“The stroke of brilliance was the wheel-and-axle concept,” said David Anthony, a professor of anthropology at Hartwick College and author of “The Horse, the Wheel, and Language” (Princeton, 2007). “But then making it was also difficult.”
To make a fixed axle with revolving wheels, Anthony explained, the ends of the axle had to be nearly perfectly smooth and round, as did the holes in the center of the wheels; otherwise, there would be too much friction for the wheels to turn. Furthermore, the axles had to fit snugly inside the wheels’ holes, but not too snugly — they had to be free to rotate. [What Makes Wheels Appear to Spin Backward?]
The success of the whole structure was extremely sensitive to the size of the axle. While a narrow one would reduce the amount of friction, it would also be too weak to support a load. Meanwhile, a thick axle would hugely increase the amount of friction. “They solved this problem by making the earliest wagons quite narrow, so they could have short axles, which made it possible to have an axle that wasn’t very thick,” Anthony told Life’s Little Mysteries.
The sensitivity of the wheel-and-axle system to all these factors meant that it could not have been developed in phases, he said. It was an all-or-nothing structure.
And here I’d thought it was because it was done on a cost-plus contract.
Not to be picky, but the title probably should be why it took so long to invent the floating wheel and axle concept.
Fixed wheel and axle configurations have none of the issues cited by the prof. A water wheel or winch, or a wheelbarrow for example, can have a fixed assembly that simply turns haphazardly in a half bearing.
Further, look at a fixed arrangement in the event the two wheels are precise enough to turn at the same speed. Or in an ancient wagon, if the fixed arrangement sat again in a large half bearing and you were willing to put up with some slippage between the wheel and the dirt or vector drag. You still achieved great mechanical advantage.
What the prof is really saying is that precisely fitted floating shell and axles had the issues cited. I’m sure they came down the road ( get it?) much later than when the wheel was invented. ( I know, keep the day job.)
The engineer in me still comes out at times.
Wheel and axle, not shell and axle
Because their fingers were large and they didn’t ask their women to help?
If that doesn’t confirm Drew has a background in engineering, I don’t know what does.
Andy
Sometimes I write these things on the fly and am not clear. A charitable explanation for the profs commentary would be that he did not mean inventing the wheel in the usual context: caveman days etc. but rather he meant that the design and engineering issues he cited were relevant to what we would call a modern wheel – and axle, wheel and bearing assembly.
But I doubt it. The guy wandered off into the weeds with discussions of the axle being the only load bearing option, thick and thin axles, thin wagons etc. A 4×4 wooden beam with a double secured one sided spindle and wheel on each end of the beam would have supported massive loads.
The wheel obviously predates the profs engineering concerns, but he is on track for the issue that is the central problem with crude vs fine tolerance modern wheels: vibration. engineering design of high RPM rotating equipment is high art. Think spindles in steel or paper mills, car wheels etc.
But if memory serves the wheel was invented before they started running the Indianapolis 500……..
Enough of this…..
There are other problems with the article. The invention and widespread use of the wheel preceded the development of the floating axle by millennia. The article seems to suggest that the difficulties in inventing and fabricating the free-floating axle impeded the utility and spread of the wheel. That just isn’t so. Chariots with fixed axles were in use in Mesopotamia no later than 3,000 BC (which suggests that the wheel had been in use for a while by then). They were hard to turn. It wasn’t until about 1,500 BC that the freely rotating axle was invented.
Heh. It’s funny you mention the chariot (the racing chariot was the Porsche of the day, as viewers of Ben Hur know) as I was thinking the same thing. In addition, since two wheels with a fixed axle – if the wheel circumferences we’re not perfectly the same – would as I noted pull to the left or right, and in the limit, just go in a circle. I bet they paid a lot to craftsmen back then to get those wheels awfully close in size.
I’m not sure what the profs motives were other than to tell neat, if apocryphal, stories.
If I recall correctly, our very own Chicago based Museum of Science and Industry has just such a wooden wheel, axle and bushing assembly on display. But it’s been years. One wonders, after the smoothing of the wood, what lubricants they used. Whale oil, olive oil….? I doubt they had mastered the lead impregnated bronze bushing. ( snicker )
I must say this, against the backdrop of the debate on Solyndra, govt involvment in new technology etc the cost plus comment gets the snark of the thread award.
I just happen to know the answer to that question. The earliest-known lubricant was animal fat–tallow. Beef fat. Mutton fat. Even butter. Later olive oil or bees wax was used.
Another factoid: chariots were technologically obsolete in Roman times. They’d been replaced by cavalry. Chariots were mostly used for chariot races by then.
Tallow, eh. Must be thermally stable and resist chemical degradation. If I r ecall, Cisco is basically tallow………what does that tell you? Yech.
Speaking of unknown factoids. Chariot racing was frowned upon as an irresponsible activity because the hungry horses ate more, resulting in excessive flatulence. The ancient Roman philosopher and environmentalist – in his tablet Thruthus Inconvenientus – Al Gorus, predicted dramatic warming, rising seas, hurricanes and the eventual end of the earth. He called for the taxation of Ceasar and horse dung to pay the poorer countries for this technological outrage. In court it was decided that he would fight a gladiator in the Coliseum to establish the truth of his claims. Scholars are a bit murky on what happened next, but it appears Gorus opted in a plea bargain for a retraction of the tax request and began talking instead about “climate volatility. ”
It’s a true story.
More likely it was just handy.
I’m guessing you mean Crisco rather than Cisco.
Nah, Crisco is 100% vegetable oil. It used to be hydrogenated cottonseed oil but nowadays it’s a blend of partially and fully hydrogenated soybean and cottonseed oils.
Maybe I’m thinking good old lard. They still cook with that crap in the south.
Yeah, lard is made of rendered pork fat. Generally, what you’ll get in the stores is made from high and low quality pork fat with partially hydrogenated pork fat mixed in to keep it stable at room temperature.
Plain non-hydrogenated lard (which you might be able to get in Mexican grocery stores) is tasty for frying and for use in baking. Some of the best pie crust in the world is made with lard. A really old-fashioned Southern cook will use lard in her pies. It’s not exactly health food.
Until quite recently (about ten years ago?) McDonald’s fried its french fries in what was at least partially beef tallow. They got sued by some vegetarians.
“Another factoid: chariots were technologically obsolete in Roman times. They’d been replaced by cavalry. Chariots were mostly used for chariot races by then.”
In the Illiad, chariots are used only for taxis to carry the combatants into the single combat that forms the core of the tale. (Well, except when you want to drag your vanquished opponent around the walls of the city…) I’m not aware that the Greeks used chariots much at all in warfare.
Except maybe for Alexander, but he was a Macedonian…
Well, at least we’ve established one thing today. I’m not a cook., although………