little scrubber, which has a handle of half the length, and with this he ceaselessly stirs the concentrates or tin-stone which have settled in the upper
part of the strake ; in this way the mud and water flow down into the
transverse launder, and from it into the settling-pit which is outside the
building.
Before the short strake and the jigging-sieve had been invented, metalliferous ores, especially tin, were crushed dry with stamps and washed in a large
trough hollowed out of one or two tree trunks ; and at the head of this trough
was a platform, on which the ore was thrown after being completely crushed.
The washer pulled it down into the trough with a wooden scrubber which
had a long handle, and when the water had been let into the trough, he stirred
the ore with the same scrubber.
