XVIII. W. H. WARREN. 
was more than five times as great as on the railways worked by 
steam power. 
San Francisco, which was one of the first cities to adopt Cable 
Tramways, is now provided with a considerable mileage of 
Electrical Street Railways. During the last year seventy miles 
of horse tramways have been converted to the electric system. 
San Francisco is preéminently a city of heavy grades, but these 
‘ have been successfully dealt with on the Electric Railways, grades 
of one in twelve to one in eighteen being taken in the ordinary 
way with powerful motors on the cars, while a few short grades 
of one in four are dealt with on the balance weight system. 
In Chicago, the Metropolitan West Side Elevated Electric. 
Railway was opened last year, and the result was so satisfactory 
that the other elevated railway companies have decided to adopt 
electricity in place of the present steam locomotives. Chicago is 
well provided with street railways, but enormous extensions are 
contemplated on the electric system. 
In New York, the elevated railways worked by steam, and the 
splendid cable tramway down the principal thoroughfare know? 
as Broadway, deal with a considerable portion of the traffic in the 
direction of what may be called the length of the city, but the 
streets which run across are worked by horse and electric cars 
It is proposed to dispense with the horse, in favor of electric cars, 
and to greatly extend the electric system in the city and suburbs. 
In Boston, and in other large American cities, electricity bids 
fair to supersede every other mode of transport for street and 
suburban traffic. 
Power Stations.—In some cases the engine is connected to the 
generator by means of a flexible spring coupling. The power 
houses of America contain some of the finest steam engine plants 
in the world. The most usual type of generator for street 
railway purposes is the direct current multipolar machine, which 
delivers a current at a pressure of about 500 volts. And when 
these are driven directly from the crank shaft of the engine the 
