A publication of the Archaeological Institute of America
British engineer Cliff Osenton has discovered how Neolithic portal dolmens could have been built by as few as two people in only a couple of hours. Archaeologists long supposed dozens of people would have been needed to build one of these aboveground tombs, which consist of a capstone supported on upright stones, together weighing several tons. Osenton proposes that the capstone was raised gradually, one side after the other, by lifting it slightly with a long wooden lever. A second person could then prop it up with timbers placed at the three corners of a triangle so that a fulcrum between any two points would be near the stone's center of gravity. By balancing the stone alternately on each fulcrum, the builders could tilt it easily as if it were a giant seesaw. The upright stones were inserted afterward. Though we cannot be certain that prehistoric people used this very technique, Osenton's demonstration fits nicely with the notion that portal dolmens, with their small chambers, were family tombs; small groups could indeed have built them.