X @Nick Szabo

RT Nick Szabo (@NickSzabo4)The boiler in the OP is more than a novelty. Hero's toy steam spinner was a novelty (and also quite irrelevant to actual steam engine technology, showing how shallow a lot of the analysis of tech history is).If I had to guess, it would be the observation that the first c. 80 years of steam engines in Britain was dominated by mine pumping, but Romans had much less need for such an engine because of (a) cheap slave labor, and (b) a drier climate with drier mines.Another possibility ...