It would be very interesting to go at length into the details of cost
in this, the latest development of central station transmission, but
time will not permit; nor have I the time at my disposal to go at
length into the central station business as developed by the electric
street railways now so universally in use, or another phase of the
business as exemplified by the large transmission plants, the two
greatest examples of which, in this country, are probably those at
Niagara Falls, N.Y., and Lachine Rapids, near Montreal. So far as
street railways and power transmission are concerned, I would draw
your attention to the fact that the same underlying principle of
multiple-arc mains and feeders originally conceived by Mr. Edison is
as much a necessity in their operation as it is in the electric
lighting systems, whether those systems be operated on the old
two-wire plan, the three-wire plan or by means of alternating
currents.

Passing from a review of central station plants and distribution
system naturally bring us to the operating cost and the factors
governing profit and loss of the enterprise. In considering this
branch of the subject, I will confine my remarks to the business as
operated in Chicago by the company with which I am connected.

Our actual maximum last winter came on December 20, our load being
approximately 12,000 horse power. A comparison of the figures of
maximum capacity and maximum load of last winter shows that we had a
margin in capacity over output of about 20 per cent. The load curves
shown this evening represent the maximum output of last winter
(December 20), an average summer load last year (June 4), and an
average spring load of this year (May 2). For our purposes we will