Electric Traction.
—There are reports of attempts to obtain magnetic traction by the use of batteries, but not until the electric dynamo and motor had become practical working machines was anything like a successful working electrically propelled car developed. The ordinary method is to generate the electricity at a central station, carry it along the track by means of a wire, from which it is taken by a trolley or some form of conductor to a motor on the car completing the circuit through the track and ground. Such a car was practically demonstrated at the Berlin Exposition of 1879, by Werner Siemens, with a line 219 yards long.[117] This was the first practical electric railway. But long before this time in America experiments had been made with electric traction. Dever exhibited a model at Springfield, Massachusetts, in 1835.[118] In 1879, the year of Siemens’ exhibition, another model railway having a “third rail” to carry the current was exhibited at Stockbridge, Massachusetts. Edison had a car in operation at Menlo Park, New Jersey, in 1882, and the following year a small road carried passengers at an exhibit in Chicago. Miniature roads were exhibited at Philadelphia, Denver, Cleveland, New Orleans, and possibly elsewhere. The first electric railway built and operated for profit in American streets was at Richmond, Virginia, in 1885 on 21⁄2 miles of track. During the same year 2 miles between Baltimore and Hampton were put in operation.[119] By 1890 the number of cities having trolley cars had increased to forty-nine.[120] From that time on the change from horse-drawn cars was very rapid. Trolley lines were even extended throughout the country districts. At one time it looked as though they might replace steam cars for passenger traffic, especially short-haul traffic. There was a complete network of interurban trolley lines in the Eastern and Central Western states by 1910.[121] The trolley is also being used upon hard-surfaced roads without tracks by buses and trucks. Steam railroads running into New York City through the tubes use electric locomotives to draw the trains, thus avoiding the smoke nuisance and the danger therewith connected. The Milwaukee Railroad is using electric locomotives on its mountain division in Montana and Idaho. Electricity is generated by water power; also the trains going down grade are run against a dynamo and storage battery thus acting as a brake as well as renewing the batteries.