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The Adams Manufacturing Co was an English automobile manufacturer in Bedford between 1905 and 1914.
American-born Edward Ringwood Hewitt had helped Hiram Maxim to build a large steam plane in 1894. He later designed a "gas buggy" along the lines of an Oldsmobile; this machine was built by the Adams Manufacturing Company. The Adams had a supposedly foolproof epicyclic transmission with a 10 hp single-cylinder engine.
Hewitt returned to the United States to manufacture similar cars under his own name, after which more conventional shaft-driven cars with vertical engines were produced (beginning in 1906) as Adams. Models offered included two- and four-cylinder ones and one of the first British V-8s; this last had a 35/40 hp engine based on the French Antoinette model (an aero engine for which Adams were agents). But the V-8 was plagued by crankshaft breakages.
1906 Produced a single-cylinder 9-10 h.p. car with single chain-drive branded as Adams-Hewitt. 
1906 April. Details of the sixteen-cylinder petrol engine.
1907 October. Details of the 10-hp car.
1908 November. Details of the 14-16-hp car shown at Olympia.
1909 March. Description and images of the 14-16hp model.
1909 November. details of the 16-hp car.
In 1910, the company produced an advanced 16 hp model with front-wheel brakes; it came with compressed-air starting, tire-inflating, and jacking equipment. The "pedals-to-push" gear was still offered, as was a conventional four-speed transmission and an unusual planetary gear change (three-speed), which was operated by a pedal that moved in a gate.
1910 November. Details of the three-speed planetary gear.
1911 May. Details of the 16-20hp car.
1912 October. Details of the only model; 16-20hp.
1913 October. Details of the 10hp single-cylinder light car.
1914 The company folded.