Henry Royce an engineer, tested an engine in September 1903. In April 1904 he drove his first 10 hp out of the works at Hulme. Based on a Decauville he owned, he correctly believed he could improve it. His car was quieter than any other. On May 4, 1904 he met Charles Rolls who sold quality cars in London. They agreed Royce Limited would build cars for CS Rolls & Co to sell. Two more prototypes came in 1904. A water-cooled twin-cylinder engine of 1800 cc with overhead inlet and side exhaust valves was based on Royce’s engine with an improved crankshaft. Power was 12 hp (9 kW) at 1000 rpm. With a top speed of 39 mph (63 km/h) its transmission brake is fitted behind the gearbox operated by foot pedal. Internal expanding drum brakes on the back axle operated by handbrake lever. Semi-elliptic leaf springs mounted on both axles. A small car with a wheelbase of 75 in (1,905 mm) and track of 48 in (1,219 mm), Royce’s prototype had a flat-topped radiator, the Rolls-Royce 10 a triangular top which would appear on all subsequent cars. Rolls-Royce cars made their debut at the Paris Salon in December 1904. Rolls and Charles Henry Royce decided to make 20 “Rolls-Royce 10 hp Type A” models, but only 16 were built. On March 15, 1906, Rolls and Royce formalised their partnership by creating Rolls-Royce Limited, with Royce appointed chief engineer.