The Notebooks

256. If several objects in shadow, standing very close together, are seen against a bright background they will appear separated by wide intervals. 257. Of several bodies of equal size and tone, that which is farthest will appear the lightest and smallest. 258. Of several objects equal in size, brightness of background and length that which has the flattest surface will look the largest. A bar of iron equally thick throughout and of which half is red hot, affords an example, for the red hot part looks thicker than the rest. 259. Of several bodies of equal size and length, and alike in form and in depth of shade, that will appear smallest which is surrounded by the most luminous background. 260. DIFFERENT PORTIONS OF A WALL SURFACE WILL BE DARKER OR BRIGHTER IN PROPORTION AS THE LIGHT OR SHADOW FALLS ON THEM AT A LARGER ANGLE. The foregoing proposition can be clearly proved in this way. Let us say that _m q_ is the luminous body, then _f g_ will be the opaque body; and let _a e_ be the above-mentioned plane on which the said angles fall, showing [plainly] the nature and character of their bases. Then: _a_ will be more luminous than _b_; the base of the angle _a_ is larger than that of _b_ and it therefore makes a greater angle which will be _a m q_; and the pyramid _b p m_ will be narrower and _m o c_ will be still finer, and so on by degrees, in proportion as they are nearer to _e_, the pyramids will become narrower and darker. That portion of the wall will be the darkest where the breadth of the pyramid of shadow is greater than the breadth of the pyramid of light. At the point _a_ the pyramid of light is equal in strength to the pyramid of shadow, because the base _f g_ is equal to the base _r f_. At the point _d_ the pyramid of light is narrower than the pyramid of shadow by so much as the base _s f_ is less than the base _f g_. Divide the foregoing proposition into two diagrams, one with the pyramids of light and shadow, the other with the pyramids of light [only]. 261. Among shadows of equal depth those which are nearest to the eye will look least deep. 262. The more brilliant the light given by a luminous body, the deeper will the shadows be cast by the objects it illuminates. _V._ _Theory of colours._ _Leonardo's theory of colours is even more intimately connected with his principles of light and shade than his Perspective of Disappearance and is in fact merely an appendix or supplement to those principles, as we gather from the titles to sections_ 264, 267_, and _276_, while others again_ (_Nos._ 281, 282_) are headed_ Prospettiva. _A very few of these chapters are to be found in the oldest copies and editions of the Treatise on Painting, and although the material they afford is but meager and the connection between them but slight, we must still attribute to them a special theoretical value as well as practical utility--all the more so because our knowledge of the theory and use of colours at the time of the Renaissance is still extremely limited._ The reciprocal effects of colours on objects placed opposite each other (263-272). 263. OF PAINTING. The hue of an illuminated object is affected by that of the luminous body. 264. OF SHADOW. The surface of any opaque body is affected by the colour of surrounding objects. 265. A shadow is always affected by the colour of the surface on which it is cast. 266. An image produced in a mirror is affected by the colour of the mirror. 267. OF LIGHT AND SHADE. Every portion of the surface of a body is varied [in hue] by the [reflected] colour of the object that may be opposite to it. EXAMPLE. If you place a spherical body between various objects that is to say with [direct] sunlight on one side of it, and on the other a wall illuminated by the sun, which wall may be green or of any other colour, while the surface on which it is placed may be red, and the two lateral sides are in shadow, you will see that the natural colour of that body will assume something of the hue reflected from those objects. The strongest will be [given by] the luminous body; the second by the illuminated wall, the third by the shadows. There will still be a portion which will take a tint from the colour of the edges. 268. The surface of every opaque body is affected by the colour of the objects surrounding it. But this effect will be strong or weak in proportion as those objects are more or less remote and more or less strongly [coloured]. 269.