This section is from the book "Cyclopedia Of Architecture, Carpentry, And Building", by James C. et al. Also available from Amazon: Cyclopedia Of Architecture, Carpentry And Building.
The method of finishing a stone has a great effect, not only upon its appearance, but upon its durability. The less pounding a stone receives the stronger it will be, since the repeated jar tends to separate the particles and render the stone less durable. For this reason it is only granite and hard sandstones that are usually treated by hammering the surface, the softer stones being generally finished by the use of some form of chisel.
The principal tools used in stone-cutting are:
1. The axe or pean hammer. This is a solid tool with two cutting edges, and is used for making the draft line or margin on granite and in leveling off the face. (Fig. 123A.)
2. The tooth axe is similar to the axe, except that the cutting edges are divided into teeth. This is used on sandstones as well as on granite. (Fig. 123B.)
3. The bush hammer, a square head cut into a number of points. This is used for finishing sandstone and granite. (Fig. 124A.)
4. The crandall, an iron handle with a long slot at one end into which are wedged a number of double-headed points. These points are secured by a key and may be removed for sharpening.
Fig. 123. Axe and Tooth Axe.
Fig. 124. Bush Hammer and Crandall.
This is a common way of finishing sandstone after the surface has been leveled by means of a tooth chisel. (Fig. 124B.)
5. The patent hammer, a hammer formed of a number of thin blades of steel which are bolted into a heavy head and used for finishing granite and hard sandstones. (Fig. 125A.)
G. Chisels of various form, among which are to be found the point No. 1, chisel and tooth chisel Nos. 2 and 3, the drove No. 4, all for use with a mallet, the hammer chisel No. 5, and pitching tools Nos. 6 and 7. (Fig. 125.)
The simplest of the various finishes which are given to cut stone is the rockface, shown in Fig. 126. In this, the face of the stone is left rough, the edges being pitched off to a line. A margin or draft line is often cut around the edge, leaving the center with rockface. (Fig 127.) Pointed work (Fig. 128) is done by taking off the surface of the stone with a point, and is made rough or fine-pointed according to the position or importance of the stone. This is used mainly in granite, a similar effect being obtained in soft stones by use of the tooth chisel. Tooled work (see Fig. 129) is done in straight lines clear across the face of the stone and is used a great deal for sandstone and limestone.
Fig. 135. Patent Hammer and Chisels.
Bush hammering, as its name implies, consists in hammering the stone, usually granite, with a bush hammer, leaving the surface covered with points.
Fig. 126. Pitching off for Rock Fact-.
Fig. 137. Rock Face with Draft Line.
Fig. 138. Pointed Work.
Patent hammered work, Fig. 130, leaves the surface covered with a series of ridges and is known as "six-cut," "eight-cut," or "ten-cut " work, according to the number of points to the inch. This is a usual finish for granite and is generally called for as "eight-cut" work. Crandalled work, Fig. 131, is used for sandstone more than any other finish, and consists of a series of lines crossing each other, or running all one way, according to whether the crandall is used from one side or from both. If a smooth finish is desired the stones may be rubbed. This is easily and cheaply done when the stone is first sawed, and makes a good finish. Vermiculated work, shown in Fig. 132, is obtained by working the surface all over in imitation of the destruction by worms. This is expensive and is rarely used except for quoins.
Fig. 129. Tooled Work.
Fig. 130. Patent Hammered Work.
Fig. 131. Crandalled Work.
The inspection of stone at the building should be very thorough especially in the matter of finish. The finer the degree of finish, the more costly will be the labor, and for this reason there is often a tendency to slight the work. Eight-cut granite will often be found to be six-cut, and fine-pointed or fine-crandalled work will sometimes be found to be rough and coarse.
Fig. 132. Vermiculated Work.