Like so many other of the world’s greatest wonders, the construction that surrounds Beijing’s Forbidden City is shrouded in mystery.
Until now, no one quite understood how workers some 500 years ago were able to haul more than 100 tons of stone blocks to build the imperial palace. (Via Wikimedia Commons / Rabs003)
Which got Princeton University professor Howard Stone thinking ….
With the help of some of his Chinese colleagues, Stone discovered a 500-year-old document that describes the stone as having come from a rock quarry 45 miles away. Still, that didn’t explain how they got there. (Via NPR)
By this point in China’s history, the wheel had been around for about 3,000 years. Historians have long assumed that’s how the ancient builders moved the massive marble. (Via Wikimedia Commons / Zhang Zeduan)
But turns out they likely used something much more like a sled. (Via YouTube / PawshPal)
The team figured out winter temperatures in Beijing were cold enough to ice the roads. And it was just warm enough that if the builders poured water on the roads, the ground under their sleds would stay slick for a few minutes.
The researchers did some math and figured out over 28 days, a team of workers slid the rocks down the icy roads. If a wooden sled had been used, the researchers estimate it took 46 men to drag it over the ice. If it was dragged on dry ground, more than 1500 would have been needed. (Via YouTube / MarkAllan)
All this makes perfect sense, according to the researchers, who told LiveScience they believe the workers would have preferred hauling the stones on the smooth ice to dragging them over a bumpy road.
Stone told the Proceedings of the National Academy of Sciences it was an amazing feat, writing: “You had on the order of a month to pull this off at the temperature conditions of Beijing … I think this just says a lot about their ability to engineer, their ability to plan.”
An archaeologist at University College of London called the idea plausible, but told Nature this technique would not have worked in other parts of the world where the winters are not as cold.
In other words, as for Stonehedge, jury’s still out on that one. (Via Wikimedia Commons / Teacher13)
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