arkness; the black water
flashed and sparkled, and as the beam of light was directed from side
to side the walls of the cavern loomed up out of the gloom. As yet
there was no sign of the end of the cave, which was of a size
altogether out of proportion to its narrow opening. It was lofty as
well as long, and from the manner in which the walls went down
perpendicularly into the sea, I imagined that there was a good depth of
water beneath our keel.

"Turn the light ahead!" ordered Lewis, and once more the sculling oar
was set in motion.

Slowly we penetrated farther and farther into the mighty foundation of
the great cliff; then suddenly there was a bump, which shook us on our
seats. I thought at first that the boat had grounded on a rock; but
she gathered way again, though with something grating against her side.

"Hullo!" came from the man who was acting the part of lookout in the
bow; "there's something floating in the water."

The lamp was brought to bear, and a number of dark objects were
discovered alongside.

"It's wreck-wood," said Nat, leaning over the gunwale and grasping the
end of a broken spar. "There's quite a lot of it, and cargo too. That
over there looks like the top of a barrel."

Lewis bent down and examined the floating _debris_ with a critical eye.

"The set of the current brings a good bit of driftwood in here," he
mumbled, "specially after a south-easterly gale. Hum! that's bad," he
continued, as something seemed to catch his eye. "Looks uncommon as if
one of the boats had gone ashore, or maybe been driven on Sawback Reef.
It was blowing hard a week back; I could tell that even in the jail at
Welmington."

Once more the boat moved on, a slight jar every now and then bespeaking
the presence of more wreckage; then a shout from the lookout warned us
that we had reached the end of our journey.

The cavern terminated in a platform of rock raised some six or eight
feet above high-water level, and having a surface which might in all
have afforded as much space as the floor of a fairly large sized room;
some niches and ledges in the side of the cavern formed a sort of rude
natural staircase from the water's edge, while a rusty iron ring seemed
to show that boats had been moored there before.

"Now then, up with you!" said Lewis. "But mind what you're about.
There's water running down from the roof which makes the rock uncommon
slippery."

There being no longer any chance of our giving