Note 14 — CATEGORIES
Reading edition
: When the perspective object is accurately measured by instrument at a known distance from the eye, and the tactual size of the object is also known, the associative distance can be calculated by simple proportion. Multiply the measuring distance by the tactual size and divide the product by the perspective size—the quotient is the distance. The perspective size of objects is greatly exaggerated in realism. Most people think they see a man at his full stature for a distance of fifty yards or so. At that distance the tallest man does not measure half an inch in height. At twenty feet a six-foot man measures 3·6 inches—at ten feet 7·2 inches. The people assembled in a room forty feet long range in real—perspective—height from seven inches to two inches. When a man is nearer than ten feet we do not perceive him in one operation—we observe him in parts which we put together in the mind.