
Sir David Brewster.

Sir David Brewster.
'Sir David Brewster' FRS, (
11 December 1781 –
10 February 1868) was a
Scottish scientist, inventor and writer.
He was born at
Jedburgh, where his father, a teacher of high reputation, was
rector of the
grammar school. At the age of twelve, he was sent to the
University of Edinburgh, being intended for the clergy. However, 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, who was particularly skilful in making
telescopes.
Though he duly finished his
theological course and was licensed to preach, Brewster's 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 philosophers, notably
Etienne 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:
# The laws of
polarization by
reflection and
refraction, and other quantitative laws of phenomena
# The discovery of the polarizing structure induced by
heat and
pressure
# 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
# The laws of
metallic reflection
# Experiments on the absorption of light.
In this line of investigation, the prime importance belongs to the discovery
# of the connection between the refractive index and the polarizing angle
# of biaxial crystals, and
# of the production of double refraction by irregular heating.
These discoveries were promptly recognized. So early as the year
1807 the degree of
LL.D. was conferred upon Brewster by
Marischal College,
Aberdeen; in
1815 he was made a member 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.
Among the non-scientific public his fame spread more effectually by his rediscovery in about
1815 of the
kaleidoscope, for which there was a great demand in both the United Kingdom and the
United States. An instrument of higher interest, the
stereoscope, which, though of much later date (
1849–
1850), may be mentioned here, since along with the kaleidoscope it did more than anything else to popularize his name, was not, as has often been asserted, the invention of Brewster. Sir
Charles Wheatstone discovered its principle and applied it as early as
1838 to the construction of a cumbersome but effective instrument, in which the binocular pictures were made to combine by means of
mirrors. To Brewster is due the merit of suggesting the use of
lenses for uniting the dissimilar pictures; and accordingly the lenticular stereoscope may fairly be said to be his invention.
A much more valuable practical result of Brewster's optical researches was the improvement of the British
lighthouse system. It is true that Fresnel, who had also the satisfaction of being the first to put it into operation, perfected the dioptric apparatus independently. However, it is indisputable that Brewster was earlier in the field than Fresnel; that he described the dioptric apparatus in
1812; that he pressed its adoption on those in authority at least as early as
1820, two years before Fresnel suggested it; and that it was finally introduced into lighthouses mainly by his persistent efforts.
Brewster's own discoveries, important though they were, were not his only; perhaps not even his chief, service to science. He began literary work in
1799 as a regular contributor to the
Edinburgh Magazine, of which he acted as editor at the age of twenty. 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. The work was strongest in the scientific department, and many of its most valuable articles were from the pen of the editor. At a later period he was one of the leading contributors to the
Encyclopedia Britannica (seventh and eighth editions), the articles on
electricity,
hydrodynamics,
magnetism,
microscope,
optics,
stereoscope,
voltaic electricity, etc., being from his pen.
In
1819 Brewster undertook further editorial work by establishing, in conjunction with
Robert Jameson (
1774–
1854), the
Edinburgh Philosophical Journal, which took the place of the Edinburgh magazine. The first ten volumes (
1819–
1824) were published under the joint editorship of Brewster and Jameson, the remaining four volumes (
1825–
1826) being edited by Jameson alone. After parting company with Jameson, Brewster started the
Edinburgh Journal of Science in
1824, sixteen volumes of which appeared under his editorship during the years
1824–
1832, with very many articles from his own pen.
To the transactions of various learned societies, he contributed from first to last between three and four hundred papers, and few of his contemporaries wrote so much for the various reviews. In the
North British Review alone seventy-five articles of his appeared. A list of his larger separate works will be found below. Special mention, however, must be made of the most important of them all–his biography of Sir
Isaac Newton. In
1831 he published a short popular account of the philosopher's life in Murray's Family Library; but it was not until
1855 that he was able to issue the much fuller ''Memoirs of the Life, Writings and Discoveries of Sir Isaac Newton'', a work which embodied the results of more than twenty years' patient investigation of original manuscripts and all other available sources.
Brewster's relations as editor brought him into frequent communication with the most eminent scientific men, and he was naturally among the first to recognize the benefit that would accrue from regular intercourse among workers in the field of science. In an article in the
Quarterly Review, he made a suggestion for "an association of our nobility, clergy, gentry and philosophers," which was taken up by others and found speedy realization in the
British Association for the Advancement of Science. Its first meeting was held at
York in
1831; and Brewster, along with
Charles Babbage and Sir
John F. W. Herschel, had the chief part in shaping its constitution.
In the same year in which the British Association held its first meeting, Brewster received the honour of knighthood and the decoration of the
Guelphic order of Hanover. In
1838, he was appointed principal of the united colleges of St Salvator and St Leonard,
University of St Andrews. In
1849, he acted as president of the British Association and was elected one of the eight foreign associates of the
Institute of France in succession to J. J. Berzelius; and ten years later, he accepted the office of principal of the University of Edinburgh, the duties of which he discharged until within a few months of his death.
Of high-strung and nervous temperaments, Brewster was somewhat irritable in matters of controversy; but he was repeatedly subjected to serious provocation. He was a man of highly honourable and fervently religious character. In estimating his place among scientific discoverers, the chief thing to be borne in mind is that the bent of his genius was not characteristically mathematical. His method was empirical, and the laws, which he established, were generally the result of repeated experiment. To the ultimate explanation of the phenomena with which he dealt he, contributed nothing, and it is noteworthy in a connection that if he did not maintain to the end of his life the corpuscular theory he never explicitly adopted the wave theory of light. Few would dispute the verdict of James D. Forbes, an editor of the eighth edition of the
Encyclopedia Britannica: "His scientific glory is different in kind from that of
Young and Fresnel; but the discoverer of the law of polarization of biaxial crystals, of optical mineralogy, and of double refraction by compression, will always occupy a foremost rank in the intellectual history of the age." In addition to the various works of Brewster already mentioned, the following may be added: ''Notes and Introduction to Carlyle's translation of Legendre's Elements of Geometry'' (
1824); ''Treatise on Optics'' (
1831); ''Letters on Natural Magic'', addressed to Sir Walter Scott (
1831); ''The Martyrs of Science, or the Lives of Galileo, Tycho Brahe, and Kepler'' (
1841); ''More Worlds than One'' (
1854).
See also
Brewster's angle.
References
★ ''The Home Life of Sir David Brewster'', by his daughter Mrs Gordon.
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External links
★
Sir David Brewster -- a short biography
★
The Brewster Kaleidoscope Society