A kaleidoscope is a tube containing loose, small, colorful objects. These objects can be beads or something similar. The inside is made using three long mirrors.
Sir David Brewster began work leading towards invention of the kaleidoscope in 1815 when he was conducting experiments on light polarization but it was not patented until two years later. His initial design was a tube with pairs of mirrors at one end, pairs of translucent disks at the other, and beads between the two. Brewster chose renowned achromatic lens developer Philip Carpenter as the sole manufacturer of the kaleidoscope in 1817. It proved to be a massive success with two hundred thousand kaleidoscopes sold in London and Paris in just three months. Realising that the company could not meet this level of demand, Brewster requested permission from Carpenter on 17 May 1818 for the device to be made by other manufacturers, to which he agreed. Initially intended as a scientific tool, the kaleidoscope was later copied as a toy. Brewster later believed he would make money from this popular invention; however, a fault in his patent application allowed others to copy his invention.