BRUSHES AND BROOMS. Brushes are implements used for two distinct purposes: (1) The sweeping or whisking away of dust and dirt, and (2) the laying on of liquids in thin layers, as in painting. Brooms in general, are brushes with longer handles; the whisk-broom, or whisk, is a little broom with a short handle. Brushes are made of many kinds of material, to suit the many purposes for which they are used. Some of these are bristles, rice root, bass, Tampico (grass), Jaumave (istle), palma fibre, bristle fibre or coir (cocoanut husk), broom corn, rushes, rattan (split), bamboo (fibre), oiled kitool (a wood fibre), rubber, wire of brass, steel and German silver; the hair of the camel, cow, horse, goat, squirrel, sable and bear; feathers, and whalebone.
Notwithstanding the great variety of pos sible material, about 92 per cent of all brushes are made from the bristles of the hog. The best quality comes from Russia and China, where certain breeds of hogs are raised espe cially for their black bristles and, in some sections, not for eating. The Russian bristles are most highly esteethed. They are from 3rA to 7 inches in length. The Chinese bristles are from 2% to 7 inches long. A considerable part of the supply of bristles on the market comes from France and Germany, and these bristles are white, yellowish or bleached and vary in length from 2 to nearly 5 inches in length. In the year ending 30 June 1915, the United States imported 4,062,060 pounds of bristles (valued at $3,613,084), of which 2,400,000 pounds came from China. In order to get enough to supply their needs, the larger brush-houses keep em ployees at the great packing-houses to collect the better quality of bristles from the hogs as they are slaughtered.
Except in the largest plants, the brush making industry consists in assembling parts made elsewhere in specializing factories. The handles are made in one place and finished in another. The bored blocks are made in still other factories. Twine, broom nails and staples, plush and metal bands, caps for whisks — each has its specialized trade. One concern special
izes in badger hair, and every sort of brush material has its particular importing and trade houses.
Brushes have been classified as simple and compound—in the first class those composed of a single tuft of brush material; in the sec ond class those made up of a number of tufts. The first class comprises the brushes made for the use of artists and painters and the °hair pencils') used in medicine for the outward ap plication of certain remedies, for example, the tincture of iodine. Some painters' brushes made for roof painting are compound, or per haps, more exactly, are formed of a single rank of simple brushes.
For painters' brushes no material has been found acceptable but the bristles of the hog, which have a fag or split end tending to hold the paint. Several different lengths of bristles are used in each brush, so that as the brush wears down there are always new tips at the end to keep the brush in good working order. The bristles are gathered in a tuft of the re quired size and set into a socket in the handle with some kind of cement, the kind of cement depending upon the use to be made of the finished brush; if in alcohol varnishes, they are set with glue; if in water solutions, they are set with a cement whose solvent is alcohol or benzine. The problem of the brush makers is to find some cement which will resist the dissolving action of all the common solvents in use— water, oils, alcohol, turpentine, petroleum spirit and the like. A comparatively recent improvement has been the setting of the bris tles with rubber (paste) and then vulcanizing the rubber. This is successful with small brushes, particularly the flat varnishing brushes, but the great heat required destroys the liveli ness or elasticity of the bristles, and, besides, the process is slow, consuming several days. It is entirely useless for large brushes.