Mould stone in Merrivale Bridge Blowing House

This photograph is dated 4 May 1889. It shows evidence of the tin mining industry which operated on Dartmoor until around 1939. Blowing houses (sometimes called blowing mills) contained small blast furnaces into which a forced draught of air was blown using waterwheel-powered bellows. Cassiterite (tin oxide) ore was smelted in the blast furnace and cast into ingots using a mould stone. The tin mine to the north of Merrivale Bridge was called Wheal Fortune.