learly deep down through the crystal sea.

"Soon know how to manage a boat yourselves," said the old man grimly, as
he thrust an oar over the stern and used it to steer.

"Manage a boat ourselves!" cried Mike. "I should think we could--eh,
Vince?"

"Should think you could!" said the old man laughing. "Ah! you think you
could, but you can't. Why, I hardly know how yet, after trying for
fifty year. Wants some larning, boys, when tide's low, and the rocks
are bobbing up and down ready to make holes in the bottom. Don't you
two be too sure, and don't you never go along here far without me."

The boys said nothing; but they felt the truth of the man's words as he
steered them in and out among the jagged masses of granite, around which
the glassy currents glided, now covering them from sight, now leaving
bare their weed-hung, broken-out fangs; while on their left, as they
steered north toward a huge projection, which ran right out on the far
side of a little bay, the perpendicular cliffs rose up grey and grand,
defended by buttresses formed by masses that had fallen, and pierced
every here and there by caverns, into which the water ran and rushed
with strange, hollow, whispering noises and slaps and gurglings, as if
there were peculiar creatures far up in the darkness resenting being
disturbed.

Every now and then the sea, as it heaved and sank, laid bare some
rounded mass covered with long, hanging sea-weed, which parted on the
top and hung down on either side, giving the stone the appearance of
some strange, long-haired sea monster, which had just thrust its head
above the surface to gaze at the boat, and once this was so near that
Mike shrank from it as it peered over the thwart, the boat almost
grating against the side.

"Wasn't that too close?" said Vince quickly.

"Nay," said the old man quietly: "if you didn't go close to that rock,
you'd go on the sharp rock to starboard. There's only just room to
pass."

A minute later, as the two lads, were gazing in at the gloomy portals of
a water-floored cave, in and out of which birds were flying, a dexterous
turn of the oar sent the boat quickly round, head to wind, the sail
flapped over their heads, and Vince seized the boat-hook without being
told, and, reaching over the side, hooked towards him a couple of
good-sized pieces of blackened cork, through which a rope had been
passed and knotted to prevent its return.

This rope Mike seized, hauled upon it, drawi