With the stone in
place, all its weight is now lost into the ground as the circular motion
of the roller puts everything into balance. It would take only a few
people to pull the stone on a flat surface, although much more effort
would be needed on a steep hill.
The critical advantage
of this method is that on arrival at the sea there is no lifting of the
stone onto a boat. The complete assembly is simply rolled into the sea.
When the roller is in the water it can then be supported by tree-trunks
lashed to the casing and sailed away, just like a raft. On arrival at
the other side, the stone may simply be rolled onto the beach and then
overland directly to Stonehenge.
the simplest route for the Bluestones would then have been across the
Somerset Levels to Stonehenge. There are no hills or steep inclines to
encounter on this route.