They found a bluestone inside a longbarrow. Aubrey Burl says:
"Following his excavation of Boles Barrow of 1801, William Cunnington wrote of the barrow's `large stones' amongst which he discovered a `Blue hard stone ye same as the upright Stones in ye inner circle at Stonehenge'. For his period, Cunnington was a competent geologist, well able to distinguish between sarsen and dolerite. He removed ten stones from the barrow and arranged them in a circle in his garden at Heytesbury. After his death, a bluestone was taken from his garden to Heytesbury House. From there, it was given to the Salisbury and South Wiltshire Museum by Siegfried Sassoon in 1934."
