David Brewster

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David Brewster bigraphy, stories - British astronomer and mathematician

David Brewster : biography

11 December 1781 – 10 February 1868

Sir David Brewster KH PRSE FRS FSA(Scot) FSSA MICE (11 December 1781 – 10 February 1868) was a Scottish physicist, mathematician, astronomer, inventor, writer and university principal. Most noted for his contributions to the field of optics, his inventions include the kaleidoscope and an improved version of the stereoscope.

Early life

David Brewster was born at the Canongate in Jedburgh, Roxburghshire, to Margaret Key (1753–1790) and James Brewster (c. 1735–1815), the rector of Jedburgh Grammar School and a teacher of high reputation. David was the third of six children, two daughters and four sons: James (1777–1847), minister at Craig, Ferryden; David; David; George (1784–1855), minister at Scoonie, Fife; and Patrick (1788–1859), minister at the abbey church, Paisley.A. D. Morrison-Low . Oxford Dictionary of National Biography, Oxford University Press, 2004; online edn, Oct 2005

At the age of 12, David was sent to the University of Edinburgh (graduating MA in 1800), being intended for the clergy. He 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, and this had been fostered by his intimacy with a "self-taught philosopher, astronomer and mathematician," as Sir Walter Scott called him, of great local fame—James Veitch of Inchbonny—a man who was particularly skilful in making telescopes.

Career

Work on optics

Though Brewster duly finished his theological studies and was licensed to preach, his other interests distracted him from the duties of his profession. In 1799 fellow-student Henry Brougham persuaded him to study the diffraction of light. The results of his investigations were communicated from time to time in papers to the Philosophical Transactions of London and other scientific journals. The fact that other scientists – notably Étienne-Louis Malus and Augustin Fresnel – were pursuing the same investigations contemporaneously in France does not invalidate Brewster’s claim to independent discovery, even though in one or two cases the priority must be assigned to others. A lesser-known classmate of his, Thomas Dick, also went on to become a popular astronomical writer.

The most important subjects of his inquiries can be enumerated under the following five headings:

  1. The laws of light polarisation by reflection and refraction, and other quantitative laws of phenomena;
  2. The discovery of the polarising structure induced by heat and pressure;
  3. The discovery of crystals with two axes of double refraction, and many of the laws of their phenomena, including the connection between optical structure and crystalline forms;
  4. The laws of metallic reflection;
  5. Experiments on the absorption of light.

In this line of investigation, the prime importance belongs to the discovery of

  1. the connection between the refractive index and the polarising angle;
  2. biaxial crystals, and
  3. the production of double refraction by irregular heating.

These discoveries were promptly recognised. As early as 1807 the degree of LL.D. was conferred upon Brewster by Marischal College, Aberdeen; in 1815 he was elected a Fellow of the Royal Society of London, and received the Copley Medal; in 1818 he received the Rumford Medal of the society; and in 1816 the French Institute awarded him one-half of the prize of three thousand francs for the two most important discoveries in physical science made in Europe during the two preceding years. In 1821, he was made a foreign member of the Royal Swedish Academy of Sciences.

Among the non-scientific public, his fame spread more effectually by his invention in about 1815 of the kaleidoscope, for which there was a great demand in both the United Kingdom, France, and the United States. As a reflection of this fame, Brewster portrait was later printed in some cigar boxes. Brewster chose renowned achromatic lens developer Philip Carpenter as the sole manufacturer of the kaleidoscope in 1817. Although Brewster patented kaleidoscope in 1817 (GB 4136), a copy of the prototype was shown to London opticians and copied before the patent was granted. As a consequence, kaleidoscope became produced in large numbers, but yielded no direct financial benefits to Brewster.Gordon, p. 54 It proved to be a massive success with two hundred thousand kaleidoscopes sold in London and Paris in just three months., Victorian Microscope Slides. Accessed 1 August 2011