Awoke and startled by the explosion, Becker’s wife and Mrs. Wolston came running towards them.  As for the girls, their guardian angel had too closely enveloped them in its wings to admit of their sleep being disturbed.

“The sloop on the coast!” said Frank; “for the sound is too distinct to come from a distance.”

“Unless Willis has got upon Shark’s Island,” objected Fritz, running towards the terrace, armed with a telescope.  “Just so; he is there, I see him distinctly; he is recharging our four-pounder.”

“God be praised! you relieve my conscience of a great burden,” said Ernest, placing his hand on his breast.

“He is going to discharge it,” cried Fritz—­boom.  Then a second shot reverberated in the air.

“If Captain Littlestone be within hearing of that signal, he will be sure to reply to it.” said Becker.  “Listen!”

They hushed themselves in silence, each retaining his respiration, as if their object had been to hear the sound of a fly’s wing rather than the report of a cannon.

“Nothing!” said Becker sadly, at the expiration of a few minutes.

“Nothing!” reiterated successively all the voices.

“How in all the world did Willis contrive to get transported to Shark’s Island?” inquired Mrs. Becker.

“Simply, wife, by watching when asleep, whilst one of our gentlemen slept when he watched.”

“Yes, mother,” said Ernest, “and if you would not have me blush before Mrs. Wolston, you will not insist upon an explanation of the mystery.”

“Mrs. Wolston,” she replied, “is not so exacting as you seem to think, Master Ernest—­the only difference that her presence here should make amongst you is that you have two mothers instead of one.”

“That is,” said Mrs. Wolston smiling, “if Mrs. Becker has no objections to dividing the office with me.”

“Shall I not have compensation in your daughters?” said Mrs. Becker, taking her by the hand.

“Still,” interrupted Fritz, “I cannot yet conceive how Willis managed to reach Shark’s Island in a wretched canoe, without oars, through waves that ought to have swallowed him up over and over again.”

“Bah!” exclaimed Jack; “what use has a pilot for oars?”

“There is a question!  You, who modestly call yourself the best horseman on the island, how would you do, if you had nothing to ride upon?”

“I could at least fall back upon broomsticks,” retorted the imperturbable Jack.  “Besides, in Willis’s case, the canoe was the steed, the oars the saddle—­nothing more.”

“We shall not stay here to solve the riddle,” said Becker; “the storm seems disposed to abate; and the more that it was unreasonable to face certain destruction in a vain endeavor to assist a problematical shipwreck, the more it is incumbent upon us now to go in quest of the Nelson.”

“But the sea will still be very terrible!” quickly added Mrs. Becker.