I303

In representing Objects after their natural bigness, it must be observed that the front Figures in Pieces of Miniature, be equally finish'd and distinct, with the larger Ones in Painting: But then the Figures in Miniature, being small, must be viewed very near, and those of Painting at a much greater Distance; by which means, how different soever they may be in their real Dimensions, they ought to appear of the same bigness; The Eye, in that Case, viewing them, under equal Angles, as may be thus demonstrated: Let B C be a Painting, [Tab. 1. Fig. 4.] A the Eye, and D E a Glass through which the Species of B C pass to the Eye; I say that the Eye A remaining fix'd, the Image of the Painting B C, thrown upon the Glass D E, will be smaller than the Painting, in proportion as the Glass is nearer to the Eye, and will be equally finish'd and distinct with the Painting it self; because it perfectly represents the Painting at that distance: But if you wou'd make a Copy of B C upon D E; in that Case, the Painting, by reason of its Distance, appearing indistinct, the Figure you make from it, must not be equally finished and distinct with the Painting; tho', at the same time it must be more distinct than another Figure M N, made upon the Glass F G: For if the Figure P O, were as much finished as B C, the Perspective of the former wou'd be false; since, tho' with regard to the Diminution of the Figure, it wou'd be right, B C, being reduced to the Extent P O, yet wou'd it be too much finished for its Distance: So that by finishing P O, as much as B C, B C will appear at the nearness of P O, and by diminishing B C to the Compass P O, P O, will appear at the distance B C.