London, Nov 19 (ANI): Experts from the University of Exeter have claimed that Neolithic engineers might have used ball bearings in the construction of Stonehenge.
They showed how balls placed in grooved wooden tracks would have allowed the easy movement of stones weighing many tonnes, reports The Daily Mail.
Nobody has yet explained successfully how the heavy slabs used to build Stonehenge more than 4,000 years ago were shifted from their quarries to Salisbury Plain.
Some, the 'bluestones', weighed four tons each and were brought a distance of 150 miles from Pembrokeshire, Wales.
Attempts to re-enact the transporting of the blocks on wooden rollers or floating them on the sea have not proved convincing. The hard surfaces and trenches needed when using rollers would have left marks on the landscape, but are missing.
Experts hit on their new theory after examining mysterious stone balls found near similar monuments in Aberdeenshire, Scotland.
About the size of a cricket ball, they are precisely fashioned to be within a millimetre of the same size, suggesting they were used together rather than individually.
To test the theory, the researchers constructed a model in which wooden balls were inserted into grooves dug out of timber planks.
When heavy concrete slabs were placed on a platform above the balls, held in position by more grooved tracks, they could be moved with ease.
Archaeologist Andrew Young described the experiment in which he sat on top of the slabs to provide extra weight.
"The true test was when a colleague used his index finger to move me forward - a mere push and the slabs and I shot forward. This proved the balls could move large heavy objects and could be a viable explanation of how giant stones were moved," he said.
The team then went on to carry out a life-size test. This time, they used hand-shaped granite spheres as well as wooden balls.
The results proved the technique would have made it possible to move very heavy weights long distances.
"The demonstration indicated that big stones could have been moved using this ball bearing system with roughly 10 oxen and may have been able to transport stones up to 10 miles per day," said Professor Bruce Bradley, director of experimental archaeology at the University of Exeter.
"This method also has no lasting impact on the landscape, as the tracks with the ball bearings are moved along leap-frogging each other as the tracks get moved up the line," he added.
Although the tests do not prove for certain that the ball bearing method was used, they show 'the concept works', Bradley said.
"This is a radical new departure, because previous ideas were not particularly effective in transporting large stones and left unanswered questions about the archaeological record they would have left behind," he added.
The next stage in the project is to provide mathematical evidence of how much force would be needed to keep a stone moving.
Ultimately, the scientists hope to conduct a full-scale experiment in Aberdeenshire using more authentic materials, stone balls and a team of oxen. (ANI)