was visible. It was like trying to scale a fifty-foot smooth steel wall. There was no place for a foothold. Again the sailor made some peculiar motions, and the lad puzzled over them. They had gone nearly around the wreck now, and as yet had seen no way in which to get at the gold. As they passed around the bow, which was in a deep shadow from a great rock, they caught sight of the submarine lying a short distance away. Light streamed from many bull's-eyes, and Tom felt a sense of security as he looked at her, for it was lonesome enough in that great depth of water, unable to speak to his companion, who was a few feet in advance.
Suddenly there was a swirling of the water, and Tom was nearly thrown off his feet by the rush of some great body. A long, black shadow passed over his head, and an instant later he saw the form of a great shark launched at Captain Weston. The lad involuntarily cried in alarm, but the result was surprising. He was nearly deafened by his own voice, confined as the sound was in the helmet he wore. But the sailor, too, had felt the movement of the water, and turned just in time. He thrust upward with his pointed bar. But he missed the stroke, and Tom, a moment later, saw the great fish turn over so that its mouth, which is far underneath its snout, could
