Page:An Encyclopædia of Cottage, Farm, and Villa Architecture and Furniture.djvu/630

 GOG COTTAGE, FARM, AND VILLA ARCHITECTURE. 1 293. Covered Kilns for burning Bricks or Tiles are very simple in their construction. Like limekilns, they may be formed either above the surface, or more or less under it- The objects are to generate an intense heat, to equalise it as much as possible over a given space, and to continue it in that space for a certain length of time. The form which we have already given for a limekiln would answer perfectly for a brick-kiln ; provided arched ribs were thrown across it, at the height of ten feet one above another, in order to prevent the pile of unburned bricks from being crushed or deformed by their own weight. Where the situation admits, a brick-kiln will always be constructed on the most durable plan when the body of the kiln is sunk in a dry soil ; because, in this case, the side walls may be much narrower, and also because the escape of heat by them will be much more difficult. A kiln to burn 20,000 bricks at a time need not have the chamber more than sixteen feet by fourteen feet, and eight feet high ; above which, the sides may be gradually gathered in, so as to terminate, at the height of twenty or twenty-five feet, in an opening of two or three feet in diameter. The fire is supplied below the floor of the kiln ; this floor being of open work, and at such a height above the fire as that the flames and heat may be equally diffused in their ascent through the openings in the floor. The fire is made in two or more furnaces, which generally extend the whole length of the kiln ; and these furnaces are made larger or smaller, according as they are intended to burn coal or faggot wood. Those who are desirous of building a complete brick and tile kiln may consult Ware's Architecture, chapters xii. and xv., in which they will find the plan and description of one for burning 34,000 tiles ; and, at the same time, about half as many bricks. We shall confine ourselves here to a kiln of a very small size, which will burn bricks, tiles, lime, or clay, at pleasure. It may also be used for coking coal, to be employed for chamber fires, or French cooking ; for making charcoal of wood, or peat ; and various other purposes. For example, when the kiln is employed in burning bricks, or charring wood or peat, a quantity of timber to be saturated with the pyrolignous acid of the smoke may be placed over the mouth of the kiln, under the tiled roof; and all the large openings in the latter closed. In wet seasons, corn in the sheaf may be placed under this roof; and coke, coal, or peat, burned below. By removing the arched top, and replacing it by a flat one, like that of a malt or hop kiln, it is evident that malt, hops, and corn, previously to being ground into meal ; peas, before being split ; or sliced potatoes, to be preserved ; and other articles, may be dried, using coke or charcoal as the fuel. 1 294. Details of the Design. The situation of this kiln is supposed to be similar to that of the limekilns, on the face of a steep bank ; but it may be built on a level surface, of the same dimensions, surrounding the brickwork with two iron hoops. The walls of the ground plan are shown curved outwards ; in which form they are found to expand and contract with less injury than when they are built straight. In the latter case, they contract to a concave line, and ultimately give way. Fig. 1164 is the ground plan ; in which a shows the walls two feet thick; h, an outer wall ^ of nine inches, with a vacuity of six inches between ; c is the ash-pit, sixteen feet long, and two feet six inches wide ; d, part of the iron bars laid over it, two inches deep, one inch broad, and half an inch apart : these bars are cast hollow, and laid loose ; e is the opening or doorway over the furnace by which the kiln is charged with brick or other materials to be burned, after which the door is built up. Fig. 1 1(55 is a dissected horizontal section from A to B in fig. 1167, in which / is part of the ash-pit ; <7, part of the grating; h, part of the bearing arches over the grating ; i, the first layer of open brick- work on edge over the bear- ing arches ; k, the second layer crossing the first, which 1165