then constructed of
slabs 2 ft. 6 in. in height to ground level, the outer wall being thus
30 ft. and the inner 15 ft. in circumference. The circular space between
is floored with smooth hardwood slabs or boards, and the whole made
secure and water-tight. In the middle of the inner enclosure a
stout post is planted, to stand a few inches above the wall, and the
surrounding space is filled up with clay rammed tight. A strong iron pin
is inserted in the centre of the post, on which is fitted a revolving
beam, which hangs across the whole circumference of the machine
and protrudes a couple of feet or so on each side. To this beam are
attached, with short chains, a couple of drags made like V-shaped
harrows by driving a piece of red iron through a heavy frame, shaped as
a rectangular triangle.

To one end of the beam an old horse is attached, who, as he slowly walks
round the circular track, causes the harrows and drags to so puddle
the washdirt and water in the great wooden enclosure that the clay is
gradually disintegrated, and flows off with the water which is from time
to time admitted. The clean gravel is then run through a "cradle," "long
Tom," or "sluice," and the gold saved. This, of course, is the simplest
form of gold mining. In the great alluvial mines other and more
intricate appliances are used but the principle of extraction is the
same.

A MAKESHIFT PUMP

To make a temporary small "draw-lift" pump, which will work down to
a hundred feet or more if required, take a large size common suction
Douglas pump, and, after removing the top and handle, fix the pump as
close to the highest level of the water in the shaft as can be arranged.
Now make a square water-tight wooden column of slightly greater capacity
than the suction pipe, fix this to the top of the pump, and by means
of wooden rods, work the whole from the surface, using either a longer
levered handle or, with a little ingenuity, horse-power. If you can
get it the iron downpipe used to carry the water from the guttering of
houses is more easily adapted for the pipe column; then, also, iron pump
rods can be used but I have raised water between 60 and 70 feet with a
large size Douglas pump provided only with a wooden column and rods.

SQUEEZING AMALGAM

For squeezing amalgam, strong calico, not too coarse, previously soaked
in clean water, is quite as good as ordinary chamois leather. Some gold
is fine enough to escape through either.

MERCURY EXTRAC