191 



marked as true hysteresis when the 

 magnetism of iron was reversed. In his 

 lecture before the Institution in 1883, he 

 not only explained why alternate- current 

 machines could be run parallel but also 

 mentioned that an alternate-current 

 machine could be run as a motor. The 

 theory of both cases had been fully 

 developed by himself in a paper read 

 before the Society of Telegraph En- 

 gineers ;* and, at his suggestion, Pro- 

 fessor Adams successfully tried the 

 experiment of running a machine as a 

 motor at the South Foreland. In 1887 

 he presented to the Royal Society two 

 short papers. | The first related to trans- 

 formers, and showed how to treat them, 

 taking proper account of the true mag- 

 netic properties of the iron. The second 

 treated the theory of alternate-current 

 machines ; showed how the true differ- 

 ential equation of currents could be 



* Journal of the Society of Telegraph Engineers 

 and Electricians, vol. xiii. 1884, p. 496. 



f Proceedings of the Royal Society, vol. xlii. \-\-_ 

 184 and 167. 



