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564 MINERAL RESOURCES.
ing
the different companies began. Originally the mines were worked as
3,238 separate claims, each 31 feet square, with a 7-1/2 foot roadway
between every two claims; now these are all united in about forty
companies. A mine in the early days was a bewildering sight. Miles of
wire cables running from individual claims were stretched across it in
all directions; to these were attached the buckets for carrying the
earth, reef, or wall rock of the mines, and at times water. Some of the
claims were almost level with the surface, while others next to them
might be cut down 200 feet, and others only 100 feet, yet all being
worked independently. At the sides were endless belts with pockets for
carrying the earth. One of the results of this independent system of
working was that rock was dropped so recklessly that it is said to
have been as dangerous as the battlefield to stand around the edges of
the claims. Not only was the loss of life great from this source, but
also from the falling of immense masses of reef, loosened by the
blasting, which sometimes buried a score of men at once. But improved
methods were gradually introduced. Steam railroads were run into the
mine, and parts of it were leveled down. Millions of tons of reef
required removing, and the only way to accomplish this was to assess
every company iu the miue proportionately. At first many mistakes were
made, if mistakes they can be called when the problems offered for
solution were entirely new and untried. The yellow or surface soil
which overlaid the blue stuff pulverized so readily that it could be
taken to the washing machine direct; but as the claims were extended
down into the blue rock this proved harder, and dynamite became
necessary. Immense quantities of it are now used for blasting. Through
careless storing, 30 tons of dynamite, 10 tons of blasting powder, and
gelatine, in all worth $80,000, exploded on January 10, 1884, with
terrific effect; the smoke column, 1,000 feet high, was visible at the
River diggings, 35 miles distant.
After
the earth is raised it is put on the sorting ground, where it is
partially disintegrated by water and the action of the atmosphere. It
is then further broken up by hand and taken to the "compound" or
diamond-sorting machine. After being more finely broken up it is passed
down into large vats containing immense centrifugal wheels, by which,
as they rapidly revolve, the rock is finely divided. The lighter
minerals, such as quartz, mud, and mica, are then floated out, while
the diamonds, garnets (some of which are exceedingly rich iu color, and
of large size and are sold under the name of cape rubies), and other
heavy minerals, are concentrated iu the lower part of the "compound."
So thoroughly does this pulverize the rock and earth that all the
diamonds, even those of the size of a pinhead, are saved.
A
prize of £5,000 was offered for the best tunnel or shaft system for use
at the Kimberley mines, and the prize was awarded to the Jones system,
which is sunk on the coffer-dam principle. At present there are seven
shafts and inclined planes in the Kimberley mine alone, all sunk at
some point in the reef outside of the mine. From 11,000,000
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