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many as one hundred lamps simultane- 

 ously would be infinitesimal in compari- 

 son with the large number of lamps 

 alight. He did not think that a switch 

 that contained mercury troughs which 

 would bob up and down was as good 

 as a switch with solid contacts. The 

 switches used at the Grosvenor Gallery 

 were of the latter type, and in his opinion 

 far superior to the mercury switches 

 which Professor Forbes had praised so 

 much. Professor Forbes was a little too 

 severe on English engineers when he 

 said that they merely copied foreign 

 dynamos. It was quite true that in a 

 certain sense all machines resembled 

 each other, in so far namely as all con- 

 tained field-magnets and an armature ; 

 but this was also the case with continu- 

 ous-current dynamos, of which many 

 different types were nevertheless recog- 

 nized. He did not think high frequency 

 was objectionable on the ground of 

 parallel working, but it was on the 

 grounds which he had mentioned in the 

 paper. He was sorry Professor Forbes 



