It is impossible that an object mirrored on water should correspond in form to the object mirrored, since the centre of the eye is above the surface of the water.
This is made plain in the figure here given, which demonstrates that the eye sees the surface a b, and cannot see it at l f, and at r t; it sees the surface of the image at r t, and does not see it in the real object c d. Hence it is impossible to see it, as has been said above unless the eye itself is situated on the surface of the water as is shown below [13].
[Footnote: A stands for ochio [eye], B for aria [air], C for acqua [water], D for cateto [cathetus].—In the original MS. the second diagram is placed below line 13.]
Taken from The Notebooks of Leonardo da Vinci edited by Jean Paul Richter, 1880.