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Hierapolis Sawmill

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76 pointsbenbreen21 comments

I think one of the largest examples of water-based mechanical engineering from around that time is at Barbegal [0], the greatest known concentration of mechanical power in the ancient world and The capacity of the mills has been estimated at 4.5 tons of flour per day, enough to supply bread for as many as 10,000 of perhaps 30–40,000 inhabitants of Arelate at that time. Spain mines also had very interesting (albeit slave-powered) solutions, with up to 16 wheels draining a mine over 30 vertical meters[1] (and possibly more in other sites), one of which was discovered "intact"! [2, 3] Pre-industrial era engineering in general can be very fascinating.

0. https://en.wikipedia.org/wiki/Barbegal_aqueduct_and_mills

1. https://en.wikipedia.org/wiki/Reverse_overshot_water_wheel#E...

2. https://www.naturalhistorymag.com/sites/default/files/media/...

3. https://www.britishmuseum.org/collection/object/G_1889-0622-...

The carving is photographed here: https://static.cambridge.org/content/id/urn%3Acambridge.org%...

Via https://doi.org/10.1017/S1047759400005341

They didn’t have the metallurgy to make a reliable steam engine. However I think they could’ve industrialized a lot of things using a bronze turbine or waterwheel and a ton of belt systems like old factories once did with line shafts.[1]

[1]https://en.m.wikipedia.org/wiki/Line_shaft

> didn’t have the metallurgy

I wonder if in theory they could've made in bronze. It was still generally the superior metal compared to iron/steel in most ways till the middle ages (IIRC) and much easier to work. It's only downside was cost.

If you make both piston and cylinder out of bronze, they stick together and wear quickly. It's better to make one from bronze and one from iron.

And not much motive to develop it. Slaves were abundant and the practice was widely accepted in paganism. This skewed the economics to favor making use of them.

Slaves were cheaper than the early steam engines. As such even if you built a steam engine (I think historians have documented primitive ones that did work - but they were small, very low power, and inefficient) it wasn't clear that the effort to develop it into something better is worth the cost.

Machines can work 24/7, don't get sick, don't get lazy, don't need training, don't need to be fed, etc.

Even in a world where slave labor was cheaper, machines were obviously better. Fewer people could produce the same output no matter how you look at it.

Machines break all the time. Particularly when you are faced with the metals available back then. They are a lot more reliable today, but we have had ~200 years of industrial revolution to learn how to make reliable machines. We also have a lot more population, and that means a lot more people thinking about how to make machines more reliable.

Modern machines are clearly better than slave labor today. However 2000 years ago a lot of things were different.

The machines need lots of fuel which either needs to be chopped from forests or dug out of coal mines. Both those tasks were labor-intensive and costly.

Some water mills were cost effective though.

The acoup blog went into detail on this topic [0]. Central idea was that early steam power was so inefficient the only way it was worthwhile was for use in coal mines where the fuel was basically free. It took years of improvements to make the technology cost effective in other domains.

[0] https://acoup.blog/2022/08/26/collections-why-no-roman-indus...

>Slaves were abundant and the practice was widely accepted in paganism.

Slavery in various forms was widely utilized across all of humanity until the last few centuries, and in some ways it still is utilized today. We just don't call it slavery anymore.

"Paganism" has nothing to do with it.

Christianity promoted this teaching: "There is neither Jew nor Greek, there is neither slave nor free, there is no male and female, for you are all one in Christ Jesus"

This was a radically different teaching from other world views at the time, paganism being the main one in question during Roman times.

Paganism may or may not have specifically promoted slavery, but it did not offer any teaching that there might be a fundamental problem with it.

Unless you're deliberately cherry picking, Christianity was the poster child of slavery both explicit and implicit. Of course, they are not any more wrong than all the others who utilized slavery.

Framing slavery as rooted in paganism isn't accurate, and more importantly isn't helpful in having a worthwhile conversation. All it does is paint Christianity as some moral paragon, which it is not.

There's some truth to the argument that Christianity introduced novel concepts and ethical ideas that eventually led to the opposition to slavery, ideas that were not present in Graeco-Roman thinking, for example. The fact that those ideas took so long to come to fruition doesn't invalidate that line of argument.

Not only they didn't have the metallurgy, the British didn't have it in 1712, when the Newcomen engine was invented. Some brave souls tried to create engines with steam under pressure, but ended up blowing up things. So, for almost one hundred years, the steam engine worked on negative pressure. The work was not done by the steam, but rather by the atmosphere when the steam condensed and created a vacuum. James Watt's big innovation was not to allow somehow for more pressure in a cylinder, but to improve the condensation of the steam.

So, what was missing in the early Roman empire was not the metallurgy, but the understanding that air has weight, and it's a considerable amount of weight, which can be harnessed to perform work. To us that insight seems trivial, but if you think about it, it could not have come before the scientific method was developed. The Magdeburg experiment [1] that showed that a team of horses cannot separate two hemispheres kept together by the weight of the atmosphere was not only truly brilliant, but it depended fundamentally on a culture of experimentation, culture that simply did not exist on thousand years before.

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

for the first time, all essential components of the much later steam engine were assembled by one technological culture

Though comments here indicate they lacked sufficient metallurgy.

It makes me think of the wolf riders books. A series about "elves" that are basically descendants from a crashed alien ship and there are two groups of them, forming a mini civilization.

Humans seem endlessly fascinated with the question of what is the minimum viable product to make civilization as we know it? or something along those lines. That seems to be a basic impetus behind a lot of dystopian/post-disaster stories. It seems to be a means to strip away a lot of current social stuff and imagine a world with fewer people where someone -- or a few people -- with the right knowledge can create a more civilized microcosm by keeping some of our achievements while largely eliminating the hell is other people parts.

On the flip side is Kyle in Terminator saying "I didn't build the fucking thing!" in exasperation, a scene with seemingly broad appeal, like it hits a nerve for a lot of people.

And maybe we should be wondering in more practical, real world terms about the technological MVP for civilization. Like if you were a bit of a luddite, how would you arrange a comfortable existence where you could understand a lot of the essential tech required to sustain the lifestyle to which you've become accustomed.

> It makes me think of the wolf riders books. A series about "elves" that are basically descendants from a crashed alien ship and there are two groups of them, forming a mini civilization.

This [1], I presume?

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

Yes.

Relevant HN discussion on why Romans didn’t achieve Industrial Revolution: https://news.ycombinator.com/item?id=32607187 Spoiler: it wasn’t because slaves were cheap.

Any time a human arm is used to turn a crank, you have a crank mechanism in reverse: reciprocating rod translating to rotation.

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