40 TlMEHRI, 
placed on some convenient support and tilted at an angle 
of from 6 to 10 degrees. The screen at the end projects 
over a riffled box extending in the same direction and 
at the same angle of inclination. Six or more cleats are 
nailed across the bottom of the box. A constant stream 
of water is directed through the upper box or Tom, and 
the dirt thrown in by several men who keep it well 
stirred, the larger stones being thrown out with a fork 
like an agricultural fork. 
As, however, the longer the "dirt" is subjected to the 
action of water the more fully is it disintegrated and the 
gold set free, and the larger the number of riffles the 
more impediments are offered to the escape of the gold, 
these greater advantages are obtained by the use of the 
Sluice-box. 
This is made in twelve-foot long sections varying 
in width from one to two feet, and about ten inches high, 
out of three boards riveted together with open ends. 
One end is a little wider than the other so that the 
various sections may be joined telescope or stove-pipe 
wise. The support is of trestles — widened to the 
requisite degree — and upon it are placed the sections, 
each entering the lower one for about four inches. In 
lieu of trestles piles of stone or heaps of earth are some- 
times used. This construction of triangles is extended 
as far as the miner judges proper. Movable riffles are 
placed along the floor of these troughs, and water is 
brought to the head of the sluice, when the " dirt " is 
shovelled in — an inclined board having been first nailed 
to the side of the trough opposite each shoveller, so as to 
prevent the dirt being thrown beyond the sluice. The 
number of shovellers is limited by the supply of water, 
