FUNDAMENTAL PRINCIPLES. 9 
condition of things. 'T'he normal condition of an electric 
road of any kind is a plurality of cars. This means that 
current is taken from the working conductor at a certain 
limited number of points. In general, these points repre- 
sent approximately equal loads and, so long as the time 
table is maintained, are approximately equidistant. In 
Fig. 6, the uniform straight conductor, A B, is loaded, not, 
C 
500 F 
400 
Pressure in Volts 
@ 
o 
g 
100 
  
B 
15 20 
Street Ry, Journal 
5 
10 
Distances — 1000 £t. units, 
G X, 
as in Fig. 5, at one point, but at ten equidistant points, 
the loads being assumed equal, as they would be quite 
nearly if each load were a car on a level track. 
Here the conditions of fall in voltage are radically dif- 
ferent from the conditions of Fig. 5. At the power sta- 
tion, A, the full current for the entire load is supposed to 
be delivered at a uniform pressure of 500 volts. Assume 
the total current to be 200 amperes, and the resistance of