Gold beating

( Arts.) The proce by which gold is extended to thin leaves used for gilding. Attempts have been made to apply machinery to G. B., but though very ingenious, their application is very limited; most of the gold-leaf is still beaten by hand, as follows: The gold is first cast into oblong ingots about 34ths of an inch wide, and weighing two ounces. The ingot is flattened out into a ribbon of about gth of an inch in thickne by pa ing it between polished steel rollers. This is annealed or softened by heat, and then cut into pieces of one inch square; 150 of these are placed between leaves of vellum, each piece of gold in the centre of a square vellum leaf, another placed above, and so on till the pile of 150 is formed. This pile is enclosed in a double parchment case, and beaten with a 16-pound hammer. The elasticity of the packet considerably lightens the labor of beating, by causing the hammer to rebound with each blow. The beating is continued until the inch-pieces are spread out to four-inch squares; ares; they are then taken out, and cut into four pieces, and squares thus produced are now placed between gold beater's skin instead of vellum, made into piles, and enclosed in a parchment case, and beaten as before, but with a lighter hammer. Another quartering and beating produces 2,400 leaves, having an area of about 190 times that of the ribbon, or a thickne of about 베이이이이th of an inch. An ounce of gold is thus extended to a surface of about 100 square feet. A still greater degree of thinne may be obtained, but not profitably. After the last beating, the leaves are taken up with wood pincers, placed on a cushion, blown out flat, and their ragged edges cut away, by which they are reduced to squares of 314 inches. 25 of these are placed between the leaves of a paper book, previously rubbed with red chalk, to prevent adhesion of the gold, and are sold in this form. Gold'berg, a city of Pru ian Silesia, 12 m. S.W. of Liegnitz. Manuf . Cloths, flannels, woollen socks, and gloves. Pop . 7,500.- Another G. in MecklenburgSchwerin, on a lake of same name, is only remarkable for its baths, which are of high repute. sand, leaving the gold behind. The fine particles are amalgamated with mercury, and by that means retained and separated from the powdered rock, and the mercury is then distilled off. It is further refined by being finely granulated and boiled with concentrated sulphuric acid until every other constituent is di olved out. Perfectly pure gold is denominated gold of 24 carats, or fine gold. Gold containing 2 parts of alloy in 24 is said to be 22 carats fine. Perfectly pure gold is too soft for use as coins, ve els, ornaments, ., and is therefore alloyed with copper and silver. By being alloyed it loses much of its ductility and malleability, but gains in hardne and fusibility. For coins, the standard G. of the United States consists of 900 parts of gold to 100 of an alloy of silver and copper. The English standard gold contains of alloy, now of copper. Jewelry is generally made of 18 carat gold. For methods of applying G. to gla , porcelain, ., see GILDING. G. alloys are a ayed in 2 ways, by rubbing the article on a touchstone so as to make a metallic streak, which is touched with nitric acid, and the effect is compared with that of a similar streak made by an alloy of known composition. An experienced operator will in this way estimate the amount of alloy in any mixture correctly within 1 per ct. When great exactne is required, the proce of cupellation is