Out Stones

OUT STONES. This class covers all squared stones with smoothly dressed beds and joints. As a rule, all the edges of cut stones are drafted, and between the drafts the stone is smoothly dressed. The face, however, is often left rough where the construc tion is massive.

"In architecture there are a great many ways in which the faces of cut stone may be dressed, but the following are those that will usually be met in engineering work: "Rough-pointed. When it is necessary to remove an inch or more from the face of a stone, it is done by the pick or heavy point until the projections vary from inch to 1 inch. The stone is then said to be rough-pointed (Fig. 60). In dressing limestone and granite, this operation precedes all others.

(Fig. 61). If a smoother finish is desired, rough pointing is followed by fine pointing, which is done with a fine point. Fine pointing is used only where the finish made by it is to be final, and never as a preparation for a final finish by an other tool.

"Orandalled.

This is only a speedy method of pointing, the effect being the same as fine pointing, except that the dots on the stone are more regular. The variations of level are about inch, and the rows are made parallel. When other rows at right angles to the first are introduced, the stone is said to be cross crandalled. Fig. 62 shows a crandalled and also a cross-crandalled surface. • " Axed, or Pean-hammered, and Patent-hammered. These two vary only in the degree of smoothness of the surface which is pro duced (see Fig. 63). The number of blades in a patent hammer varies from 6 to 12 to the inch; and in precise specifications the number of cuts to the inch must be stated, as 6-cut, 8-cut, 10-cut, or 12-cut. The effect of axing is to cover the surface with chisel marks, which are made parallel as far as practicable. Axing is a final finish.

"

The tooth-ax is practically a number of points, and it leaves the surface of a stone in the same condition as fine pointing. It is usually, however, only a preparation for bush-ham

mering, and the work is then done without regard to appearance so long as the surface of the stone is sufficiently leveled.

"

The roughnesses of a stone are pounded off by the bush hammer. and the stone is then said to be `bushed' (see Fig. 64). This kind of finish is dangerous on sandstone or other soft stone, as experience has shown that stone thus treated is likely to scale off. In dressing limestone which is to have a bush hammered finish, the usual sequence of operation is (1) rough pointing, (2) tooth-axing, and (3) bush-hammering.

" Rubbed. In dressing sandstone and marble, it is very common to give the stone a plane surface at once by the use of the stone-saw [§ 533]. Any roughnesses left by the saw are removed by rubbing with grit or sandstone [§ 533]. Such stones, therefore, have no margins (see Fig. 65). They are frequently used in architecture for string courses, lintels, door jambs, etc.; and they are also well adapted for use in facing the walls of lock chambers and in other localities where a stone surface is liable to be rubbed by vessels or other moving bodies.

" Diamond Panels. Sometimes the space between the margins is sunk immediately adjoining them and then rises gradually until the four planes form an apex at the middle of the panel. In general, such panels are called diamond panels, and the one just described, Fig. 66, is called a sunk dia mond panel. When the surface of the stone rises gradually from the inner lines of the margins to the middle of the panel, it is called a raised diamond panel. Both kinds of finish are common on bridge quoins and similar work. The details of this method should be given in the specifications."