Robert Stirling

Robert Stirling
Reverend Dr Robert Stirling
Born	(1790-10-25)25 October 1790 Methven, Perthshire
Died	6 June 1878(1878-06-06) (aged 87) Galston, East Ayrshire
Nationality	Scottish
Citizenship	United Kingdom
Children	Patrick Stirling b.1820 Jane Stirling b.1821 William Stirling b.1822 Robert Stirling b.1824 David Stirling b.1828 James Stirling b.1835 Agnes Stirling b.1838
Parent(s)	Patrick Stirling and Agnes Stirling
Engineering career
Significant projects	Stirling engine

The Reverend Dr Robert Stirling (25 October 1790 – 6 June 1878) was a Scottish clergyman, and inventor of the Stirling engine.

Background and Christian ministry

Stirling was born at Cloag Farm near Methven, Perthshire, the third of eight children of Patrick and Agnes Stirling and a grandson of Michael Stirling, inventor of a threshing machine.^[1][2] He inherited his father's interest in engineering, but studied divinity at the Universities of Edinburgh and Glasgow.^[1] and was licensed to preach in the Church of Scotland in 1816 by the Presbytery of Dunbarton.^[1] Later that year he became a minister on appointment as second charge of the Laigh Kirk of Kilmarnock. On 12 February 1824 Stirling was appointed as the minister of nearby Galston Parish Church from 1824, where he continued his ministry until 1878. In 1840 he was awarded an honorary Doctor of Divinity by University of St Andrews.^[2][3]

Engineering and science

Hot air engine

He invented what he called the Heat Economiser (now generally known as the regenerator), a device for improving the thermal/fuel efficiency of a variety of industrial processes, obtaining a patent for the economiser and an engine incorporating it in 1816. In 1818 he built the first practical version of his engine, used to pump water from a quarry.^[4]

The theoretical basis of Stirling's engine, the Stirling cycle, would not be fully understood until the work of Sadi Carnot (1796–1832).

Optical instruments

While in Kilmarnock, he collaborated with another inventor, Thomas Morton, who provided workshop facilities for Stirling's research. Both men were interested in astronomy, and having learnt from Morton how to grind lenses, Stirling invented several optical instruments.

Patents

Robert, together with his brother James, an engineer, took out several further patents for improvements to the air engine and in the 1840s James built a large air engine driving all the machinery at his Dundee Foundry Company.

Bessemer process

In a letter of 1876, Robert Stirling acknowledged the importance of Henry Bessemer's new invention – the Bessemer process for the manufacture of steel – expressing a hope that the new steel would improve the performance of air engines.^[5]

Personal life and death

On 10 July 1819, Stirling married Jean Rankine at Kilmarnock. They had seven children:^[1][3]

• Patrick Stirling, born 29 Jun 1820, became a locomotive engineer
• Jane Stirling, born 25 Sep 1821, fed ideas to her brothers
• William Stirling born 14 Nov 1822, became a civil engineer and railway engineer in South America
• Robert Stirling, born 16 Dec 1824, became a railway engineer in Peru.
• David Stirling, born 12 Oct 1828, became the Minister of Craigie, Ayrshire
• James Stirling, born 2 Oct 1835, became a locomotive engineer
• Agnes Stirling, born 22 Jul 1838, became an artist

Rev. Robert Stirling died in Galston, East Ayrshire on 6 June 1878. He is buried in Galston Cemetery where a new gravestone was erected in December 2014 by public subscription replacing the original stone which was in a ruined state. It was rededicated on Sunday 3 May 2015.^[3]

Honours

On 3 October 2014 Stirling was inducted into the Scottish Engineering Hall of Fame^[2][6]

References