FAST AND HEAVY RAILWAY SERVICE. 237 
the maximum load conditions for the road as a whole will 
be properly met. We may now count up the copper as 
follows: 
Ft. Ebs. 
Trolley wire 100,000 100,000 
750,000 C. m, 40,000 90,000 
900,000 C. m, 50,000 135,000 
  
Total 325,000 
This copper would cost in ronnd numbers $50,000, and in 
place, including the pole line, nearly or quite $60,000. At 
average load during busy hours, say, 1800 amperes total, 
the loss would not be far from ten per cent, while the aver- 
age loss for the all-day run would be considerably smaller. 
But this is not the last word on the working conductor 
question by any means. A daring and apparently highly 
successful experiment has just been tried on a new section 
of the Nantasket Beach line 314 miles long, which promises 
good results on a larger scale. It consists of the applica- 
tion of third rail supply to the service track of a steam 
railroad. 'The line thus changed was that section of the 
Plymouth division of the New York, New Haven & Hart- 
ford Railroad, lying between FEast Weymouth and Nan- 
tasket Junction. An insulated steel rail was placed mid- 
way between the track rails and made to serve as the 
working conductor. Current is taken from this rail by 
means of a soft cast iron shoe carried beneath each of the 
trucks. The third rail is laid in thirty foot lengths, each 
supported by four ash blocks, saturated with insulating 
compound by treatment in vacuum pans. ‘These blocks 
are so let into the ties that the surface of the third rail is 
one inch above the track rail. The third rail is bonded" 
with two heavy copper bonds at each joint, and where 
there are crossings the rail is omitted and the cars pass 
over on momentum. ‘The rail is made continuous electri- 
cally over the crossings by a buried lead covered cable, and 
a sloping leading-block of hard wood is spiked to the ties 
at each side of the crossing to prevent shock to the shoes. 
The arrangement of the third rail and the contact shoe is