Source: Grace's Guide
The Rev. Dr. Robert Stirling is the inventor of the regenerator, that became famous during the 19th century, to be used on hot air engines.
Stirling invented also a close-cycle hot-air engine, that was different than what had been done until then.
Stirling was born in the year 1790, near Methven, in Perthshire. Educated at St. Andrews, he was licensed to preach by the Presbytery of Dumbarton in the year 1815; and in the following year he received a presentation from the Commissioner of the Duke of Portland to the Kilmarnock second charge.
In the year 1824 he was translated to the neighbouring parish of Galston, where the living was in the gift of the same patron; and there he lived And laboured during the remainder of his long ministerial career, which in all extended over a period of sixty-three years.
The honorary degree of D.D. was conferred upon Mr. Stirling in the year 1840 by the University of St. Andrews, in recognition of his scholarly and scientific attainments, which were of an unusually high order.
Dr. Stirling was decidedly of a mechanical turn of mind, and indeed there seems to have been a special bent in that direction in the family. His brother, Mr. James Stirling, was a very accomplished engineer; and of his sons no fewer than three have inherited his taste for mechanical pursuits, and have become well known in railway engineering, their honourable positions being due alike to their professional abilities, and to the possession of much resolute and independent spirit, such as specially distinguished their father's character.
The eldest son, Mr. Patrick Stirling, was for a long time the locomotive superintendent on the Glasgow and South-Western Railway, with headquarters at Kilmarnock, and is now well known as the locomotive superintendent of the Great Northern Railway.
The youngest son, Mr. James Stirling, succeeded Patrick in the service of the Glasgow and SouthWestern Railway Company, and has recently been appointed to a similar position on the South-Eastern Railway.
Another son, William, was engineer to the Lima and Callao, and is still in South America.
Like his brother James, the late Dr. Stirling early developed a remarkable taste for mathematics and mechanics, and, as already indicated, so early as the year 1816, when he was about twenty-six years of age, he invented and patented his air engine, which was afterwards improved somewhat by his brother James, and re-patented in 1827, and again in 1840.
In its best form Stirling's air engine was constructed at the Dundee Foundry in the year 1842, for the purpose of driving the machinery there; it had a working cylinder of 16 inches in diameter, with a stroke of 4 feet. The engine drove the machinery at the Dundee Foundry for a few years at a very small cost for maintenance, there being little tear and wear of parts. It was then discontinued.
During his whole life mechanics formed the favourite pursuit of Dr. Stirling, and he constructed, with great neatness and dexterity, many optical and other scientific instruments. He also discharged the duties of his pastorate with great fidelity, and his upright, straightforward character won for him the esteem, not only of his own people, but also of the whole community who enjoyed the benefits of his public spirit and active benevolence.
Robert Stirling died in Galston, East Ayrshire on 6 June 1878, in his 88th year.