Historic Engineering Wonders: Photos That Reveal How They Pulled It Off
(rarehistoricalphotos.com)137 points by dxs 8 days ago
137 points by dxs 8 days ago
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
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.
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...
Fascinating! I would buy this in a "coffee table" style book.
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.
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.
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.
Interesting collection but mostly focused on western world and mixing different eras so feels incoherent, like a low-effort ‘content creation’
It also features many examples from pre-Colombian South American cultures
When 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...