Watch Servant Of Mankind (1940) : Full Movie Online Free This short dramatizes how profoundly the inventions of Thomas A. Edison have affected the world in which we live. In addition to the electric light, Edison developed the system of alternating current that carries virtually all of the world's electricity, as well as storage batteries and electric motors. Other highlighted inventions include the phonograph, automatic stock ticker, wireless telegraphy, mimeograph machine, and, of course, the world's first motion picture studio.