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 



A HEAD OF FRAME. B SMALL LAUNDER THROUGH WHICH WATER FLOWS INTO HEAD OF 



FRAME. 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 letting 

 in water. In this way the particles of gold settle in the turf, the mud and 

 sand, together with the water, are carried down into the settling-pit or trough 

 below, which is opened when the work is finished. After all the water has 

 passed out of the settling-pit, the sand and mud are carried away and washed 

 over again in the same manner. The particles which have clung to the turf 

 are afterward washed down into the settling-pit or trough by a stronger 

 current 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 not 

 ignorant of this method of washing gold. " The ulex," he says, " after being 

 dried, is burnt, and its ashes are washed over a grassy turf, that the gold 

 may settle on it." 



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