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Doc. 205.] 51
SWEDENBORG’S TRAVELS IN 1733.
poorer kind of ore, in which the grains of the vein cannot be
so well distinguished, is taken into a sort of common mill
where it is crushed. In one building there are two wheels
and six crushing hammers of considerable weight ; the crushing
boxes are coarse. At the side near the farthest hammer is
raised a triangular box, which stands in an oblique direction
in respect to the upper part of the side elevation of the
hammer. This box is loaded with ore, and at different inter
vals as much of it as can be received is dropped into the
crushing box. Muddy water runs out on both sides of the
box, as well through the sieve near the farthest hammer, as
through that which is near the first hammer. The streams
from both ends meet in a common trough, and the water
flows thence somewhat obliquely until it reaches its first dam,
which is at a distance of three and a half ells. Only the
pulverized ore which remains in this upper part of the trough
is collected, the remaining part being allowed to flow off.
This powder is first washed in a Schlammbank, which is a
narrow and deep box, six ells long, and three quarters
of an ell wide ; it is taken out thence on inclined planes,
where it is washed three times before the powder is in a
perfect state. In respect to the richer ore, it is not re
duced to powder, but is calcined at once in the open air.
The hearth for calcining is from three and a half to four ells
in length and breadth, and square ; in the rear it is from
an ell and three quarters to two ells in height. After the
wood has been piled up, the ore is put on, broken into pieces
of nearly the same size, each the size of one-half or three
fourths of a fist; 250 hundred-weight of ore are usually calcined
at the same time on such a hearth. The heap is not, as in
other places, covered with some kind of powder ; but after the
fire has been kindled, the calcination is continued for nearly
a whole week under the open sky. About five hundred-weight
of copper are usually obtained out of such a heap, so that the
ore contains two and a half per cent of metal ; the poorer kind
of ore is also calcined, so that it may be introduced into the
furnace at the same time, and may be of assistance to the
other ore. 4. There are three furnaces ; formerly there were
five; they are of the kind called Krummofen. Their fire-place
4*
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