Kaleidoscope, ka li'do skope, a well-known optical toy, invented by David Brewster, by which an infinite variety of symmetrical, and often beautiful, colored designs is obtained. The ordinary kaleidoscope consists of a tube containing three glass plates acting as mirrors, which extend along its whole length and make an angle of 60 degree with one another. One end of the tube is closed by a metal plate with a small hole at its center, to which the eye is applied; at the other end there are two plates, one of ground glass, the other of clear glass, the latter being nearer the eye. A number of pieces of colored glass or beads lie loosely between them. When the eye is applied to the aperture the mirrors produce a beautiful, symmetrical figure, and when the tube is turned about or shaken, new images, always symmetrical, are formed. This arrangement may be modified in various ways. The instrument has been used by designers of patterns for calicoes and other fabrics.