ELECTRIC TRUNK-LINE OPERATION—SPRAGUE. 133 
of various types of overhead and third-rail constructions. High and 
low potentials, 15 and 25 cycle frequencies, gearless and geared mo- 
tors, and air and electric controls—all are actively discussed. 
But above the discordant notes there arises now and then the cry 
of standardization. For example, in a recent paper the view was 
expressed that but a single plan—the high-tension overhead trolley, 
with 15-cycle single-phase alternating-current motors—was possible 
of serious consideration on trunk-line service, and that this system 
should now be adopted and standardized, despite the fact that there 
was not in existence a single equipment of this character in practical 
railway operation ! 
I do not intend to burden this paper with statistics—one can prove 
almost anything by them—but I will epitomize certain conclusions 
which I think will bear the test of time. 
1. Of the two broad lines on which electrification can be considered, 
if increased economy, that is, reduction of operative expenses by re- 
placing the steam locomotive with an electric one, with concentration 
of prime power and perhaps the use of water power, be deemed the 
dominant reason for change of motive power, then every wheel in an 
electrified division should be turned electrically; and the savings 
effected should pay not only a fair rate of depreciation of the total 
equipment, but a satisfactory rate of interest on the new capital ex- 
pended, in fact a better rate than if spent in some other way. 
2. Increase of capacity, both in locomotive haulage, schedule speeds, 
motor-car trains and terminal facilities, of a character impossible 
to steam service—all resulting in augmented traffic, and increased 
use and capacity of the dead part of the systems, the tracks and 
roadbed—will ordinarily be the more potent influence in leading to 
the adoption of electric operation, and will often warrant heavy 
capital expenditures. 
3. Every large road is a problem which must be considered finan- 
elally and technically on its own merits, and in most features other 
than those which without effort can be harmonized its decision will 
be of little practical concern to other roads. 
4. The adoption of electricity will ordinarily begin with those 
divisions where traffic is comparatively dense, and once adopted the 
territory over which it can be extended will naturally increase. 
5. Terminal properties in great cities, underground and tunnel sec- 
tions, and heavy mountain sections where duplication of tracks 
because of extra heavy construction cost is prohibitive offer an imme- 
diate field for the serious consideration of electrification. 
6. There can not now be safely established any final standard, or 
any single system selected as the best for all roads. What is the best 
for one might easily be less advantageous for another, and there is no 
valid reason why any road should adopt something fitting to a less 
