Thomas Edison of the Edison patent to charge a more reasonable rate for the use of the Edison patent rights and lowering the price of the electric lamp. On October 8, 1883, the US patent office ruled that Edison's patent was based on the work of William E. Sawyer and was, therefore, invalid. Litigation continued for nearly six years, until October 6, 1889, when a judge ruled that Edison's electric light improvement claim for "a filament of carbon of high resistance" was valid. To avoid a possible court battle with Joseph Swan, whose British patent had been awarded a year before Edison's,
Timeline of United States inventions (before 1890) the outside surface which could be reproduced when the cylinder was played. Later, the gramophone record with modulated spiral grooves set atop a rotating turntable. The phonograph was invented in 1877 by Thomas Alva Edison at his laboratory in Menlo Park, New Jersey. On February 8, 1878, Edison was issued the first patent (U.S. patent #200,521) for the phonograph. 1877 District heating District heating distributes heat generated in a centralized location for residential and commercial heating requirements. The heat is often obtained from a cogeneration plant burning fossil fuels but increasingly biomass, although heat-only boiler stations, geothermal heating and central