A major Amercan inventor who obtained more than 350 patents during his lifetime, Elmer Sperry contributed greatly to the momentous technological changes that occured between 1880 and 1930. Best known for the Sperry gyrocompass and automatic pilot, his inventions included arc-light systems, mining machinery, electric automobiles and streetcars, and electrochemical processess. Characteristic of his various inventions were feedback controls that have made automation a fact of life. Richly illustrated with 149 photographs and line drawings, the first full-length biography now returns to print in a paperback edition.