He had quite a bump of caution for a youth who did not hesitate at times to do things that others considered reckless. “Oh, it’s still as a mill-pond,” replied Harvey. “We’ve had the clearing-off blow, and there are the clouds banking up off to southward, where the breeze will come from in the morning. See, there isn’t a man out on any of the other boats. No, we’ll just turn in and sleep like kittens in a basket.” So they went below. The roaring of the reef was, in truth, a not all unpleasant sound to those who felt safe and snug in its lee, securely anchored. To be sure, there was a grim suggestion in the crashing of the swell against its hollows and angles at first, but the steady repetition of this became in time almost monotonous. There was the heavy, roaring, thudding sound, as the swell surged in against its firm base. Then this blended into a crisp rushing, as the waters raced along its sides; and then a crash as of shattered glass as the mass thrown up broke in mid-air and fell back in countless fragments of white, frothing water upon the cold rocks. The boys went off to sleep with this ceaseless play of the waters in their ears. The hours of the night passed one by one. And if any boy aboard the _Viking_ roused up through their passing and heard the surf-play upon the reef, there was no more menace in it than before. Just the same steady hammering of water upon rock. Yet Harvey’s prophecy of sound sleep was not wholly borne out—at least, in the case of Henry Burns. He was a good sleeper under ordinary conditions, but he roused up several times and listened to the wash of the seas. “It may be grand music,” he muttered once, drowsily, “but I can’t say I like it quite so near.” Something awoke him again an hour later. His perception of it as he half-sat up was that it sounded like something grating against the side of the _Viking_. He sat still for a moment and listened. The sound was not repeated. “I thought I heard something alongside,” he said aloud, but talking to himself. “Did you hear anything, Jack?” he inquired in a louder tone, as Harvey stirred uneasily. There was no reply. Harvey had not wakened. “Hm! guess I’ve got what my aunt calls the fidgets,” muttered Henry Burns, rolling up in his blanket once more. “It’s that confounded reef. No, it’s no use. I don’t like the sound of it at night. Pshaw! I’ll go to sleep, though, and forget it.” Something just alongside the _Viking_ that looked surprisingly like a dory, with some sort of a figure crouched down in it,—and which may or may not have caused the sound that had awakened Henry Burns,—lay quiet there for ten, fifteen, twenty minutes,—a good half-hour in all. Then it moved away from the side of the boat, passed on ahead for a moment, and stole softly away over the waves. The booming of the seas upon the reefs! How the hollow roar of it sounded far over the waters. How the thin wisps of spray, like so much smoke, shot up through the darkness, white and ghostlike!