Volta made his experimental cell in 1800,producing for the first time a steady reliable electric current. During the nineteenth century, the development of practical applications of electrical energy advanced rapidly. The first major uses of electricity were in the field of communications-first for the telegraph and the telephone. They used not only electric current but also electromagnetic effects.
Thomas Edison’s invention of the electric light bulb was perhaps the most momentous development of all, but not because it was such a unique invention. It was momentous because it led to the creation of an electric power system which has since reached into nearly every corner of the world. Actually, other people were working simultaneously on the same problem, and Edison’s claim to the invention was disputed. Perhaps Edison’s most important claim to fame is his pioneering work in engineering, which helped to provide for New York City in 1882.
The application of electricity has grown to the point where most of us lead electrified life, surrounded by a variety of devices that use electric energy. Less visible, but probably more important, are the thousands of ways industry has put electric energy to work. The direct-current machine is one of the most important ways.