Rodwood had plundered a tinder-box from one of the warders, and the next moment the oarsman's request was responded to with the click, click of flint and steel. Even the strong glare of the big coach lamp did little more than reveal the surrounding darkness; 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.