Mortar Stone and Crazing Mill Stone at Gobbett Blowing House

This photograph is dated 7 March 1888. It shows evidence of the tin mining industry which operated on Dartmoor until around 1939. The stone in the centre of the photograph is a mortar stone. They were used for crushing the tin ore in a stamping mill. The round stone in the background is a crazing mill stone. They were used for grinding the tin ore between two flat-faced circular stones. Crazing mills could only grind the alluvial gravels and they were replaced by stamping mills when coarser ores started being mined. Gobbett is one of only three crazing mill remains on Dartmoor.