The problems experienced in the Millennium Stone project (NCE 12 July) suggest that, in transporting the bluestones to Stonehenge, our Neolithic forebears were unlikely to have used sledge transportation over land, or for that matter have followed any route requiring long distance water transportation.
For long distance transportation it is much more efficient to roll the objects than to use sledges. Any stone of reasonable shape, particularly if slabby in form as most of the bluestones appear to have been, can be transformed into an approximate cylindrical form by lashing to it suitably shaped timber pieces. This is a technique well within the capabilities of Neolithic carpenters.
Rivers and streams could have been crossed at natural or specially prepared fording points with a firm bed, where the buoyancy of the stone would have reduced the required pulling force. It is generally accepted that the sarsens were hauled some 32km from Marlborough Downs to Stonehenge. Transporting the bluestones, a tenth the weight of the sarsens, from Carne Meini would have been much simpler.
Dick Parry (F), 5 Farm Rise, Whittlesford, Cambridge, CB2 4LZ