69

A parallel case.

Just as a stone flung into the water becomes the centre and cause of many circles, and as sound diffuses itself in circles in the air: so any object, placed in the luminous atmosphere, diffuses itself in circles, and fills the surrounding air with infinite images of itself. And is repeated, the whole every-where, and the whole in every smallest part. This can be proved by experiment, since if you shut a window that faces west and make a hole [Footnote: 6. Here the text breaks off.] . .

[Footnote: Compare LIBRI, Histoire des sciences mathématiques en Italie. Tome III, p. 43.]

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

68 * 70
I * III
Notebooks of Leonoardo da Vinci
II: Linear Perspective.
. . .
49
The nature of the outline.
50
Definition of Perspective.
51
Experimental proof of the existence of the pyramid of sight.
52,
53,
54
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
. . .