Limestone Facings (as shown in figs. 206, 208, 210, 211, and 212) may have the faces of the stones treated in various ways, as follows: -
1. Axed, by which is meant that the face is gone over with a mason's axe, leaving rough, irregular, coarse, vertical ribs or marks.
2. Chopped, which is a superior finish to the last-named, the ribs being much closer and finer.
3. Rock-faced, in which the beds and joints are squared, as in the others, but, from a line all round, the face is knocked off slanting from the four sides towards the centre to look rough and with a rock-like appearance.
4. Dragged is the finish made on plain limestone ashlar by means of a tool, toothed like a saw, which is drawn backwards and forwards across its face.
Sandstone Facings of a hard nature may be treated as follows: -
1. Scappled, or scabbled, punched, or boasted, which are terms applied to the rough labour employed on beds, and the rough squaring up of hard stones for engine beds, etc.
2. Chiselled work has the face worked over either on the straight or skew with a chisel, the marks or "bats" often being as close as 8 to the inch.
3. Tooling is done with a broad "chisel," the strokes being parallel to the joints, and from 3 to 5 to the inch. (This is called " droved " work in Scotland.)
4. Hammer-dressed is the term applied to work done with a hammer with a chisel point, by which the face is roughly levelled, leaving indents where the chisel has been. It is also called "broached " work.
5. Scutched work is similar to the last, but more finely executed.
6. Drafted and broached is the term used for the work done to quoins, a draft or margin being chiselled or tooled round the face of the stone, and the panel enclosed thereby is hammered or broached down to give it a rough appearance.
7. Drafted and diamond-picked or hammered work is similar to the last, but the panel from its roughly chiselled face is "picked up" by a number of small points in the form of a hammer, which is like "frcsted" work on tombstones.
8. Vermiculated work is that used in large base stones; the face being first chiselled, and afterwards large deep holes are picked out, no maik of the tool being left, as in fig. 213.
9. Rubbed, cleansed, or polished work, as the name implies, has its face smoothly rubbed, after being chiselled down level or to the required shape.
10. Pointed work has its face first chiselled, after which the "chisel hammer" is driven along its face longitudinally with a long sweep whereas "scutching" is done with short strokes.
Polled work is the term applied to hard stones such as granite and whinstones, a large square short hammer being used to split and square up the stones.
Some stones, and especially limestones, in some atmospheres will never weather nor last without being coated over with some material There are numerous preparations which are recommended in order to prevent this decay, those containing a silicate of an alkaline nature being the most efficacious; though such simple things as paint, soft soap, milk, or paraffin are frequently used, in a smaller degree, with a fair amount of success. The best remedies now in use may be said to be: (1) Szerelmy's, said to be a bituminous solution of a silicate, which is applied in two or three coats with a brush; and (2) Carbolinium Avenarius, a preparation made by Peters of Derby, which is said to preserve both stone and wood with success. The Houses of Parliament were coated with Szerelmy's solution.
The Bath stones class should be coated with the "fluate" recommended by the firms who supply the stone.