“Why Mr. Jenks has just proposed that we build a big raft, and launch it.  He thinks we should leave the island.”

“It might be a good idea,” agreed the lad, as he thought of the scant food supply.  “Of course, I can’t say when a reply will be received to my calls for aid, and it is best to be prepared.”

“Especially as the island may sink any minute,” added Mr. Parker.  “If it does, even a raft will be little good, as it may be swamped in the vortex.  I think it would be a good plan to make one, then anchor it some distance out from the island.  Then we can make a small raft, and paddle out to the big one in a hurry if need be.”

“Yes, that’s a good idea, too,” conceded Tom.

“And we must stock it well with provisions,” said Mr. Damon.  “Put plenty of water and food aboard.”

“We can’t,” spoke Tom, quietly.

“Why not?”

“Because we haven’t plenty of provisions.  That’s what I came down to speak about,” and the lad related what Mrs. Nestor had said.

“Then there is but one thing to do,” declared Mr. Fenwick.

“What?” asked Captain Mentor.

“We must go on half rations, or quarter rations, if need be.  That will make our supply last longer.  And another thing—­we must not let the women folks know.  Just pretend that we’re not hungry, but take only a quarter, or at most, not more than a half of what we have been in the habit of taking.  There is plenty of water, thank goodness, and we may be able to live until help comes.”

“Then shall we build the raft?” asked Mr. Hosbrook.

It was decided that this would be a good plan, and they started it that same day.  Trees were felled, with axes and saws that had been aboard the whizzer, and bound together, in rude fashion, with strong trailing vines from the forest.  A smaller raft, as a sort of ferry, was also made.

This occupied them all that day, and part of the next.  In the meanwhile, Tom continued to flash out his appeals for help, but no answers came.  The men cut down their rations, and when the two ladies joked them on their lack of appetite, they said nothing.  Tom was glad that Mrs. Nestor did not renew her request to him to get out the reserve food supply from what remained in the wreck of the airship.  Perhaps Mr. Nestor had hinted to her the real situation.

The large raft was towed out into a quiet bay of the island, and anchored there by means of a heavy rock, attached to a rope.  On board were put cans of water, vhich were lashed fast, but no food could be spared to stock the rude craft.  All the castaways could depend on, was to take with them, in the event of the island beginning to sink, what rations they had left when the final shock should come.

This done, they could only wait, and weary was that waiting.  Tom kept faithfully to his schedule, and his ear ached from the constant pressure of the telephone receiver.  He heard message after message flash through space, and click on his instrument, but none of them was in answer to his.  On his face there came a grim and hopeless look.