Brewster's main experiments were on the theory of light and its uses and Some Properties of Light, his first paper, was published in 1813. `Brewster's Rule' was named after his 1814 researches into polarisation using biaxial crystals. He often adapted and improved existing technical instruments to suit his researches, as well as developing new tools. His studies led to the discovery of the principle behind the kaleidoscope in 1816. His invention was faultily patented on 30th August 1817, and he published his Treatise on the Kaleidoscope in 1819. Although intended as a scientific tool, the discovery was sold very quickly as a toy for the amusement of adults and children . It was extremely popular and soon became something of a craze, like the fad for Rubik's Cube in the 1980s. It is hoped that the giant kaleidoscope in the second room of this exhibition will proove to be as popular!
Another of Brewster's instruments quickly became a favourite toy. The Lenticular Stereoscope was used to produce a 3-D image, and came as a result of his involvement in early photography. When examples were sent to the 1851 Great Exhibition at Crystal Palace, Queen Victoria was apparently fascinated by it, starting off another craze.
Reports on Brewster's character vary. He was apparently liked by his young students at St Andrews (average age 12-13), however, it is also said that, `Nobody ever had dealings with him and escaped a quarrel,' and in 1859 he left St Andrews to become Principal of Edinburgh University. He has the distinction of being awarded all three principal medals of the Roual Society for his optical researches: the Copley, Rumford and Royal medals, which he gained in 1815, 1818 and 1830 respectively. Brewster was certainly one of the most energetic scholars of his period, interested in a great variety of areas, and he has left behind an intriguing set of scientific instruments.