A kaleidoscope is an optical instrument invented by Brewster about 1815. It became very popular as a toy. It consists essentially of a tube, within which are fixed longitudinally two mirrors at a certain angle ACB -- any even submultiple of 360º, in practice generally 60º -- an eyepiece at one end,  and an object box containing fragments of colored glass at the other. On shaking the instrument, an infinite series of always symmetrical patterns is presented.

Kaleidoscope

A kaleidoscope is an optical instrument invented by Brewster about 1815. It became very popular as a…