[3] The various quarries visited by the commissioners are noticed in the fullest and fairest manner. They have stated for each quarry its name and situation; the names and addresses of the freeholder, of his agent, and of the quarryman; the name of the stone; its composition; colour; weight per cubic foot; entire depth of workable stone; description of the beds; size of blocks that can be procured; prices, per cubic foot, of block stone at the quarry; description and cost of carriage to London; cost, per cubic foot, of the stone delivered in London; cost, per foot of surface, of plain rubbed work, as compared with Portland stone; and, finally, where known or reported to have been employed in building.
Chapter III.
THE WALLS. BRICKS AND BRICK-WORK.
We now come to that material which is, in England, a more important agent than stone in the construction of dwelling-houses; namely, bricks made from clay. There were three millions and a half of houses in Great Britain in the year 1841; and there can be no doubt that of this number those which were built of brick constituted a vast majority. It is only in a few particular districts that stone is a more available material for houses than bricks. In other countries, too, as well as our own, the arts of brick-making and bricklaying are carried on more extensively than the operations of the stone-mason.
Bricks and Brick-work in Early Times.
It has been observed that “the art of making bricks is so simple, that it must have been practised in the earliest ages of the world; probably before mankind had discovered the method of fashioning stones to suit the purposes of building.” It is stated in the Book of Genesis that burnt bricks were employed in the construction of the Tower of Babel. Now, as this structure appears to have been raised about four hundred years after the Deluge, it is scarcely an exaggeration to say that the art of making bricks was invented almost as soon as men began to build. Bricks seem to have been in common use in Egypt while the Israelites were in subjection to that nation; for the task assigned them was the making of brick, and we are informed in the Book of Exodus, that the Israelites built two Egyptian cities. No particulars are given in Scripture of the method of making bricks; but as straw was one of the ingredients, and as very little rain falls in Egypt, it is probable that their bricks were not burned, but merely baked by the heat of the sun. The same mode of baking bricks seems still to be practised in the East. The ruins of the tower near Bagdad are formed of unburnt bricks. The art of brick-making was carried to considerable perfection among the Greeks. Pliny states that they made use of bricks of three sizes, distinguished by the following names: didoron, or six inches long; tetradoron, or twelve inches long; and pentadoron, or fifteen inches long. That the Romans excelled in the art of making bricks there is the amplest evidence, since brick structures raised at Rome seventeen hundred years ago, still remain nearly as entire as when first built.
A remarkable kind of floating brick, used by the ancients, has been made the subject of investigation in modern times, with a view to the suggestion of improvements in the making of bricks for particular purposes. Pliny states that at various places in Spain, in Asia Minor, and elsewhere, bricks were made which, besides possessing considerable strength and a remarkable power of enduring heat, were yet of such small specific gravity, that they floated on the surface of water. Like many of the arts of the ancients, the method of making these bricks, as well as the material of which they were made, were forgotten for many ages. About the year 1790, however, an Italian, named Fabbroni, turned his attention to the subject, and after various experiments on minerals of small specific gravity, he came to the conclusion that these bricks must have been composed of a substance called “mountain-meal;” or, at least, he found that he could make of this substance bricks which appeared to agree in every respect with those described by the ancients. This mountain-meal is an earth composed of flint, magnesia, clay, lime, iron, and water, in certain definite proportions. The bricks which Fabbroni formed of this material had the property of floating in water; they could not be fused by any ordinary degree of heat; and so low was their conducting power, that while one end of the brick was red-hot, the other could be held in the hand without the smallest inconvenience. It has been supposed that a peculiar kind of earth, found in some parts of Cornwall is the same as that with which Fabbroni experimented on in Italy, and that both are analogous to the kind of which the ancients made their floating bricks. Proceeding on this supposition, it has been proposed to make such bricks for the construction of floating houses upon ornamental waters. At present such structures can be made only of timber; and, however the owner may decorate them, they have always a flimsy and unsubstantial appearance, and they are soon injured by the weather. If, however, a platform of good timber were employed as the base of the whole, and the weight so contrived as to keep this platform constantly under water, it would last a long time. The upper part of the structure formed of the floating bricks, might have all the appearance, and, indeed, all the stability of a brick house upon land; for this description of brick resists the influence of the atmosphere as well as the action of fire; and although it is not absolutely so strong as the heavy brick in common use, it is far more so in proportion to its specific gravity. We do not know whether these conjectures have yet been put to the test.
That the early inhabitants of many countries in the eastern and central parts of Asia were acquainted with the use of bricks in building, we have abundant proof from the descriptions of intelligent travellers; and there are even grounds for attributing to them a very high degree of mechanical skill both in the making of the bricks and the formation of brick walls. Dr. Kennedy, in his Campaign of the Indus, says:—“Nothing I have ever seen has at all equalled the perfection of the early brick-making, which is shown in the bricks to be found in these ruins [ancient tombs near Tatta]: the most beautifully chiselled stone could not surpass the sharpness of edge, and angle, and accuracy of form; whilst the substance was so perfectly homogeneous and skilfully burned, that each brick had a metallic ring, and fractured with a clear surface, like breaking freestone. I will not question the possibility of manufacturing such bricks in England, but I much doubt whether such perfect work has ever been attempted.”
Making Bricks by Hand.
In the mechanical arrangements for making bricks two very different systems are adopted; the one handicraft, and the other by machinery. The former has always been and still is far more extensively adopted than the latter.
In the selection of materials for brick-making, a brown loamy clay, that is, clay which contains a small quantity of calcareous matter, is considered best for ordinary bricks, but the ingredients vary according to the purposes for which the brick is required; and every one must have remarked the difference in colour between the light yellow marl stocks, as they are called, employed in the facing of houses of the better kind, and the dark red brick used in Lancashire and other northern counties. The colour also varies with the proportion of ashes or sand employed in the mixture, and with the degree of heat they are subjected to in drying. The general process is, however, much the same everywhere; and we shall describe that used in England, where bricks are always burnt.