139

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

[figure]

Every shadow with all its variations, which becomes larger as its distance from the object is greater, has its external lines intersecting in the middle, between the light and the object. This proposition is very evident and is confirmed by experience. For, if a b is a window without any object interposed, the luminous atmosphere to the right hand at a is seen to the left at d. And the atmosphere at the left illuminates on the right at c, and the lines intersect at the point m.

[Footnote: A here stands for levante (East), B for ponente (West).]

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.
. . .
Definition of the nature of shadows.
119,
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
. . .