d of perfect\nharmony, untouched by chance or arbitary conflicting wills. Now,\nhowever, we do not believe this is because heaven is essentially\ndifferent from earth: it is because we see there only the grand\noutlines, only the working of great laws, of a system which includes\nour own earth. Could we but lose sight of the details here, and view\nthe history of man as we view the stars, the harmony would be as grand.\n\n\nHYMN TO ZEUS.\n\n Most glorious of the Immortals, many-named, Almighty for ever,\n Zeus, Ruler of Nature, that governest all things with law,\n Hail! for lawful it is that all mortals should address thee.\n For we are thy offspring, taking the image only of thy voice,\n as many mortal things as live and move upon the earth.\n Therefore will I hymn thee, and sing thy might for ever.\n For thee doth all this universe that circles round the earth\n obey, moving whithersoever thou leadest, and is gladly swayed\n by thee.\n Such a minister hast thou in thine invincible hands\u2014the\n two-edged, blazing, imperishable thunderbolt.\n For under its stroke all nature shuddereth, and by it thou\n guidest aright the universal Reason, that roams through\n all things, mingling itself with the greater and lesser\n lights, till it has grown so great, and become supreme\n king of all.\n Nor is aught done on the earth without thee, O God, nor in\n the divine sphere of the heavens, nor in the sea,\n Save the works that evil men do in their folly.\n Yea, but thou knowest even to find a place for superfluous\n things, and to order that which is disorderly, and things\n not dear to men are dear to thee.\n Thou dost harmonize into one all good and evil things, that\n there should be one everlasting Reason of them all.\n And this the evil among mortal men avoid and heed not\n wretched, ever desiring to possess the good; yet they\n nor see nor hear the Universal Law of God, which,\n obeying with all their heart, their life would be well.\n But they rush graceless each to his own aim,\n Some cherishing lust for fame, the nurse of evil strife,\n Some bent on monstrous gain,\n Some turned to folly and the sweet works of the flesh,\n Hastening indeed to bring the very contrary of these things to pass.\n But thou, O Zeus, the all-giver, dweller in the darkness of cloud,\n lord of thunder, save thou men from their unhappy folly,\n Which do thou, O Father, scatter from their souls, and give them to\n discover the wisdom, in whose assurance thou governest all\n things with justice;\n So that, being honoured, they may pay thee honour,\n Hymning thy works continually, as it beseems a mortal man,\n Since there can be no greater glory for men or gods than this,\n Duly to praise for ever the Universal Law.\n CLEANTHES (3rd century B.C.).\n _Translation by T. W. Rolleston._\n\n\n\n\nINDEX.\n\n(Pages 1 to 206 are in Part I.: 207 onwards, in Part II.)\n\n Abrachis (Hipparchus), 193\n Abul Hazan, 184\n Abul Wefa, 183, 194\n \u201cAcerba,\u201d 227, 243\n Achernar, 12, 155, 156, 295\n Achilles, Shield of, 53\n Adam, 349, 438\n Albategnius, 183, 193, 202, 239, 275\n Albertus Magnus, 204, 232, 237, 239, 241, 292,\n 306, 324, 342, 432, 443, 454\n \u201d and meteors, 319\n Albert of Saxony, 464, _n._465\n Al Betrugi (Alpetragius), 184\n Albumassar, 239, 245, 443, 473\n Alchabicius, 202\n Alchemy, 212-13, 215\n Aldebaran, 155, 156\n Alexander the Great, 79, 80, 112, 145\n Alexandria, 113, 118, 122, 134, 135, 156, 157, 172\n \u201d Astronomers of, 122, 124, 137, 153, 163, 171, 175, 288\n \u201d Museum and observatory of, 113, 114, 116, 117, 122, 135\n \u201d School of, 112 _et seq._, 163\n Alfarcatein, 187, 234\n Alfonso X., 195, 203, 242\n Alfraganus, 183, 233-37, 243\n \u201d editions of, 235, 437, _n._458\n \u201d geography of, 337\n \u201d writings of, 184 _et seq._, 193-4\n \u201d and climates, 324, 397\n \u201d \u201d colure, 403\n \u201d \u201d Dante, 253, 254, 273, 275, 286, 288-90, 299, 313,\n 315, 328, 335, 347, 403, _n._403, 436-37,\n 444, 448-51, 458-9\n \u201d and eclipses, 338\n \u201d \u201d meteors, 320\n \u201d \u201d moon, 349, 448-49\n \u201d \u201d precession, 288, 439\n \u201d \u201d Regulus, 406\n \u201d \u201d Ristoro, 245-47\n Algazel, 245\n Almagest, 114, _n._115, 123, 136, 154, 159,\n 163, 182, 184, 193, 209, 218, 232, 238\n \u201d translations of, 201-2\n Al Mamun, 182, 185, 186, 192\n \u2018Almanach Dantis Aligherii,\u2019 421-23\n Al Mansur, 181\n Alpha Draconis, 127\n \u201d Centauri, 155, 191\n \u201d Ph\u0153nicis, 156\n Amerigo Vespucci, 294\n Anaxagoras, 60, 61, 76, 98, 239, 305\n Anaximander, 26, 56, 66, 75, 76, 91, 99\n Anaximenes, 60, 98\n Andrea Corsali, 294\n Angelitti, Prof., 281, 410, 415, 417, 423\n Angels, 249, 284, 302, 311, 388, 414-15, 441, 477, 482-84, 489, 494\n Angelo de Gubernatis, _n._399\n Anomaly, of planets, 140, 143\n Ant\u00e6us, 371\n Antares, 30\n Antichthon, 71, 75, 101, 236\n Antipodes, 66, 176, 324\n Antonelli, _n._295\n Apogee, 119;\n of moon, 148, 449, 450;\n of sun, 146, 193\n Apollonius, 118, 141\n Aquarius, 33, _n._36, 145, 149, 156, 277, 290, 385\n Aquila, 12\n Aquinas, St. Thomas, 201, 204 _et seq._, 211, 237, 238,\n 241, 306, 339, 454, 479, 483, 484\n Arabs (_see also Mahomedan_)\n \u201d astronomers, 218;\n year, 39;\n zodiac, 30\n \u201d and astrology, 213;\n astronomy, 181 _et seq._\n Aratus, 25 _Note_, 31, 32, 34, 35, _n._35, 58, 168\n Archimedes, 107\n Arcturus, 36, 52, 155, 190, 191\n Arculf, 176\n Argo, _n._36\n Aries (_see also Ram_), 40, _n._43, 265, 279, 281, 290,\n 325, 356, 368, 373, 374, 387, 398, _n._399\n \u201d first point of, 129, 185, 277, 357, 403, 404\n \u201d and astrology, 249\n \u201d \u201d Jupiter, 418\n \u201d \u201d Mars, 476\n \u201d \u201d Sun, 277, 278, 281, 323, 325, 333, 367, 368, 383, 396,\n 398, 402-5, 418, 419, 422, 473\n Aristarchus, 107 _et seq._, 111, 120, 121, 153, 191, 492\n Aristophanes, 162\n Aristotle, 58, 66, 95 _et seq._\n \u201d cosmogony of, 101-02, 103 _et seq._, 123, 160, 201, 204\n \u201d influence on science, 80, 136, 182, 184, 193\n \u201d translations of, 214, 237\n \u201d and Arabs, 184\n \u201d \u201d Averro\u00ebs, 463\n \u201d \u201d Calippus, 95, 107\n \u201d \u201d the Galaxy, 237, 305, 306\n \u201d \u201d Dante, 235-38, 241, 254-55, 261, 301, _n._321, 342,\n 431, 442, 451, 454, 464-65, 480-84\n \u201d \u201d gravity, 445\n \u201d \u201d Latin authors, 170\n \u201d \u201d Mars, 310, 433\n \u201d \u201d meteors, 319, 321\n \u201d \u201d music of the spheres, 455\n \u201d \u201d Plato, 85\n \u201d \u201d southern hemisphere, 353\n \u201d \u201d spheres 431, 432, 434, 461\n Aruns, 472\n Aryabhata, 110-11\n Arym, 247, 329\n Arzachel, 184, 195\n Asdente, 212, 472\n Assisi, St. Francis of, 271\n Astrolabe, 114, 115, 122, 144, 192, 202, 203, 341\n \u201d invention of, 115, 133\n Astrologers, 213, 231, 369, 419, 469, 476\n \u201d of Brescia, 211;\n 13th century, 216\n Astrology (_see also Star Influence_, and _Astronomy, Judicial_),\n 6, 45, 47, 157, 161, 172, 211 _et seq._, 218,\n 243, 245, 249, 308, 471, 476, 478-9\n \u201d Arab, 183, 200, 213\n \u201d books on, 202-3\n \u201d Egyptian, 113, 157\n \u201d Jewish, 213\n \u201d professors of, 200\n \u201d and planets, 211\n Astronomy, Alexandrian, 112 _et seq._, 218, 231, 288, 335\n \u201d Arab, 181 _et seq._, 190, 204, 232, 239, 243, 245, 461-3\n \u201d Babylonian, 40 _et seq._, 209, 421 (_see also Babylonians_)\n \u201d Chinese, 29 _et seq._, 115\n \u201d Egyptian, 209 (_see also Egyptians_)\n \u201d Greek, 209, 236, 314, 445, 461 (_see also Greeks_)\n \u201d Indian (_see Hindu, and India_)\n \u201d judicial, 124, 213, 233, 261 (_see also Astrology_)\n \u201d Moorish, _n._200, 203\n \u201d Persian, 195\n \u201d primitive of, 25 _et seq._\n \u201d in Spain, 183, 194\n \u201d taught by Church, 176\n \u201d personified, 217\n \u201d and Dante, 1\n Atlas, 98;\n Mt. Atlas, 53\n Augustine, St., 175, 238, 239, 479\n Augustus, Emperor, 171, 175, 319, 359\n Auriga (Charioteer), 144\n Averro\u00ebs, 184, 204, 232, 239, 246, 342, 432, 462\n Avicenna, 202, 239, 247, 305\n\n Babylon, 69, 80, 156, 181\n Babylonia, 18, 36, 81\n Babylonians, 36-38;\n astronomers, 110, 125, 127, 144, 161\n \u201d and astronomy, 43-4\n \u201d \u201d calendar, 40 _et seq._\n \u201d \u201d cosmogony, 45, 46, 47, 48, 55, 57\n \u201d \u201d day division, 27\n \u201d \u201d eclipse records, 80, 81, 144\n \u201d \u201d gnomon, 26\n \u201d \u201d occultations of planets, 105\n Bacon, Roger, 202, 249, 275, 292, 342, 343\n Baghdad, 141-3, 181 _et seq._, 245, 432\n \u201d astronomers, 194-5\n \u201d observatory, 142 (_see also Arab Astronomers_)\n Bartolommeo della Scala, 226, 227\n Bear: Great, 12, 25, 36, 52, 56, 157, 187, 297-8, 334;\n Little, 25, 56, 187, 297-98, 334\n (_see also Ursa Major and Minor_)\n Beatrice, 1, 253, 237, 284, 376, 390, 392, 394, 401, 441, 455, 473\n \u201d age of, 253, 288, 413-4\n \u201d death of, 224, 253, 254, 314, 316, 414\n \u201d Dante\u2019s first meeting with, 253, 272, 273\n \u201d guiding Dante, 262, 330, 367, 373, 392, 393, 400, 401\n \u201d and Moon, 462, 475\n \u201d \u201d Sun, 271, 392\n Beazley, _n._342, _n._384\n Bede, 178, 250, 454\n Belacqua, 376\n Benet Naax, 187, 234\n Benevento, 242\n Benvenuto da Imola, 383, 418\n Betelgeux, 155\n Boccaccio, 224, 225, 228, 231, 274, 413, 414, 418, 422\n Bo\u00ebthius, 1, 177, 284, 296\n Boffito, Prof., 423\n Bologna, 199 _et seq._, 227, 277 (_see also Universities_)\n Bo\u00f6tes, 52, 284, 298\n Borneo, natives of, and gnomon, 26\n British Astronomical Association, Journal of, _n._29, _n._34\n \u201d Museum, 36, 40\n Brown, Robert, 24 _Note_, 32, _n._34, 35, 156\n Brunetto Latini, 218, 225-6, 241-2, 248-9, 274-5, 292, _n._349,\n 369, 414, 470, 473, 481\n Bull, _see Taurus_\n\n Cacciaguida, 3, 313\n Calendar, 29, 36, 47;\n Ancient, 33, 34\n \u201d Arab, 39, 184\n \u201d Babylonian, 40, 41, 127\n \u201d Berber, Persian, Syrian, 184\n \u201d Chinese, 39\n \u201d Ecclesiastical, 176, 203\n \u201d Egyptian, 39, 184\n \u201d Greek, 161, 162, _n._172\n \u201d Hindu and Parsee, 127\n \u201d Julian, and Roman, 171, 176, 184, 274 _et seq._\n \u201d luni-solar, 176\n \u201d Mahomedan, 39\n Calippus, 93, 107, 145, 162;\n cycle, 172\n Callisthenes, 80\n Campaldino, 224\n Cancer, 145, 174, 185, 269, 277, 280-2, 325, 394, 397\n Can Grande della Scala, 416, 426, 441, 473\n Canopus, 12, 67, 134, 155, 295\n Canton, 27\n Capella (star), 155\n \u201d Martianus, 170, 177\n Capricornus, 33, 43, 144, 185, 277, 282, 325, 342, 360, 374\n Carnac, 29\n Casella, 374, 414, 426\n Cassiodorus, 177\n Cassiopeia, 12\n Castor and Pollux, 43, 290, 333\n Catalano, Friar, 227\n Cato, 373-4\n Cecco d\u2019 Ascoli, 200, 216, 226, _n._227, 241-4, 249, 478\n Celestial Movements, 9-20, 25, 28, 29, 38, 47, 56, 62, 65, 86,\n 102-3, 105, 136 _et seq._, 159, 174,\n 209, 248, 261-4, 299, 357, 367, 409, 429,\n 430, 432, 438, 457, 483, 487\n \u201d direct, 16, 147\n \u201d and Alfraganus, 185 _et seq._\n \u201d \u201d astrology, 211\n \u201d \u201d Brunetto Latini, 243\n \u201d \u201d tables of, 22, 23\n \u201d \u201d daily, 13\n \u201d \u201d retrograde, 16, 18, 44, 116, 147\n Centaur, _n._36, 294;\n Alpha Centauri, 155\n Central Fire, 75, 85, 101, 102, 109, 159\n Cetus, _n._36\n Chalcidius, 238\n Chaldea, 172\n Charioteer, _see Auriga_\n Charlemagne, 178, 182\n Charles of Hungary, 256\n Charles of Valois, 318\n Chinese, and comets, 45;\n gnomon, 20, 114;\n year, 38;\n zodiac, 29, 31\n China, 291, 343\n Christian Era, Introduction of, 177\n Church, Catholic, 210, 216, 219, 335, 346-8, 410,\n 419, 431, 432, 480, 483;\n and spheres, 433\n Cicero, 1, 109, 167-8, 171, 217, 237-9\n Cleanthes, 496\n Cleomedes, 135, 457\n Clepsydra, 27, 115, 122, 133, 141\n Climates, 158, 186, 187, 247-8, 324, 347, 397\n Clocks, pendulum, 16;\n water, 27, 115 (_see also Clepsydra_)\n Colure, 185, 403\n Comets, 45, 66, 103, 174, 175, 176, 262,\n 318 _et seq._, 487, 490, 491\n \u201cComposizione del Mondo,\u201d 244 _et seq._, 292\n Conjunction, 24, 142, 191\n \u201cConsolations of Philosophy,\u201d 1\n Constantine, 262\n Constantinople, 201\n Constellations, 454;\n ancient, 33, 34, 80\n \u201d Arab, 30, 188, 234\n \u201d Egyptian, 34;\n Hebrew, 34;\n Hindu, 30\n \u201d figures of, 115, 154-55, 168, 246, 248, 289, 443, 451\n \u201d influences of, 246, 451\n \u201d naming and origins of, 24 _Note_, 32, 33, 36, 47,\n 51, 80, 161\n \u201d southern, 246\n \u201d and Astrology, 211\n \u201cConvivio,\u201d 255, 258, 357, 464, 466, 468, 476\n Copernicus, 66, 111, 136, 210\n Cordova, 183\n Corona Borealis, 299\n Corsica, 344, 383, 384\n Corvino, 293, 343\n Corvus, _n._36\n Cosmas Indicopleustes, 175\n Cosmogonies, Ancient, 45, 63, 160;\n Babylonian, 45, 53, 57;\n Egyptian, 45, 53, 83, 109;\n Hebrew, 45, 47;\n Hindu, 45;\n Homeric, 53 do. of Anaximander 58-59;\n Aristotle, 103;\n Cosmas, 175;\n Democritus, 63;\n Eudoxus, 88;\n Leucippus, 63;\n Philolaus, 70;\n Plato, 83;\n Ptolemy, 150;\n Pythagorean, 66-75;\n Thales, 55, 56\n Coulton, _n._212\n Creation, 403, 411, 419\n Crystal Spheres, 74, 159 (_see also Spheres_)\n Cunizza, 415, 426, 472\n Cycles, 45, 55\n Cyprus, 102\n\n Dante, birth of, 211, 273, 413, 426;\n childhood, 223;\n as Councillor, 224, 414;\n as Prior, 224;\n in exile, 224;\n in Ravenna, 224, 273;\n in Mantua, 444;\n in Rome, 224, 318;\n in Verona, 256, 444;\n death, 165, 216, 224, 273\n \u201d studies, 223 _et seq._;\n quoted, 25\n \u201d shadow of, in Purgatory, 374, 387-8\n \u201d wife of, 224-5\n \u201d and Alfraganus, 234, 254, 289, 449;\n Asdente, 212\n \u201d \u201d Aristotle, 96, 102, 105, 235, 241, 254, 480, 482\n \u201d \u201d ancient writers, 57, 62, 70, 82, 86\n \u201d \u201d astrology, 261;\n and astronomy, 25\n \u201d \u201d Brunetto Latini, 225, 226, 242\n \u201d \u201d Beatrice, 1, 273\n \u201d \u201d calendar, 274, 275\n \u201d \u201d Date of Vision, 357, 409 _et seq._\n \u201d \u201d Classical authors, 237 _et seq._\n \u201d \u201d Frederick II., 214\n \u201d \u201d Greek astronomy, 105, 262, 306\n \u201d \u201d philosophers, 461\n \u201d \u201d Homer, 209\n \u201d \u201d geography, 337, 339 _et seq._\n \u201d \u201d Jerusalem, 176\n \u201d \u201d Michael Scot, 215\n \u201d \u201d Milton, 210\n \u201d \u201d Moon, 265 _et seq._\n \u201d \u201d music of the Spheres, 455-6\n \u201d \u201d precession, 274 _et seq._, 439\n \u201d \u201d Philosophy, 255\n \u201d \u201d Ptolemy, 135, 154, 209, 232, 256, 458-9, 468\n \u201d \u201d Roman Empire, 167, 178\n \u201d \u201d science, 1, 219, 258\n \u201d \u201d the Acerba, 244\n \u201d \u201d stars, 283 _et seq._\n \u201d \u201d southern stars, 293-5\n \u201d \u201d universities, 226 _et seq._\n \u201cDante e gli Astronomi Italiani,\u201d _n._235, _n._315\n Day, Arab, 253;\n definitions of, 14, 22, 25, 26;\n divisions of, 52, 161;\n length of, 186;\n sidereal, 12,\n definition of, 22;\n solar, 12;\n Church, 348\n Decimal Notation, introduced, 182\n Declination, definition of, 126\n \u201cDe C\u0153lo\u201d (\u201cOn the Heavens\u201d), of Aristotle, 96, _n._96, 105,\n 170, _n._232, 236, 431, 464\n translations of, 214\n \u201cDe C\u0153lo\u201d of Albertus Magnus, _n._232, 342\n Deferent, definition of, 138; 145, _n._149, 193\n Degrees, invention of, 44\n Delambre, _n._35, _n._126, 149, 156, _n._460\n Della Lana, Jacopo, 418\n Della Valle, _n._398\n Del Virgilio, 227\n Democritus, 64 _et seq._, 98, 239, 305\n Denebola, 155\n \u201cDe Substantia Orbis,\u201d 184\n Dicuil, 178\n Dilgan, 40, 42, 127\n Dionysius Exiguus, 177\n \u201d the Academician, 239\n \u201d \u201d Areopagite, 483\n Direct Motion, 16\n Divine Comedy, 237-8, 353, 402, 409\n Dominicans, 204, 241\n Domitian, 171\n Dream of Scipio, 109, 169, 237\n Dreyer, _n._460\n Dupuis, 34\n\n Earth, 393, 395, 398-401, 490, 491\n \u201d centre of, 353, 372, 424, 481\n \u201d \u201d of universe, 66, 75, 83, 84, 85, 88, 91, 96, 98, 99,\n 100, 109, 112, 120, 137, 160, 169, 185,\n 203, 205, 209, 219, 431, 444, 461, 489\n \u201d Counter-, _see_ Antichthon\n \u201d dimensions of, 71, 102, 117, 118, 134, 157, 160, 169,\n 182, 185, 186, 190, 216, 458, 487, 490\n \u201d distance from sun, 108, 189\n \u201d form of, 56, 59, 63, 66, 67-8, 71, 72, 83, 91,\n 96, 98, 100, 160, 175, 185, 186\n \u201d habitable part, 205, 247, 248, 335, 342, 353, 369, 372,\n 391, 397, 398, 436, 444, 446, 451, 487\n \u201d in equilibrium, 100\n \u201d measurement of, 103, 117, 134\n \u201d motion of, 17, 66, 70, 71, 85, 88, 99, 101, 142, 186;\n \u201d movement of, 431, 438\n \u201d resting on air, 63;\n on water, 56, 98\n \u201d revolution round sun, 13, 66, 107, 109, 110, 120,\n 146, 159, 210, 256, 492\n \u201d rotation on axis, 13, 72, 75, 85, 88, 101, 108,\n 110, 136, 159, 210, 492\n \u201d shadow of, 67, 96, 191, 346, 459, 460\n \u201d spherical form of (_see also_ form of earth), 102, 209, 219,\n 237, 487\n Earthly Paradise, _see_ Eden\n Easter, 176, 177, 203, 275, 405, 418, 420, 422, 424\n \u201d year, 415\n Ebn Jounis, 183\n Eccentrics, 118, 119, 121, 141 _et seq._, 193, 210, 235\n Eclipses, 18, 55, 57, 67, _n._76, 117, 168, 174, 175,\n 192, 203, 262, 255 _et seq._, 266, 465\n \u201d annular, 44\n \u201d Babylonian records, 80, 96, 113, 144\n \u201d lunar, 44, 45, 55, 67, 125, 185, 338, 340, 341, 469\n \u201d solar, 245, 338\n Ecliptic, 18, 55, 117, 126, 129, 130, 145, 147, 185, 279,\n 312, 325, 330, 331, 333, 397, 403, 404, 476\n Ecphantus, 75, 102\n Eden, 205, 295, 296, 334, 349, 353, 394, 401, 453, 454\n \u201d Richard, 299\n \u2018Egyptian System,\u2019 109, 120\n \u201d year, 38, 45\n Egyptians (_also_ Egypt), 27, 28, 36, 45, 67\n \u201d astronomers, 55, 56, 105, 124, 125, 144\n \u201d astrology, 113, 120, 156\n \u201d astronomy, 34, 45, 46, 51, 80, 113, 184\n \u201d cosmogony, 45, 53, 55\n \u201d and Eudoxus, 66, 88, 100, 151\n \u201d \u201d Pythagoras, 67\n \u201d \u201d eclipses, 45\n \u2018Elementa Astronomica,\u2019 184, 234, 253, 273, 313, 320, 347\n \u201d translations of, 234\n Elements, The Four, 62, 83, 103, 236, 441 _et seq._, 461, 478\n \u201d \u201d creation of, 441\n \u201d \u201d and Aristotle, 236, 442\n Ellipse, _n._94\n Elongation, Greatest, E. and W., 142;\n definition of, 15\n Empedocles, 60, 62, 98, 369\n Empyrean, 204, _n._232, 253, 296, 313, 353, 393, 401,\n 433, 440, 444, 462, 447, 484\n Epicycles, def. of, 138 _et seq._, 121, _n._149, 187, 193, 194,\n 210, 235, 256, 314, 429, 435, 449, 457, 466, 483, 488, 492\n \u201d of Venus, 142, 435\n Epping and Strassmeier, _n._36\n Equator (celestial), 10 _et seq._, 18, 35, _n._35, 65, 115,\n 126, 130, 185, 323, 330, 334, 368, 383, 392,\n 397, 403, 404, 439, 448, 476\n \u201d terrestrial, 238, 246, 247, 322, 324, 329, 336, 337, 342\n Equinox, 30, 124, 126, 274, 278, 282, 326, 330, 334, 340, 347,\n 348, 349, 354, 356, 368, 372, 383, 387, 392, 402-7,\n 410, 418, 420-3\n \u201d date of, 26, 176, 177, 185\n \u201d definition of, 12\n \u201d observation of, 39, 94, 116, 124, 125\n \u201d position of, _n._44, 185\n \u201d precession of, 23, 24, 35, 125, 133, 135, 137, 161, 193, 194,\n 232, 275, 287, 356, 384, 432, 435, 439, 483, 488\n \u201d and Alfraganus, 439\n Eratosthenes, 117, 134, 240\n Eridanus, (\u201cThe River\u201d) _n._35, _n._36, 155, 156\n Eridu, 46\n Esdras, 342\n Ether, 104, 110, 137, 159, 193, 433, 461, 466, 480, 488, 491\n Ethiopia, 336;\n Ethiopians, 53\n Euclid, 118, 202\n Euctemon, 93, 161\n Eudoxus, 66 _et seq._, 34, 80, 235;\n spheres of, 90, 106, 107, 109, 112, 113,\n 118, 123, 141, 159, 161, 170\n \u201d and Calippus, 93, 94;\n and Egypt, 80, 100, 159;\n and Plato, 81, 88, 159\n Eunoe, 366, 390, 392\n Evection, 147\n\n Farinata, 413, 417\n Fergil, 178\n Filelfo, 471\n Fire;\n Central, 431;\n sphere or region of, 58, 308, 442, 480, 487\n First Mover, 106, 159, 204, 254, 444, 478, 483, 484, 489\n Fishes (_see_ Pisces)\n Florence, 1, 158, 201, 211, 215, 216, 224, 225, 226, 242, 283,\n 318, 345, 350, 406, 411-14, 417, 421, 471\n Folco, 346, 459, 472\n Fomalhaut, 155, 156\n Forese, 367\n Forest, The, 266, 358, 367, 369, 378, 386, 406\n Francis, St., 271\n Frederick II., 202, 213 _et seq._\n\n Gades, 340, 345, 366, 395, 397\n Galaxy, 61, 103, 115, 154, 168, 232, 239,\n 301, 303 _et seq._, 477\n Galileo, 107, 210\n Gallus, Sulpicius, 167\n Ganges, 205, 340-5, 360, 365, 388, 397, 400\n Gardner, E. G., 228\n Gemini (_see also_ Twins), 43, 44, 145, 149, 273, 280-1, 290,\n 333, 366, 387, 393, 394, 397, _n._399, 404, 461, 473\n Geminus, _n._93, 134\n Genoa, 293\n Geography, 240, 344;\n Arab, 246, 247;\n Alfraganus\u2019, 186;\n Ptolemy\u2019s, 146, 157, 186\n Geryon, 369\n Ghibellines, 213, 227\n Giambullari, 419\n Giuliani, 280\n Gnomon, defined, 13, 26, 28, 47, 56, 114, 116, 122, 125, 161\n \u201d introduced into Greece, 26\n \u201d and Babylonians, 26;\n Chinese, 29, 114;\n Borneo, 26\n Goat, _see_ Capricorn\n Golius, 235\n Good Friday, 423-26\n Gravity, 100, 137, 160, 169, 191, 237, 445, 447, 482, 493\n Greek Astronomers and Astronomy, 27, 28, 36, 51 _et seq._, 112,\n 159, 168, 171, 172, 176, 178, 200, 204, 433, 446, 463, 495\n Gruppe, _n._76\n Guelfs, 413\n Guido Bonatti, 213, 472\n Guido Cavalcanti, 416, 426\n Guido of Montefeltro, 213\n\n Hades, 54\n Hammurabi, 40\n Haroun al Raschid, 182\n He, and Ho, Chinese astronomers, 30\n Heath, _n._75-76\n Heaven, eighth, 366, 402, 475\n \u201d fourth, 284\n \u201d ninth, 233\n \u201d seventh, 284, 455\n \u201d third, 429, 483\n \u201d of fire, 58 (_see also_ fire)\n \u201d of Jupiter, 393\n \u201d of Mars, 303, 313, 393\n \u201d of Mercury, 332, 441\n \u201d of the Moon, 392, 431, 447, 455, 484\n \u201d of Saturn, 301, 393, 407\n \u201d of Stars, 288, 304, 393\n \u201d of the Sun, 240, 256, 272, 373, 381, 431\n \u201d of Venus, 256, 393, 429, 435, 459, 483\n Heavens (_see also_ Star sphere), 58, 59, 67, 91, 209, 253,\n 254, 256, 262, 300, 393, 429, 431, 435, 484, 447\n \u201d influence of, 266\n \u201d revolution of, 9, 18, 20, 51, 57, 62, 63, 70, 74, 75, 82, 85,\n 88, 98, 102, 104, 108, 124, 136, 137, 185\n (_see also_ Celestial motions)\n Hebrew cosmogony, 46, 57;\n year, 39\n Heinrich of Mainz, 343, 384\n Heliacal rising, 39, 40, 44, 45, 52, 191\n Hell, 205, 353, 358, 367 to 371, 390, 423\n Hemisphere, Southern, 286, 322, 329, 330, 334, 336,\n 339, 353, 407, 443, 447\n Henry VII., Emperor, 271\n Heracleides, 74, 75, 102, 109\n Hercules, Pillars of, 34, 54, 103, 205, 340, 344, 345\n Herodotus, 55\n Hesiod, 51, 52, 161\n Hesperus, 52\n Hicetas, 74, 75\n Hindu arithmetic, 182;\n astronomy, 181;\n calendar, 127;\n constellations, 30;\n cosmogony, 45;\n zodiac, 30\n Hindus and eclipses, 45\n Hipparchus, 50, 122 _et seq._, 138, 143, 153, 189,\n 191, 193, 233, 240, 275, 287, 288, 432, 493\n \u201d Star Catalogue of, 123, 144, _n._188\n \u201d and Ptolemy, 133-5, 137, 143, 158\n Homer, 34, 51, 52, 72\n Horoscope, 173, 174, 201, 203, 216, 226\n Hose, Dr., 27\n Hours, Church, 347, 348;\n \u201cEqual,\u201d 27, 347, 356;\n \u201cTemporary,\u201d 27, 347, 356\n Hyades, 43, 44\n Hypatia, 163\n\n Imbriani, _n._227, _n._414\n India (_see also_ Hindu), 103, 111, 181, 339, 343\n Inferno, 283, 307, 367 _et seq._, 409-10\n \u201d and Brunetto Latini, 226\n \u201d \u201d Michael Scot, 214\n Instruments, astronomical, 13, 113, 133, 135, 182, 203, 218\n Intelligences, 249, 483\n Isaiah, 34, 175\n Isidore, 178, 243, 250\n\n Japanese, 38\n Jerusalem, 157, 333, 339, 340, 345, 360, 373,\n 374, 388, 395, 397, 400, 401;\n centre of earth, 176, 341, 343, 344, 353, 369;\n latitude of, 387, 406\n Jews, 25, 213, 216;\n astrologer, 202;\n astronomers, 203, 421\n Job, 34\n Johannes Hispalensis, _n._235\n Jowett, _n._82\n Jubilee year (1300 A.D.), 415\n Julius C\u00e6sar, 170, 175, 274\n Jupiter, 16, 120, 141, 145, 150, 169, 189,\n 310, 311, 407, 418, 451, 491\n \u201d colour, 17, 311, 467, 473, 477;\n dimensions, 488, 490\n \u201d period, 23, 69, 91, 109, 142, 436, 437\n \u201d and astrology, 174, 243, 468, 473, 476, 477\n Justinian, 300\n\n Kepler, _n._94\n King, L. W., _n._37\n Knobel, _n._30\n Kugler, _n._35\n\n Leo, 31, 43, 144, 155, 174, 290, 313, _n._399, 406,\n 407, 410, 411, 418, 420, 422, 423, 473, 476\n Lethe, 390\n Leucippus, 62, 63\n Libra, 31, 185, 265, 278, 325, 365, 378, 380, 388\n \u201d and moon, 367, 379, 383, 384, 402, 406, 418\n \u201d and sun, 278, 323, 382\n Ligni\u00e8res, De, Canons of, 202\n \u201cLibros de Saber,\u201d 195\n Lion, _see_ Leo\n Lionardo Bruni, 223, 225, 236, 413\n Livy, 238\n Lockyer, Sir Norman, 29, 155\n Lodestone (_see also_ magnet), 211, 291\n Longfellow, _n._393\n Longitude, 338, 339\n Lucifer, 371, 372\n Lubin, _n._236, _n._315\n Lucan, 238, 239, 324, _n._330\n Lucia (imaginary city), 323-27\n \u201d the lady, 380\n\n Macrobius, 109\n Magnet (_see also_ lodestone), 211, 291, 292, 443, 451\n Mahaffy, _n._113\n Mahomedans, 39, 209, 216\n Malacoda, 370, _n._370, 410-12, 426\n Malaspina, 278, 279, 473\n Manfred, 242, 318, 376\n Manilius, 168\n Maps, 205, 343, 344, 384;\n climate maps, 247, 248;\n Greek maps, 247\n Marco Lombardo, 479\n Marco Polo, 293, 342\n Mars, 3, 16, 17, 23, 69, 90, 93, 109, 112, 118, 120, 138,\n 150, 169, 173, 189, 248, 310, 321, 411, 418, 420,\n 451, 467, 468, 476, 488, 490\n \u201d colour of, 17;\n dimensions, 488\n \u201d period, 436\n \u201d occultation of, 105, 310, 433\n \u201d sphere of, 477\n \u201d and astrology, 174, 243, 473, 477\n Mathematics, 79, 81, 105, 107, 121, 135, 151, 184, 203\n Matilda, 453\n Maunder, E. W., 24 Note, 35, 127\n Mediterranean, 395, 398\n Mercury, 15, 16, 23, 69, 70, 91, 93, 109, 121, 142\n _et seq._, 144, 169, 189, 245, 249, 309\n _et seq._, 407, 418, 451, 467, 490\n \u201d diameter, 236;\n dimensions, 458, 477, 488;\n period, 436\n \u201d and astrology, 173\n Meridian, 22, 26, 280, 338, 346, 349, 361, 365, 368,\n 371,387, 390, 394-7, _n._398, 439\n Meroe, 118\n Meteors, 61, 174, 239, 318, 319, 473, 476, 493;\n meteorites, 490\n Meteorology, 236\n Meton, 93, 145, 161, 162, 172, 177, 419\n Michael Scot, 213 _et seq._, 237, 306, 472\n Milky Way, _see_ Galaxy\n Milton, 66, 210, 420, 456\n Mimnermus, 53\n Montaperti, 242, 413\n Month, Babylonian, 41;\n Egyptian, 144;\n Roman, 253;\n Syrian, 253\n \u201d defined, 22, 30\n \u201d anomalistic, 23;\n intercalary, 38, 170;\n sidereal, 22, 30\n \u201d names of, 171\n \u201d synodic, 15, 20, 30, 52, 162, 163\n \u201d and moon, 266, 350, 436\n Moon, 308, 402, 406, 407, 418, 419, 456, 469, 491\n \u201d apogee of, 449\n \u201d distance, 105, 108, 148 _et seq._, 150, 152, 160,\n 189 _et seq._, 488\n \u201d dimensions of, 56, 114, 152 _et seq._, 160,\n 188 _et seq._\n \u201d ecclesiastical, 419-422\n \u201d eclipses, 55\n \u201d epicycle, 449\n \u201d god, 37\n \u201d influence of, 237, 266, 450, 473, 489\n \u201d inhabited, 71\n \u201d mansions of, 30\n \u201d markings on, 61, 231, 248, 266, 269, 392, 393,\n 462 _et seq._, 469, 476\n \u201d movements of, 13, 14, 18, 29, 100, 105, 114, 117,\n 146 _et seq._, 219, 257, 264, 265,\n 339, 350, 383, 402 _et seq._\n \u201d orbit, 256\n \u201d perigee of, 448, 449\n \u201d nodes of, 147\n \u201d periods:\u2014sidereal, 264, 436, 437;\n synodic, 437\n \u201d phases of, 14, _n._76, 191, 264, 266, 469, 476;\n full, 14, 264, 266, 367, 386, 371, 406, 410, 411, 419, 423;\n gibbous, 264, 266;\n half, 108, 446;\n new, 14, 29, 40, 52, 264\n \u201d positions of, 402\n \u201d rising, 14, 263, 266, 350\n \u201d \u201d in Purgatory, 363, 378-80, 389\n \u201d setting, 14, 263, 265, 350, 367, 369\n \u201d \u201d in Purgatory, 380\n \u201d sphere of, 169, 308, 449, 465, 477, 484, 487\n \u201d substance, 55, 71, 114, 463 _et seq._, 494\n \u201d waning, 262, 266, 380\n \u201d worship of, 25\n \u201d and astrology, 173, 174, 249, 268, 407,\n 419, 450, 472 _et seq._\n \u201d \u201d Dante, 261 _et seq._\n \u201d \u201d Mars, 310, 433\n \u201d \u201d month, 13, 14, 15, 28, 30, 38, 41, 52, 171\n \u201d \u201d sun, balancing, 265;\n contrasted, 268\n \u201d \u201d tides, 189 _et seq._, 237, 445\n \u201d \u201d time, 266, 349, 367, 369, 370, 406, 419, 488\n \u201d \u201d zodiac, 265\n Moore, Dr. E., 236, _n._236, _n._237, 308, _n._326, _n._330,\n 334, _n._340, _n._380, 384, _n._411, _n._415,\n 419, 448, _n._452, _n._469, 471, _n._471\n Moors, 201, 203, 214\n Morning Star, 312, 314, 373, 410, 420, 421, 422, 470, 477\n Morocco, 340, 361\n Motion, Law of, 93, 100, 121, 159, 480\n Movers, _see_ First Mover, and Spheres\n Mulmul, 41\n Music of the Spheres, 67, 104\n\n Nabonassar, 144\n Naples, 240\n Nasir-ed-din, 195\n Nestorians, 181, 182, 209\n Nero, 171\n Newton, 100, 481\n Nineveh, 34, 44\n Night personified, 278\n Nino, 378, 416, 426\n Nile, 344\n Nones, 219, 348\n\n Observatories, Alexandria, 113, 116, 135;\n Baghdad, 182;\n Greenwich, 153;\n Pekin, 114;\n Persian, 195;\n The Cape, 153;\n of Eudoxus, 88;\n of Hipparchus, 122\n \u201cObservatory, The,\u201d _n._24, 34\n \u201cOn the Heavens,\u201c _see_ De C\u00e6lo\n Occultations, 105, 145\n Omons, 218\n Opposition, defined, 174, 119, 141\n Orion, 12, 36, 52, 155\n Orosius, 240, 341, 343, 384, 438\n Ottimo, 273, 418, _n._473\n Ovid, 168, 238, 239, 297, 305\n\n Padua, 227\n Paradise (_see also_ Eden), Earthly, 285, 295, 344, 345, 353,\n 366, 373, 385, 390, _n._391, _n._399, 401, 482\n Paradise Lost, 210\n Parallax, 153, 191\n Paris, 158, 201, 204;\n University, 154, 228, 241, 242\n Parmenides, _n._76, 428\n Parsis, 127\n Pekin, 114, 116\n Pericles, _n._61\n Perigee, 23, 119, 148, 150, 448-51\n Persia, 209\n Petrarch, _n._332\n Pha\u00ebton, 303, 333\n \u201cPhainomena,\u201d of Aratus, 32, 35\n Philolaus, 70, 85, 431\n Philosophy, 255, 281, 314, 315, 346\n Ph\u0153nicians, 25, 56\n Phosphor, 68, 80\n Piccarda, 300\n Pietro d\u2019 Abano, 342\n Pinches, T. C., 48\n Pisces (_see also_ Fishes), 32, 129, 138, 290, 295, 307, 309, 359,\n 360, 368, 370, 373, _n._380, 383, 385, _n._399,\n 403, 406, 407, 410, 411, 418, 420, 423, 494-95\n Planets, defined, 16, 45, 52, 58, 60, 63, 65, 68, 70, 79, 219, 254,\n 257, 269, 279, 289, 307 _et seq._, 312,\n _n._399, 419, 461, 466, 468, 488, 494-95\n \u201d aspects of, 200, 476\n \u201d astrology and, 173-4, 211, 219, 243, 249, 405\n \u201d distances of, 150, 189, 194\n \u201d houses of, 174, 476, _n._473\n \u201d influences of, 254, 472, 473, 474\n \u201d movements of, 15, 16, 29, 44, 58, 68, 69, 70, 79, 80,\n 88-90, 104, 118, 123, 138, 159, 248, 312,\n 330, 331\n \u201d names of, 80, 83\n \u201d nature of, 461\n \u201d periods of, 23, 29, 69, 83, 89, 91, 100, 109,\n 141, 219, 313, 436\n \u201d positions of, 402 _et seq._, 419\n \u201d shadows cast by, _n._280\n \u201d varying velocity of, 94, _n._94\n \u201d and the sciences, 312\n Plato, 80 _et seq._, 85, 91, 98, 101, 104, 159, 217, 238,\n 239, 313, 431, 444, 462, 479, 482, 483\n Pleiades, 28, 29, 35, 40, 52, 155\n \u201d and Australian legend, 28\n \u201d \u201d Tahitan natives, 28\n Pliny, 50, 123, 170, 342\n Plunkett, Miss, 34\n Plutarch, 85, 107, 137, 463\n Pole, celestial, 12, 18, 51, 65, 105, 157, 185, 186, 187, 286,\n 287, 289, 297, 302, 323, 335, 434, 439, 477;\n north, 373;\n south, 286, 292, 293, 335, 373, 378, 489\n \u201d terrestrial, 247, 322;\n north, 323, 370;\n south, 323\n Pole star, 9, 67, 127, 291, 323\n Popes, 276, 316;\n Boniface VIII., 415, 416;\n Gregory IX., 213;\n Honorarius II., 214;\n Urban IV., 318, 413\n Poseidonius, 134, 157, 170, 240\n Precession of Equinoxes, _see_ Equinox\n Prickard, _n._463\n Primum Mobile, 194, 204, 210, 299, _n._232, 291, 308, 313, 381,\n 400, 401, 432-434, 436, 440, 451, 455, 456, 477, 484\n Proclus, 170\n Proctor, R. A., _n.24_, 34, 35\n Procyon, 155, 187\n Ptolemy, 5, 24 _n.24 n._34, 134 _et seq._, 154,\n 156, 160, 163, 170, 178, 182, 186, 202, 209, 210, 218,\n 242, 245, 261, 275, 288, 290, 291, 305, 333, 350\n \u201d Almagest, 113, 115, 123, 182, 184, 201\n \u201d dimensions of earth, 182;\n of heavenly bodies, 191\n \u201d geography of, 157, 205, 337, 341\n \u201d quoted, 134\n \u201d system of, 381, 431, 432, 491\n \u201d \u201d \u201d epicycles, 256, 315\n \u201d works by, 156, 157, 182\n \u201d and Apollonius, 118\n \u201d \u201d Aristarchus, 107\n \u201d \u201d Arabs, 147, 152, 183, 188, 192-4\n \u201d \u201d colure, 403\n \u201d \u201d Dante, 232, 235, 239, 459, 468\n \u201d \u201d eclipses, 338;\n and ecliptic, 185\n \u201d \u201d Hipparchus, 126, 133, 143, 146\n \u201d \u201d moon, 146, 448, 449\n \u201d \u201d precession, 187, 193, 432\n \u201d \u201d Regulus, 406\n \u201d \u201d stars, 292, 294, 339\n \u201d \u201d Venus, 315\n Ptolemy Philadelphus, 144\n \u201d Ptolemies, Royal, 113\n Purgatory, 105, 205, 295, 345, 360, 367, 370, 372, 373,\n 390, 401, 407, 453, 454\n \u201d gate of, 362, 380, 385, 453\n \u201d latitude of, 286, 353, 387\n \u201d Mountain of, 105, 262, 286, 295, 311, 312, 332-5, 353,\n 360 _et seq._, 373, 375, 378, 381, 382,\n 385, 386, 388, 390, 452, 453, 455\n Pyramids, 45, 81, 127\n Pythagoras, 66 _et seq._, 236, 238, 302, 431\n Pythagoreans, 62, 66 _et seq._, 75, _n._76, 79, 85, 88,\n 91, 96, 100, 101, 102, 104, 110, 111, 304, 490\n\n Quadrivium, 177\n \u2018Qu\u00e6stio de Aqua et Terra,\u2019 256, 258, 340, 444, 452\n\n Ram (_see_ Aries), 279\n Ravenna, _n._227, 273\n Regulus, 43, 144, 155, 187, 290, 406, 411, 420\n Retrograde Motion, 16\n Rhodes, 67, 122, 134, 158\n Rigel, 155\n Ristoro, 217, 241 _et seq._, 257, 268, 274, 292, 288, 300,\n 328, 329, 444, _n._451, 464, _n._478\n \u201d and comet, 318;\n constellations, 443, 451;\n eclipses, 317;\n ecliptic, 331;\n habitable earth, 446;\n meteors, 319\n Rizzacasa d\u2019Orsogna, Prof., 400\n Rome, 111, 157, 241, 316, 319, 323, 345, 383, 385, 396, 415\n \u201d Church of, influence on astronomy, 175, 178\n \u201d Empire of, 262;\n influence on astronomy, 138, 167, 172, 178\n Rome, and calendar, 172, 175\n Rubruquis, Friar, 342\n\n Sacrobosco, 202, 249\n Sagittarius, 279, 281, 290, 380, 383, 385\n St. Bernard, 312, 354, 401\n St. John, 282, 317\n St. Louis, King, 342\n St. Paul, 32, 483\n St. Peter, 396, 468\n Salimbene, 212\n Saracens, 214\n Sardinia, 344, 364, 383, 384\n Saturn, 16, 23, 69, 91, 105, 109, 120, 141, 169, 189, 279, 281,\n 311, 364, 389, 393, _n._398, 406, 407, 410, 411, 417,\n 420, 422, 423, 450, 456, 468, 469, 490\n \u201d dimensions, 488;\n movements, 311;\n period, 436\n Scales, _see_ Libra\n Scartazzini, 379, _n._455\n Schiaparelli, _n._35, _n._39, _n._236\n Schwary, 34\n Scipio, 168-69, 393;\n Dream of, 168, 237\n Scorpio, 30, 31, 43, 365, 378, 379, 380, 383, 384, 385,\n 387, 405, 476, 489\n Seleucus, 110\n Seneca, 66, 169, 174, 237, 239, 342, 473;\n and meteors, 319\n Shakespear, 456\n Sheol, 46\n Sigieri, 228\n Simplicius, 90, 170\n Sirius, 39, 52, 67, 115, 155, 187\n Socrates, 82, 83, 239\n Solstice, definition of, 11, 26, 29, 107, 117, 127, 185, 277, 394\n Sordello, 378, 382\n Sosigines, 171\n Southern Cross, 12, 156, 294\n Spain, 339-42, 388\n Spheres, 9, 57, 58, 62, 65, 68, 83, 84, 104, 137, 169, 184, 187,\n 204, 219, 249, 254, 257, 262, 302, 358, 392, 393,\n _n._399, 429 _et seq._, 444, 452, 457,\n 473, 478, 418\n \u201d crystalline, 433\n \u201d eighth sphere, 466\n \u201d elevating power of, 443\n \u201d homocentric, 112\n \u201d influence of, 239, 249, 254, 478, 479, 485, 488, 494\n \u201d movement of, 395, 400, 453\n \u201d movers of, 106, 159, 204, 254, 400, 482, 483, 484, 496\n \u201d music of, 67, 68, 104, 169, 302, 392, 455, 456\n \u201d ninth, 432-3\n \u201d sky as a, 51\n \u201d substance of, 95, 104, 193, 433, 461\n \u201d \u2018unrolling,\u2019 95, 102, 106\n \u201d of air, 442, 452\n \u201d of Eudoxus, 88, 89, 94, 106, 107, 112\n \u201d of fire, 103, 159, 308, 392, 442, 453, 455, 490\n \u201d of moon, 103, 308, 477\n \u201d of sun, 88, 93, 253\n \u201d of stars, 13, 67, 70, 72, 89, 94, 95, 96, 109, 129, 137,\n 152, 160, 187, 253, 313, 356, 433, 437, 438,\n 456, 476, 477\n \u201d of water, 442, 443\n \u201d and Arabs, 194\n \u201d \u201d Roger Bacon, 118, 202\n \u201d \u201d time, 401\n Spica, 124-6, 130, 155\n Stars, 219, 283 _et seq._, 489, 402, 493-94\n \u201d brightness of, 123, 154, 187\n \u201d catalogues, 123, 133, 144, 154, 187, 288;\n Abu Hazan\u2019s, 184;\n Hipparchus\u2019, 188;\n Ptolemy\u2019s, 187\n \u201d Dante\u2019s \u2018quindici stelle,\u2019 155\n \u201d dimensions of, 190, 488\n \u201d globes, 115\n \u201d distance of, 17, 108, 153, _n._190, 488, 492-93\n \u201d influence of, 211, 254, 256, 443, 450, 473, 475,\n 478, 479, 488\n \u201d magnitudes of, 154, 187, 188, 234, 289, 299, 488;\n first-magnitude, 154, 187\n \u201d movements of, 9, 51, 52, 83, 84, 86, 97, 136, 187, 284, 286,\n 287, 289, 301, 354, 424, 495, 496\n \u201d new, 123\n \u201d number of, 123, 187, 288, 477, 495\n \u201d Pole, 291, 299\n \u201d positions of, 42, 123, 126, 193\n \u201d shooting, 103, 185, 262, 301, 319, 487, 490\n \u201d southern, 283, 293, 373, 378, 489\n \u201d substance of, 103, 104, 136\n \u201d worship of, 37, 38, 51\n \u201d and human souls, 86\n \u201d \u201d Milky Way, 103\n \u201d \u201d time, 257, 285, 289, 367, 488\n Stationary points, 16, 44, 121\n Statius, 385-7, 453\n Stilbon, 80\n Stoics, 112, 134, 463\n Stob\u00e6us, 107\n Stonehenge, 29\n Strabo, 170, 240\n Styx, 54\n Sumerians, 36, 38;\n year, 38\n Sun, boat of, 45, 46\n \u201d brightness of, 270, 282, 462, 477, 488, 469\n \u201d centre of universe, 101, 110\n \u201d dimensions of, 56, 110, 146, 153, 188, 457-8, 469, 488, 491\n \u201d distance of, 108, 146, 153, 189, 193, 457-8\n \u201d door of, 46\n \u201d god, 37, 48, 54\n \u201d heaven of, _see_ Heavens\n \u201d Lake of, 54\n \u201d movements of, 10, 13, 39, 53, 55, 62, 115, 116, 120, 145, 146,\n 185, 187, 247, 256, 272-4, 276, 322 _et seq._,\n 338, 346, 349, 390-2, 402, 403\n \u201d perigee of, 448\n \u201d period of, 436\n \u201d positions of, during Vision, 402 _et seq._\n \u201d rise, 10, 13, 14, 25, 28, 54, 267, 270, 271, 273, 339, 346,\n 348, 356, _n._356, 406\n \u201d rise in Forest, 354, 358, 367, 369\n \u201d \u201d in Purgatory, 271, 360, 362, 363, 364, 366,\n 374, 385, 389, 406\n \u201d set, 10, 13, 14, 48, 253, 262, 271, 273, 279, 280, 282, 294,\n 339, _n._336, 350, 356, 383, 385\n \u201d \u201d in Purgatory, 271, 361, 363 to 366, 378, 382, 388\n \u201d source of all light, 470, 477, 488\n \u201d worship of, 25, 37, 45\n \u201d and astrology, 173, 473, 477\n \u201d \u201d comets, 103\n \u201d \u201d Dante, 267, 270 _et seq._\n \u201d \u201d stars, 254, 470, 477\n \u201d \u201d time, 219, 254, 257, 349, 367, 372, 488\n Sundial, 27, 115, 158, 182, 192, 219\n Syene, 117, 156\n Sylvester II., 203\n Synodic revolution, 22, 30\n \u2018Syntaxis\u2019 (_see_ Almagest), _n._125,\n 136, 157, 182, 193, 209\n\n Tabit ben Korrah, 194\n Tables:\u2014\n \u201d Alfonsine, 195, 202, 203, 242, 275, 341;\n astronomical, 203, 242, 245;\n Greek, 117;\n Hakemite, 183;\n Toledo, 184, _n._202, 421\n \u201d of constellations, 31, 154;\n Days of the Vision, and positions of sun, etc., 425;\n Ptolemy\u2019s first-magnitude stars, 155;\n planetary distances and dimensions, 189;\n positions of sun and moon, 190;\n planetary periods, 91, 436;\n planets in zodiac, 325;\n revolutions of sun, moon, and planets, 22, 23;\n time references in the Divine Comedy, 358-66\n Tartarus, 54\n Taurus, _n._35, 43, _n._43, 144, 148, 149,\n 365, 387, 399, 403, 410, 422\n \u201cTesoretto,\u201d 226, 242\n \u201cTetrabiblios,\u201d 156, 233, 234\n Thales, 50, 55 _et seq._, 60, 61, _n._76, 98, 238, 239, 297\n Theon of Alexandria, 163\n Theon of Smyrna, 135, 144\n Tides, 134, 257, 445\n Tierce, 220, 347, 348, 372\n Tim\u00e6us, 82, 101, 238\n Time, measurement of, 25, 47, 84, 86, 161, 162, 170, 186\n Thule, 157\n Timocharis, 124, 125, 144\n Toledo, 202, 213\n \u201d tables of, 184, _n._202, 421\n Toynbee, Paget, _n._225, _n._236, _n._241, _n._417,\n _n._437, _n._464\n Tozer, H. F., _n._476\n Trepidation, 194, _n._232-3\n \u201cTr\u00e8sor, Li Louvres dou,\u201d 218, 226, 243\n Trigonometry, spherical, 113, 123, 153, 183;\n invention of, 133\n Trivium and Quadrivium, 177, 261, 312\n Twins, _see also_ Gemini, 279, 400\n Tycho Brah\u00e8, 120\n\n Ulysses, 51, 52, 292, 335, 340, 370, 395\n Universe (_see_ Cosmogonies), 97;\n dimensions, 390, 459;\n of Dante, 257, 258, 353 _et seq._, 489\n Universities, Bologna, 199, 216, 226, 227, 241, 478;\n medi\u00e6val, 199 _et seq._;\n Naples 240;\n Padua, 227;\n Paris, 199, 213, 228, 241;\n Oxford, 199, 213;\n Rome, 241\n Ur, 37\n Urban IV., 201\n Ursa, Major, (_see also_ Bear, and Wain), 234,\n 295 _et seq._, 322, 368\n \u201d Minor, 234, 297, _n._299\n\n Varaha Mihira, _n._111\n Vega, 155, 187\n Venturi, 453\n Venus, 3, 15, 17, 23, 69, 80, 90, 93, 109, 112, 121, 144, 150, 169,\n 279, 281, 286, 300, 307, 309, 314, 373, 389, _n._399,\n 406-11, 418-25, 481-66\n \u201d dimensions, 488\n \u201d distance, 458 _et seq._\n \u201d goddess of, 38\n \u201d movements of, 314, 315, 435, 477\n \u201d movers of, 483\n \u201d phases of, 492\n \u201d period of, 314, 315, 436\n \u201d and astrology, 173, 189, 472, 477\n \u201d as evening star, 52, 142\n \u201d as morning star, 15, 52, 64, 68, 142\n Verona, 226, 256, 444\n Vespers, 219, 348\n Villani, 213, 223, 226, 319\n Virgil, 167, 168, 239, 271, 328, 374, 381, 441\n \u201d quoted, 173, 279\n \u201d works of, 238\n \u201d as guide, 286, 354, 367, 371, 387, 409, 481\n \u201d and sun, 271, 333, 381, 392\n Virgin, Virgo, 12, 32, 124, 141, 144, 290, 384, 418\n Vision, date of Dante\u2019s, 357, 407 _et seq._;\n duration of 354-7, 401\n \u2018Vita Nuova,\u2019 253, 257, 411, 432\n\n Wain, The (_see also_ Bear), 293, 295, 359, 368, 373\n Wellhausen, _n._39\n Wicksteed, P. H., _n._277, 306, 447\n World-soul, 98, 159\n\n Xenophanes, 98\n\n Yaou, Emperor, 29;\n Canon of, 38\n Year, 253;\n definition of, 23\n \u201d Arab, 39;\n Babylonian, 40, 128, 161;\n Chinese, 38;\n Egyptian, 39, 45;\n Hebrew, 39;\n Greek, 161, 162, _n._172;\n Mahomedan, 39;\n Persian, 313;\n Roman, 170;\n Sumerian, 38\n \u201d civil, 22;\n luni-solar, 38, 39, 93;\n lunar, 39;\n sidereal, 22, 128;\n solar, 22, 56, 128, 163;\n tropical, 22, 129, 161, 162, 171, 193, 274, 275\n \u201d leap, 171, 276\n \u201d length of, 187, 274\n \u201d and Hipparchus, 128, 135\n\n Ziggurat, 37\n Zodiac, 10, 13, 14, 15, 16, 18, 23, 28, 30, 31, 43, _n._43,\n 69, 119, 143, 185, 265, 272, 278, 280, 289, 300, 309, 311,\n 333, 349, 382, 384, 402, 405, 448, 470, 488\n \u201d age of, 34\n \u201d Chinese and Hindu, 29, 30\n \u201d constellations of, 31, 42, 43, 47, 129, 219, 248,\n 290, 356, 368, 402, 476\n \u201d lunar, 30\n \u201d signs of, 129, 174, 185, 186, 245, 329,\n 356, 368, 379, 383, 402\n \u201d sun in, 276, 282\n \u201d and months, 276, 281, 282\n Zodiacal revolutions, 23\n Zoroaster, 218","title":"Dante and the early astronomers","tradition":"scripture-revelation","translated_text":null,"word_count":139365}