This richly documented overview of the evolution of power systems completes a major contribution to the history of American technology, business, and society. Volume 1, a survey of the continuing use of water power in the nineteenth century, was published in 1979 and was awarded the Dexter Prize in the history of technology. Volume 2, published shortly after Hunter's death in 1984, dealt with the advent of steam power. Now Lynwood Bryant has edited and completed Hunter's draft materials to create the concluding volume he had planned, which carries the story of water power and steam power into the twentieth century and introduces the revolution in power supply created by electric transmission. Louis Hunter brought to his historical work a combined interest in economics and the details of technology. The Transmission of Power begins with the use of men and animals as prime movers for the earliest American industry and continues with the development of many new types of engines to provide mechanical power for workshops too small for steam, which comprised the bulk of nineteenth-century America's manufacturing base. It then reviews the long transition from single prime movers to networks of electric power transmitted from central stations. The concluding section focuses on the special energy distribution problems of the mining and oil-drilling industries. Louis C. Hunter taught for many years at American University. Lynwood Bryant is Professor Emeritus of History at MIT, where he also once served as director of The NUT Press.