At Deep Swincombe no bellows were used; the draught probably came in through the hole behind the furnace.
But in the reign of Queen Elizabeth a great revolution in the smelting of tin was wrought by the introduction of German workmen and their improved methods. They brought in the water-wheel. The ruins that are found in such abundance of "blowing-houses," as they are called—one at the least beside every considerable stream—belong, for the most part, to the Elizabethan period. They have their "leats" for carrying water to them, and their pits for tiny wheels that worked the bellows.
The situation of these smelting-houses may be found usually by the mould-stones that lie near them. There is one below the slide or fall of the Yealm, with its moulds in and by it, and another just above the fall. There is one near the megalithic remains at Drizzlecombe, also with its mould-stones. But it is unnecessary to particularise when they are so numerous. I will, however, quote Mr. R. Burnard's description of two in the Walkham valley as typical:
"The first is about 250 yards above Merrivale Bridge, on the left bank of the river. One jamb is erect, and, like most of the doorways of Dartmoor blowing-houses, was low, and to be entered necessitated an almost all-fours posture. Very little of the walls is standing, but what remains is composed of large moor-stones, dry laid. Near the entrance is a stone, 3 feet long and 2½ feet wide, containing a mould, which at the top is 18 inches long, 13 inches wide, and 6 inches deep. The sides are bevelled, so that the bottom length is 12½ inches, with a width of