Robert Stirling was a Scottish clergyman and engineer. He invented the Stirling engine and was inducted into the Scottish Engineering Hall of Fame in 2014.
Robert Stirling
Rev Stirling's concept air engine, 1827, Hunterian Museum, Glasgow
A Stirling engine is a heat engine that is operated by the cyclic expansion and contraction of air or other gas by exposing it to different temperatures, resulting in a net conversion of heat energy to mechanical work.
A model of a Stirling engine showing its simplicity. Unlike the steam engine or internal combustion engine, it has no valves or timing train. The heat source (not shown) would be placed under the brass cylinder.
A typical late nineteenth/early twentieth-century water-pumping engine by the Rider-Ericsson Engine Company
Philips MP1002CA Stirling generator of 1951
Stirling engine running