252 POWER DISTRIBUTION FOR ELECTRIC RAILROADS. 
Intramural line during the Columbian Ixposition, and 
subsequent results on the Metropolitan and Lake Street 
elevated roads in Chicago, have shown, what theoretical 
investigation had indicated, that for such service electric 
power is the cheapest available means of propulsion. 
Elevated serviceis of a rather trying nature on account 
of the frequent stops—generally about every quarter of a 
mile—and the large amount of power that has to be used 
     
   
MAP OF 
THE METROPOLITAN 
WEST SIDE ELEVATED R. R. 
Chicago, lllinois 
    
  
ND A AVE. 
54 LAWNDALE 
o] 
W.48TH.ST. 
CRAWFORD J|| AVE. 
Douglas Park 
Street Ry Journal 
FIG. 128. 
in acceleration. The experimentsof Mr. Sprague made on 
the Third Avenue elevated road in New York established 
the facts very clearly. It was found that for .the ordinary 
train, weighing from eighty to ninety tons, with a speed 
reaching, between stations, twenty to twenty-five miles per 
hour, the average indicated horse power of the locomotives 
during service was 70.3 reaching an occasional maximum 
of 185. 'These great inequalities almost vanished when the 
whole power for the line was considered. Sixty-three 
trains were in ordinary use and the mean power, smoothed 
out by the large number of units, varied little from 4500 in- 
    
    
      
   
    
     
    
     
     
    
    
   
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