Douglas was a British motorcycle manufacturer from 1907–1957 based in Kingswood, Bristol, owned by the Douglas family, and especially known for its horizontally opposed twin cylinder engined bikes and as manufacturers of speedway machines. The company also built a range of cars between 1913 and 1922. History The brothers William and Edwin Douglas founded the Douglas Engineering Company in Bristol in 1882. Initially doing blacksmith work, they progressed to foundry work. Joseph F. Barter's Light Motors Ltd. was one of Douglas's customers. Barter built a single-cylinder bicycle engine between 1902 and 1904; he then developed the Fée bicycle engine system. The Fée's 200 cc flat-twin engine was mounted in-line with the frame, using chain drive to a countershaft beneath (with clutch); this then used a drive belt to power the bicycle's rear wheel. Barter founded Light Motors Ltd. to build the Fée system. Production began in 1905; the Fée's name was anglicized to Fairy shortly afterward. In 1916 The Motor Cycle magazine claimed that the 1904 Fée was the earliest flat-twin motorcycle engine, of which there had since been many copies. Douglas made castings for Light Motors and took over the manufacturing rights when Light Motors went out of business in 1907. From 1907 a 350 cc Douglas version was on sale, similar to the Fairy with the engine in-line mounted high in the frame, but without the chain driven countershaft beneath, and with belt final drive. At the 1907 Stanley Show they attracted a lot of attention with a V4 engined motorcycle, with automatic inlet valves, and 2-speed drive. The V4 was not to go into production and by the 1908 show it was only the updated in-line twin that was on show, now lighter and with a lower engine position. Around 1911 the frame was modified to make the engine still lower, and in 1912 the automatic inlet valves were replaced by mechanically operated valves. During World War I Douglas was a major motorcycle supplier, making around 70,000 motorcycles for military use. In a 1916 review of flat-twin engines in Motor Cycle magazine two models of Douglas engine are listed. The 2.75 hp (350cc) with 60.5mm bore and 60mm stroke, with the valves placed side-by-side on the side of the engine. The other engine was the 4 hp (544cc) flat twin of 72mm bore and 68mm stroke. One of the significant differences with this larger engine was the