344 ' Scientific Proceedings, Royal Dublin Society. 



until the desired effect was produced. In any arrangement, with a 

 number of coils in parallel circuit, it would he necessary to he par- 

 ticular as to the arrangement of the magnetic field, for fear of the 

 currents being reversed in some of the coils. This would evidently 

 waste a good deal of energy in heating the coils. In the proposed 

 arrangement the energy of self-induction usually wasted in sparks 

 would be spent in keeping the current running in the line, and 

 there is reason to expect that such a dynamo would not exhibit the 

 apparent increase of resistance with speed pointed out by Messrs. 

 Ayrton and Perry. 



