A kaleidoscope is an optical instrument used to produce symmetrical geometric patterns on carpets, sarees, wallpapers etc. It is also an entertaining toy for the children.
Kaleidoscope was invented by a Scottish physicist, Sir David Brewster in 1816. It illustrates the image forming properties of combined inclined mirrors by successive reflections. If one object is placed between two plane mirrors, at right angles to each other, three images are produced by successive reflections. Similarly, if the mirrors are inclined at 60°, five symmetrical images are formed.
A kaleidoscope consists of three strips of mirrors inclined at an angle of 60° to one another. They are enclosed in a cylindrical tube. One end of this tube is closed by means of a piece of ground glass, while the other is closed by a piece of cardboard with a hole at its centre. Several multi-coloured glass pieces and beads are loosely enclosed between the three inclined mirrors with the help of a disc made of plane glass. Now when viewed through the hole of the cardboard, along the axis of the tube, a symmetrical pattern of images of the coloured glass pieces are seen.
When a person turns the kaleidoscope, the coloured glass pieces and beads change positions, thereby new patterns are produced. And so in this manner, an infinite number of combinations and patterns can be formed. The tubes used in most of the kaleidoscope are usually 25cm in length and 5 – 8cm in diameter. It is a very useful instrument for the designers.
