GOLD-BEATING, the process by which gold is extended to thin leaves used for gild ing. The gold used for this purpose is usually alloyed with silver or copper, according to the color required. See GOLD. For deep geld, an alloy containing about 1 part of copper to 20 of pure gold is used. As gold-leaf is not sold by weight, but by superficial measure. and as increasing the, quantity of alloy diminishes the malleability, there is but little temptation to use the baser metals as an adulteration, The gold is first cast into oblong ingots about iths of an inch wide, and two oz. The ingot is flattened out into a ribbon of about of an inch in thickness by passing 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 vel lum, each piece of gold in the center of a square vellum leaf, another placed above, and so on till the pile of 150 is formed. This pile is inclosed 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; they are then taken out, and cut into four pieces, and squares thus produced are now placed between skin instead of vellum, made into piles, and inclosed in a parchment case, and beaten as before, but with a light hammer. Another quartering and beating produces 2,400 leaves, having an area of about 190 times that of the ribbon, or a thickness of about legtz-trath of an inch. An oz. of gold is thus extended to a sur face of about 100 square feet. A still greater degree of thinness may be obtained, but not profitably. After the last beating, 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 31. inches. Twenty-five 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.
Attempts have been made to apply machinery to gold-beating, but though very ingenious, their application is very limited; most of the gold-leaf is still beaten by hand.