80 POWER DISTRIBUTION FOR ELECTRIC RAILROADS. 
when the maximum load is to be met at E. Therefore it 
is not safe to count on more than twenty or twenty-five 
volts help from this source. Bearing this in mind the first 
thought would be to try the No. ooo that served for a sim- 
ilar load at A. From F to E we have a No. ooo plus the 
trolley wire, i.e., 300,000 c. m. ‘The drop over this line would 
then be fifty-two volts. It is clear from this that to come 
within decent limits there must be extra feeder capacity 
from H to F. A second No. ooo here would give a drop 
of forty-six volts in all from H to F or a total of ninety- 
eight to E. 'This is rather large, but considering the fact 
that this extreme load at E is only occasional and at known 
times it is not worth while installing still more copper. 
Instead, it is a very simple matter to raise the voltage at 
the station twenty-five volts or so in preparation for the 
extra load. ‘The feeder should be tied into the trolley at 
frequent intervals near E and once at F. 
Step 7. Now as regards the line from F to C, we reach 
the final step of reinforcing for the grade F G. Thesimplest 
way of doing it is to extend the feeder to g, connecting it 
to the trolley wire at several points. For a load of even 
300 amperes at G the drop would be only 46-+26=72 volts, 
less the overcompounding. On the stretch from G to C 
help is received from C so that there is little to be feared. 
We have now completed the feeding system and may 
now pause to take account of stock. It aggregates 25,000 
ft. of No. ooo wire weighing, in ‘‘weatherproof’’ grade 
about 15,000 1bs. and costing about $2250. It meets the 
condition of an average total loss of less than ten per cent 
in the system at average load and gives not less than 423 
volts at the motors under the worst conditions of load. 
It should be noted that the feeders are practically 
determined by the requirements of maximum load. Asa 
general rule, if one takes care of the maximum loads the 
average loads will take care of themselves. 
To facilitate the calculation of feed wire Plate II 
shows the wire to be used in transmitting 100 amperes 
various distances up to 25,000 ft. at 50 volts loss, and for