"Niagara ffalte power appliances. 205 



wires would offer to a current of such com- 

 paratively low voltage as 2200. To overcome 

 this difficulty if the voltage, is not increased 

 it would be necessary to use conductors that 

 are very much larger in cross-section (thicker) 

 than the present ones are. And as these con- 

 ductors are made of copper the expense would 

 be too great to admit of any profit to the com- 

 pany. 



If we go back to an illustration we used in 

 one of the early chapters on electricity we can 

 better explain what takes place by increasing 

 the voltage. If we have a column of water 

 kept at a level say of ten feet above a hole 

 where it discharges, that is one inch in diam- 

 eter, a certain definite amount of water will 

 (lix'harire there each minute. If now we sub- 

 stitute for the hole that is one inch in diam- 

 eter one that is only one-half inch in diameter 

 a ve'ry much smaller amount of water will dis- 

 charge each minute, if the head is kept at the 

 same point namely, ten feet. But if now we 

 raise the column of water we shall in time 

 reach a height which will produce a pressure 

 that will cause as much water to discharge 

 per minute through the one-half-inch hole as 

 before discharged through the one-inch hole 

 with only the premie of a ten-foot column. 

 is exactly what takes place when the volt- 

 age is " stepped-up," which is equivalent to an 

 increase of pressu; 



