I00 POWER DISTRIBUTION FOR ELECTRIC RAILROADS. 
than three-fourths of the copper would be saved, with the 
additional advantage of using standard generators instead 
of those of somewhat abnormal voltage. 
It is a fact to be regretted that in spite of the great 
advantage of even moderate increases in voltage most of 
the existing interurban roads have hastily gone ahead and 
equipped themselves with 500 volt apparatus. There is 
generally some conservative adviser to say, ‘“ Well I think 
copper is a pretty good investment; let us stick to the 
well tried 500 volt apparatus.”” True, copper is a very 
safe investment, so safe that money once locked up in 
it never gets out again, and 500 volt apparatus is ¢ well 
tried,”” but so also is 110 VoIt apparatus, and for a still 
  
  
  
  
— 
F1G6. 509. 
longer period. 'The point of the matter is that most men 
do not realize that standard apparatus can be made to give 
good results in more than one way. 
A short investigation of the interurban line shown in 
Fig. 50 will show how terribly uneconomical is the method 
of operating too often employed, and how the conditions 
can be greatly improved without involving anything in the 
least degree truly experimental. 
The problem really involved in equipping roads of this 
sort is as follows : given standard motors and generators 
as the basis of operations, so to utilize them as to give the 
greatest. economy in construction and operation with the 
fewest possible variations from every-day practice. 
Fig. 59 shows in skeleton form Fig. 50, ready for lay- 
ing out the interurban part of the system. With the main 
urban system we need not concern ourselves, since the feed- 
ing system would be developed in accordance with princi-