Drawings by Leonardo Da Vinici on on the mechanical powers and forces, percussion, gravity, motion, optics and astronomy, with various arithmetical and geometrical propositions, Written backwards in the author's own hand, and illustrated by diagrams and delineations. Leonardo Da Vinci's rough Book of observations and demonstrations on subjects chiefly of mixed Mathematics, being unconnected notes written by him at different times, commencing 22 March, 1508. Author Leonardo da Vinci, Illustrated by Leonardo da Vinci.