EWING, SIR JAMES ALFRED (185 5 ), Scottish physicist, was born at Dundee on March 27, 1855. He studied at Edinburgh and held successively the following appointments: Professor of mechanical engineering, University of Tokyo (1878 83) ; professor of engineering, University College, Dundee (1883 9o) ; professor of mechanism and applied mechanics, King's col lege, Cambridge (189o-1903) , director of naval education to the British Admiralty (1903-16) ; and principal and vice-chancellor of the University of Edinburgh from 1916.
Ewing's work on the magnetic properties of iron, steel and other metals is noteworthy. He modified Weber's theory of induced magnetism, and constructed a magnetic model which behaved in accordance with his theory; he also observed the phenomenon which he named "hysteresis" (q.v., see also MAG NETISM). The Royal Society awarded him their Royal medal for this work in 1895. He is the author of a number of papers on thermoelectric properties of metals, on the effects of stress and magnetization on the thermoelectric properties of iron, on the crystalline structure of metals (in conjunction with Rosenhain), and on seismology. He invented an extensometer, a hysteresis tester, a permeability bridge, and other apparatus for magnetic testing.
Ewing was a member of the explosives committee and of the Ordnance Research board ; from 1914-1917, he was in charge of the department of the Admiralty dealing with cipher. He was a member of a number of learned societies and was awarded medals and honorary degrees. In 1911 he was knighted.
Ewing wrote A Treatise on Earthquake Measurements (1883), Mag netic Induction in Iron and other metals (1891, etc.), The Steam Engine and other Heat Engines (1894; 4th ed. 1026), The Strength of Materials (1899, etc.) , The Mechanical Production of Cold (1Q08), Thermodynamics for Engineers (Two), An Engineer's Outlook (1933).