David Brewster (December 11, 1781 - February 10, 1868) was a Scottish physicist, mathematician, astronomer, inventor, writer and university principal. He graduated from the University of Edinburgh in 1800 and was licensed a minister of the Church of Scotland, but only preached from the pulpit on one occasion. He had already shown a strong inclination for natural science so he turned instead to the study of optics and diffraction of light. In 1807, he undertook the editorship of the newly projected Edinburgh Encyclopaedia, of which the first part appeared in 1808, and the last not until 1830. At a later period he was one of the leading contributors to the Encyclopedia Britannica (seventh and eighth editions) writing, among others, the articles on electricity, hydrodynamics, magnetism, microscope, optics, stereoscope, and voltaic electricity. Among the non-scientific public, his fame spread more effectually by his invention in about 1815 of the kaleidoscope. He contributed in the invention of the stereoscope and the improvement of British lighthouse systems. He was knighted in 1832. He died in 1868 at the age of 86.