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Who invented the Kaleidoscope?
Who invented the Kaleidoscope?
The kaleidoscope, a tube containing bits of coloured glass, etc., which arrange themselves in beautiful and ever-changing shapes, was one of the most popular inventions of the nineteenth century.
The kaleidoscope was invented by the Scottish physicist Sir David Brewster in 1816. He also devised an instrument to project images of objects into the kaleidoscope so that they are multiplied and reproduced to form symmetrical patterns.
However, the instrument could be made so easily that the patent rights were violated, and Brewster missed the fortune it might have brought him. He had discovered the principle on which the effects of the kaleidoscope depend, while engaged in experiments on the polarization of light by successive reflections between plates of glass.
A simple device for producing symmetrical colored patterns, kaleidoscopes were popular toys.
A simple kaleidoscope consists of a cylinder of cardboard with two plane mirrors that extend from one end to the other and are set at an angle to each other. At one end of the cylinder are two glass plates, an outer frosted one and an inner clear one. Between the two plates are several small pieces of colored glass. When the cylinder is rotated, the pieces of glass fall into a variety of patterns. When viewed through an eyehole at the opposite end of the tube, the patterns are multiplied and made into symmetrical forms by the many reflections between the mirrors.
It was soon in everybody's hands, admirably fitting in with the Regency taste in elegant coloured bric-a-brac. 'Every person who could buy or make one', runs a contemporary report, 'had a Kaleidoscope. Men, women and children, rich and poor, in houses, or walking in the streets, in carriages or on coaches, were to be seen looking into the wonder-working tube, admiring the beautiful patterns it produced, and the magical changes which the least movement of the instrument occasioned.
We all know that we can form several images from one object by using two mirrors. If inclined to each other at an angle of 90° they give three images of an object placed between them, the images and the object being apparently placed at the four corners of a rectangle. If the mirrors are inclined to each other at an angle of 60°, five images are produced which, with the original object, show a hexagonal arrangement.
It was these symmetrically arranged images which suggested to Brewster the kaleidoscope, in which two long, narrow mirrors are placed lengthways in a tube, inclined to each other at 60°. One end of the tube is closed by two parallel plates of glass, the outer one ground-glass, the inner one transparent, leaving between them a space in which are placed small pieces of coloured glass, pieces of twisted glass of varying curvature, small glass tubes partly filled with colored liquid, etc. At the other end of the tube is a small eye-hole or, in better instruments, a convex lens. On looking into the tube one sees the images of the pieces of glass so reflected that beautiful symmetrical coloured patterns are produced, of infinite variety, for with every movement of the instrument the pieces of glass rearrange themselves in new combinations.
According to the inventor, the express object of the kaleidoscope was less to amuse than 'to exhibit and create beautiful forms and patterns, of great use in all the ornamental arts'. In conjunction with a magic lantern, the images could be enlarged on a screen, affording entertainment to a number of people at the same time.
As with almost every popular invention, the primacy of Brewster's discovery was disputed by people interested in getting the patent set aside; they alleged that Athanasius Kircher had described the effects of repeated reflections in his Ars Magna (1646). However, there is only a superficial resemblance between Brewster's kaleidoscope and Kircher's instrument, which consisted of a many-faceted piece of cut-glass in a tube, through which one could either see patterns or project them on to a screen.