SOLDERING.--Hard soldering or brazing consists in fusing an alloy of high melting point between two junctions of the metal to be soldered so as firmly to connect them. The solder in fine powder is mixed with powdered borax, and made into a puddle with water, and then spread about the parts to be soldered together. The article is now heated by fire or gas, and the moment when the solder runs, is carefully watched. Gold and silver soldering used in the jewellery trades is on a small scale similar to brazing, the solder used is a gold or silver alloy of slightly lower melting point than the article to be soldered: the borax is commonly applied by previously rubbing down a crystal on a piece of slate and the white puddle thus obtained applied by means of a camel hair pencil to the junction on which the solder is placed. The article is supported on a piece of pumice stone and the necessary heat produced by the flame from a mouth blowpipe. In soft soldering an alloy of tin and lead is used, the melted alloy being spread by means of a “bit” or “doctor,” consisting of a piece of copper attached to an iron rod set in a wooden handle. A flux called “monkey” or “spirit,” consisting of muriatic acid with dissolved zinc, having previously been applied. Formerly resin was used as a flux, but this is now to a great extent superseded by the mixture just spoken of. SCRATCH BRUSHING is used to produce a rich rough surface previous to gilding. Revolving brushes of brass wire scratch the surface of the article which is kept well moistened with stale beer or with water to which size has been added. Of late years the SAND BLAST has been introduced for roughing surfaces. Sand is fed into a powerful blast of air, and a fine frosted surface produced. If the article is protected in places by a mask of paper or soft metal cut out in any desired pattern, an ornamental pattern is produced requiring only a little chasing to finish it. The sand blast is used too in the production of an imitation of engraved glass, in embossing glass as a substitute for hydrofluoric acid, and for re-cutting old files. DIPPING.--In order to clean brass articles, they are dipped into a mixture of nitric and sulphuric acids, the temperature and strength of acid determining whether the dipping is bright or dead. The bright articles are now finished by burnishing or polishing, and are then ready for LACQUERING.--The articles are laid on an iron table heated to a temperature of about 230° F. by super-heated steam. When warm, the lacquer, which is a solution of shell-lac in spirits of wine, is brushed over, the spirit evaporates and leaves a protecting coating of gum.