3998624A Treatise on Painting — Of the Measures of the human Body, and the bending of MembersJohn Francis RigaudLeonardo da Vinci
Chap. XXX.—Of the Measures of the human Body, and the bending of Members.
It is very necessary that painters should have a knowledge of the bones which support the flesh by which they are covered, but particularly of the joints, which increase and diminish the length of them in their appearance. As in the arm, which does not measure the same when bent, as when extended; its difference between the greatest extension and bending, is about one eighth of its length. The increase and diminution of the arm is effected by the bone projecting out of its socket at the elbow; which, as
Plate 1.
Chap 37.
Page 15.
London Published by J. Taylor High Holborn.
is seen in figure A B, Plate I. is lengthened from the shoulder to the elbow; the angle it forms being less than a right angle. It will appear longer as that angle becomes more acute, and will shorten in proportion as it becomes more open or obtuse.
