Hotwall

(Gardening.) A wall for the growth of fruit-trees, which is built with a flue or other contrivance for being heated in severe weather, so as to facilitate the ripening of the wood or the maturation of the fruit. The most common form of H. is that in which flues or tunnels are conducted through them, into which the smoke and heated air from fires are made to ascend from a furnace at the bottom of the wall to a chimney on the top; but in some cases H. are formed by constructing the entire wall hollow, tying the two sides together by cro -stones or bricks, and introducing heat by means of metal pipes containing steam or hot water along the bottom of the vacuity, the heat of which rises to the top of the wall, and heats every part in its progre .