Ingenious engineers constructed a 43-mile ice road to transport the huge stones needed to build parts of China's Forbidden City in the 15th century, academics believe.
Despite having already had the wheel for 3,000 years, it is thought engineers believed sliding the stones on wooden sledges along the artificial ice path - lubricated with water - was more reliable and safer than using wheeled transport despite higher costs and the need for more manpower.
The Forbidden City was built at the beginning of the Ming dynasty and is one of Beijing's top tourist attractions.
Declared a World Heritage Site in 1987, it is listed as the world's biggest collection of preserved ancient wooden structures and now houses the Palace Museum, having for 500 years been home to a succession of Chinese emperors.
Howard Stone, a professor of mechanical and aerospace engineering at Princeton University, said he had wondered how the huge stones had been transported to the site during his first visit to the Forbidden City.
And a translation of 500-year-old documents has now found mention of the artificial paths running between the site and a quarry 43 miles outside Beijing.
Writing in the PNAS journal, Professor Stone said: "If you look at the frictional characteristics of ice for the rocks of this size, we estimate that 300 people were needed for this kind of dragging."
Using the method to move the stone carvings would have required meticulous advance planning as water would have had to be run over the paths during the winter months so it could freeze along the route.
Dr Sally Church, of Cambridge University's Faculty of Asian and Middle Eastern Studies, said researchers had been aware of the use of ice to transport marble stone to the Forbidden City. But she said the method had never been published academically before, adding that it was interesting to view it from an engineering point of view.
|< Newer||Older >|