Clergyman who made his name as an engineer, inventing the Stirling-cycle engine. Born at Cloag, near Methven (Perth & Kinross), Stirling received a classical education at the University of Edinburgh and then read Divinity at the University of Glasgow, before accepting the charge of the Laigh Kirk in Kilmarnock (1817-24). He then served at Galston Parish Church in East Ayrshire (1824-78).
He invented a regenerative heat exchanger, which he referred to as the 'heat economiser', which he incorporated into a remarkable hot-air engine in 1816. This made use of a process later known as the Stirling Cycle. Stirling engines are unique because of their great efficiency. They are powered by the expansion of a gas when heated, followed by the compression of the gas when cooled. The Stirling engine remains important today and has been suggested as a future replacement for the internal combustion engine and also for use in space.
Stirling died in Galston, where he lies buried.