Identifier: reportofgeologic03unit (find matches)
Title: Report of the geological exploration of the fortieth parallel
Year: 1870 (1870s)
Authors: United States Geological Exploration of the Fortieth Parallel (1867-1881) King, Clarence, 1842-1901 Hague, A. (Arnold), 1840-1917 Emmons, Samuel Franklin, 1841-1911 Hague, James D. (James Duncan), 1836-1908 Meek, F. B. (Fielding Bradford), 1817-1876 Hall, James, 1811-1898 Whitfield, R. P. (Robert Parr), 1828-1910 Ridgway, Robert, 1850-1929 Watson, Sereno, 1826-1892 Eaton, Daniel Cady, 1834-1895 Bien, Julius, 1826-1909, engraver
Subjects: Discoveries in geography Geology Mines and mineral resources Paleontology Botany Birds
Publisher: (Washington, D.C. : G.P.O.)
Contributing Library: University of Illinois Urbana-Champaign
Digitizing Sponsor: University of Illinois Urbana-Champaign

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ion isresumed without delay. Settlers or Separators.—These, like the pans, differ somewhat in detailsof construction, but they usually are round tubs of iron or of wood with cast-ironbottoms, resembling the pans in general features, but larger in diameter. Ahollow pillar or cone, C, Figs. 1 and 2, Plate XVII, is cast in the center of thebottom, within which is an upright shaft, S. This shaft is caused to revolveby gearing below the pan. To its upper end is attached a yoke or driver, D,that gives revolving motion to arms, A, extending from the center to the cir-cumference of the vessel. The arms carry a number of plows, or stirrers, oivarious devices, usually terminating in blocks of hard wood, P, that rest lightlyon the bottom. No grinding is required in the operation, but a gentle stirringor agitation of the pulp is desired in order to facilitate the settling of theamalgam and the quicksilver. The stirring apparatus, or muller, makes aboutfifteen revolutions per minute. Plait- XVII
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IEEATMENT OF THE COMSTOCK ORES. 201 The settler is usually placed directly in front of the pan and on a lowerlevel, so that the pan is readily discharged into it. In some mills two pans aredischarged into one settler, the operation of settling occupying four hours, orthe time required by the pan to grind and amalgamate another charge. Inother mills the settling is allowed only two hours, and the two pans connectedwith any one settler arc discharged alternately. The consistency of the pulp in the settler is considerably diluted by thewater used in discharging the pan and by a further supply, which in manymills is kept up during the settling operation. In other mills, however, thepulp is brought from the pan into the settler with the addition of as littlewater as possible, and allowed to settle for a time by the gentle agitation of theslowly revolving muller, after which cold water is added in a constant stream.The quantity of water used, affecting the consistency of the pulp, and thesp

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