PRINCIPAL SOUTH AFRICAN MINES 307
quently the yield would fall to the mine's actual average, taking the bad with the good.
At
the start, the equipment was small and the expense of mining and
washing very moderate. The earth was removed by endless rope haulage
from the open workings to the washing plant on a small elevation at
the edge of the crater, where the tailings were simply run over to the
other side. There was one washing plant of four pans, and one of six
pans. The diamonds were all picked by hand. The material from the
pulsators was first picked by skilled white sorters and afterwards, the
tailings, by young Kaffir boys, for the small diamonds. It was
difficult to get satisfactory help. In 1904 there were three open-cut
mines in work, and it was estimated that there were ten million loads
above the fifty-foot level, and one hundred and five million loads
above the four-hundred-foot level, to which depth the work could be
carried on by open cut.
Constant
additions have been made to the plant, which for the year ending
October 31, 1908, washed nearly 27,-000 loads per day, reckoning 300
working days in the year. In 1909 it will probably be increased to a
capacity of forty thousand loads per day. By arrangement with the De
Beers, grease tables were put in use and the whole plant has been
rapidly brought to a high standard of efficiency, though, it being an
open-cut mine, little machinery is required compared to that necessary
for the underground workings of the De Beers mines.
The
diamondiferous material carries fewer garnets than that of the
Kimberley district, nor are serpentine and olivine as conspicuous. Mr.
Troge describes it as
