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Archive image from page 360 of De re metallica (1950). De re metallica deremetallica50agri Year: 1950 ROOK VIII. 323 particles or concentrates of gold, together with the sand, pass through the holes into the trough which is placed under the frame, and after being collected are washed in the bowl. A box which has a bottom made of a plate full of holes, is placed over the upper end of a sluice, which is fairly long but of moderate width. The gold material to be washed is thrown into this box, and a great quantity of water is let in. The lumps, if ore is being washed, are mashed with an iron sho
Archive image from page 360 of De re metallica (1950). De re metallica deremetallica50agri Year: 1950 ROOK VIII. 323 particles or concentrates of gold, together with the sand, pass through the holes into the trough which is placed under the frame, and after being collected are washed in the bowl. A box which has a bottom made of a plate full of holes, is placed over the upper end of a sluice, which is fairly long but of moderate width. The gold material to be washed is thrown into this box, and a great quantity of water is let in. The lumps, if ore is being washed, are mashed with an iron shovel. The fine portions fall through the bottom of the box into the sluice, but the coarse pieces remain in the box, and these are removed with a scraper through an opening which is nearly in the middle of one side. Since a large amount of water is necessarily let into the box, in order to prevent it from sweeping away any particles of gold which have fallen into the sluice, the sluice is divided off by ten, or if it is as long again, by fifteen riffles. These riffles are placed equidistant from one another, and each is higher than the one next toward the lower end of the sluice. The little compartments which are thus made are filled with the material and the water which flows through A—Sluice. B—Box. C—Bottom of inverted box. D—Open part of it. E—Iron HOE. F—Riffles. G—Small launder. H—Bowl with which settlings are taken AWAY. I—Black bowl in which they are washed.
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Keywords: 1900, 1950, agricola_georg_1494_1555, archive, book, bookauthor, bookcentury, bookdecade, bookpublisher, booksubject, bookyear, drawing, historical, history, hoover_herbert_1874_1964, illustration, image, metallurgy, mineral_industries, new_york_dover_publications, page, picture, print, reference, vintage