A practical treatise on the manufacture of colors for painting : comprising the origin, definition, and classification of colors; the treatment of the raw materials .. etc. . hich is hermeticallyclosed during the operation. The packing of the 250kilogrammes of black requires about 25 casks of 400litres, or a cask for about 10 kilogrammes of black. The tar should be free from earthy substances, orthe yield will be less. The same apparatus may be used for the prepara-tion of lampblack, with the heavy (dead) oils of tarand schist. These oils, very rich in carbon, are veryadvantageous for this man
A practical treatise on the manufacture of colors for painting : comprising the origin, definition, and classification of colors; the treatment of the raw materials .. etc. . hich is hermeticallyclosed during the operation. The packing of the 250kilogrammes of black requires about 25 casks of 400litres, or a cask for about 10 kilogrammes of black. The tar should be free from earthy substances, orthe yield will be less. The same apparatus may be used for the prepara-tion of lampblack, with the heavy (dead) oils of tarand schist. These oils, very rich in carbon, are veryadvantageous for this manufacture, and produce a veryhandsome black which is much esteemed. Lampblackis sometimes prepared from the soft pitch left afterthe incomplete distillation of coal-tar. This latterblack is not much esteemed; but its quality may beimproved by burning the pitch with the dead oils oftar and schist. Third Process.—Oil or lampblack. This black is the lightest and finest of all, and isobtained by burning certain kinds of oils, the vege- 522 MANUFACTURE OF COLORS. table ones preferably, in lamps of a peculiar construc-tion. The apparatus is represented in Fig. 61. Fig. A, lamp, the liquid level of which remains is fed from a reservoir b, filled with oil. At thelower part of A there is a bent tube c, the upperopening of which is on the same level as the oil in combustion takes place with the aid of a wickmade of cotton or amianthus. This latter substanceis preferable, because it is incombustible, and may beused quite indefinitely. The flame burns under a coneD, fixed to an elbow-tube opening into a large hori-zontal pipe E. This pipe cools the smoke, and con-denses the water, and other condensable liquid pro-ducts, formed during the operation. From this pipe,the smoke passes through a series of large sacks f, f,F, six metres high, and one metre in diameter, whichare kept open at the top and bottom by funnels ofgalvanized h^on. The first and second sacks, and th
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Keywords: ., bookcentury1800, bookdecade1870, bookpublisherphila, bookyear1874
