“Wait a bit, boy, wait a bit,” answered Grimshaw. “Now, you youngsters, what are you skylarking away there for?” he shouted out to several of the lads, who were, as usual, in spite of the hot sun, frolicking about in the rigging, accompanied by Queerface, the monkey.

Just as he spoke, Tommy Rebow was hunting the animal from shroud to backstay, up over the mast-head and down again. At last, Master Queerface made a spring out on the fore-yard. Tommy pursued him with thoughtless eagerness, and, in his attempt to get hold of him, lost his grasp. Over he went. In vain he caught at the foot-rope; and giving a turn, struck the water with his head. Down beneath the surface he went. Bill saw him falling, and knew well he could not swim. In spite of old Grim’s caution about the sharks, without a moment’s hesitation in he plunged, and swam towards the spot where Tommy had gone down.

“A man overboard! A man overboard!” was shouted by numbers who saw the accident.

The corvette was going at the rate of only three or four knots through the water. Bill swam rapidly on, his eye fixed on the centre of the circle made by Tommy as he fell.

“He’s gone! He’s gone!” shouted out several voices from the ship. Tommy, however, quickly again came to the surface, and Bill caught him as he appeared.

“A shark! A shark!” cried several voices.

Among the first who saw the shark was Jack Windy. He had a large knife in his hand, employed in some work, and, without waiting to cry out, overboard he went, and swam up to where the boys were struggling in the water. Old Grimshaw at the moment saw the danger of his young friend, and not knowing what Jack was about, overboard he went, with a boat’s stretcher in his hand, purporting to do battle with the monster. At that instant the captain came on deck.

“Who’s overboard?” he asked.

“Bill Sunnyside—Sunshine Bill, sir,” cried out several voices.

“The lad whom I promised his widowed mother to protect,” thought the captain, for he scarcely uttered the words aloud.