Edison, Thomas (Alva) 1847 -- 1931
Inventor. Born February 11, 1847 in Milan, Ohio. His father was a jack-of-all-trades, his mother a former teacher. Edison spent three months in school, then was taught at home by his mother. At the age of 12 he sold fruit, candy, and papers on the Grand Trunk Railroad. In 1862, using his small handpress in a baggage car, he wrote and printed the Grand Trunk Herald, which was circulated to 400 railroad employees. That year he became a telegraph operator, taught by the father of a child whose life Edison had saved. Exempt from military service because of deafness, he was a tramp telegrapher until he joined Western Union Telegraph Company in Boston in 1868.
Probably Edison's first invention was an automatic telegraph repeater (circa 1864). His first patent was for an electric vote recorder. In 1869, as a partner in a New York electrical firm, he perfected the stock ticker and sold it. This money, in addition to that from his share of the partnership, provided funds for his own factory in Newark, N.J. Edison hired technicians to collaborate on inventions; he wanted an "invention factory." As many as 80 "earnest men," including chemists, physicists, and mathematicians, were on his staff. "Invention to order" became very profitable.
From 1870 to 1875, Edison invented many telegraphic improvements: transmitters; receivers; the duplex, quadruplex, and sextuplex systems; and automatic printers and tape. He worked with Christopher Sholes, "father of the typewriter," in 1871 to improve the typing machine. Edison claimed he made 12 typewriters at Newark about 1870. The Remington Company bought his interests.
In 1876 Edison's carbon telegraph transmitter for Western Union marked a real advance toward making the Bell telephone practical. (Later, Emile Berliner's transmitter was granted patent priority by the courts.) With the money Edison received from Western Union for his transmitter, he established a factory in Menlo Park, N.J. Again he pooled scientific talent, and within six years he had more than 300 patents. The electric pen (1877) produced stencils to make copies. (The A. B. Dick Company licensed Edison's patent and manufactured the mimeograph machine.)
Edison's most original and lucrative invention, the phonograph, was patented in 1877. From a manually operated instrument making impressions on metal foil and replaying sounds, it became a motor-driven machine playing cylindrical wax records by 1887. By 1890 he had more than 80 patents on it. The Victor Company developed from his patents. (Alexander Graham Bell impressed sound tracks on cylindrical shellac records; Berliner invented disk records. Edison's later dictating machine, the Ediphone, used disks.)
To research incandescence, Edison and others ncluding J. P. Morgan rganized the Edison Electric Light Company in 1878. (Later it became the General Electric Company.) Edison made the first practical incandescent lamp in 1879, and it was patented the following year. After months of testing metal filaments, Edison and his staff examined 6,000 organic fibers from around the world and decided that Japanese bamboo was best. Mass production soon made the lamps, although low-priced, profitable.
Prior to Edison's central power station, each user of electricity needed a dynamo (generator), which was inconvenient and expensive. Edison opened the first commercial electric station in London in 1882; in September the Pearl Street Station in New York City marked the beginning of America's electrical age. Within 4 months the station was lighting more than 5,000 lamps for 230 customers, and the demand for lamps exceeded supply. By 1890 it supplied current to 20,000 lamps, mainly in office buildings, and to motors, fans, printing presses, and heating appliances. Many towns and cities installed central stations. Increased use of electricity led to Edison-base sockets, junction boxes, safety fuses, underground conduits, meters, and the three-wire system. Jumbo dynamos, with drum-wound armatures, could maintain 110 volts with 90 percent efficiency. The three-wire system, first installed in Sunbury, Pennsylvania, in 1883, superseded the parallel circuit, used 110 volts, and necessitated high-resistance lamp filaments (metal alloys were later used).
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