the name of an instrument used for finding the bigness of fine round pearls. It consists of thin pieces or leaves, about two inches long and half an inch broad, fastened together at one end by a rivet. In each of these are round holes drilled of different diameters. Those in the first leaf serve for measuring pearls from half a grain to seven grains; those of the second, for pearls from eight grains, or two carats, to five carats, &c.; and those of the third, for pearls from six carats and a half to eight carats and a half.
SIZE is also a sort of paint, varnish, or glue, used by painters, &c.
The shreds and parings of leather, parchment, or vellum, being boiled in water and strained, make size. This substance is used in many trades.
The manner of using size is to melt some of it over a gentle fire; and scraping as much whiting into it as may only colour it, let them be well incorporated together; after which you may whiten frames, &c., with it. After it dries, melt the size again, and put more whiting, and whiten the frames, &c., seven or eight times, letting it dry between each time: but before it is quite dry, between each washing, you must smooth and wet it over with a clean brush-pencil in fair water.
To make gold-size, take gum animi and asphaltum, of each one ounce; minium, litharge of gold, and umber, of each half an ounce; reduce all into a very fine powder, and add to them four ounces of linseed-oil, and eight ounces of drying-oil; digest them over a gentle fire that does not flame, so that the mixture may only simmer, but not boil; for fear it should run over and set the house afire, keep it constantly stirring with a stick till all the ingredients are dissolved and incorporated, and do not leave off stirring it till it becomes thick and ropy; and being boiled enough, let it stand till it is almost cold, and then strain it through a coarse linen-cloth and keep it for use.
To prepare it for working, put what quantity you may have occasion to use in a horse-muscle shell, adding so much oil of turpentine as will dissolve it; and making it as thin as the bottom of your seed-lac varnish, hold it over a candle, and then strain it through a linen rag into another shell; add to these so much vermilion as will make make it of a darkish-red: if it is too thick for drawing, you may thin it with some oil of turpentine. The chief use of this size is for laying on metals.
The best gold-size for burning is made as follows: take fine bole, what quantity you please; grind it finely on a marble; then scrape into it a little beef suet; grind all well together; after which mix a small proportion of parchment size with a double proportion of water, and it is done.
To make silver-size: take tobacco-pipe clay, in fine powder; into which scrape some black-lead and a little Genoa-soap; and grind them all together with parchment-size, as already directed.