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 in. got of silver, of 24 pounds, is forged Mtn a cylinder of about an inch in diameter then it is drawn through eight or tea holes, of a large, coarse, wire-drawing iron, both to finish the roundness, and to re. duce it to about three-fourths of its for mer 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 26 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.
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 se cond time, both to solder the gold more perfectly, and to finish the polishing. The finished, it remains to draw the ingot into wire.
In order to this, they pass it through 20 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 boles more of a lesser iron leaves s small enough for the least iron ; the finest holes of which last scarcely exceed ing the hair of the head, finish the work.
To dispose the wire to be spun on silk, they pass it 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 ether. The gold wire, in passing between the two, is rendered quite flat, but with. out 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 w spool or bobin.