205

On reverberation.

OF REVERBERATION.

Reverberation is caused by bodies of a bright nature with a flat and semi opaque surface which, when the light strikes upon them, throw it back again, like the rebound of a ball, to the former object.

WHERE THERE CAN BE NO REFLECTED LIGHTS.

All dense bodies have their surfaces occupied by various degrees of light and shade. The lights are of two kinds, one called original, the other borrowed. Original light is that which is inherent in the flame of fire or the light of the sun or of the atmosphere. Borrowed light will be reflected light; but to return to the promised definition: I say that this luminous reverberation is not produced by those portions of a body which are turned towards darkened objects, such as shaded spots, fields with grass of various height, woods whether green or bare; in which, though that side of each branch which is turned towards the original light has a share of that light, nevertheless the shadows cast by each branch separately are so numerous, as well as those cast by one branch on the others, that finally so much shadow is the result that the light counts for nothing. Hence objects of this kind cannot throw any reflected light on opposite objects.

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.
. . .
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
. . .