Frank J. Sprague was renowned in electrical circles around the world as "The Father of Electric Traction." The control and safety systems which make railroads and mass transit work today are his. He was the first to design electric motors capable of earning their way in industry, and helped perfect the high-speed electric elevators that made skyscrapers possible. He created the basic circuitry that ran, and still runs, subways, elevators, and electrified railroads. Sprague was among the first men to bring rigorous mathematical discipline to replace cut-and-try research, making him the life-long rival of Thomas Edison. Sprague helped change electricity from a laboratory and lecture-platform oddity to a vital part of the modern world. Almost single-handedly he wired electricity into the second industrial revolution as a basic source of power and transportation.