Franklin stove

The Franklin stove is a metal-lined fireplace named after Benjamin Franklin, who invented it in 1742. It had a hollow baffle near the rear (to transfer more heat from the fire to a room's air) and relied on an "inverted siphon" to draw the fire's hot fumes around the baffle. Also known as a "circulating stove" or the "Pennsylvania fireplace", it was intended to save firewood and produce more heat and less smoke than an ordinary open fireplace. Over the course of 45 years, Franklin would produce five different designs of stoves, with the last ones burning coal rather than wood.