necessity for united action became greater. Millions were spent in overcoming the difficulties encountered.
By
this time, the volcanic origin of the pipes was generally understood,
and the miners realized that larger and more expensive methods must be
used, for the workings were nearly four hundred feet deep in places.
Conditions were fast reaching a point where open-cut working would
have to be abandoned. Before this time, a crisis had been reached in
which the future of the industry and of the fortunes of those engaged
in it were staked upon their judgment, for the end of the yellow ground
which had been so prolific in diamonds came. There were generally about
fifty or sixty feet of it, after which in some cases came a sort of
transitional stratum of a rusty color,' sixteen to twenty feet thick,
before the " blue," which has been worked ever since, was reached. When
the yellow ground came to an end, and the " rusty " earth or the first
blue under it yielded few diamonds, many thought the end had come, and
that the time had arrived to get out, sell out if possible, and seek
new fields. Barnato used to tell of a man who had some good claims on
the Kimberley, and who when he got through the yellow and saw the blue,
allowed a friend to dump a lot of worthless yellow into his claims so
as to cover the bottom. He then sold them for what he could get and
cleared out. That man sold his claims for four hundred pounds because
he thought the diamond mines were basins, into which the yellow
diamond-bearing material had been somehow washed, and that the blue was
bed rock. A little later he could not have bought back the claims for
forty thousand pounds, for the belief of others that the diamonds came
from below,
