EDISWAN

Edison Swan of 36-7 Queen Street, London (1908)

Joseph Swan experimented with incandescent lamps but lacked an adequate vacuum pump. He heard about a newly invented air pump known as a Sprengel pump and applied this to his experiments.

• 1877 Thomas Edison turned his attentions to electric lighting towards the end of 1877. He believed that commercially successful lighting needed to have similar characteristics to the existing gas lighting. His early experiments using carbonized paper and carbon were failures. The lamp usually cited as his first success was made on 19th October 1879 but the carbonized cotton used as the conductor was still very fragile. He later found that a particular type of Japanese bamboo was the most satisfactory.

• Edison was not the first to patent the modern design of the light bulb. It seems that Joseph Swan demonstrated the same carbon filament light bulb in Newcastle at least ten months prior to Edison's announcement. In addition, Swan received a British patent in 1878 for the same bulb that Edison patented in the U. S. in 1879.

• Edison lost in the British courts for infringement of Swan's patent. As part of the settlement, Edison was forced to take Swan in as a partner in his British electric works. The company was called the Edison and Swan United Electric Light Co. Eventually, Edison acquired all of Swan's interest in the company. In 1882 it seemed the obvious choice to merge their British companies and join forces in developing the electric filament light.

• 1883 In the United States, Edison didn't have the chance to put up a fight. The U.S. Patent Office had ruled on October 8, 1883 that Edison's patents were based on the prior art of a man named William Sawyer and were invalid. In addition, Swan had already sold his U.S. patent rights to the Brush Electric Company in June of 1882. The Edison and Swan United Electric Light Co Ltd was registered on 26th October, manufacturers of electric lamps and fittings.

• 1883 The Swan catalogue from 1883 displays the number and types of lamps available. The catalogue lists more than 100 houses and other buildings and 25 ships all lit by Swan's lamps.

• 1889 Engines and dynamos for the electric light installation at the Adephi Theatre.

• 1889 Electrical lamp for optical lanterns.

• 1893-4 Patents expired. Market opened up to domestic and foriegn competition.

• 1896 Absorbed the Manchester Edison and Swan Co Ltd in November.

• 1904 Professor Sir. Ambrose Fleming and his original diode valve, made in the Edison Swan (later Mazda) factory at Ponders End near London in 1904. Professor 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.

• 1905 British Carbon Lamp Association formed with membership including: Ediswan, BTH, GEC, Siemens, Cryselco, Pope's Electric Lamp Co, Stearn Electric Lamp Co

• After this time the company seems to have been known mostly as Edison Swan Electric Co

• 1909 Tungsten filaments had largely replaced carbon filaments in lamps made by all manufacturers for most purposes.

• 1914 Manufacturers of drawn wire (tungsten) and carbon filament lamps, general electric light apparatus and fittings.

• WWI: Edison and Swan Electric Light works (Ponder's End, Middlesex) doubled production of bulbs and tubing; special glasses developed for 0.5W lamps, signalling lamps and wireless valves    Edison Swan and Cossor began quantity production of thermionic valves for the armed forces

• 1920 Jan. Physical and Optical Societies Exhibition. Exhibited wireless telegraphy.

• 1925 Ediswan Crystal Set was designed for personal listening through a single pair of headphones. It used a mineral crystal, commonly galena, as a detector. Ediswan is a trademark name conflated from the Edison and Swan United Electric Light Co Limited, the company formed between Briton, Joseph Swan, and the American, Thomas Alva Edison, as a result of the major court battle they fought over who was the original inventor of the electric light bulb.

• 1928 As part of the formation of AEI, the new company bought Edison Swan Electric Co (Ediswan) which then took on valve production for the whole company.

• 1936 Started production of cathode ray tubes for the new BBC television service.

• 1937 Radio valves, accumulators, electric lamps and cable manufacturers. "Ediswan" Electrical Products.

• 1952 The Edison Swan Co purchased British Mechanical Productions Ltd and its subsidiary General Accessories Co Ltd, which made electrical accessories under the Clix brand and radio and television components, thereby filling a gap in parent AEI's range of products