714 



THE APPLICATIONS OF PHYSICAL FORCES. [BOOK v. 



the objects to be silvered or gilded may be supported by it when 

 they are plunged in the bath. A horizontal rod fixed to the column 

 of the balance carries on one side the soluble anode which is held 

 in the bath and communicates on the other side with the positive 

 -pole of the battery. The other side of the beam carries a double 



FIG. 461. Roseleur's balance or gold aiid silver electro-plating. 



scale-pan; in the upper is placed a counterpoise which produces 

 equilibrium and keeps the beam horizontal. In this position no 

 current passes, since the rods carrying the objects which form the 

 negative pole do not communicate with the battery. But if in the 

 second pan of the balance are placed weights equal to the amount 



