William Murdoch (sometimes spelled Murdock) (21 August 1754 – 15 November 1839) was a Scottish engineer and long-term inventor.Murdoch was employed by the firm of Boulton and Watt and worked for them in Cornwall, as a steam engine erector for ten years, spending most of the rest of his life in Birmingham, England.Murdoch was the inventor of the oscillating cylinder steam engine, and gas lighting is attributed to him in the early 1790s, also the term ""gasometer"". However, Archibald Cochrane, ninth Earl of Dundonald, had already in 1789 used gas for lighting his family estate. Murdoch also made innovations to the steam engine, including the sun and planet gear and D slide valve. He invented the steam gun and the pneumatic tube message system, and worked on one of the first British paddle steamers to cross the English Channel. Murdoch built a prototype steam locomotive in 1784 and made a number of discoveries in chemistry.Murdoch remained an employee and later a partner of Boulton & Watt until the 1830s, and his reputation as an inventor has been obscured by the reputations of Boulton and Watt and the firm they founded.