Among objects of equal size that which is most remote from the eye will look the smallest. [Footnote: This axiom, sufficiently clear in itself, is in the original illustrated by a very large diagram, constructed like that here reproduced under No. 108.
The same idea is repeated in C. A. I a; I a, stated as follows: Infra le cose d’equal grandeza quella si dimostra di minor figura che sara più distante dall’ ochio.—]
Taken from The Notebooks of Leonardo da Vinci edited by Jean Paul Richter, 1880.