er of the cradle which separates
the larger stones and pebbles, the remainder passing down over inclined
ledges as the cradle is slowly rocked and supplied with water. At
the bottom of each ledge is a riffle to arrest the particles of gold.
Sometimes, when the gold is very fine, amalgamated copper plates are
introduced and the lower ledges are covered with green baize to act as
blanket tables and catch gold which might otherwise be lost.

A long tom is a trough some 12 feet in length by 20 inches in width at
the upper end, widening to 30 inches at the lower end; it is about 9
inches deep and has a fall of 1 inch to a foot. An iron screen is placed
at the lower end where large stones are caught, and below this screen
is the riffle box, 12 feet long, 3 feet wide, and having the same
inclination as the upper trough. It is fitted with several riffles in
which mercury is sometimes placed.

Much more work can be done with this appliance than with the cradle,
which it superseded. Of course, the gold must be coarse and water
plentiful.

When, however, the claim is paying, and the diggings show signs of some
permanency, a puddling machine is constructed. This is described in the
chapter called "Rules of Thumb."

Hydraulicing and ground sluicing is a very cheap and effective method
of treating large quantities of auriferous drift, and, given favourable
circumstances, such as a plentiful supply of water with good fall and
extensive loose auriferous deposits, a very few grains to the ton or
load can be made to give payable returns. The water is conveyed in
flumes, or pipes to a point near where it is required, thence in wrought
iron pipes gradually reduced in size and ending in a great nozzle
somewhat like that of a fireman's hose. The "Monitor," as it is
sometimes called, is generally fixed on a movable stand, so arranged
that the strong jet of water can be directed to any point by a simple
adjustment. A "face" is formed in the drift, and the water played
against the lower portion of the ledge, which is quickly undermined, and
falls only to be washed away in the stream of water, which is conducted
through sluices with riffles, and sometimes over considerable lengths
of amalgamated copper plates. This class of mining has been most
extensively carried out in California and New Zealand, and some
districts of Victoria, but the truly enormous drifts of the Shoalhaven
district in New South Wales must in the near future add largely t