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places a little calcareous spar, or other vein stuff, and
sometimes a superficial glazing of black-lead without the
substance; but the wad is only found in sops, or bellies, which
appear generally to be formed by the intersection or crossing of
the veins, and are often at considerable distance from each
other, and found with difficulty.
Formerly this mine was worked only at intervals, and when a
sufficient quantity had been procured to supply the demand for a
few years, it was strongly closed up until the stock was reduced;
but of late, it has been obtained less plentifully, and the
demand being greater, the working has been continued for several
years successively.
An old level, which was re-opened in 1769, was found to have been
cut through this very hard rock, without the help of gunpowder;
and a kind of pipe vein which had produced a great quantity of
wad, having been pursued to the depth of one hundred yards or
more, much inconvenience was experienced in working it: to
obviate which, in 1798, an adit or level was begun in the side of
the hill, which at the length of 220 yards communicates with the
bottom of the former sinking; since which time the works have
been carried on internally through various ramifications; a
survey of which was made a few years since by the late Mr. Farey.
Through this principal level the water now passes off, and the
produce and rubbish are brought out upon a railway in a small
waggon; and over its mouth a house
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