Vol. II: XIX. Philosophical Maxims. Morals. Polemics and ...
The Da Vinci Notebooks
Instrumental or mechanical science is of all the noblest and the most useful, seeing that by means of this all animated bodies that have movement perform all their actions; and these movements are based on the centre of gravity which is placed in the middle dividing unequal weights, and it has dearth and wealth of muscles and also lever and counterlever.