FERRARIS, GALILEO

born Oct. 31, 1847, Livorno Vercellese, Kingdom of Sardinia [now in Italy] died Feb. 7, 1897, Turin, Italy Italian physicist who established the principles of the induction motor, which is now the principal device for the conversion of electrical power to mechanical power. Ferraris was the son of a pharmacist and the nephew of a Turin physician, to whom he was sent at age 10 and who supervised his education in the classics and the sciences. He was a graduate of the University of Turin and the Scuola d'Applicazione of Turin. While teaching physics he conducted research into light and optics, and the study of optical phase differences in light waves led him to look into similar phenomena in other forms of radiation, including magnetism. Ferraris devised a motor using electromagnets at right angles and powered by alternating currents that were 90 out of phase, thus producing a revolving magnetic field. The motor, the direction of which could be reversed by reversing its polarity, proved the solution to the last remaining problem in alternating-current motors. The principle made possible the development of the asynchronous, self-starting electric motor that is still used today. Believing that the scientific and intellectual values of new developments far outstripped material values, Ferraris deliberately did not patent his invention; on the contrary, he demonstrated it freely in his own laboratory to all comers. Meanwhile, other physicists came independently to the same principleamong them Nikola Tesla, who applied and patented it. Ferraris was also an early advocate of alternating-current distribution systems for electrical power.