27. The double-face hammer, shown at (a), Fig. 1, weighs from 20 to 30 pounds, and is used for breaking and roughly shaping the stones as they come from the quarry.

The face hammer, shown at (d), is a lighter tool than the double-face hammer, but is used for the same purposes when less weight is required. It has one blunt and one cutting end, the latter being used for roughly dressing the stones preparatory to using the finer tools. The pick, shown at (c), is used for coarsely dressing the softer stones. Its length is from 15 to 24 inches, and the width at the eye is about 2 inches.

The ax, or peen hammer, is shown at (d). This hammer is about 10 inches long and has two cutting edges, about 4 inches in length; its principal uses are in making drafts, or margin lines, around the edges of stones, and also for dressing the faces, being used after the point, and before the patent hammer.

The tooth ax, shown at (e), has its cutting edges a notched to form teeth, the number varying according to the fineness of the work. Its principal use is to reduce sandstones to a level, ready for the crandail, or tool. It is not used on hard stones like granite and marble, as the points would quickly become dull and need constant sharpening.

Fig. 1.

The bush, hammer, shown at (/), is from 4 inches to 8 inches long, with ends from 2 to 4 inches square, cut into a number of pyramidal points, as shown at a. This hammer is used for finishing limestones and sandstones after the surfaces have been made nearly even.

The crandall, shown at (g), is made from a malleable-iron bar c about 2 feet long, slightly flattened at one end d, which has a slot, 3/8 inch wide and 3 inches long, cut in it. Ten double-headed points a, made of 1/4-inch square steel, about 9 inches long, are inserted and are held in place by a key, shown at d. The crandall is used to complete the finish of sandstone after the surface has been partially worked by the tooth ax, or chisel.

The patent hammer, shown at (h), is made of from four to ten thin blades of steel a, which are ground to an edge and held together by bolts, as shown at b, so as to form a single piece. It is used for finishing granite or hard limestone, and the number of blades required to give the proper fineness to the cutting is usually specified as 4, 6, 8, or 10 cut.

The hand hammer, shown at (i), is used for drilling holes, and in pointing and chiseling the harder rocks. It is about 5 inches in length, and weighs from 2 to 5 pounds.

The mallet, shown at (j), is used when the softer stones are to be cut. It is made of wood, the head being about 7 or 8 inches in diameter, and 5 or 6 inches high.

28. Chisels

Chisels. Fig. 2 represents the different chisels used in dressing stone. At (a) is shown the point, which is made of round or octagonal steel, 8 to 12 inches long, with one end pointed. It is used for chipping off the rough faces of the stone and reducing them to approximately plane surfaces, ready for the peen hammer. It is also used to give a rough finish to stone in broach and picked work. At (b) is shown the tooth chisel, used only on soft stones, and serving much the same purpose as the tooth ax. At (c) is shown a drove chisel, 2 to 3 inches long at the end, used for cutting or driving the rough surfaces of the stone. At (d), (e), (g), and (h) are shown other forms of chisels used for dressing soft stone. At (/) is shown a pitching chisel, used for making pitched-face work, as shown in Fig. 3.

Fig. 2.

29. Machine Tools

Machine Tools. Besides the hand tools described in the previous articles, there are a number of machine tools used to prepare the stone for the finer treatment to be given by hand work. These include saws, cutters, planers, grinders, and polishers.

The saws are either drag, circular, or band saws, each consisting of a thin sheet of steel, and having blunt edges. The former has a forward and backward movement, the cutting being done by aid of sand and water fed into the cut. The operation of the others is similar, except as to the manner of driving.

The cutters are used on the rough stone to somewhat reduce the inequalities. Cutters and planers are made on two principles, one kind being used for homogeneous and tough stones, free from grit, etc., which are dressed by machines resembling those used for iron and steel; the other kind is for hard, brittle stones, whose structure necessitates a treatment resembling that employed in hand dressing. From the cutter and planer the stone goes to the grinder and polisher, which are practically alike, differing only in the fineness of the surface which they are capable of producing. A polisher consists principally of a large plate of iron, revolving horizontally, upon which the stone to be polished is laid, but is secured to prevent its moving with the plate. Sand and water is supplied between the disk and the stone, whose surface is thus abraded till the proper degree of smoothness is attained.