"Those who consider what an immense quantity of air is required to supply the current that sets up the chimney of an open fire place, where there is a fire burning, must perceive what an enormous loss of heat there must be, when all this expence of air is supplied by the warmed air of the room, and that all this warmed air is necessarily and constantly replaced by the cold air from without, which finds its way into the room, by the crevices of the doors and windows. But all this waste of heat, or any part... may be prevented by the scheme proposed, for if the air necessary to the combustion of the fuel, and to the supplying of the current up the chimney, be furnished by the air-tube, the warmed air in the room will remain in its places and as this will in a great measure prevent the cold currents from the crevices of the door and windows, the heat in the room will be the more equable, and consequently the more wholesome and agreeable on that account."