the sides of
the pit; covering the whole mass like a gigantic cobweb. (See Plate
II. fig. 12.) The buckets of blue ground were hauled up these ropes by
means of horse whims, and in 1875 steam winding engines began to be
employed. By this time also improved methods in the treatment of the
blue ground were introduced. It was carried off in carts to open
spaces, where an exposure of some weeks to the air was found to
pulverize the hard rock far more efficiently than the old method of
crushing with mallets. The placer-miner's cradle and rocking-trough
were replaced by puddling troughs stirred by a revolving comb worked
by horse power; reservoirs were constructed for the scanty
water-supply, bucket elevators were introduced to carry away the
tailings; and the natives were confined in compounds. For these
improvements co-operation was necessary; the better claims, which in
1872 had risen from L100 to more than L4000 in value, began to be
consolidated, and a Mining Board was introduced.

PLATE I.

[Illustration: FIG. 9.--DE BEERS MINE, 1874.]

[Illustration: FIG. 10.--KIMBERLEY MINE, 1874.]

[Illustration: FIG. 11.--DE BEERS MINE, 1873. (From photographs by C.
Evans.)]

PLATE II.

[Illustration: _Fig. 12._--KIMBERLEY MINE, 1874.]

[Illustration: _Fig. 13._--KIMBERLEY MINE, 1902. (From Photographs by
C. Evans.)]

In a very few years, however, the open pit mining was rendered
impossible by the mud rushes, by the falls of the masses of barren
rock known as "reef," which were left standing in the mine, and by
landslips from the sides, so that in 1883, when the pit had reached a
depth of about 400 ft., mining in the Kimberley crater had become
almost impossible. By 1889, in the whole group of mines, Kimberley,
Dutoitspan, De Beers and Bultfontein, open pit working was practically
abandoned. Meanwhile mining below the bottom of the pits by means of
shafts and underground tunnels had been commenced; but the full
development of modern methods dates from the year 1889 when Cecil
Rhodes and Alfred Beit, who had already secured control of the De
Beers mine, acquired also the control of the Kimberley mine, and
shortly afterwards consolidated the entire group in the hands of the
De Beers Company. (See KIMBERLEY.)

The scene of native mining was now transferred from the open pit to
underground tunnels; the vast network of wire ropes (Plate II.