The Mine in the Sea.

True to their appointment, young Tregarthen and Oliver Trembath met at the western end of the town of Penzance, close to the sea-beach, where a mass of buildings and a chimney indicated the position of the Wherry Mine.

Oliver’s countenance betrayed anxiety as he came forward.

“Nothing wrong, I hope?” said Tregarthen.

“Well, I can’t say exactly that things are wrong; but, at the same time, I don’t know that they are altogether right.”

“Much the same thing,” said Tregarthen, smiling; “come, Oliver, unbosom yourself, as novelists say. It will do you good, and two heads, you know, are better than one.”

“It’s not easy to unbosom myself, old fellow,” returned Oliver, with a troubled look; “for my poor uncle’s affairs are in a perplexed condition, and I hate explanations, especially when I don’t understand the nature of what I attempt to explain, so we’ll not talk about it, please, till after our visit to the mine. Let it suffice to say that that notorious smuggler Jim Cuttance is concerned in it, and that we must go 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. After this a framework, or caisson, of stout timber and boards, was built round the mouth of the shaft, and rendered watertight with pitch and oakum. It rose to a height of about twelve feet above the surface of the sea, and was strengthened and supported by stout bars, or buttresses of timber. A platform was placed on the top, and a windlass, at which four men could work, was fixed thereon. This erection was connected with the shore by a stage or “wherry” erected on piles. The water was cleared out; the men went “underground,” and, with the sea rolling over their heads, and lashing wildly round the turret which was their only safeguard from terrible and instant destruction, they hewed daily from the submarine rock a considerable portion of tin.

These first workers, however, had committed an error in carrying on their operations too near the surface, so that water permeated freely through the rock, and the risk of the pressure above being too great, for it rendered the introduction of immense supporting timbers necessary. The water, too, forced its way through the shaft during the winter months, so that the regular working of the mine could not be carried on except in summer; nevertheless, this short interval was sufficient to enable the projector to raise so much ore that............