Chap. CLXII.—How to represent Night.
Those objects which are entirely deprived of light, are lost to the sight, as in the night; therefore if you mean to paint a history under those circumstances, you must suppose a large fire, and those objects that are near it to be tinged with its colour, and the nearer they are the more they will partake of it. The fire being red, all those objects which receive light from it will appear of a reddish colour, and those that are most distant from it will partake of the darkness that surrounds them. The figures which are represented before the fire will appear dark in proportion to the brightness of the fire, because those parts of them which we see, are tinged by that darkness of the night, and not by the light of the fire, which they intercept. Those that are on either side of the fire, will be half in the shade of night, and half in the red light. Those seen beyond the extent of the flames, will be all of a reddish light upon a black ground. In regard to their attitudes, let those who are nearest the fire, make screens of their hands and cloaks, against the scorching heat, with their faces turned on the contrary side, as if ready to run away from it. The most remote will only be shading their eyes with their hands, as if hurt by the too great glare.
Chap. CLXIII.—The Method of awakening the Mind to a Variety of Inventions.
I will not omit to introduce among these precepts a new kind of speculative invention, which though apparently trifling, and almost laughable, is nevertheless of great utility in assisting the genius to find variety for composition.
By looking attentively at old and smeared walls, or stones and veined marble of various colours, you may fancy that you see in them several compositions, landscapes, battles, figures in quick motion, strange countenances, and dresses, with an infinity of other objects. By these confused lines the inventive genius is excited to new exertions.
Chap. CLXIV.—Of Composition in History.
When the painter has only a single figure to represent, he must avoid any shortening whatever, as well of any particular member, as of the whole figure, because he would have to contend with the prejudices of those who have no knowledge in that branch of the art. But in subjects of history, composed of many figures, shortenings may be introduced with great propriety, nay, they are indispensable, and ought to be used without reserve, as the subject may require; particularly in battles, where of course many shortenings and contortions of figures happen, amongst such an enraged multitude of actors, possessed, as it were, of a brutal madness.