A kind of factitious stone, made of a fatty earth formed into a parallelogram about 4 inches broad by 8 or 9 inches in length, by a wooden mould, and then baked or burnt either in a kiln or a clamp, to serve the purposes of building. Bricks appear to have been used for architectural purposes at a very remote period, as we learn from the Scriptures that the Israelites were employed to make bricks in Egypt; and some of the most durable of the Greek and Roman monuments which have come down to us, are wholly, or in great part, constructed of this material. In the East they bake their bricks in the sun; the Romans used them crude, only leaving them a long time in the air to dry, about four or five years. In modern times, brickmaking is no where carried to greater perfection than in Holland, where most of the floors of the houses, and frequently the streets, are paved with excellent and very durable bricks. Loam and marl are in England considered the best materials for bricks. The former is a natural mixture of sand and clay, which may be converted at once into bricks; marl is a mixture of limestone and clay in various proportions The neighbourhood of London is remarkably adapted for the making of bricks, the soil of the whole surrounding country being clay at a certain depth, generally below a bed of gravel, and the bottom of the Thames yielding the sand which is used in this manufacture; but great practical carelessness seems to pervade the whole business as conducted there.

The following is a description of the process as it is usually conducted around the metropolis: The earth is dug up in the autumn, and suffered to remain in a heap until the next spring, that it may be well penetrated by the air, and particularly by the winter frosts, which, by pulverising the more tenacious particles, greatly assists the operations of mixing and tempering. In making up this heap for the season, the soil and ashes, or sand, are laid in alternate layers or strata, each stratum containing such a thickness as the stiffness of the soil may admit or require. In tempering the earth, much judgment is required as to the quantity of sand to be thrown into the mass, for too much renders the bricks heavy and brittle, and too little leaves them liable to shrink and crack in the burning. The addition of sea-coal ashes, as practised about London, not only makes it work easy but saves fuel, as when the mixture is afterwards sufficiently heated these bricks are chiefly burned by the fuel contained in the clay.

When the brick-making season arrives, the heap is dug up, the stony particles carefully removed, and the mass properly tempered by a thorough incorporation and intermixture of the materials, with the addition of as little water as possible, so as to form a tough viscous paste. If, in this operation, too much water be used, the paste will become almost as dry and brittle as the soil of which it is composed. In order more effectually and regularly to mix the loam and ashes, it is now generally performed in a sort of mill, named a pug mill. This consists of a large tub or tun, fixed perpendicularly in the ground, and having an upright bar, fitted with knives, placed obliquely. The upright bar is turned by a horizontal lever, to which a horse is attached, and the soil being put in at top, is, by the revolution of the knives, forced through a hole in the side of the tub near the bottom, whence it is removed to the mould table, which is placed under a movable shed, and is strewed with dry sand. A girl rolls out a lump somewhat larger than the mould will contain.

The moulder receives this lump from the girl, throws it into his mould previously dipped in dry sand, and with a flat smooth stick about 8 inches long, kept for the purpose in a pan of water, he strikes off the overplus of the soil; he then turns the brick out of the mould upon a thin board rather larger than the brick, upon which it is removed by a boy, who places it on a light barrow of a particular construction, which being loaded with a certain number of bricks, they are sprinkled with sand, and wheeled to the hacks. The hacks for drying are each wide enough for two bricks to be placed edgeways across, with a passage between the heads for the admission of the air, to facilitate the circulation of which the bricks are usually laid in an angular direction. The hacks are usually carried eight bricks high; the bottom bricks at the ends are usually old ones. In showery weather the hacks must be carefully covered with wheat or rye straw, unless sheds or roofs be built over the hacks, as is done in some parts of the country, but in London this is impracticable, from the very great extent of the grounds. In fine weather the bricks will be ready for turning in a few days, in doing which they are reset more open than at first, and in six or eight days more they will be ready for burning.

In the vicinity of London bricks are commonly burned in clamps. In building the clamps, the bricks are laid after the manner of arches in the kilns, with a vacancy between every two bricks for the fire to play through. The flue is about the width of a brick, carried straight up on both sides for about three feet; it is then nearly filled with dry bavins or wood, on which is laid a covering of sea coal and cinders (or, as they are termed, breeze); the arch is then overspanned, and layers of breeze are strewed over the clamp, as well as between the rows of bricks. When the clamp is about six feet wide, another flue is made in every respect similar to the first. This is repeated at every distance of six feet throughout the clamp, which, when completed, is surrounded with old bricks, if there be any on the grounds, if not, with some of the driest of the unbaked ones reserved for the purpose; on the top of all, a thick layer of breeze is laid. The wood is then kindled, which sets fire to the coal; and when all is consumed, which will be in about twenty or thirty days if the weather be tolerable, the bricks are concluded to be sufficiently burned.