particles or concentrates of gold, together with the sand, pass through the
holes into the trough which is placed under the frame, and after being
collected are washed in the bowl.
A box which has a bottom made of a plate full of holes, is placed over
the upper end of a sluice, which is fairly long but of moderate width. The
gold material to be washed is thrown into this box, and a great quantity of
water is let in. The lumps, if ore is being washed, are mashed with an iron
shovel. The fine portions fall through the bottom of the box into the sluice,
but the coarse pieces remain in the box, and these are removed with a scraper
through an opening which is nearly in the middle of one side. Since a large
amount of water is necessarily let into the box, in order to prevent it from
sweeping away any particles of gold which have fallen into the sluice, the
sluice is divided off by ten, or if it is as long again, by fifteen riffles. These
riffles are placed equidistant from one another, and each is higher than the one
next toward the lower end of the sluice. The little compartments which are
thus made are filled with the material and the water which flows through
