107,242. British Thomson-Houston Co., (General Electric Co.). June 22, 1916. Systems for alternating-current motors only.- The stators 7, 7<1> of two induction motors have each two primary windings giving different numbers of poles or a single winding arranged to give two pole-numbers, for example, four and eight poles. The secondary windings of the motors (not shown) are connected together through slip-rings and brushes, and the connexions are shunted by high resistances. The primary windings may be connected by switches 13, 14 to two generators 15, 16 working in synchronism and preferably driven by a common prime mover 26. The fieldmagnet windings of the generators are connected to the exciting source 19 through rheostats 22, 23 and reversing switches 20, 21. At starting, the eight-pole primary windings of the stators 7, 7<1> are connected to their respective generators, the voltage of one generator is next gradually weakened, and then built up in the opposite direction. The four-pole primary windings are next connected to the generators, the applied voltage of one generator is next gradually weakened, and finally reversed. The apparatus is especially adapted for electric ship propulsion and for use on petrol-electric vehicles.