BOOK VIII. 



309 



it on each edge narrow strips, of no great thickness, and fix them to the beams 

 with nails. They agitate the metalliferous material with wooden scrubbers 

 and wash it in a similar way. As soon as little or no mud remains on the 

 canvas, but only concentrates or fine tin-stone, they lift one beam so that 

 the whole strake rests on the other, and dash it with water, which has been 

 drawn with buckets out of the small tank, and in this way all the sediment 

 which clings to the canvas falls into the trough placed underneath. This 

 trough is hewn out of a tree and placed in a ditch dug in the ground ; the 

 interior of the trough is a foot wide at the top, but narrower in the bottom, 

 because it is rounded out. In the middle of this trough they put a cross- 

 board, in order that the fairly large particles of concentrates or fairly large- 

 sized tin-stone may remain in the forepart into which they have fallen, and 

 the fine concentrates or fine tin-stone in the lower part, for the water flows 

 from one into the other, and at last flows down through an opening into the 

 pit. As for the fairly large-sized concentrates or tin-stone which have been 

 removed from the trough, they are washed again on the ordinary strake. 



A CANVAS STRAKE. B MAN DASHING WATER ON THE CANVAS. C BUCKET. 

 D BUCKET OF ANOTHER KIND. E MAN REMOVING CONCENTRATES OR TIN-STONE 



FROM THE TROUGH. 



