Thomson, Sir William, Lord Kelvin

SUBJECT AREA: Electricity, Telecommunications

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b. 26 June 1824 Belfast, Ireland (now Northern Ireland)

d. 17 December 1907 Largs, Scotland

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Irish physicist and inventor who contributed to submarine telegraphy and instrumentation.

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After education at Glasgow University and Peterhouse, Cambridge, a period of study in France gave Thomson an interest in experimental work and instrumentation. He became Professor of Natural Philosophy at Glasgow in 1846 and retained the position for the rest of his career, establishing the first teaching laboratory in Britain.

Among his many contributions to science and engineering was his concept, introduced in 1848, of an "absolute" zero of temperature. Following on from the work of Joule, his investigations into the nature of heat led to the first successful liquefaction of gases such as hydrogen and helium, and later to the science of low-temperature physics.

Cable telegraphy gave an impetus to the scientific measurement of electrical quantities, and for many years Thomson was a member of the British Association Committee formed in 1861 to consider electrical standards and to develop units; these are still in use. Thomson first became Scientific Adviser to the Atlantic Telegraph Company in 1857, sailing on the Agamemnon and Great Eastern during the cable-laying expeditions. He invented a mirror galvanometer and more importantly the siphon recorder, which, used as a very sensitive telegraph receiver, provided a permanent record of signals. He also laid down the design parameters of long submarine cables and discovered that the conductivity of copper was greatly affected by its purity. A major part of the success of the Atlantic cable in 1866 was due to Thomson, who received a knighthood for his contribution.

Other instruments he designed included a quadrant electrostatic voltmeter to measure high voltages, and his "multi-cellular" instrument for low voltages. They could be used on alternating or direct current and were free from temperature errors. His balances for precision current measurement were widely used in standardizing laboratories.

Thomson was a prolific writer of scientific papers on subjects across the whole spectrum of physics; between 1855 and 1866 he published some 110 papers, with a total during his life of over 600. In 1892 he was raised to the peerage as Baron Kelvin of Largs. By the time of his death he was looked upon as the "father" of British physics, but despite his outstanding achievements his later years were spent resisting change and progress.

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Principal Honours and Distinctions

Knighted 1866. Created Lord Kelvin of Largs 1892. FRS 1851. President, Royal Society 1890–4. An original member of the Order of Merit 1902. President, Society of Telegraph Engineers 1874. President, Institution of Electrical Engineers 1889 and 1907. Royal Society Royal Medal 1856, Copley Medal 1883.

Bibliography

1872, Reprints of Papers on Electrostatics and Magnetism, London; 1911, Mathematical and Physical Papers, 6 vols, Cambridge (collections of Thomson's papers).

Further Reading

Silvanus P.Thompson, 1910, The Life of William Thomson, Baron Kelvin of Largs, 2 vols, London (an uncritical biography).

D.B.Wilson, 1987, Kelvin and Stokes: A Comparative Study in Victorian Physics, Bristol (provides a present-day commentary on all aspects of Thomson's work).

J.G.Crowther, 1962, British Scientists of the 19th Century, London, pp. 199–257 (a short critical biography).

GW