e. The tom may be used to advantage
in diggings where the amount of pay-dirt is small and the gold coarse.
The riffle-box contains quicksilver, and as the dirt in it is kept
loose by the water falling down on it from the riddle above, a large
part of the gold is caught; but where the particles are fine, much must
be lost.

_Cradle._--The rocker or cradle is still less than the tom and inferior
in capacity. It bears some resemblance in shape and size to a child's
cradle, and rests upon similar rockers. The cradle-box is about forty
inches long, twenty wide, and four high, and it stands with the upper
end about two feet higher than the lower end, which is open so that the
tailings can run out. On the upper end of the cradle-box stands a
hopper or riddle-box twenty inches square, with sides four inches high.
The bottom of this riddle box is of sheet-iron, perforated with holes
half an inch in diameter. The riddle-box is not nailed to the
cradle-box, but can be lifted off without difficulty. Under the riddle
is an "apron" of wood or cloth, fastened to the sides of the cradle-box
and sloping down to the upper end of it. Across the bottom of the
cradle-box are two riffle-bars about an inch square, one in the middle,
the other at the end of the box. The dirt is shovelled into the hopper,
the "cradler" sits down beside his machine, and while with one hand
with a ladle he pours water from a pool at his side upon the dirt, with
the other he rocks the cradle. With the water and the motion the dirt
is dissolved, and carried down through the riddle, falling upon the
apron which carries it to the head of the cradle-box, whence it runs
downward and out, leaving its gold, black sand, and heavier particles
of sand and gravel behind the riffle-bars. The man who rocks a cradle
learns to appreciate the fact, that the "golden sands" of California
are not pure sand, but are often extremely tough clay, a hopperful of
which must be shaken about for ten minutes before it will dissolve
under a constant pouring of water. Many large stones are found in the
pay-dirt. Such as give an unpleasant shock to the cradle, as they roll
from side to side of the riddle-box, are pitched out by hand, and after
a glance to see that no gold sticks to their sides, are thrown away;
but the smaller ones are left until the hopperful has been washed, so
that nothing but clean stones remain in the riddle, and then the
cradler rises from his seat, lifts up his hopper, a