Yes, that was it! Thank you! How did you know?

Usually "Roman"+"Good post" or "Medieval European"+"Good" can be replaced by "acoup"+"I'm feeling lucky".

PS 1: If you can remember how to spell "acoup", it's the harder part.

PS 2: IIRC he only (mostly?) post about those topics, not about random old stuff, because it's his expertise area.

I remembered the same article too, I'm sure I could have found it again knowing it was listed on HN and/or recalling the wording. Good article too, going in depth on steam engines - the first ones were so inefficient they had to be really close to a really cheap source of fuel and be useful.