Historic Engineering Wonders: Photos That Reveal How They Pulled It Off
rarehistoricalphotos.comWhen visiting Bath[1] in UK (mentioned in the article), I learned the Romans used a clever contraption, the "three legged lewis", to lift heavy stones[2].
Referring to the diagram[3] on Wikipedia, a concave hole is first cut into the stone. Parts 1 and 2 of the lewis are inserted, one at a time. Inserting part 3 between 1 and 2 results in all three locking into place. A pin and ring at the top keeps the 3 parts from separating.
[1] https://www.romanbaths.co.uk
[2] https://bathgeolsoc.org.uk/journal/articles/2021/2021_Moving...
[3] https://en.wikipedia.org/wiki/Lewis_(lifting_appliance)#/med...
#/media/File:Three-legged_lewis_diagram_-_02.png){kind=link}
The article lists a "Snake Bridge on the Macclesfield Canal". Here's a spiral bridge on that canal, but not the same one:
https://www.google.com/maps/place/Spiral+Bridge/@53.2849203,...
https://www.google.com/maps/place/Spiral+Bridge/@53.2850202,...
There are 2 in quick succession in Marple ([1] and [2]), very near the Marple Lock Flight ([3]). This happens to be at the very start of Macclesfield Canal.
[1] https://maps.app.goo.gl/tYBvtfJwSSo6nBm29
Though really amazing engineering, I'd say not all of them show "how they pulled it off". I'd like to know how the Byzantine geared mechanical calendar was "pulled off", especially those gears.
Clickspring on YouTube has a whole series into construction methods likely used with the Antikythera mechanism: https://www.youtube.com/watch?v=dRXI9KLImC4&list=PLZioPDnFPN...
And another on building a working reproduction: https://www.youtube.com/watch?v=BGHq4O-ib2U&list=PLZioPDnFPN...
Clickspring also did the Byzantine calendar in specific. Though not in nearly as much detail as the Antikythera series.
The gear teeth are cut with a file. For the angularity, draw a circle with a compass and subdivide it by measuring linearly with a measuring tool. This can be done larger than the part, and the teeth locations marked with a straightedge. By cutting the teeth where marked, you avoid a stack-up of error.
Cool to see how much engineering relied on intuition and improvisation before modern tools existed. These methods look primitive now, but they worked because people understood materials so well. Makes me wonder how much of that hands-on knowledge we’re losing today.
It was often neither intuition nor improvisation, but rules. Bill Hammack's "The Things We Make" goes into a number of examples.
For a slightly more modern example, take European Gothic Cathedrals. People weren't guessing, they weren't improvising, and they weren't relying on intuition - if they did most of them would have collapsed long ago.
These structures were made without blueprints, and often many of the head masons may have been illiterate, but a knowledge of forms and rules such as "the thickness of the wall of an arch should be a bit more than a fifth the span of the arch" allowed for reliably producing stable structures.
These rules were less precise than modern engineering math and mean that many of the structures are overengineered / have higher margins of error than are considered necessary in modern construction, but they are not based on intuition or guessing.
Where did the rules come from?
The deaths of masons and builders. All the way back to Hammurabi.
BTW, Hammurabi was particularly dastardly in his building code specifications. You could, of course, be put to death if a building or wall collapsed and killed someone. But that was just table stakes. Even Ur-Nammu had that much figured out.
Hammurabi added on to the punishment by forcing you to rebuild the wall..
to the specifications of reputable builders..
at your own expense..
and then be put to death.
Don't even get me started on Asian "building codes" back in the day.
HN user Arainach is right, no one was guessing, or intuiting, while building in a lot of these empires. It was wayyy too risky. Pretty much everyone was following rules passed down by the builders for centuries. In some cases, millennia. Only an actual ruler would dare even consider deviating from the known good building forms.
Life was worth a lot less back then. If they were putting people to death over every construction accident that claimed a life nothing would've got built. And back then they weren't building skyscrapers and suspension bridges where one key joint fails and the rest falls over with no warning. They were building simple fairly short structures that can only really kill you if the roof hits you on its way down and gave a whole lot of warning before that happened. Castles and cathedrals and city walls and the like don't fall down unless you intentionally ignore or obfuscate a ton of cracking a slumping and things moving, etc, etc. The people who'd have faced consequences like specified in these code are people who've actually done malicious things.
> They were building simple fairly short structures that can only really kill you if the roof hits you on its way down and gave a whole lot of warning before that happened.
So, you don't believe roofs were invented until very recent times? The only building I've ever been in where roof collapse couldn't be fatal is my neighbor's chicken coop.
> Castles and cathedrals and city walls and the like don't fall down unless you intentionally ignore or obfuscate a ton of cracking a slumping and things moving, etc, etc.
Easily disproven. Here's one refutation:
https://en.wikipedia.org/wiki/Erfurt_latrine_disaster
Seriously: your lack of knowledge about historical architecture is impressive.
Yes, I'm generalizing. Yes, I know that opens my up to low effort "but exceptions" comments with a looking down one's nose town from you and your ilk. No, I don't care.
A barn is a lot more forgiving than a tilt up Walmart. Castles don't pancake like the Surfside Condos (which gave a ton of warning BTW). I think it speaks volumes that your example is a rotted floor overloaded beyond it's capacity. This stuff isn't rocket science except in the rare cases when it is. Anyone trying to portray it as such is doing a disservice to society.
>Castles and cathedrals and city walls and the like don't fall down unless you intentionally ignore or obfuscate a ton of cracking a slumping and things moving, etc, etc.
There are many failure modes other than gradually cracking and eventually failing. Even in that case, by the time you notice such cracking, the cost of repair - if it can be repaired - is dramatically higher, and has tons of effects.
Yes, technically there are other ways things can fall down but they're generally exceptional. You can probably write off 100yr+ weather events let alone any consideration of seismic loading as issues for god. Nowhere did I mention cost. That things cost more to fix after construction is kind of a given.
Being a successful architect was enough to make you a god in ancient Egypt
Fascinating! I would buy this in a "coffee table" style book.
If you liked the Snake Bridge, check out US 441 as it passes (around itself) through Great Smokey National Park (Newfound Gap). The road literally underpasses itself in a very tight loop.
[•] https://www.loc.gov/pictures/resource/hhh.tn0278.photos.3658...
Quibble: I hate, despise, loathe the dilution of the word "rare" to mean, well, in this case "somewhat interesting and not commonly known".
Photos cannot be rare. Physical copies of a photograph might be. Photos are by their nature singular instances of artistic or technical action, so all of them are equally rare.
> Photos cannot be rare. Physical copies of a photograph might be.
"Photo" means both the image itself and a physical copy of said image. So if you agree that physical copies can be rare, then either you agree that photos can be rare or you are idiosyncratically using a different definition of "photo" than everyone else.
unique is pretty rare, i'd say
>Photos cannot be rare
BS. Only if you pedantically define 'photo' as collecting an image at xyz location at a particular instant. I'm quite certain that photos of the Eiffel Tower are NOT rare.
Interesting collection but mostly focused on western world and mixing different eras so feels incoherent, like a low-effort ‘content creation’
the iranian windmills were not expected, neither the absorbing layers of south american cultures brilliant
This article seems to focus mainly on Western civilization. Not saying they aren't wonders. There were many engineering feats in the South/East Asian subcontinents that are not covered.
Syria, China, and Iran are 3 of the examples.
It also features many examples from pre-Colombian South American cultures