BRUSH. 587 BBUSH. varies with the shape of the conductor where the discharge takes phice. and has been examined iiy means of revolvinfr mirrors (see CnRoxo- scoPE) and found to consist of a series of par- tial sparks. In the case of a dynamo or motor the brushes are either bundles of strips of cop- per or gauze or blocks of carbon, which press against the commutator or collecting rings and complete the circuit through the line. They will be found described and illustrated in the article i^YNAMO ELECTRIC MACHINERY. BRUSH. Charles Francis (1849—). An American inventor, born in Euclid, Ohio. He graduated in 1809, at the engineering depart- ment of the University of ilichigau. and was an analytical chemist in Cleveland. Ohio, from 1809 to 1871. From 1871 to 1875 he was in the iron industry. He perfected in 1876 the dynamo- electric machine known by his name, and not long after the "series' arc-lamp, which might, with uniform results, be used in circuit in large numbers. Since that time he has patented more than fifty other inventions, chiefly detailed im- provements on the two jireceding. He founded in Cleveland the Bnish F.lectrie Company, which controls all his American patents, and in 1899 received the Rumford medal. BRUSH, Edward X. (1852 — ). An Ameri- can pliysician. He was born at Glenwood, Erie County, X. Y. ; graduated in 1874 at the Uni- versity of Buffalo; was editor of the Buffalo Medical Journal in 1874-89. and assistant phy- sician at the State Lunatic Asylum. Utica. From 1884 to 1891 he was assistant at the Penn- sylvania Hospital for the Insane, Philadelphia, -and in the latter year became physician-in- chief and medical superintendent of the Shep- pard and Enoch Pratt Hospital, Baltimore, Md. He was associate editor of the Ameriran- Journal of Insaiiiti/ from 1878 to 1884, and again as- sumed that post in 1897. He has written much on insanity. BRUSH, George de Fore.st (18.5.5 — ). An American figure-painter. He was born in Shel- byville, Tenn.. September 28, 185.5, and was a pupil of Gerome in Paris. Public notice was iirst attracted to his work, in 1883, by his pic- tures of Indian life in the West. In 1892 he ■exhibited at the Society of American Artists "The Portrait" and "Ossian and the Bard." After his later visits to Paris his work was more strictly confined to figure-composition, por- traying mother and child, or children, in some- what the manner of the Italian Renaissance painters. He interested himself in plastic art, vith a view to improving works of handicraft in general use. Brush took the Hallgartcn prize of the Xational Academy in 1888, and received a gold medal at the Paris Exposition of 1900. He was chosen a member of the Society of American Artists, and an associate of the Na- tional Academy of Design. His color sense is strong, and his canvases are composed with great care. His work seems little affected by the new school of light and air, but remains faithful to the older traditions of 'seeing' and of the manipulation of pigment. BRUSH, George .Tarvis (18.31 — ). An American mineralogist, born in Brooklyn, X. Y. He graduated at Yale in 1852. and later studied in Munich and Freiberg. In 1855 he became pro- fessor of metallurgy' in the Yale, now Shefiield, Vol. in.— .■)». Scientific School, exchanging this chair for that of mineralogy in 1804. He was director of the scientific school from 1872 to 1898. He has con- tributed much to the American Journal of Soi- cnc'C and similar ])erio(licals. and has published a Manual of Dcfcrininatirc Mincraloyij (1875). BRUSH-BIRDS. Birds of the family Atri- chiid;c. inhabiting the .scrub of Australia. BRUSH and BROOM (bruah, OF. broche, brosse. bush, brushwood, possibly akin to AS. byrst, OHG. burst, Ger. Borst, bristle; and see Broom). A brush is an instrument for sweeping or rubbing surfaces, either to remove dirt or to apply some material, as paint or blacking. It is composed of a bunch or bunches of fibrous and flexible material attached to a hiindle or back. A broom is simply a long-handled brush. These familiar instruments are of very ancient origin, for they are mentioned in the writings of Homer. They are used for a great variety of purposes, and are made from an indefinite immber of ma- terials. Among the commoner materials used in their manufacture are bristles, feathers, whale- bone, and rubber, the hair of the camel, Russian squirrel, badger, bear, and goat, rattan, split cane, broom-corn, and coir. The last-named ma- terial, which is simply the husk of the cocoanut- palm, is largely superseding hog's bristles for the coarser kinds of brushes. Brushes are said to be simple when they con- sist of a single tuft, and compound when they consist of a series of tufts. The crudest fonn of all is the ordinary paint-brush, in which the handle is forked at the end and a bunch of bristles is inserted between the two prongs, which are then bound together with twine and secured with a coating of glue. Artists' paint- brushes are made from camel's or Russian squirrel's hair; the roots "are forced into a quill which has been soaked previously, and which on drying holds them fast. In making the cheaper grades of compound brushes, such as floor and scrub brushes, dusters and blacking-bruslies. the tufts of bristles, coir, or whatever the material used, are simply stuck into holes bored in a piece of wood. Tbe.se holes may be bored at an angle, so that the tufts will project outward. The root-ends are dipped in melted pitch, bound with thread, and then dipped again and inserted with a twisting mo- tion. In the finer grades of brushes the tufts are tied in the middle with wire or thread, which is drawn up through the hole piercing the wood, and are secured by interueaving at the back. A veneer is then glued or cemented on the back to cover the wires. The best brushes are trepanned — that is, the holes are driven longitudinally or transversely through the back, and other holes sunk to niec?t them on the face of the brush. The tufts are then tied in the middle with strong threads, which are drawn through the holes piercing the brush, after which the holes running transversely or longi- tudinally through the brush are plugged. Brushes arc made by machinery, and nuiny dif- ferent devices for tlicir construction have been invented. In the Woodbury process— an Ameri- can invention and one of the earliest in brush manufacture — the back of the brush is tre- panned, and as the holes do not go clear through the wood, an extra back is not required. This machine consists essentially of a metal comb
