Hi Tim,
Brief history here for you of names marked on lamps made by this company:
1880 Swan
1882 Swan United
1883 The Edison Swan (or just Ediswan)
1905 Royal "Ediswan"
1928 Royal Ediswan (under AEI ownership)
1958 Royal Ediswan (under BLI ownership_
1967 Ediswan (under Thorn ownership)
1972 End of the Ediswan name. Over the years the Thorn Lighting Group had expanded to include the lampmaking activities of BTH, AEI, Ediswan, Mazda, Omega, Atlas, Ensign, Ecko, British Siemens, British Westinghouse, Metropolitan-Vickers and these names were gradually all dropped in the run-up to 1972 when the amalgamations were completed and Thorn Lighting Limited was formed. However the Mazda name was re-introduced for domestic lamp sales in 1987. In 1991 GE took over the Thorn Lamps division and therefter the Thorn name disappeared but GE-Mazda continues as the brand name for domestic lamp sales.
Hope this info is of help!
Best regards,
James.
