MAGNETIC EFFECTS OF ELECTRIC CURRENTS 239 



and the current decreased, but this is impossible with the 

 direct-current system. Therefore, when very large voltage is 

 required, the alternating-current generator is used, and by 



Attic 



Base- 

 ment 



FIG. 121. The wiring circuits of a dwelling house 



means of it energy can be transmitted at high voltage with 

 low current strength. A table will show the economy of 

 this method for the transmission of power. 



TABLE SHOWING THE ADVANTAGE OF TRANSMITTING A SMALL 



CURRENT AT HIGH VOLTAGE RATHER THAN A LARGE CURRENT 



AT Low VOLTAGE (LINE RESISTANCE, 3 OHMS) 



