They sprang upon a small pan, and, utilizing it as a raft, Bobby paddled a few yards.
"There! There!" shouted Bobby. "There he is. He's most dead. You can get him!"
Jimmy jumped to the side of the pan upon which Bobby was kneeling with his paddle, and poising the harpoon was about to cast it when the pan, too heavily weighted on that side, began slowly to turn. Bobby did not see this, but Jimmy did.
"Don't move!" shouted Jimmy. "Stay where you are!"
And, without hesitation, Jimmy slipped from the pan and into the icy sea, though he knew there was small chance for him to swim, and, overcome by the shock of the terrible cold, he sank beneath the waves.
The pan righted itself immediately it was relieved of Jimmy's weight, and Bobby, realizing what Jimmy had done, and that his friend had sacrificed himself for his sake, stood bewildered and stunned, gazing blankly at the spot where Jimmy had sunk.
CHAPTER XXI
WHO WAS THE HERO?
Bobby did not lose his head. After his manner in emergencies, he thought quickly, and acted instantly, and now his bewilderment was for only a moment.