I don't think the Rev. Stirling had any notion of what he had started, when he designed the first engines nearly two centuries ago.
It looks like the technology is now becoming available to make these engines into real commercial and world energy saving enterprises.
I think the next twenty years will see the real potential of the design, maybe even sooner. They are already being used in outer space.
As they say, there are very few new inventions, just old ones being reinvented.
What gets me, how is the old Rev going to pick up his royalties?
John