This photograph is dated 21 December 1887. It shows evidence of the tin streaming industry on Dartmoor. The caption refers to Har Tor, which is nowadays marked on OS maps as Hartor Tors (Higher and Lower). The blowing house is on the bank of the River Plym nearby. Blowing houses were used for smelting cassiterite tin ore dug by hand from the river valley.
Image - Glass Plate