What is known is the first stones - weighing about five tons - were brought at Stonehenge from Wales by water in about 2500 BCE. Some 200 years later, they were dug up and rearranged into the familiar 100m-diameter outer circle and inner horseshoe seen today. Heavier stones were also brought in - weighing up to 45 tons - which were dragged from the Marlborough Downs.
     It is accepted sheer manpower played some part in erecting each upright in holes in the ground. But the real puzzle is how ancient Britons managed to hoist the massive 'crossbars' on to the top of the towering edifices, up to 22ft high. Engineer Nick Weegenaar claims simple mechanics and a cunning invention played their part. Mr Weegenaar has built a model of how he thinks the stones were put in place, and christened it the Litho Lift.
     According to Mr Weegenaar, the uprights were wrapped in a wood case and rolled forward, before being pulled into holes in the ground using pulleys and counter-weights. But it is the stones resting on top of the uprights - the lintels - which really excite him. "The lintels were rolled in the wheel until they were above the uprights, and then lowered down. The wheel would have been on a track, with counterweights to act as ballast." He points to sockets in the top of the uprights to back up this view and insists the counterweights would not have weighed as much as the lintels themselves.
     Archaeologist and broadcaster Julian Richards, who has also seen the Litho Lift, said it was an "interesting idea". "The principles all work - but was it too sophisticated for the people at the time? I would be very interested to see how it would scale up." But Dave Batchelor, head of local authority, historic environment liaison, at English Heritage, raised more serious concerns. "This level of infrastructure is very likely to have left some traces and none have yet been found." He also questioned whether the wheel would have been in use in England when the stones were raised.
     Mr Weegenaar is now keen to build a proper version of his invention - draft carpentry plans are in place - with a wheel some 12ft to 14ft in diameter, to prove his thesis. "If it isn't this way, it must be another and we would continue to modify it until it worked," he said.

Source: BBC News (22 August 2007)