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where overhead wires were chiefly em- 

 ployed. There was another reason why 

 in America it had been preferred not to 

 work in parallel, and that was that the 

 alternations of current in the machines 

 were more frequent, and such machines 

 could not be worked in parallel so easily 

 as those which had a small number 

 of alternations. Dynamo machines for 

 alternate currents might be divided into 

 two classes, those which had little or no 

 self-induction, and those which had large 

 self-induction. The Siemens machine 

 was one of those with little or no self- 

 induction, and the Mordey machine was 

 another of the same type. The armature 

 of the Mordey machine looked very like 

 that of the Siemens machine ; but it was 

 a fixture, and the Mordey machine had a 

 peculiarity, in common with the Kennedy 

 machine, which made it extremely origi- 

 nal. In machines of the Siemens and 

 Mordey types, where there was no self- 

 induction, if it was desired to introduce 

 it, all that had to be done was to put 

 large self-induction into the circuit. This 



