BOOK VIII.

333

Some people construct a frame not unlike the one covered with canvas,but shorter. In place of the canvas they set pieces of turf in rows. They

->^Si

mm

wm.

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A —Head of frame. B —Small launder through which water flows into head offrame. C— Pieces of turf. D— Trough placed under frame. E— Tub in which

PIECES OF TURF ARE WASHED.

wash the sand, which has been thrown into the head of the frame, by lettingin water. In this way the particles of gold settle in the turf, the mud andsand, together with the water, are carried down into the settling-pit or troughbelow, which is opened when the work is finished. After all the water haspassed out of the settling-pit, the sand and mud are carried away and washed°ver again in the same manner. The particles which have clung to the turfare afterward washed down into the settling-pit or trough by a strongercurrent of the water, which is let into the frame through a small launder.The concentrates are finally collected and washed in a bowl. Pliny was notignorant of this method of washing gold. “ The ulex,” he says, “ after beingdried, is burnt, and its ashes are washed over a grassy turf, that the goldmay settle on it.”

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