THE CONQUEST OF NATURE 



may be handled with impunity, while a similar wire 

 carrying a current of high voltage may not safely be 

 touched. But when we attempt to visualize the dif- 

 ference in the two currents we are all at sea. We may 

 suppose, of course, that electrons spread out over a long 

 stretch of the secondary coil must be more widely scat- 

 tered. One can conceive that the electrons, thus rela- 

 tively unimpeded, may acquire a momentum, and hence 

 a penetrative power, which they retain after they are 

 crowded together in a straight conductor. But this sug- 

 gestion at best merely hazards a guess. 



Arrived at the other end of its journey, the current 

 which travels under this high voltage is retransformed 

 into a low-voltage current by means of an apparatus 

 which simply reverses the conditions of the step-up 

 transformer, and which, therefore, is called a step- 

 down transformer. The electricity which came to 

 Buffalo as a twenty-two-thousand-volt current is thus 

 reduced by any desired amount before it is applied to 

 the practical purposes for which it is designed. It may, 

 for example, be " stepped-down " to two thousand volts 

 to supply the main wires of an electric-lighting plant; 

 and then again " stepped-down" to two hundred volts 

 to supply the electric lamps of an individual house. 



Who that reads by the light of one of these electric 

 lamps, let us say in Buffalo, and realizes that he is read- 

 ing by the transformed energy of Niagara River, dare 

 affirm that in our day there is nothing new under the 

 sun? 



[200] 



