. A dictionary of arts, manufactures and mines : containing a clear exposition of their principles and practice. re,are to cover outwardly with earth the portions where too much activity is displayed,and to pierce with holes or to give air to those where it is imperfectly developed. Rains,winds, variable seasons, and especially good primary arrangements of a calcination, havemuch influence on this process, which requires, besides, an almost incessant inspection atthe beginning. Nothing in general can be said as to the consumption of fuel, because it varies withits quality, as well as with the
. A dictionary of arts, manufactures and mines : containing a clear exposition of their principles and practice. re,are to cover outwardly with earth the portions where too much activity is displayed,and to pierce with holes or to give air to those where it is imperfectly developed. Rains,winds, variable seasons, and especially good primary arrangements of a calcination, havemuch influence on this process, which requires, besides, an almost incessant inspection atthe beginning. Nothing in general can be said as to the consumption of fuel, because it varies withits quality, as well as with the ores and the purpose in view. But it may be laid downas a good rule, to employ no more fuel than is strictly necessary for the kind of calci-nation in hand, and for supporting the combustion; for an excess of fuel would produce,besides an expense uselessly incurred, the inconvenience, at times very serious, of sucha heat as may melt or vitrify the ores; a result entirely the reverse of a well-conductedustulation. Figs. 681, 682, 683, represent the roasting in mounds, as practised near Goslar in the681 682 J.
Size: 2715px × 920px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1840, booksubje, booksubjecttechnology
