Abstract :
C. F. Scott: It happened to be my lot to be associated with Mr. Tesla in his early work in the development of his polyphase motor. I remember very well his statement that his motors were of two kinds: the synchronous motor, a splendid motor to run; and the induction motor, which he called a torque motor, that would start. The difficulty with the synchronous motor was first to get it started and second to excite it. The difficulty with the induction motor, primarily, was the lagging or magnetizing or exciting current which it required. That lagging current was a mysterious sort of thing; it was the practise to attribute anything we didn´t understand in those early days to “lag.”