to
be so hard after all; pieces of it came up, and there was a crystal
embedded in one of them. It glittered only feebly, but it was the
harbinger of terrific things. Excitement had never run so high, and
there was a new rush over the old diggings. In time, the miners learned
a lot about the blue ground; for one thing, they learned that when it
was exposed to the air it weathered into the friable yellow stuff they
had first encountered. But it took geologists to find out what the blue
ground really was and how deep it went. Evidently, as Atherstone said,
it was of igneous origin, and eventually the geologists determined that
it occurred in the form of huge tubes, which appeared to be escape
valves for some great reservoir of boiling material in the middle of
the earth. A long time ago, the tubes, necks, pipes— the geologists use
all these terms—terminated at the earth's surface as volcanoes; then
the volcanoes had died down and had been eroded, leaving the supply
pipes exposed just as the forces of wind and water had sliced them off.
The pipe of diamond-iferous soil under the kcpje, it was now clear, was a regular oval, about ten acres in area and, for all practical purposes, bottomless.
There
was a rhythm to the early history of the Kimberley Mine—boom, disaster,
boom, disaster—and it was now to be repeated again. The blue ground
held out, of course, but as the mine reached its present outlines a new
problem had to be faced, and this probably was ultimately to put an end
to open-pit mining in Kimberley. The diamondiferous ground, the
diggers had gradually discovered, was surrounded by reef, or rock and
shale, and as more and more of the reef was exposed it began to break
off and slide. Here it might be well to point out that in South Africa
the word "reef" means two things. The
Flickr
Stumbleupon
Scribd
