for instance, a clay slate or sandy slate set at a certain angle; then,
in all probability, unless there be a distinct fault or change in the
country rock between the slate outcrop and your shaft, the bottom will
be a similar slate, standing at the same angle; and this will
very probably be overlaid by a deposit of pipeclay, formed by the
decomposition of the slates.

From the crevices of these slates, sometimes penetrating to a
considerable distance, you may get gold, but it is useless attempting to
sink through them. If the outcropping strata be a soft calcareous (limy)
sandstone or soft felspathic rock, and that be also the true bottom,
great care should be exercised or one is apt to sink through the bottom,
which may be very loose and decomposed. I have known mistakes made in
this way when many feet have been sunk, and driven through what was
actually bed rock, though so soft as to deceive even men of experience.
The formation, however, must be the guide, and except in some specially
difficult cases, a man can soon tell when he is really on bed rock or
"bottom."

On an alluvial lead the object of every one is to "get on the gutter,"
that is, to reach the lowest part of the old underground watercourse,
through which for centuries the gold may have been accretionising from
the percolation of the mineral-impregnated water; or, when derived from
reefs or broken down leaders, the flow of water has acted as a natural
sluice wherein the gold is therefore most thickly collected. Sometimes
the lead runs for miles and is of considerable width, at others it is
irregular, and the gold-bearing "gutter" small and hard to find. In many
instances, for reasons not readily apparent, the best gold is not found
exactly at the lowest portion of these narrow gutters, but a little
way up the sides. This fact should be taken into consideration in