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,
Edison Sault Electric Company Edison Sault Electric Company Edison Sault Electric Company was a public utility that provided electricity to the eastern portion of Michigan's Upper Peninsula. Its service area covered four counties (Chippewa, Mackinac, Schoolcraft and Delta). The company was founded in 1892 in Sault Ste. Marie. Wisconsin Energy Corporation acquired the Edison Sault Electric Company with its purchase of its parent company, ESELCO in 1998. In 2009, Wisconsin Energy announced it had reached a definitive agreement to sell Edison Sault Electric to the Cloverland Electric Cooperative of Dafter. Edison Sault's only generating station was the Saint Marys Falls Hydropower Plant located on