75° 



THE POPULAR SCIENCE MONTHLY. 



cago Exposition. It will be noticed that one pole of the generator 

 (dynamo) is connected with the auxiliary middle rail, and the other 

 with one of the two side-rails which are metallically connected togeth- 

 er, as shown. The current goes to 

 the motor on the car by the middle 

 conductor, and is returned to the 

 generator by the side-rails. 



The advantages of the electric 

 railway, should it be made practi- 

 cable in all respects, are obvious, 

 and there is good reason for believ- 

 ing that in time it will be made 

 available and economical even for 

 lines of considerable length. 



In the streets of a city, electric 

 cars would be advantageous upon 

 the surface roads for the reason 

 that they could be run more quietly 

 and swiftly than horse-cars, and, as 

 an electric car can be stopped in 

 less than its own length, just as 

 safely ; in crowded parts of the 

 city, they could thread their way 

 more rapidly through the crowds 

 of carts and other vehicles, because 

 they can be stopped and started 

 more quickly and require less room. 

 But it would be upon elevated roads 

 that their advantages would be pro- 

 nounced, for we should 

 then escape much of the 

 noise and all of the smoke 

 and smell that now at- 

 tend the passing of ele- 

 vated trains. 



By reason of our abil- 

 ity to make every elec- 

 trical car its own loco- 



, . motive, it is clear that we 



UO/lBrd toy can secure greater safety 

 in traveling, and greater 

 frequency in the times of 

 arrival and departure, so that to reach the depot half a minute too 

 late would not be so serious a thing as it now is. As each car is very 

 light, it can be stopped in a much shorter distance than is now possible 

 with a heavy train ; and, even if a collision should occur, it would not 



