Cheers Mate..
So William Cunnington found the Stone and as a Geologist recognised it as a 'Bluestone' like those to be found at Stonehenge..
He took this stone and others from the Barrow and formed them in a circle in His Garden..
After He died the 'Bluestone' was given to Salisbury Museum.
But some say that the Salisbury Stone is from Stonehenge.
Now, I wonder why?
Tony