tone 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
prospecting new ground, for many times a claim has been deserted after
cleaning up the "bottom," and another man has got far better gold
considerably higher up on the sides of the gutter. For shallow alluvial
deposits, where a man quickly works out his 30 by 30 feet claim, it may
be cheaper at times to "paddock" the whole ground--that is, take all
away from surface to bottom, but if he is in wet ground and he has to
drive, great care should be taken to properly secure the roof by means
of timber. How this may best be done the local circumstances only can
decide.

CHAPTER III

LODE OR REEF PROSPECTING

The preceding chapter dealt more especially with prospecting as carried
on in alluvial fields. I shall now treat of preliminary mining on lodes
or "reefs."

As has already been stated, the likeliest localities for the occurrence
of metalliferous deposits are at or near the junction of the older
sedimentary formations with the igneous or intrusive rocks, such as
granites, diorites, etc. In searching for payable lodes, whether of
gold, silver, copper, or even tin in some forms of occurrence, the
indications are often very similar. The first prospecting is usually