Frank Julian Sprague

Frank Julian Sprague

Edison’s Engineer

Frank Julian Sprague, as much as anyone else in the 19th century, helped to develop the modern city, with elevators that made skyscrapers possible and electric railways for commuters.
Born in Milford on July 25, 1857, Sprague won a commission to the U.S. Naval Academy in Annapolis, Maryland, graduating seventh in his class in 1878. His practical and technical nature didn't take long to emerge-- a born tinkerer, Sprague came up with the first electric call bell system on a U.S. Navy ship. During his military service Sprague also developed an inverted dynamo and sketched plans for a system to transmit pictures by wire.
Back on land, the local man went to work in Thomas A. Edison's famous Menlo Park, N.J. laboratory, as a consultant to the famed inventor. Among the projects Sprague worked on in Edson's lab were designs for a central power station and a feeder system to deliver electricity to far-flung customers.
Sprague was restless, though, and had different goals so in 1884 he left to open his own company. The firm built electric motors, including the first to run at a constant speed under different loads.
Sprague also worked to solve one of the most pressing environmental and health problems of his day. Horse-drawn "trolleys'' and hired carriages were a popular means of public transportation in big cities, but the animals left thousands of pounds of manure on the streets of New York, Boston and other urban centers.
Coal-fired locomotives deposited ash and dust all along their route, turning buildings a drab gray and impairing people's breathing and general health.
Two of his key innovations, the traction motor and the "pole and shoe'' assembly helped Sprague and his investors develop and build the first commercially successful electric railway, in Richmond, Virginia. It began service in 1888, easily handling the steep grades found on some Richmond streets.
Within a few years electric streetcars and interurban trolleys based on Sprague's designs had virtually replaced all of the older, horse-drawn, public transportation in most U.S. cities.
Edison, whose company manufactured most of Sprague's motors, bought out the Milford inventor's company in 1890. By then, 110 streetcar systems using Sprague's tractor motors and pole-and-shoe assembly were in use across the United States and in Europe.