William Murdoch (sometimes spelled Murdock) (21 August 1754 – 15 November 1839) was a Scottish chemist, inventor, and mechanical engineer.
Murdoch was employed by the firm of Boulton & 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, as well as the term "gasometer". However the Dutch-Belgian Academic Jean-Pierre Minckelers had already published on coal gasification and gas lighting in 1784, and had used gas to light his auditorium at the University of Leuven from 1785. Archibald Cochrane, 9th Earl of Dundonald, had also used gas for lighting his family estate from 1789 onwards.
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 and Watt until the 1830s, but his reputation as an inventor has been obscured by the reputations of Matthew Boulton, James Watt, and the firm they founded.
William Murdoch was born in Bello Mill Lugar, near Old Cumnock in Ayrshire, Scotland, the third of seven children and the first son to survive beyond infancy. A son of John Murdoch, a former Hanoverian artillery gunner and a Millwright and tenant of Bello Mill on the estate of James Boswell in Auchinleck, he was educated until the age of ten at the Old Cumnock Kirk School before attending Auchinleck school under William Halbert, author of a highly regarded arithmetic textbook. Murdoch excelled in mathematics.
Murdoch also learned the principles of mechanics, practical experimentation and working in metal and wood by assisting in his father's work. Together with his father, he built a "wooden horse" about 1763. His "Wooden Horse on Wheels" was a tricycle propelled by hand cranks. There are reports that in his youth Murdoch was responsible for the construction of one of the bridges over the River Nith; this possibly derives from his father's work in building the Craikston Bridge over Lugar Water in 1774, which William would have been involved in. He is also said to have carried out experiments in coal gas, using coal heated in a copper kettle in a small cave near his father's mill.
In 1777, at age 23, Murdoch walked to Birmingham, a distance of over 300 miles (480 km), to ask for a job with James Watt, the steam engine manufacturer. Both Watt and Murdoch were probably aware of each other because of their connections with James Boswell, who had made several visits to Watt's workshop at Soho. Watt's partner Matthew Boulton was so impressed by Murdoch's wooden hat, made on a lathe of his own design, that he hired him. Murdoch began his career with Boulton and Watt in the pattern workshop of their Soho Foundry, making patterns for the casting of machine parts. By 1778 Watt wrote:
if William Murdoch is not at home he should be sent for immediately as he understands the patterns and care must be taken to avoid mistakes of which our engine shop has been too guilty.
He Anglicised his name to "Murdock" when he settled in England. Murdoch progressed to work in fitting and erecting steam engines and was often sent from Soho for this purpose.
By 1779 Boulton was writing to Watt:
I think Wm. Murdock a valuable man and deserves every civility and encouragement.
On his first solo job erecting an engine at Wanlockhead Mine, Murdoch made the first of many improvements to the standard Boulton and Watt engine by rearranging the gears to enable the steam valve to be worked automatically by the action of the exhaust shaft.
In September 1779 Murdoch was sent to Redruth in Cornwall as a senior engine erector, responsible for the erection, maintenance & repair of Boulton & Watt engines. These were used for pumping water out of the Cornish Tin mines, and therefore the efficiency and efficacy of the engines was an important factor in the amount of tin, and money, which could be extracted from a mine. At that time steam engines were not simply sold to customers but operated, and maintained by the builders for groups or individuals known as 'adventurers' (shareholders). The engine manufacturers were paid not for a completed engine but through a complex formula calculated on the basis of that engine's performance, as Watt described:
Our profits arise not from making the engine, but from a certain proportion of the savings in fuel which we make over any common engine, that raises the same quantity of water to the same height.
Therefore, Murdoch's skill in getting the most out of his engines directly impacted upon Boulton and Watts profits. This he did so successfully that by 1782 Boulton was writing:
We want more Murdocks, for of all others he is the most active man and best engine erector I ever saw...When I look at the work done it astonishes me & is entirely owing to the spirit and activity of Murdoch who hath not gone to bed 3 of the nights.
Due to the frequent problems which could occur with steam engines Murdoch was kept busy travelling around the area repairing and attempting to improve the performance of the engines under his care.