JOULE, James Prescott, English physicist: b. Salford, Lancashire, 24 Dec. 1818; d. Sale, Cheshire, 11 Oct. 1889. He was educated by private tutors at his father's house near Man chester and also received special instruction in chemistry from John Dalton (q.v.). His father, a brewer, was a man of considerable wealth. This enabled young Joule during his early manhood to pursue scientific research for which he quickly developed great enthusiasm. As early as January 1838 he described in the 'Annals of Electricity' an electromagnetic en gine he had invented. While it was afterward found that this invention was impracticable as a substitute for the steam-engine, the further investigation to which it led brought to light many important facts concerning the laws of heat, its electrical and mechanical nature and evolution, chemical affinity as related to heat, etc. The mechanical equivalent of heat (see HEAT) was first ascertained by Joule, who also, in 1847, announced the doctrine of the correla tion and conservation of energy, in a paper read at Manchester which failed at the time to im press men of science, as did also an address of like import before the British Association, but which was taken up by William Thomson (Lord Kelvin) (q.v.), with whom, from that time on, he collaborated to a considerable extent and by whom its momentous significance was brought home to the scientific world. No principle of
science is now more fully established than Joule's law for determining i the energy de veloped by an electric current n overcoming the resistance of a circuit, a law which he verified by experiment. He received the highest honors of scientific bodies and universities, amongst which were a gold medal from the Royal So ciety in 1852, the Copley Gold Medal from the same body in 1866, and the Albert Medal from the Society of Arts in 1880. In 1872 and 1:7.7 he was made president of the British Asso ciation for the Advancement of Science. A statue has been erected to his memory in Man chester and a tablet in Westminster Abbey. His writings are to be found mainly in the i proceedings of scientific societies and in Eng lish periodicals, but were collected and pub lished by the Physical Society of London as 'The Scientific Papers of J. P. Joule> (2 vols., London 1884 and 1887). Consult Kelvin, Lord, 'J. P. Joule' (in Cassier's Magazine, Vol. VI, p. 405, New York 1894) • Reynolds, 0.. Memoir of J. P. Joule' (in Memoirs axd Proceedings of the Manchester Lit. and Phil. Society, Series IV, Vol. VI, Manchester 1892) ; Tyndall, J., 'The Copley Medalist of 1870' (in Nature, Vol.
V, p. 137, London 1872).