Ferraris, Galileo(gälēlā`ō fār-rä`rēs), 1847–97, Italian physicist and electrical engineer. He is noted for his work on alternating current and for his discovery (1885) of the rotary magnetic field, through which he promoted the development of alternating-current motors.
Born Oct. 31, 1847, in Leghorn; died Feb. 7, 1897, in Turin. Italian physicist and electrical engineer. Member of the Academy of Sciences in Turin (1880).
Ferraris graduated from the Higher Technical School in Turin in 1869. He became a professor of physics at the Turin Museum of Industry in 1877. Ferraris’ main works dealt with the theory of alternating current. In 1884 and 1885, Ferraris became one of the first to carry out a theoretical and experimental study of the operation of the transformer. In 1885 he observed the rotating magnetic field and built laboratory models of two-phase induction motors with an artificial second phase (Ferraris motors). In 1888 he reported on his experiments and, independently of N. Tesla, gave a rigorous scientific description of the rotating magnetic field. Ferraris also published a number of works on geometrical optics and the theory of heat.