to Newlyn this afternoon on a piece of business which I shall
afterwards disclose. Meanwhile, where is this mine?"

"Lift up your eyes and behold," said Tregarthen, pointing to an object
which was surrounded by the sea, and stood above two hundred yards from
the beach.

"What! that martello-tower-like object?" exclaimed Oliver in much
surprise.

"Even so," replied Tregarthen, who thereupon proceeded to give his
friend a history and description of the mine--of which the following is
the substance:--

At the western extremity of the sea-beach at Penzance there is a reef of
sunken rocks which shows its black crest above water at low tide. It
was discovered that this reef contained tin, and the people of the town
attacked it with hammers and chisels, when each receding tide left it
exposed, as long as the seasons would permit, until the depth became
unmanageable. After having been excavated a few fathoms the work was
abandoned.

Fortunately for the progress of this world there exist a few
enterprising men whom nothing can discourage, who seem to be spurred on
by opposition, and to gather additional vigour and resolution from
increasing difficulties. These men are not numerous, but the world is
seldom without a few of them; and one made his appearance in Penzance
about the end of last century, in the person of a poor miner named
Thomas Curtis. This man conceived the bold design of sinking a shaft
through this water-covered rock, and thus creating a mine not only
_under_, but _in_ the sea.

With the energy peculiar to his class he set to work. The distance of
the rock from the beach was about two hundred and forty yards; the depth
of water above it at spring tides about nineteen feet. Being exposed to
the open sea, a considerable surf is raised on it at times by the
prevailing winds, even in summer; while in winter the sea bursts over
with such force as to render all operations on it impossible.

That Curtis was a man of no common force of character is obvious from
the fact that, apart from the difficulties of the undertaking, he could
not expect to derive any profit whatever from his labour for several
years. As the work could only be carried on during the short period of
time in which the rock was above water, and part of this brief period
must necessarily be consumed each tide in pumping out the water in the
excavation, it of course progressed slowly. Three summers were consumed
in sinking the pump-shaft