Part one of term paper
Thomas Alva Edison is considered one of the greatest inventors in history. He was born in Milan, Ohio on February 11, 1847 and died in 1931. During his life he patented 1,093 inventions. Many of these inventions are in use today and changed the world forever. Some of his inventions include telegraphy, phonography, electric lighting and photog ...

Part two of term paper
... was a major theoretical discovery, which enabled Edison to invent a "pressure relay" using carbon rather than magnets, which was the usual way to vary and balance electrical currents. In February of 1877 Edison began experiments designed to produce a pressure relay that would amplify and improve the audibility of the telephone, a device that Edison and others had studied but which Alexander Graham Bell was the first to patent, in 1876. By the end of 1877 Edison had developed the carbon-bu ...