Bristol, observing large quantities of it lying amongst the heaps of
rubbish round the tin mines, contracted to purchase as much of it as
could be supplied, and continued to gain by Cornish ignorance for a
considerable time. The first discoverer of the ore was called Poder
(it long went by his name), who actually abandoned the mine in
consequence; and we find that it was for some time considered that
"_the ore came in and spoilt the tin_." In the year 1822 the produce
of the Cornish copper mines amounted to 106,723 tons of ore, which
produced 9,331 tons of copper, and 676,285 l. in money. In the same
year, the quantity of tin ore raised was only 20,000 tons. The Irish
and Welsh ores are generally much richer than those of Cornwall; but
occasionally they strike on a very rich _lode_ (or vein) in that
county. Last spring, some ore from the Penstruthal mine was ticketed
at Truro, at the enormous price of 54 l. 14s. per ton; and a short time
previous, in the Great St. George Mine, near St. Agnes, a lode was
struck five feet thick, which was worth 20 l. a ton. There are only six
other copper-works in the kingdom besides those of Swansea, five of
which are within fifteen miles of that town; the other is at Amlwch
(in the isle of Anglesea), where the Marquess of Anglesea smelts the
ore raised in his mines there. The annual import of ore into Swansea
in 1812 was 53,353 tons; in 1819, 70,256 tons were brought coastwise:
besides which, several thousand tons of copper ore are imported from
America every year. Since this period there has been a large increase.
Most of the ships which are freighted with copper ore load back with
coal, for the Cornish and Irish markets. Of bituminous, in 1812,
43,529 chalders, and in 1819, 46,457 chalders were shipped coastwise,
besides a foreign trade of about 5,000 chalders every year. Most of
this goes to France, the French vessels coming here in ballast for
this purpose; but all coal shipped for abroad must be riddled through
a screen composed of iron bars, placed three-eighths of an inch apart,