Patented in 1816 by Reverend Dr Robert Sterling, this heat-engine was designed to replace the notoriously dangerous steam engines during the industrial revolution. Stirling's invention never replaced the steam engines on a large scale, but it did drive the invention of better grades of steel and safer steam engines.

But how does it work?

Simple apply a heat source that is more than 20c above the environment temperature, such as a cup of tea, and place your Sterling Engine on top to see it go! Where steam engines require very high temperatures and pressures to function, the Stirling Engine uses the external heat source to cause expansion and contraction of the gas inside the chamber, which in turn drives the piston. Elementary!