BRICKS AND TILES.
PUG MILL.
STOOL, OR WORKING SHED.
BARROW FOR WET BRICKS.
BARROW FOR DRY BRICKS.
Bricks are made of clay mixed with sand or ashes. The brick-field is first covered with either of these to the depth of an inch or two, and is well dug in and turned about during several weeks; when the bricks are to be made, the mixture is put into a “pug mill;” this is a large tub having an upright iron bar passing up from the bottom, and having several broad iron blades fixed to its sides at the part which is in the tub; at the top there is a cross-bar of wood, to which a horse is harnessed; the horse, when driven round in a circle, turns the upright iron bar and consequently the iron blades. Into this tub the clay and ashes are now put, a little at a time, and as the horse goes round they are thoroughly mixed together; a man takes pieces of this clay of the proper size, and hands them to another who stands before a table in the shed, and has a mould before him; this consists of a piece of wood with sides of the size of the brick, which is always ten inches long, five broad, and three thick, before burning. The sides of this mould can be turned up and down; they are now put up, and the piece of clay forced into the mould and scraped off even at the top, the sides are put down, and the brick placed carefully on a barrow, which when filled is wheeled off by another man, and its contents arranged on the ground in long lines having a small space between each brick, that they may not stick together and the air may dry them. Long rows of these bricks are formed one on the top of the other, for four or five deep, and are changed in their position from time to time till they are quite dry and hard; they are now ready to be burnt. This is done made by placing the bricks in long rows, with narrow spaces between each row which are filled with straw or twigs of wood and cinders (these cinders are got from the ashes when they are sifted before mixing with the clay); the spaces being filled they are covered with other bricks, and then the straw, &c., is lighted. Layer after layer of bricks are next built up around the fire, so that the heat shall be well kept in, and in this way the bricks are gradually baked till they are quite hard and fit for use.
BURNING BRICKS.
Tiles are the same as bricks, but of a different form, being flat, and having two holes in them to receive nails. These are used to form the roofs of houses, and are nailed on to the rafters, each layer overlapping the one below it, so that the rain falling on the sloping roof shall run from the top to the bottom without coming through.
Bricks have lately been made with perforations through them, which is done by having a mould with a number of iron rods projecting from its bottom, so that when the clay is forced on them they pass right through it, and leave holes. The objects gained by this are two; in the first place, the bricks are much lighter, a great advantage in building, and in the second place they do not get so much out of form in burning, as there is no great substance between the holes, and therefore the shrinking takes place more evenly. Most of these bricks are of a light straw color, and are used for facing. They are mixed with a quantity of chalk, which is worked up with the clay, and are not baked at such a heat as would burn it into lime.
MIXING CHALK.