Trompe
A water-blowing machine, consisting of a cistern supported about twenty feet above the air-chamber and connected with the latter by a wooden pipe, near the top of which are several oblique holes. Another pipe connection on the lower cistern or wind-chamber leads to the tuyere. When working, the upper cistern is kept full of water, and the flow therefrom is regulated by a conical plug. As soon as opened, the water rushes down the long pipe, carrying some air, which enters through the holes along with it; the water falls on a projection inside the wind-chamber, and its height in the latter is regulated by an escape-pipe on the side; while the air carried down with the water is forced to the furnace through the discharge previously spoken of. See CATALAN FORGE.