187 



the way of transmitting power by alter- 

 nating currents."* The use to which the 

 author put the diagrams, namely, to 

 determine the safety of running a given 

 machine in parallel with others, was 

 admirable, and quite put an end to the 

 doubts hitherto entertained by practi- 

 tioners on this head. 



Professor J. A. Ewing said that at p. 

 65 of the paper there was a remark 

 about the dissipation of energy in the 

 armatures of dynamos through magnetic 

 hysteresis, from which it seemed to 

 him that the author had perhaps some- 

 what misunderstood in one respect the 

 position he had taken up in the paper 

 there referred to. What he had shown 

 was that the energy dissipated in iron, 

 through magnetic hysteresis in reversals 

 of magnetism, might be very much 

 reduced if the metal were subjected to 

 vibration during the process. When a 

 soft iron wire, for example, was sharply 



* The Telegraphic Journal and Electrical Review 

 vol. xxiv. 1889, p. 112; and Elektrotechnische Zeitschrift 

 vol. x. 1889, p. 1. 



