The New Student's Reference Work/Joule, James Prescott

Joule (jo͞ol), James Prescott, a distinguished English physicist, born at Salford, Dec. 24, 1818, died at his country place near Manchester, Oct. 11, 1889. He was a brewer by trade, as were his father and grandfather before him; but having become interested in chemical and physical problems through the instruction of Dalton, his father provided him with a private laboratory. His most important work includes (1) an accurate study of the heating effect of an electric current (See Joule’s Laws, “Electricity”); (2) a study of the changes in the dimensions of a body which accompany its magnetization; (3) accurate determinations of the mechanical equivalent of heat, employing various methods and showing the equivalence of energy of various forms; (4) an elaborate study of the subject of thermometry; and (5) the discovery of the exact laws according to which gases expand when they do no external work, a research of fundamental importance in establishing the absolute scale of temperatures. See Joule’s Scientific Papers.