In the latter case the rich find
would immediately be pegged out as a claim, or lease, and work commenced,
the coarse gold being won by the simple process of "dollying" the ore;
or pounding it in an iron mortar with an iron pestle, and passing it when
crushed, through a series of sieves in which the gold, too large to fall
through, is held.
To estimate roughly the worth of a reef in which only fine gold is visible
it is necessary to take several samples along the outcrop, "dolly" them,
and wash the powdered quartz by means of two iron dishes, from which the
light material is floated off, leaving the gold behind. From a series of
experiments an idea can be formed as to whether the reef is worth further
work.
It will be found on napping a reef, that the gold occurs at more or less
regular intervals. This deposit of gold in the surface outcrop is the top
of a "shoot" of gold, which may be followed down on the underlay for many
feet. And this peculiarity in the distribution of the metal has been the
cause of much disappointment and misunderstanding.
Having determined that your reef is good enough on the surface, the next
thing to be done is to ascertain, by means of cuts and shafts, its nature
below the surface. This may be done either by an underlay shaft, which
follows the reef down from the surface, or by a vertical shaft, sunk some
distance away from the outcrop, to cut the reef perhaps one hundred feet
below.
By a series of shafts with drives, or galleries, connecting them when they
cut the vein, a more accurate estimate of the value of the reef can be
made.
Now in the case of a reef which has rich shoots a prospector, naturally
anxious to make his "show" as alluring as possible to any possible buyer,
sinks his trial shaft, on the underlay, through the shoots. And so it
might happen, that by carefully selecting the sites of his shafts, he
might have a dazzling show of gold in each one, and merely blank quartz
between them. A mining expert, usually only too ready to give a glowing
report, makes his estimates on the assumption that the quartz intervening
between the shafts is as rich as that visible in them, and the purchase
price increases accordingly.
Not only do shoots occur to puzzle the expert, gladden the heart of the
prospector, and madden the shareholder, but the eccentricity of gold is
further exemplified by the way in which it has been been deposited in
"pockets."
No better example of this could be given than the Londonderry Mine, where
gold to the value of many thousand pounds was won from quite a small hole
in the outcrop.
