356 



ON THE CONSERVATION OF FORCE. 



forces, through the instrumentality of the electrical cur- 

 rent. But we can attain the same object by mechanical 



FIG. 50. 



forces, if we produce the electrical current by a magneto- 

 electrical machine, Fig. 50. If we turn the handle, the 

 anker R R 1 , on which is coiled copper-wire, rotates in front 



