338

BOOK VIII.

time first of all dig a long ditch sloping so that the water will run throughit rapidly. Into the ditch is thrown the metallic material, together with thesurface material, which is six feet thick, more or less, and often contains moss,roots of plants, shrubs, trees, and earth ; they are all thrown in with a broadmattock, and the water flows through the ditch. The sand and tin-stone, asthey are heavy, sink to the bottom of the ditch, while the moss and roots, asthey are fight, are carried away by the water which flows through the ditch.The bottom of the ditch is obstructed with turf and stones in order to preventthe water from carrying away the tin-stone at the same time. The washers,whose feet are covered with high boots made of hide, though not of rawhide,themselves stand in the ditch and throw out of it the roots of the trees,shrubs, and grass with seven-pronged wooden forks, and push back the tin-stone toward the head of the ditch. After four weeks, in which they havedevoted much work and labour, they raise the tin-stone in the followingway ; the sand with which it is mixed is repeatedly lifted from the ditch

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A—Trough. B—Wooden shovel. C —Tub. D—Launder. E —Wooden trowel.F—Transverse trough. G —Plug. H —Falling water. I —Ditch. K —Barrow

CONVEYING MATERIAL TO BE WASHED. L —PlCK LIKE THE BEAK OF A DUCK WITH WHICHTHE MINER DIGS OUT THE MATERIAL FROM WHICH THE SMALL STONES ARE OBTAINED.