202

On the relative depth of cast shadows.

The shadow cast by an object on a plane will be smaller in proportion as that object is lighted by feebler rays. Let d e be the object and d c the plane surface; the number of times that d e will go into f g gives the proportion of light at f h to d c. The ray of light will be weaker in proportion to its distance from the hole through which it falls.

FIFTH BOOK ON LIGHT AND SHADE.

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.
. . .
The effect of light at different distances.
182
Further complications in the derived shadows.
183,
184,
185,
186,
187
On the shape of the cast shadows.
188,
189,
190,
191
On the outlines of cast shadows.
192,
193,
194,
195
On the relative size of shadows.
196,
197
Effects on cast shadows by the tone of the back ground.
198
A disputed proposition.
199
On the relative depth of cast shadows.
200,
201,
202
Principles of reflection.
203,
204
On reverberation.
205
Reflection on water.
206,
207
Experiments with the mirror.
208,
209,
210
Appendix:--On shadows in movement.
211,
212
The effect of rays passing through holes.
213,
214
On gradation of shadows.
215
On relative proportion of light and shadows.
216,
217,
218,
219,
220,
221
. . .