antonhowes

Hmm, I don't think Savery's engine would have required that - it's just a copper vessel, and the pipes were often even made of wood. I've often seen the cannon theory applied to piston-using engines, but that was the next stage with Papin and Newcomen and beyond (hopefully our chapter II)

Mine too! When Matt first showed us a draft I was amazed - never thought it would look so smooth.

Though note, from the post, that there were some applications of stationary aeolipiles with their spouts directed at vanes to do some light mechanical work - things like turning roasting spits and grinding pigments. All known throughout the fourteenth through to the seventeenth centuries, if not earlier, though it's unclear how widely any of them were adopted.

It's no wonder he supervised them so closely then!

OP here: I'd recommend Daniel Defoe's travels through Britain as a good place to start, written in the 1720s. You might also like Celia Fiennes's travels in the 1690s. The travel diaries of the brothers Rochefoucauld, whom I cited, can all be easily cited - their travel through Suffolk (which is more interesting than it sounds, as it contains their general early impressions of England) can be found in its entirety online. All can be found with a little googling.

It has not been, as far as I'm aware. But King has prepared a proper reply for publication, which I expect will end up being published - if not in H&T then in some other journal.

Yes, it's the difference in pressure/heat that is exploited, as Sadi Carnot noted (by analogising the steam engine to a water-wheel exploiting a fall of water, treating it as a "fall of heat")

It is in the post!

One thing I’ll be mentioning in Part III, as I ran out of space in this one: Drebbel in the 1610s applied his insights into perpetual motion to invent a self-regulating oven/furnace. Using mercury rather than water to trap air in a tube, much like the inverted flask I described, rising temperatures would raise a float sitting on the mercury that would then close the aperture for the air feeding the oven’s flame.

Fun tidbit, which I didn’t mention in the piece: Drebbel proposed creating some kind of solar-powered central heating system for London in the 1610s. We don’t have many details, other than the fact he thought it would cost £20,000 and would involve heating some kind of very heat-conductive material on top of a hill nearby. Historians assume it would have then involved heating water to be run in pipes to London’s houses.

Ah nice. Yes, I’m not aware of full translations, though I often have to translate things myself (with a bit of help). In this particular case for Fludd I mainly used secondary literature on his use of the inverted flask experiment and (spoilers) weatherglasses, which also sometimes translate some significant sections.

Very interesting on resonance - I’ll check that out. I seem to recall there was a PhD thesis I skim-read that was all about the relationship between music and weatherglasses in Fludd’s thought.

Yup, I figured. Plausibly fits for Wilkinson and Watt (though I have my doubts). Doesn’t fit for Savery and Newcomen, the subject of my piece.

Fantastic question, which is some way down on my to-do list after the steam engine. The discussion this prompted is a real goldmine, so thank you.

Please read both parts I and II. I specifically addressed various widely-held myths about Hero’s engines, and about aeolipiles.

I don’t think this fits the evidence. At least for the 17thC. People in England did not know how to make good iron with coal, let alone steel, despite many decades of extraordinary government encouragement and special incentives - witness the many, many failed patents that had to be reissued from Sturtevant in 1612 all the way through to the 1660s and beyond.

Cities like London made the switch early on to using coal as a fuel over the course of 1570-1600, but this was for domestic use. Industrial use lagged many decades behind, with iron very much last - long after glassmaking, saltmaking, brewing, and even baking.

When the English iron industry struggled to adapt to rising fuel prices, the overwhelmimg response was just to import it from Sweden. And that was especially the case with the steel industry, which didn’t really take off in England until the breakthroughs of the mid-18thC (long after Newcomen or Savery).

If there’s evidence I’m missing, however, I’d very much like to know.

Indeed. I’ll get to that in Part III (or IV if it’s too long). And it’s why I’ve tried to point out evidence of actual use rather than just the diagrams themselves (though those are at least a start when it comes to subsequent improvement). Safety is certainly a big issue, and Savery’s engines often struggled with it (for the expansive phase of operations). As you say, it’s about the “too often”!

If you write that up, please send me the link (I’m the OP)

Neither the Savery nor Newcomen engines used rubber, so that doesn’t work as a limiting factor. That’s why I didn’t mention it.

I have written very extensively on the evolution of the early patent system - I actually have a not-yet-completed, so far 9-part series on the context of the Statute of Monopolies - but you’ll be in for something of a surprise in Part III. (Spoiler: the most generous ever English patents was seemingly granted to an early steam engine in the 1660s but to little effect)

Well-noticed! I used one of Fludd’s illustrations, but I ran out of space writing about Drebbel, which took us up to c.1607. Fludd will feature VERY heavily in Part III. Fludd eventually became totally obsessed with the inverted flask experiment - and recent historiography suggests he wasn’t seen as a crank, but actually highly respected at the time.

Exactly! Part III or IV will end up talking about boring techniques of the 1650s (long before the famous John Wilkinson methods), but that is precisely the thing with Savery engines - and indeed with Newcomen engines, which worked with pistons long before Wilkinson too!

Maybe for the Watt engine, but this does not apply to the Savery or Newcomen engines. (Though Part III, or perhaps IV, will have a few notes on some almost totally forgotten machine makers of the 1650s.

Thank you! It’s extremely gratifying to know that HN readers like yourself do actually go and read the posts. :D

Hello, author here. I mention this in Part I to link to a prior piece specifically on Ayanz, as this is hugely misunderstood. Ayanz’s machine only used the expansive force of steam, while Savery’s used both atmospheric pressure and the expansive force of steam. This is an absolutely crucial distinction. They were not at all the same, and Ayanz’s populariser and biographer specifically noted the difference.