Rock-face or pitch-faced work is shown in Fig. 77, the face of the stone being left rough as it came from the quarry, with the joints or edges "pitched off" to a line as shown. The amount of projection of the centre of the stone beyond the plane of the joints should be specified. The ashlar shown in Fig. 67 is "rock-face."
Fig. 77. - Rock-face or Pitch-face.
Fig. 78. - Rock-face with Draft Line.
Rock-face with margin lines is the next step toward finishing a stone, and is shown in Fig. 78. The margin (often called draft line) is cut with a tool chisel in soft stones and with an axe in granite. Sometimes only the angle of the quoins has a draft line, as in Fig. 79, when it is called "angle draft." Rock-face ashlar is naturally-cheaper than any kind of dressed ashlar, particularly in granite.
Broached Work. - The surface of the stone is dressed off to a level surface, with continuous grooves made in it by the point. Fig. 80 shows a stone with margin or draft lines and broach centre.
Pointed Work (Figs. 81 and 82). - When it is desired to dress the face of a stone so that it shall not project more than ¼ to ½ inch, and where a smooth finish is not required, as in basement piers, etc., the rock-face is taken off with a point and the surface is rough or fine pointed, according as the point is used over every inch or half inch of the stone. The point is used more for dressing hard stones than soft stones.
Tooth-chiseled. - The cheapest method of dressing soft stones is by the tooth chisel, which gives a surface very much like pointed work, only generally not as regular.
Fig. 79. - Rock-face with Angle Draft.
Fig. 80. - Broached with Tooled Margin.
Fig. 81. - Rough Pointed.
Tooled work is done with a flat chisel from 3½ to 4½ inches wide, and the lines are continued clear across the width of the piece, as shown in Fig. 83. When well done it makes a very pretty finish for sandstone and limestone, and especially for moulded work.
Drove work is much like tooled work, but done with a chisel about 2½ inches wide and in rows lengthways of the piece, as shown in Fig. 84. Drove work does not take quite as much time as tooled work, and hence is cheaper, but it does not look as well.
Bush-hammered. - This finish is made by pounding the surface of the stone with a bush hammer, leaving it full of points, as in Fig. 87. It makes a very attractive finish for the harder kinds of sand and limestones, but ought not to be used on soft stones.
Crandalled Work (Fig. 85). - The face of the stone is dressed all over with the crandall, which gives it a fine pebbly appearance when thoroughly done. It makes a sparkling surface for red sandstones, and is used more than any other finish in Massachusetts for sandstones. The crandall is not used on granite and other hard stones.
Fig. 8a. - Fine Pointed.
Fig. 83. - Tooled.
Rubbed. - One of the handsomest methods of finishing sand and limestones is to rub their surfaces until they are perfectly smooth, either by hand, using a smooth piece of soft stone with water and sand for rubbing, or by laying the stone, on a revolving bed called a rubbing bed. When the stone is first sawed into slabs rubbing is very easily and cheaply done, so that rubbed sandstone ashlar is often as cheap as rock-face work in yards where steam saws are used. The saws leave the stone comparatively smooth and suitable for the top of copings and unexposed places. Granites, marbles and many limestones, when rubbed long enough, take a high polish.
Fig. 84. - Drove Work.
Fig. 85. - Crandalled.
Picked Work. - In this work the face of the stone is first leveled off with the point and then picked all over as though a woodpecker had picked it. Broken ashlar finished in this way has a very pretty effect, but is quite expensive.
Patent-hammered or Bush-hammered (Fig. 86). - When it is desired to give a finished surface to granite and the hard limestones they are first dressed to a rough surface with the point and then to a medium surface with the same tool, and finally finished with the patent hammer. The fineness of the finish is determined by the number of blades in the hammer, and the work is said to oe "six-cut," "eight-cut" or "ten-cut," according as six, eight or ten blades are used. Government work is generally ten-cut. Eight-cut is mostly used for average work, and for steps and door sills six-cut is sufficiently fine. The architect should always specify the number of blades to be used when the work is to be finished with a patent hammer. The same finish may be obtained with the axe, but it requires much more time.
Fig. 86. - Patent-hammered.
Fig. 87. - Bush-hammered.
Fig. 88. - Vermiculated.
Fig. 89. - Fish Scale.
Vermiculated Work (Fig. 88). - Stones worked so as to have the appearance of having been worked by worms. It is generally confined to quoins and base courses.
Rusticated Work. - This term is now generally used to denote sunk or beveled joints, as in Figs. 69 and 90, although it originally referred to work honeycombed all over on the face to give a rough effect, as shown in Fig. 69.
Vermiculated and fish scale work are seldom seen in this country.