A Dictionary of Arts: Brass Color. Brass Foil.

A Dictionary of Arts, Manufactures, and Mines; containing A Clear Exposition of Their Principles and Practice

by Andrew Ure, M. D.;
F. R. S. M. G. S. Lond.: M. Acad. M. S. Philad.; S. PH. DOC. N. GERM. Ranow.; Mulh. Etc. Etc.

Illustrated with nearly fifteen hundred engravings on wood
Eleventh American, From The Last London Edition.
To which is appended, a Supplement of Recent Improvements to The Present Time.

New York: D Appleton & company, 200 Broadway. Philadelphia: George S. Appleton, 148 Chestnut St.
MDCCCXLVII

1847


BRASS COLOR, for staining glass, is prepared by exposing for several days thin plates of brase upon titles in the leer or annealing arch of the glass-house, till it be oxydized into a black powder, aggregated in lumps. This being pulverized and sifted, is to be again well calcined for several days more, till not particles remain in the metallic state; when it will form a fine powder of a russet brown color. A third calcination must now be given, with a carefully regulated heat; its qualitu being tested from time to time by fusion with some glass. If it makes the glass swell, and intumesce, it is properly prepared; if not, it must be still further calcined. Such a powder communicates to glass, greens of various tints, passing into turquoise.

When thin narrow strips of brass are stratified with sulphur in a crucible, and calcined at a red heat, they become friable, and may be reduced to powder. This being sifted and exposed upon tiles in a reverberatory furnace for ten or twelve days, becomes fit for use, and is capable of imparting a calcedony, red, or yellow tinge to glass by fusion, according to the mode and proportion of using it.

The glass-makers' red color may be prepared by exposing small plates of brass to a moderate heat in a reverberatory furnace, till they are thoroughly calcined, when the substance becomes pulverulent, and assumes a red color. It is then ready for immediate use.

BRASS COLOR, as employed by the colormen to imitate brass, is of two tints, the red or bronze, and the yellow like gilty brass. Copper filings, mixed with heat, and then spread with a flat camel-hair brush evenly upon the surface of the object. The best varnish is composed of 20 ounces of spirits of wine, 2 ounces of shellac, and 2 ounces of sandarach, properly dissolved. See VARNISH. Only so much of the brass powder and varnish should be mixed at a time as is wanted for immediate use.

BRASS FOIL. Dutch leaf, called Knitter or Rauschgold in Germany, is made from very thin sheet brass, beat out under a hammer worked by water power, which gives 300 or 400 strokes per minute: from 40 to 80 leaves being laid over each other. By this treatment, it acquires its characteristic solidity and lustre. See above, the process for converting the copper superficially into brass by the fumes of zinc.