e ore. Having thus gone over, through, and under all impediments,
they were informed that they were 120 feet below the level of the sea
vertically, and horizontally 480 feet below low-water mark. Boats might
even then be passing over their heads. Human beings were working still
lower down. On the roof, the strips of pure copper could be
distinguished among the crevices of the rocks through which the salt
water was seen percolating in an unpleasant abundance. In their
eagerness to obtain the rich ore, the miners had worked upwards until
they had got within five or six feet of the bottom of the ocean. There
the metal was still clearly visible, but even the most hardy miners
would scarcely have ventured on an attempt to win another grain from the
rock overhead, lest the water should rush in and overwhelm them, and
inundate the mine.

Passing into a gallery where no one was at work, the travellers listened
in perfect silence, and could hear the low murmur of the ocean rolling
above their heads.

"Oh, that is nothing now," said their guide. "When a storm is raging, I
have heard the sound of the pebbles, which some large wave has carried
outwards, bounding and rolling over the rocky bottom. On standing
beneath the base of the cliff, where not more than nine feet of rock
intervened between the sea and my head, the heavy roll of the large
boulders, the ceaseless grinding of the pebbles, the fierce thunder of
the billows with the crackling and boiling as they rebounded, produced
an uproar such as those who heard it can never forget."

For many years a blind man worked in the Botallack Mine, and supported a
large family by his labour. So complete was his recollection of every
turning and winding, that he became a guide to his fellow-labourers,
when by any accident their lights were extinguished. He being
afterwards cruelly discharged, engaged himself as an attendant to some
bricklayers. While thus employed, with a hod of mortar on his back, he
fell from a platform and was killed.

There are several other mines similarly situated to that of the
Botallack on the coast of Cornwall, where the works are carried far
under the ocean. Among them are the Wheal Edward, the Levant, the Wheal
Cock, and the Little Bounds. In the two latter, the miners have
actually followed the ore upwards until the sea itself has been reached,
but the openings formed were so small that they were able to exclude the
water, by plugging them wi