falls power Bppliances. 201 



quired, such as in electric lighting, for in- 

 stance, the alternating current can be used to 

 greater advantage than the direct current 

 when it has to be carried to some distance, 

 owing to the fact that it may be a current of 

 high voltage. A greater amount can be car- 

 ried through a small conductor; thus greatly 

 reducing the cost of an electrical plant that 

 distributes power to a distance. A transformer 

 is an apparatus that changes the current from 

 one voltage to another. 



In the ordinary electric-light plant, such as 

 is used in a small town or village, (he current 

 that is sent out from the power-station has 



-sure of from 1000 to 1500 volts, accord- 

 ing to the distance to which it is sent. It 

 would not do, however, for the current to enter 

 a dwelling at this high pressure, because it is 

 dangerous to handle, and the liability to fires 

 originating from the current would be greatly 

 increased. At some point, therefore, outside 

 of the building, and not a great distance from 

 it, a transformer is inserted which changes 

 the voltage, say, from 1000 down to 50 or 100, 

 according to the kind of lamps used. Some 



- are construct < <1 to be used with a cur- 



f fifty volts and others for 100 or more. 



Th<- lamp iini-t always be adapted to the cur- 



r the current to the lamp, as you choose. 



The human body may he placed in a circuit 



where such low voltag- i without dan- 



