Sir David Brewster FRS, physicist and inventor, was born on the 11th of December, 1781.
Sir David Brewster was a scientist, physicist, natural philosopher and inventor. He was also a child prodigy, a divinity student, a university principal, an editor and a successful writer of popular science. Despite all of that, he is probably most famous for having invented the Rubik’s Cube of the Victorian era or better still, two such crazes; namely the kaleidoscope and the 3D viewer. Indeed, he had as many facets as his famous invention. Whether it was scientific research and invention, religion, education, optics, photography or writing, Brewster was one of the most energetic scholars of his period. As one of his colleagues, R. S. Westfall, said, “What an inexhaustible reservoir of vitality” he had. Probably, few people are aware that he was also a licensed Church of Scotland Minister, but thankfully, he abandoned the Church for science. Curiously, some biographies describe him as a renowned preacher and tutor, but he was terrified of speaking in public and seems to have been unable to preach or teach, because of nerves. James Hogg wrote of Brewster that “the first day he mounted the pulpit was the last …a pity for Kirk …but it was a good day for Science”.
Dr. Peter Mark Roget, of Thesaurus fame, paid tribute to Brewster’s invention in ‘Blackwood’s Magazine’, in 1818, writing that “In the memory of man, no invention, and no work, whether addressed to the imagination or to the understanding, ever produced such an effect”. He was writing about the kaleidoscope, but Brewster’s other ‘toy’, a 3D viewer, became a favourite of Queen Victoria after the 1851 Crystal Palace Exhibition. Brewster had a lifelong interest in optics, but he earned his living by the pen; editing various journals and spending much of his time popularising science. He wrote over 300 scientific papers, including ‘A Treatise Upon New Philosophical Instruments’ in 1813. Among his most noteworthy books are ‘Martyrs Of Science: or the Laws of Galieo, Tycho Brahe, and Kepler’ and his two biographies of Sir Isaac Newton. He published a short popular account in Murray’s ‘Family Library’, in 1831, and later, in 1855, the definitive account, ‘Memoirs of the Life, Writings and Discoveries of Sir Isaac Newton’, based on more than twenty years’ patient research.
In an era renowned for artistic, intellectual, scientific, and technical vitality, Brewster's accomplishments were pretty impressive. Brewster’s experiments led to many benefits, which are taken for granted today and, in fact, it was his research on the construction of the lens of the eye that confirmed the existence of “an ordered fibrous arrangement of its parts”. Modern laser technology has scarcely improved on that knowledge. Brewster made lots of discoveries, established several ‘laws’ and invented stuff. In terms of discovery, he left it to others to interpret his empirical observations and provide the ultimate explanation of the phenomena he had proven. In terms of his inventions, sadly he didn’t make a fortune and others were better able to take advantage.
Brewster’s discoveries include: the polarizing structure induced by heat and pressure; crystals with two axes of double refraction; the connection between the refractive index and the polarizing angle; biaxial crystals; and the production of double refraction by irregular heating. Brewster’s laws include: the laws of metallic reflection; laws on the phenomena of crystals, including the connection between optical structure and crystalline forms; and ‘Brewster’s Law’. Brewster discovered his eponymous law in 1813, which has to do with the polarization of light and also identifies the ‘Brewster Angle’ of incidence – where the resultant reflected and refracted rays are at right angles. Brewster’s ‘Angle’ is useful in all kinds of practical applications; from tuning radio signals to building microscopes for examining objects on a molecular scale, and it is central to the development of fibre optics and lasers, and to the study of meteorology and cosmology.
Brewster’s inventions include: the kaleidoscope; the lenticular stereoscope; the binocular camera; the polyzonal lens; the polarimeter; and lighthouse apparatus. Forget the ‘Fresnel lens’; Brewster first described the dioptric apparatus (the polyzonal lens) in 1812 and lobbied for its adoption at least as early as 1820; two years before Fresnel. It was Brewster’s system of lighthouse illumination that fundamentally improved the British lighthouse network. Brewster’s patent for the kaleidoscope was made on the 30th of August, 1817, and its name comes from the Greek ‘kalos’, ‘eidos’ and ‘scopos’, which put together means ‘beautiful-form-watcher’. Over fifty years later, after Brewster’s death, an American called Charles Bush, who was granted patent improvements in 1873 and 1874, became the first person to mass manufacture ‘parlour’ kaleidoscopes. Brewster didn’t invent the sea thermometer (that was H. Negretti and J. W. Zambra in 1857), nor did he invent the stereoscope (that was Sir Charles Wheatstone), but he did invent the lenticular stereoscope – or 3D viewer – by fundamentally improving Wheatstone’s apparatus; introducing lenticular prisms instead of mirrors.
David Brewster was born in Jedburgh on the 11th of December, 1781, and his first introduction to science came from James Veitch of Inchbonny, otherwise known as the ‘peasant astronomer’, who encouraged young David to make sun dials and telescopes. At the age of twelve, David went to the University of Edinburgh to study for the clergy, but despite being awarded an honorary degree in 1800, which carried with it a license to preach as a Minister, he was hooked on science. The previous year, he had begun contributing to the ‘Edinburgh Magazine’ and from 1807, for more than twenty years, he edited the ‘Edinburgh Encyclopaedia’. Later, he was also a leading contributor to the ‘Encyclopaedia Britannica’. In 1808, he was elected a Fellow of the Royal Society of Edinburgh and in 1815, a Fellow of the Royal Society of London. In the meantime, in 1812, he was awarded his era’s highest literary distinction, a ‘Doctor of Letters’ degree from Marischal College, Aberdeen, and in 1813, he published his first paper.
In 1819, Brewster and Robert Jameson established the ‘Edinburgh Philosophical Journal’ and, in 1824, the ‘Edinburgh Journal of Science’. He played a major role in the formation of the British Association for the Advancement of Science in 1831 and the following year, he was knighted. Later, in 1838, Brewster was appointed Principal of the United College of St Salvator and St Leonard at St Andrews, a post he held for twenty-one years, before becoming Principle of the University of Edinburgh in 1859. Sir David Brewster died of pneumonia at Allerly, near Melrose, on the 10th of February, 1868, and he was buried at Melrose Abbey. He is included in the ‘Hall of Heroes’ in the Wallace National Monument.