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,
Process of tattooing Thomas Edison's electric engraving pen. This made the process cheaper and faster; it was taken up by the poor and abandoned by the rich. O'Reilly's machine was based on the rotary technology of the electric engraving device invented by Thomas Edison. Modern tattoo machines use electromagnetic coils. The first coil machine was patented by Thomas Riley in London in 1891, using a single coil. The first twin-coil machine, the predecessor of the modern configuration, was invented by another Englishman, Alfred Charles South of London, in 1899. Another tattoo machine was developed 1970-1978 by the German tattoo artists Horst Heinrich Streckenbach