James Alfred Ewing (27.03.1855-7.01.1935) — Scottish physicist, Fellow of the Royal Society of Edinburgh and its president in 1924 — 29. Born in Dundee. Graduated from the Edinburgh Institution and the University of St Andrews. In 1878 — 83 he was professor at the Imperial University in Tokyo, in 1883 —90 at University College in Dundee, in 1890—1903 at the University of Cambridge, and in 1916 —29 at the University of Edinburgh.
His research concerned magnetism, engineering thermodynamics and seismology. He was one of the first to observe hysteresis, established that the area of the hysteresis loop is proportional to the work done over a complete cycle of magnetisation and demagnetisation (1882), and introduced the term “hysteresis”. He studied the magnetic properties of iron, steel and other metals, and the crystal structure of some metals. He tried to explain ferromagnetism as a manifestation of forces of interaction between the atoms of a substance (Ewing's theory). He worked on the design of heat engines and seismographs.
Fellow of the Royal Society (1887). The Royal Medal (1895).