Indian Science and Technology in the Eighteenth Century: Some Contemporary European Accounts c24.19

c24.19

16. The blast pipe is a cylinder of dried clay fourteen inches long, and about four inches thick, pierced with a hole of an inch in diameter. It is introduced into the furnace at the bottom of the door, with the point about the centre of the furnace, and about five inches above the bottom. The door is then closed with a tile of dried clay, and the outside is built up and secured with wet clay plastered over, a layer of charcoal dust, about two inches thick, having been first placed at the bottom of the furnace to prevent the reduced oxide adhering to it.