720 COTTAGE, FARM, AND VILLA ARCHITECTU UK. be higher than a foot ; that height giving sufficient room for a large loaf, and there can be no reason why the roof of the oven should be higher in the centre than at the sides, except that it is impossible to build the soffit of an arch perfectly flat. The floor of the oven is laid with tiles, and the arch is formed of fire-brick, fire-stone, or trap, set in fire-clay, or in loam mixed with powdered brick. The whole is surrounded by a large mass of common brickwork, to retain the heat. A variety of details on the subject of ovens will be found in White's Treatise on the Art of Bnliing (chap. iii. p. 158); a book ■which will repay perusal, if only for the quaintness of its style, and the variety of extraneous matter which it contains. 1 506. Oven for Green Wood. Fig. 1 367 is a ground plan of a common country oven, in which a is the floor of the oven ; b, the sill of the door ; and c c, holes in the floor, communicating with a tunnel below, for the purpose of admitting air to urge combustion, when green wood is burned. Fig. 1368 is a longitudinal section on the line A B, in which d is one of the openings for the introduction of fresh air to the green fuel, but which is closed by a fire-brick, or by building up the entrance to the funnel, b, when dry fuel is used ; e is a flue from the highest part of the arch of the oven, for conveying away the smoke to the chimney, g, when green fuel is used, but which is closed by a stopper at i, when the oven is heated by dry fuel ; / is the door to the oven, and g the chimney. When dry fuel is used, the orifices at d and i are closed, and the fuel, being introduced aty, is ignited there, and pushed forward to the centre of the oven, where it burns till consumed, or till the oven is sufficiently heated ; the smoke passing out by the upper part of/, and ascending the chimney, g. When sufficient heat has been obtained, which is between 250° and 300°, and which the baker knows by experience, never using a thermometer, the floor of the oven is cleaned out, and the bread introduced ; the door, f, and the stopper, i, are then closed for a short period ; after which a very small opening is made, by loosening the stopper, i, to admit the escape of the vapour exhaled from the bread. This vapour, or whatever proceeds from the door, /, when it is opened either to examine or to take out the bread, ascends by the open chimney, g. Fig. 1365 is a trans-
