FLANDERS BRICKS, these which are now equally or better known as Bath bricks, are made in large quantities of a clay found at Bridgewater, and which contains a considerable proportion of fine sand. Besides the extensive employment of these bricks for domestic purposes, and in making founders cores, they are sometimes employed when rubbed to powder, in polishing bone, ivory, and soft metals, and also in dressing cutlers dry buff wheels, boards for cleaning table knives, etc. Trent sand is preferable when it can be procured.
FREESTONES.-Few or none of these admit of being polished, but many of them are rubbed smooth; the rubber being in general a smaller piece of the same kind of stone, sometimes used alone, at other times with a plentiful supply of sharp sand and water. In turned works, the stone rubber is smaller and held in the hand, the process being frequently conducted dry, and without additional sand.
GANNISTER STONE a species of slaty-stone somewhat resembling the Charnley Forest, or Mount Sorrel stone, and which is abundantly used in repairing the macadamized roads around Sheffield. When calcined, pulverized, sifted, and applied on a straight buff stick of the bull neck leather, the Gannister stone is preferred to most other materials, for smoothing the threaded shoulders of pocket knives after they have been filed, as it is considered better to preserve the keen threads or projecting ridges of the shoulders than other abrasive powders. The work is completed on a wheel brush fed with fine emery and oil, followed by another with crocus and oil.
GARNETS are worked by the lapidary just like Carnelian, so far as the succession of the tools is concerned, the production of the facets is further noticed in the chapter on lapidary work. The fine large Garnets when cut en cabochon, or with a rounded face, are known as Carbuncles and are supposed to be the gems so designated also in the Scriptures.
GLASS is polished in various different manners, some of which are elsewhere particularized. Thus Plate Glass, is roughed with sand, smoothed with emery, and polished with crocus. See Chap. XXXIII. Section 1. Glass Lenses, are roughed out with sand, figured with emery, and polished with putty powder. See Chap. XXXIII. Section 4. Cut glass for household purposes and toys, is roughed with sand, smoothed on a Lancashire grit-stone, then with pumice-stone, and lastly is polished with putty or rottenstone see Chap. XXXIII. Section 5.
Lapidaries in cutting glass for jewellery adopt the mode described in this catalogue as used by them for alabaster, with the exception that they omit the wooden mill.
Glass is used as a vehicle for polishing powders by watchmakers, watch-jewellers, and some others. See Brass, article 6, and Machinery, article 13.