QUARRYING SLATES AND STONES, the methods of preparing them for their different uses and applications at the quarries and pits where they have been raised. The former of these articles, particularly those of the blue, green, and purple or blackish kinds, undergo several different sorts of preparation in the quarrying, according to the purposes to which they are to be afterwards applied. They are separated and divided into very thin pieces, or slates, where light neat coverings are required, or in much demand ; but for more strong and heavy coverings, in exposed situations, or other places, they arc split into much thicker sheets, layers, or slates, and are, of course, more clumsy in their appearance.
Each sort, in the business of quarrying. is wrought in a separate manner, and packed up by itself; the diGrent sorts having appropriate names, as has been already seen.
The white or brown slates are never divided and prepared in so fine a way as the other kinds, but separated into much thicker flakes or laminae, in this intention. The blue, green, and purple or darkish sorts, are, for the most part, found capable of being split into very thin laminae, or sheets; but those of the white, or brownish freestone kinds, can seldom be separated or divided into any very thin slabs, as the layers of the large masses of the stones are of a much thicker nature, they consequently form heavy, strong, thick coverings, proper for buildings in exposed climates and situations, and of the more rough kinds, such as barns, stables, and other sorts of out-houses.
In the different operations and processes of this sort of quarrying, slate-knives, axes, bars, and wedges, arc chiefly made use of for the different purposes of splitting and clean ing the slates, they being separated into proper thicknesses by the axe, bar, and wedge, and afterwards chipped into their proper forms and shapes by the knife. All the inequalities
which may appear upon any of them, are removed by this last-named implement. In the quarrying of the latter sorts of materials, or those of stones, the work is usually performed in such a manner as to suit the different uses for which they are intended. Where flags are to be formed, they are split or riven into suitable thicknesses, and squared to different sizes, so as to be adapted to different applications. These opera tions are executed in rather a rough way, as they are after wards to be finished by the stone-mason. When for steps, they have the proper nreadths and depths given to them in a sort of squaring manner, being left, to be completed as they may be wanted for particular uses and applications. Gate posts are, for the most part, quarried so as to have from about a foot to a foot and a half or more in the square. Trough-stones have the quarrying performed so as to be formed into various proper-sized squares or other forms, in a rough manner, being left in these states to be after wards hewn and hollowed out, in the intended parts, by the stone-masons.
Stones for building purposes are usually raised and quarried out roughly into something of the square shape, being left in that state for the builders, who afterwards fit them so as to suit their own purposes and intentions.
In the quarrying of stones, the quarrymen commonly make use of large hammers, with cutting ends on one side, the other being formed in a plain manner ; strong, sharp, crow-bars, and broad, sharp, iron wedges ; by which means these matters are, from the constant practice of the men, split and torn into such forms as are wanted, with great ease and facility.