Note 28 — PROPORTION.
J. F. (John Francis) Rigaud translation
It is supposed that the figures are to appear of the natural size, and not bigger. In that case, the measure of the first, to be of the exact dimension, should have its feet resting upon the bottom line; but as you remove it from that, it should diminish.
No allusion is here intended to the distance at which a picture is to be placed from the eye.