A writer in the Encyclopædia Britannica endeavours, with much ingenuity, to show that the quality of English bricks and the system of bricklaying are very much influenced by the customary leasehold tenure of land. His remarks are as follow:—“Brick-making has been carried to great perfection by the Dutch, who have long been in the habit of forming their floors, and even, in some cases, of paving their streets with bricks. And it is remarkable how long their bricks will continue unimpaired in such situations. Though brick-making has long been carried on in England, and especially in the neighbourhood of London, upon a very great scale, and though the process upon the whole is conducted in this country with very considerable skill, yet it must be acknowledged that English bricks are by no means so durable as Dutch bricks. We are disposed to ascribe this inferiority not so much to the nature of the materials employed in the manufacture of English bricks, as to the mode most frequently adopted in London of building houses. Few of the London houses, comparatively speaking, are freeholds. Most of them are built upon ground let for a lease of a certain number of years, which seldom exceeds ninety-nine years. After the expiration of this period the house becomes the property of the landlord who let the ground. Thus it becomes the interest of the builder to construct the house so that it shall last only as long as the lease. Hence the goodness of the bricks becomes only a secondary object. Their cheapness is the principal point. The object, therefore, of the brickmaker is not to furnish durable bricks, but to make them at as cheap a rate as possible. Accordingly, the saving of manual labour and of fuel has been carried by the makers of London bricks to very great lengths. We cannot but consider this mode of proceeding as very objectionable, and as entailing a much heavier expense upon London than would have been incurred had twice the original price been laid out upon the bricks when they were first used, and had the houses been constructed to last a thousand instead of a hundred years. No doubt certain advantages attend these ephemeral structures. The inhabitants are enabled, once every century, to suit their houses to the prevailing taste of the day; and thus there are no (few?) antiquated houses in London. But as the increase of the price of all the materials of building has more than kept pace with the increase of the wealth of individuals, it is to be questioned whether the houses are always improved when they are pulled down and rebuilt.”
Chapter IV.
THE ROOF. SLATES, AND OTHER ROOF COVERINGS.
We might, perhaps, under the designation of “Slates and Slating,” have included the operations usually understood to appertain to the construction of a roof. But modern improvements have rendered such a designation incomplete. We cannot now properly understand the mode of roofing houses without referring to many other substances besides slate.
Slate-Quarries.
Slate is the popular name for a variety of rocks which are sufficiently stratified in their structure to allow of their being cleaved into thin plates, a property which renders them valuable for a variety of purposes. Slate has superseded the use of lead for covering roofs, even of the largest buildings: from its lightness it is preferable to tile, but the latter being cheaper, in flat countries which do not contain rocks, but which yield brick-clay, slate in such localities is only used on the better class of houses. In mountainous countries, a slaty rock, which admits of being split thin, though not so much as clay slate, is used under the name of shingle.
Besides being employed for roofing, slate is used in large slabs to form cisterns, for shelves in dairies, for pavement, and similar purposes, for which its great strength and durability, coolness, and the ease with which it can be cleaned, owing to its non-absorbing property, adapt it. The latter quality renders it also of great value as a cheap substitute for paper, in the business of education; the system of teaching in large classes in National and Sunday-schools would be greatly fettered but for the use of slates.
The principal slate-quarries in Britain are in Wales, Cumberland, and various parts of Scotland; the mode of working them is generally the same. The rock is got out in tabular masses by means of large wedges, and is then subdivided by smaller to the requisite thinness; the pieces are roughly squared by a pick, or axe, and sorted, according to their sizes, for roofing. The largest called imperial, are about three and a half feet long, and two and a half wide; the smallest average half those dimensions. When wanted for paving, &c., the large blocks are sawn into thinner slabs, in the same manner as stone or marble is.
A few words respecting the position and working of some of the slate-quarries may be appropriate, as illustrating the nature of this remarkable geological formation.
A Slate-Quarry.