Stone quarries are those places where stone exists of a quality suitable for building purposes, and in a situation admitting of its easy removal. All stone, with the exception of granite and marble, exists in layers or strata as they are called, so that the stone can be easily split in the direction of these strata or seams. When a large piece of stone has to be removed, wedges are driven in a row into these seams, and when the stone has started, it is notched at the sides and back, so that in general a square piece is thus removed; if it be not so, it is generally made into a somewhat square before leaving the quarry, hence the name, derived from the French “_quarre_.” Granite having none of the lines of cleavage, as they are called, is broken by a row of wedges driven till a crack forms from one to the other. Slate is a clay-stone found in layers like limestone, but much more perfect; so much so, indeed, that it can be split into slices a quarter of an inch thick and one or two feet square; these, when sorted into sizes, form the slates for roofing houses. It has been much used of late in thick slabs, cut by circular saws, for making cisterns, a purpose for which it is well adapted. WOOD. Illustration: (‡ LOGGERS.) Wood is an article of universal application; its lightness, strength, and the facility with which it can be worked, render it almost invaluable; although in ship-building and many of its applications to house-building iron has to some extent superseded it, yet there are so many other ways in which it is indispensable, that it may be looked upon as one of the greatest boons to mankind. There is scarcely a use to which wood may not be applied, whether as fuel for fires, timber for building, furniture both useful and ornamental, various parts of machinery, vessels to contain wine and other fluids, handles to instruments, (for in cold climates and cold weather metal cannot be handled with impunity), and indeed for all uses in which lightness, dryness, warmth, and variety of form are desirable, wood serves as an excellent material. The kind of trees that produce wood fit for building and other useful purposes are those called by the botanists _exogenous_. Amongst which the pine tribe, oak, ash, elm, and beech, stand pre-eminent; while mahogany, walnut, and rosewood are chiefly used for ornamental purposes; box-tree wood is also very useful on account of its closeness and evenness of grain; it is the wood used by engravers.