Plane

PLANE SUBreaam. In squaring up a rough stone, the first thing the stone-cutter does is to draw a line, with iron ore or black lead, on the edges of the stone, to indicate as nearly as possible the required plane surface. Then with the hammer and the pitching tool he pitches off all waste material above the lines, thereby reducing the surface approximately to a plane. With a chisel he then cuts a draft around the edges of this surface, i.e., he forms narrow plane surfaces along the edges of the stone. To tell when the drafts are in the same plane, he uses two straight-edges having parallel sides and equal widths—see Fig. 56. The projections on the surface are then removed by the pitching chisel or the point, until the straight edge will just touch the drafts and the intermediate surface when applied across the stone in any direction. The surface is usually left a little slack, i.e., concave, to allow room for the mortar; however, the surface should be but a very little concave.

The surface is then finished with the ax, patent hammer, bush hammer, etc., accord ing to the degree of smoothness required.

536.

To form a second plane surface at right angles to the first one, the workman draws a line on the cut face to form the intersection of the two planes; he also draws a line on the ends of the stone approximately in the required plane. With the ax or the chisel he then cuts a draft at each end of the stone until a steel square fits the angle. He next joins these drafts by two others at right angles to them, and brings the whole surface to the same plane. The other faces may be formed in the same way.

If the surfaces are not at right angles to each other, a bevel is used instead of a square, the same general method being pursued.