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,
Oil lamp Oil lamp An oil lamp is an object used to produce light continuously for a period of time using an oil-based fuel source. The use of oil lamps began thousands of years ago and continues to this day, although not commonly anymore. Oil lamps are a form of lighting, and were used as an alternative to candles before the use of electric lights. Starting in 1780, the Argand lamp quickly replaced other oil lamps still in their basic ancient form. These in turn were replaced by the kerosene lamp in about 1850. In small towns and rural areas the latter