Edison and Swan Electric Light Company

The Edison and Swan Electric Light Company Limited was a manufacturer of incandescent lamp bulbs and other electrical goods. It was formed in 1883 with the name Edison & Swan United Electric Light Company with the merger of the Swan United Electric Company and the Edison Electric Light Company.
Thomas Edison established the Edison Electric Light Company in 1878. Joseph Swan established the Swan United Electric Light Company in 1881. Swan sued Edison in the UK claiming his invention was prior which fact was upheld by the British courts and in 1882 the American Edison Company of Thomas Edison sued the Swan Company, claiming infringement of Edison's U.S. patent of 1879; however, Swan could demonstrate prior research and publication, and to avoid uncertain and expensive litigation the two companies negotiated a merger. The lamps sold in Britain were almost entirely to Swan's design, excepting the filaments. From 1887 or earlier Sir Ambrose Fleming was an adviser to the company, and conducted research at Ponders End.
The company had offices at 155 Charing Cross Road, London, and factories in Brimsdown, Ponders End and Sunderland. In 1928, the company was acquired by Associated Electrical Industries. In 1956, a new cathode ray tube plant was opened in Sunderland. The company was renamed Siemens Ediswan following the takeover of Siemens Brothers by AEI in 1957. In 1964, AEI merged its lamp and radio valve manufacturing interests with those of Thorn Electrical Industries to form British Lighting Industries Ltd.
Ediswan Valves.
Edison Swan (or later Siemens Edison Swan) produced a wide range of vacuum tubes and cathode ray tubes under the names "Ediswan" or "Mazda" and the 1964 Mazda Valve Data Book claimed: "Professor Sir. Ambrose Fleming... was Technical Consultant to the Edison Swan Company at the time. It was this close co-operation between University and Factory which resulted in the first radio valve in the world."
Ediswan still survives as a manufacturer of valves (located in Bromsgrove England).