新GRE写作名人素材库：爱迪生_GRE写作

新GRE写作名人素材库：爱迪生

　　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. 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 produced stencils to make copies.

　　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.

　　To research incandescence, Edison and others ncluding J. P. Morgan rganized the Edison Electric Light Company in 1878. 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.