140

Experiments on the relation of light and shadow within a room.

[figure]

Every body in light and shade is situated between 2 pyramids one dark and the other luminous, one is visible the other is not. But this only happens when the light enters by a window. Supposing a b to be the window and r the body in light and shade, the light to the right hand z will pass the object to the left and go on to p; the light to the left at k will pass to the right of the object at i and go on to m and the two lines will intersect at c and form a pyramid. Then again a b falls on the shaded body at i g and forms a pyramid f i g. f will be dark because the light a b can never fall there; i g c will be illuminated because the light falls upon it.

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

II * IV
Notebooks of Leonoardo da Vinci
III: Six books on Light and Shade.
. . .
120,
121,
122
Of the various kinds of shadows..
123,
124,
125
Of the various kinds of light.
126,
127
General remarks.
128,
129
On the nature of light.
130,
131
The difference between light and lustre.
132,
133,
134,
135
The relations of luminous to illuminated bodies.
136
Experiments on the relation of light and shadow within a room.
137,
138,
139,
140
Light and shadow with regard to the position of the eye.
141,
142,
143,
144,
145
The law of the incidence of light.
146,
147
Gradations of strength in the shadows.
148,
149
light.
150,
151,
152
On the proportion of light and shade.
153,
154,
155,
156,
157
Definition of derived shadow.
158,
159
Different sorts of derived shadows.
160
. . .