Though the water dripped into his eyes from his hair, and made seeing difficult, he, too, had observed the terrific lurch which the foundering vessel had just given; and if he had had any doubts as to her true condition they were instantly set aside by the mass of her stern elevated in such an ungainly manner into the air.

"Aboard there!" he shouted; "jump over into the water. She is going down."

Thanks to an oil lantern which still hung amidships, below the bridge, he could see the man for whose rescue he was striving, and as he thrust his way strenuously through the water he watched the injured passenger pick himself up on hand and knees and struggle towards the rail. He wedged his feet against a stanchion supporting the latter, and as Jim arrived within a few yards of the vessel, the man was again endeavouring to clamber over the rail.

Then there came, of a sudden, another sluggish lurch. The ship appeared to shiver throughout her framework, and rolled heavily from side to side. A moment later her bows rose rapidly from the ocean in which they had been submerged, while the stern regained almost its normal position. It looked, in fact, as if she were making one last gallant effort to float upon the surface. But again she rolled heavily from side to side, till her decks were slanting at a sickening angle, greater indeed than that to which Jim and his mates had become accustomed when cruising to the south along the Caribbean coast.

"By de power, but dat terrific, dat 'nough to shake de life out of anybody," muttered Tom, whose eyes all this while had been staring into the gloom, endeavouring to follow every movement of his young American master. Indeed, so acute was the vision of the dusky giant that details were visible to him, and to Sam, his diminutive brother, which others aboard the boat had no idea of. "Lummy, but Tom not like to see dat ship shake herself so! She go down with a bust in one little moment, and den—and den, what happen to Massa Jim?"

The very thought of the disaster which would follow drove the negro into a condition almost of frenzy. His eyes bulged from their sockets and looked as though they would tumble from his head. A whimper from Sadie set Tom's honest heart throbbing and palpitating. It was real pain to the fine fellow to know that his little mistress was in trouble. That and his own courageous, impetuous nature made it impossible to stay any longer inactive in the boat. Every muscle in his body trembled, while his breath came quick and deep.

"I's goin' ter help!" he shouted. "Nebber yo fear, missie; soon hab Massa Jim back safe and sound."

With that he floundered overboard, causing the boat to rock once more till her gunwale dipped beneath the oily surface of the ocean, a mass of water flooding the interior instantly. His head had hardly bobbed up in view again when there came a sudden exclamation from Sam, and a moment later the little fellow had slipped away to help his dusky brother in his gallant task.

"Jemima! But if that don't take it!" bellowed one of the crew of the boat, looking himself as if he were about to follow. "Every mother's son of 'em'll go down. That ship'll suck 'em under sure. Ain't we going nearer?"

In his eagerness he seized an oar, banged it into the rowlock, and proceeded to bear upon it; but a stern order from the captain at once arrested the movement.