CHAPTER [1I 
DIRECT FEEDING SYSTEMS. 
By direct feeding is meant the supply of current to 
the working system of conductors from a single central sta- 
tion, without any intermediary apparatus. It isthe system 
employed on most present electric street railroads, save a 
few of the largest size. It is ordinarily used on interurban 
lines and would be universally applied were there not many 
cases in which the distribution of power from a single 
station becomes uneconomical at any practicable voltage 
on account of the great distances involved. 
Nearly all interurban lines, and especially the systems 
which are likely to result from the conversion of steam into 
electric lines, can be best operated by other means which 
will be described in subsequent chapters. Indeed a care- 
ful examination of very many existing electric railways 
will disclose the fact that direct feeding is being worked 
far beyond its proper limits of application and isthe cause 
of serious pecuniary loss, both in interest on a huge invest- 
ment in copper and in power needlessly lost on the line. 
Direct feeding however is properly applied in most in- 
stances, and must be ultimately applied as the distributing 
system almost universally, since even where substations are 
employed the lines proceeding from them are often a case 
of direct feeding and must be treated as such. 
Electric railway feeding systems are akin in principle 
to those employed in simple cases of distribution for light- 
ing, and yet in practice differ from them very radically in 
certain particulars. Railway feeders are not generally de- 
signed to preserve uniform voltage within the area fed, 
but to hold the voltage, admittedly variable, within certain 
rather wide, but fixed limits. Lighting feeders must be de- 
signed with reference to a load varying in the same area