[lchengify]

> coal (a fuel you can run the engine on) is of course going to be very cheap and abundant directly above the mine where it is being produced and for the atmospheric engine to make sense as an investment the fuel must be very cheap indeed.

So effectively, once coal was discovered as a fuel where spending small amounts was well worth mining large amounts, steam engines were bootstrapped into product/market fit right on top of the use case.

Fun fact: Modern off-grid pump-jacks operate in a similar manner. They use the natural gas that comes from the well to power the pump that pumps the oil [1].

[1] https://en.wikipedia.org/wiki/Pumpjack