See Chemistry, p. 78, and 129.
Gold-wire, a cylindrical ingot of silver, superficially gilt, or covered with gold at the fire, and afterwards drawn successively through a great number of little round holes, of a wire-drawing iron, each less than the other, till it becomes no bigger than a hair of the head.
It may be observed, that before the wire be reduced to this exquisite fineness, it is drawn through above an hundred and forty different holes; and that each time they draw it, it is rubbed afresh over with new wax, both to facilitate its passage, and to prevent the silver's appearing through it.
Gold-wire flatted, is the former wire flattened between two rollers of polished steel, to fit it to be spun on a stick, or to be used flat, as it is, without spinning, in certain stuffs, laces, embroideries, &c. See Stuff, &c.
Gold-thread, or Spun-gold, is a flatted gold, wrapped or laid over a thread of silk, by twisting it with a wheel and iron bobbins.
Manner of forming Gold-wire, and Gold-thread, both round and flat. First, an ingot of silver, of twenty-four pounds, is forged into a cylinder, of about an inch in diameter: then it is drawn through eight or ten holes, of a large, coarse, wire-drawing iron, both to finish the roundness, and to reduce it to about three fourths of its former diameter. This done, they file it very carefully all over, to take off any filth remaining on the forge; then they cut it in the middle; and thus make two equal ingots thereof, each about twenty-five inches long, which they draw through several new holes, to take off any inequalities the file may have left, and to render it as smooth and equable as possible.
The ingot thus far prepared, they heat it in a charcoal fire; then taking some gold leaves, each about four inches square, and weighing twelve grains, they join four, eight, twelve, or sixteen of these, as the wire is intended to be more or less gilt; and when they are so joined, as only to form a single leaf, they rub the ingots reeking hot with a burnisher. These leaves being thus prepared, they apply over the whole surface of the ingot, to the number of six, over each other, burnishing or rubbing them well down with the bloodstone, to close and smoothe them. When gilt, the ingots are laid anew in a coal fire; and when raised to a certain degree of heat, they go over them a second time with the blood-stone, both to solder the gold more perfectly, and to finish the polishing. The gilding finished, it remains to draw the ingot into wire.
In order to this, they pass it through twenty holes of a moderate drawing iron, by which it is brought to the thickness of the tag of a lace: from this time the ingot loses its name, and commences gold-wire. Twenty holes more of a lesser iron leaves it small enough for the least iron; the finest holes, of which last scarce exceeding the hair of the head, finish the work.
To dispose the wire to be spun on silk, they pass it between between two rollers of a little mill: these rollers are of nicely polished steel, and about three inches in diameter. They are set very close to each other, and turned by means of a handle fastened to one of them, which gives motion to the other. The gold wire in passing between the two, is rendered quite flat, but without losing any thing of its gilding, and is rendered so exceedingly thin and flexible, that it is easily spun on silk thread, by means of a hand wheel, and so wound on a spool or bobbin.