. A dictionary of arts, manufactures and mines : containing a clear exposition of their principles and practice. into the waler-troush. n n are draught-hi/les in the vault between the two pipes, whichserve for increasing or diminishing the heat at pleasure. The ores to be eliquated (sweated) are sorted by han 1 from the gangue, broken intopieces about the size of a hazel nut, and introduced into the ignited pipes ; one chargeconsisting of about 5 cwt. ; so that the pipes are filled to half tlieir diameter, and threefourths of their lensth. The sheet-iron door is shut, and the fire strongly urg
. A dictionary of arts, manufactures and mines : containing a clear exposition of their principles and practice. into the waler-troush. n n are draught-hi/les in the vault between the two pipes, whichserve for increasing or diminishing the heat at pleasure. The ores to be eliquated (sweated) are sorted by han 1 from the gangue, broken intopieces about the size of a hazel nut, and introduced into the ignited pipes ; one chargeconsisting of about 5 cwt. ; so that the pipes are filled to half tlieir diameter, and threefourths of their lensth. The sheet-iron door is shut, and the fire strongly urged, wherebythe bismuth begins to flow in ten minutes, and falls through the holes in the clay-platesinto hot pans containing some coal-dust. Whenever it runs slowly, the ore is stirredround in the pipes, at intervals during half an hour, in which time the liquation is usuallyfinished. The residuum, called bismuth barley (graupen), is scooped out with iron rakesinto a water trough ; the pipes are charged afresh ; the pans, when full, have their con-tents cast into moulds, forming bars of from 25 to 50 pounds
Size: 1663px × 1503px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1840, booksubje, booksubjecttechnology
