KECTIFYING DEVICES 



393 



such a pulsating current is not suitable for motors or lamps 



t would do very well for charging storage batteries. But 



3 principal application of mercury arc rectifiers to-day 



i in connection with arc lamps and the current shown in 



Fig. 258 is not suitable for arc lamp operation. 



Use of Two Anodes. By the addition of another positive 

 terminal of iron and by using connections as shown in Fig. 



Connections 



Current 



Fia. 259. By the Use of Two Anodes it is Possible to Get & More 

 Nearly Continuous Current. 



259, it is possible to rectify every alternation, instead of 

 every other one. The mercury terminal, called the cathode, 

 is shown at C and the two iron terminals, called the anodes, 

 are shown at A and B. The battery is connected between 

 the cathode and a center tap H on the transformer. When 

 F is positive with respect to H, current will flow through 

 the tube and battery by the anode A and, when E is posi- 



