of the very best quality. We sell it
chiefly to dyers, who use it for colouring purposes, and for whom no tin
but the best is of any use. I will now show you two other qualities--
namely, second and inferior."
He went to a small cupboard as he spoke, and took therefrom a small
piece of tin which had already gone through the smelting process in the
crucible above described. Melting this in the ladle, he poured it into
the mould, where it lay for a few moments, quite bright and pure, but
the instant it solidified, a slight dimness clouded its centre.
"That," explained the agent, "is caused by a little copper which they
have failed to extract from the tin. Such tin would not do for the
dyers, but it is good for the tin-plate makers, who, by dipping thin
sheets of iron into molten tin, produce the well-known tin-plates of
which our pot-lids and pans, etcetera, are manufactured. This last bit,
gentlemen," he added, taking a third piece of tin from the cupboard, "is
our worst quality."
Having melted it, he poured it into the mould, where it assumed a dull,
half-solid appearance, as if it were a liquid only half frozen--or, if
you prefer it, a solid in a half molten state.
"This is only fit to mix with copper and make brass," said the agent,
throwing down the mould. "We test the tin ore twice--once to find out
the quantity of metal it contains, and again to ascertain its quality.
The latter process you have seen--the former is just the same, with this
difference, that I am much more careful in weighing, measuring,
etcetera. Every particle of dross I would have collected and carefully
separated from any metal it might contain; the whole should then have
been reweighed, and its reduction in the smelting process ascertained.
Thus, if twenty parts had been the weight of tin ore, the result might
perhaps have been fourteen parts of metal and six parts of dross. And
now, gentlemen, having explained to you the testing process, if you will
follow me, I will show you the opening of one of our furnaces. The
smelting-furnace just shows the testing process on a large scale. Into
this furnace, six hours ago," he said, pointing to a brick erection in
the building to which he led them, "we threw a large quantity of tin
ore, mingled with a certain proportion of culm. It is smelted and ready
to be run off now."
Here he gave an order to a sturdy man, who, with brawny arms bared to
the shoulders, stood close at hand. He was
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