CHAP. VIL] MAGNETO-ELECTRIC MACHINES. 



667 



use in the well-known galvanoplastic establishment of Christofle 

 and Co., of Paris. These machines weigh 750 kilogrammes, and the 

 weight of copper used in their construction is about 1 75 kilogrammes. 



FIG. 437. Gramme machine for electric light. 



With a small engine of one-horse power, one of them will deposit 

 600 grammes of silver per hour. By some recent modifications in its 

 construction this machine has been improved so as to increase the 



