. A dictionary of arts, manufactures and mines : containing a clear exposition of their principles and practice. 294. 309 fine; M C, middling; 0 C, ordinary. A melting furnace, containing 8 pots of glass,produces in 24 hours, from 24 cwts. of the mixture, 19 cwts. of blue slasi;; and fromI to I cwt. of scoriae or speiss (speise). The composition speise, according to Berthier,is—nickel, 49-0; arsenic, 37-8; sulphur, 7-8; copper, 1-6; cobalt, 3-2 in 100. Nickel,arsenic, and sulphur, are its essential constituents; the rest are accidental, and oftenabsent. The freer the cobalt ore is
. A dictionary of arts, manufactures and mines : containing a clear exposition of their principles and practice. 294. 309 fine; M C, middling; 0 C, ordinary. A melting furnace, containing 8 pots of glass,produces in 24 hours, from 24 cwts. of the mixture, 19 cwts. of blue slasi;; and fromI to I cwt. of scoriae or speiss (speise). The composition speise, according to Berthier,is—nickel, 49-0; arsenic, 37-8; sulphur, 7-8; copper, 1-6; cobalt, 3-2 in 100. Nickel,arsenic, and sulphur, are its essential constituents; the rest are accidental, and oftenabsent. The freer the cobalt ore is from foreign metals, the finer is the color, and thedeeper is the shade; paler tints are easily obtained by dilution with more glass. Thepresence of nickel gives a violet tone. The production of smalt in the Prussian states amounted, in 1830, to 7452| cwts.;and in Saxony to 9697 cwts.; in 1825, to 12,310 cwts. One process for making fine smalt has been given under the title Azure ; I shall in-troduce another somewhat difierent here. The ore of cobalt is to be reduced to very fine powder, and then roasted with
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Keywords: ., bookcentury1800, bookdecade1840, booksubje, booksubjecttechnology
