75

Refraction of the rays falling upon the eye.

[figure]

If the judgment of the eye is situated within it, the straight lines of the images are refracted on its surface because they pass through the rarer to the denser medium. If, when you are under water, you look at objects in the air you will see them out of their true place; and the same with objects under water seen from the air.

Taken from The Notebooks of Leonardo da Vinci edited by Jean Paul Richter, 1880.

74 * 76
I * III
Notebooks of Leonoardo da Vinci
II: Linear Perspective.
. . .
The relations of the distance points to the vanishing point.
55,
56
How to measure the pyramid of vision.
57
The Production of pyramid of Vision.
58,
59,
60,
61,
62,
63,
64
Proof by experiment.
65,
66
General conclusions.
67
That the contrary is impossible.
68
A parallel case.
69
The function of the eye as explained by the camera obscura.
70,
71
The practice of perspective.
72,
73
Refraction of the rays falling upon the eye.
74,
75
The inversion of the images.
76
The intersection of the rays.
77,
78,
79,
80,
81,
82
Demomstration of perspective by means of a vertical glass plane.
83,
84,
85
The angle of sight varies with the distance.
86,
87,
88
Opposite pyramids in juxtaposition.
89
On simple and complex perspective.
90
The proper distance of objects from the eye.
91,
92
eye.
93,
94,
95
. . .