If, however, you stand before the mirror with light falling upon you from one side, the picture in the mirror will be quite different in appearance. The light and shadow will be more broken up and diversified. Some part of your hand, it may be simply the edges of the fingers, will catch a high light, even if it is not the highest; and light probably will fall on your forearm, between the wrist and elbow, and again upon the upper part of the arm. Broadly speaking, your arm presents three planes of form--the hand, the forearm, and the upper arm. And, though to your untrained eye the light on all of these planes may seem the same, to an artist’s eye it would vary according to the angle at which the light hits the plane, or, as the artist himself would say, according to the angle of the plane. These angles vary all over the figure, as you may be able to see if you examine your picture in the mirror. To mention a few, in a general way, there are several angles around each of the shoulders, about the breast, round the neck, while the face, with its projecting nose, its receding eye sockets, its rounded cheeks and so on, presents a regular patchwork of angles of plane. Or shall I say, the whole figure presents a whole multitude of facets like a cut diamond? Only, unlike the diamond, its facets are uneven in size and irregular in shape. And just as the light on the facets, here very light and elsewhere not so light, informs us of the shape of the diamond, so do these differently lighted angles of plane, when presented in a picture, give us the suggestion of the figure’s shape.