3°8

BOOK VIII.

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A —Beams. B—Canvas. C —Head of strake. D —Small launder. E —Settlingpit or tank. F —Wooden scrubber. G —Tubs.

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the second division, the third is similarly laid, and so on, one on the other.If they are laid in the opposite way, the water flowing down carries theconcentrates or particles of tin-stone under the canvas, and a useless taskis attempted. Boys or men throw the concentrates or tin-stuff mixed withmud into the head of the strake, after the canvas has been thus stretched,and having opened the small launder they let the water flow in ; thenthey stir the concentrates or tin-stone with a wooden scrubber till the watercarries them all on to the canvas ; next they gently sweep the linen withthe wooden scrubber until the mud flows into the settling-pit or into thetransverse launder. As soon as there is little or no mud on the canvas, butonly concentrates or tin-stone, they carry the canvas away and wash it in atub placed close by. The tin-stone settles in the tub, and the men returnimmediately to the same task. Finally, they pour the water out of the tub,and collect the concentrates or tin-stone. However, if either concentratesor tin-stone have washed down from the canvas and settled in the settling-pit or in the transverse launder, they wash the mud again.

Some neither remove the canvas nor wash it in the tubs, but place over