, corrugated iron shed which
had been erected in the garden, and dignified by the name of laboratory.
For, to the boys' great delight, a model furnace had been made, with
bellows, and a supply of charcoal was always ready. There was a great
cast-iron mortar fitted on a concrete stand, crucibles of various sizes,
and the place looked quite ship-shape.

Both the old officers worked hard at assaying the ore brought from about
the mouth of the pit, dug no one knew when, and though they spent a good
deal of time, they were very soon superseded by Gwyn and Joe. Hardock
gave them a little instruction; everything about the work was
interesting and fresh; and in a few weeks they were able to roughly
declare how much pure metal could be obtained from a ton of the quartz
which they broke up in the great mortar, powdering, and washing and
drying, and then smelting in one of the plumbago crucibles of the
laboratory.

"There's no telling yet what we may find in that mine, Joe," said Gwyn;
"only we don't know enough chemistry to find out."

"It's metallurgy, father says," said Joe, correcting him.

"Never mind; it's chemistry all the same; and we must read more about
it, and try experiments. Why, we might get gold and silver."

"What, out of a tin mine?" said Joe, derisively.

"Well, why not? I don't know about the gold, but we may, perhaps. Sam
Hardock said there were some specks in one bit of quartz he brought up."

"But we shouldn't want specks; we should want lumps."

"There's sure to be silver."

"Why?" said Joe.

"Because there's lead, and I was reading with father about how much
silver you can get by purifying the lead. It's going to be a wonderful
business."

"Hope so," said Joe; "but they're a precious long while getting the
machinery together, and my father says the cost is awful."

"Can't get a great pump in a mine ready to work like you can one in a
back kitchen," said Gwyn. "See what an awkward job it is fitting the
platforms for the tubing. I think they're doing wonders, seeing what a
lot there is to get ready. Sam says, though, that he believes they'll
begin pumping next month."

But next month came round, and they did not begin pumping, for the
simple reason that the machinery was not ready. Still it was in fair
progress, and an arrangement was fixed so that, when the beam began to
rise and fall, the water would be sent gushing into the adit by which
Gwyn had made his escape on that adventurou