The Eyes Of Port Raits

II ow is it that the eyes of some portraits seem fco follow a spectator around the room? lt has been thus explained: Suppose, says the Baltimore American, a portrait have its face and eyes directed straight in front, so as to look at the spectator. Let a straight line be drawn through the tip of the nose and half way betvveen the eyes. On each side of this middle line there will be the same breadth of head, of cheek, of chin and of neck, and each iris will be in the middle of the vvhole of the eye. If one now go to one side, the apparent horizontal breadth of every part of the head and face will be diminished, but the parts on eaeh side of the middle line will be diminished equally, and at every position, ho wever oblique, there will be the same breadth of face on each side of the middle line, and the iris will remain in the center of the whole of the eyeball, so that the portrait will preserve all the character of a figure looking at the spectator, and must necessarily do so wherever he stands. In portraits the apparent motion of the head is generally rendered indistinct by the canvas being imperfectly stretched, as the slightest concavity and convexity entirely deforms the face. Ofttimes the obliquity is considerable. The deception is, therefore, seen best when the painting isexecuted on a flat board and in colors sufficiently vivid to represent every line in the face with tolerable distinctness at great obliquities. Distinctness of outline is also most necessary to a satisfactory exhibition of this optical delusion.