(The following example of Marcel Duchamp’s encounter with the mind of Leonardo da Vinci is exerpted from a longer essay. Duchamp discovered Leonardo’s anatomical writings and drawings, through photogravure reproductions, in the Bibliothèque Sainte Géneviève in Paris, first as a curious visitor in 1910, then as a professional librarian with a great deal of spare time, in 1913-14.)

click images to enlarge

Note by Leonardo da Vinci,
from: Charles O’Malley and J. B.
Saunders (eds.), Leonardo on the
Human Body, Dover: New York, 1982, p.296.