The morning dawned as only a perfect tropic morning can. The sea was as smooth as glass. Not a cloud was to be seen as a reminder of the elemental fury of the preceding night. The sun, as it rose, a huge red ball above the rim of the sea, showed them some things about their situation that were calculated to give them good cause for worry.

In the first place, it must be said that there was not a sign of the two boats to be seen. For anything that appeared of them, they might never have existed. Indeed, on that calm, serene dawn the fantastic events of the wild night that lay behind them did seem very much like the distorted experiences of a nightmare. But their haggard, anxious faces, and the pitiable condition of the Valkyrie, bore eloquent testimony to the fact that all that had passed was only too true.

As a matter of fact, the night’s incidents proved to be only minor matters for consideration in view of one greater fact that now confronted them. The Valkyrie lay with her bow well up amidst a tangled mass of low-growing jungle. Her stern, from just forward of midships, was almost under water. Even a casual inspection showed that if the sea should rise again it was not all unlikely that she might slide off into deep water and sink.

But the most astonishing thing about this land which they had struck was that they could see across it and to either of its limitations. It was, in fact, an island, stranded there out of sight of all other land. In shape it might have been likened to a splash of gravy on a plate, so irregular in form was it. As to dimensions, it was probably a quarter of a mile across, and perhaps twice that in length.

“This explains something that has been puzzling me,” exclaimed Mr. Chadwick, as they made this discovery. “It’s plain enough now that the crew knew there was no land to be expected in this part of the ocean, and when we struck they at once assumed that we had encountered some uncharted rock and so took to the boats.”

This explanation threw some light on the desertion of the yacht by means of the boats, for it had occurred to all of them that if the yacht had struck on the coast of the mainland there would not have been such a precipitate rush to leave her.

“My idea is to look in the pilot house and overhaul the charts,” said Captain Sprowl, after some discussion had ensued as to the best course to follow. “Our course must be marked till noon yesterday, anyhow, and we can find out about where we are.”

Whatever may have been Medway’s other faults, he could not have been called a slovenly navigator. The course of the yacht was plainly marked up till eight bells of the day preceding, and showed that they were then off the coast of Brazil. Captain Sprowl “overhauled” the pilot house some more, and at noon made an observation with a sextant he had unearthed. After making some calculations, the results of which were awaited with an eagerness that may be imagined, he announced that the position of the yacht was about one hundred and fifty miles from shore, and a little to the south of the mouth of the Amazon River.

“Himmel,” cried Professor Von Dinkelspeil, his frog-like eyes gleaming through a huge pair of horn-rimmed spectacles, “dey vos bringing us rightd vere I vanted to go!”

“Yes,” said Mr. Chadwick, “the professor’s destination was the Amazon River, but I must await his leave before telling you what his exact object was in coming to this part of the world.”

“Treasure, wasn’t it?” hazarded Dick Donovan.

“I’m afraid you have a reporter’s love of the picturesque,” smiled Mr. Chadwick. “Yet I suppose it was treasure of a kind; but not of the sort that the misguided crew imagined.”

“It’s this pesky island that puzzles me,” grunted Captain Sprowl, bending over the chart and knitting his brows. “There isn’t anything like it marked here, and this chart is based on the very latest survey made by the British cruiser, Charybdis.”

“Maybe it was too small to mark down,” suggested Jack.

“That shows all you know about navigation, my boy,” rejoined the blunt old sailor. “An island like this, stuck right bang out in the track of ships, wouldn’t be left uncharted.”

“And yet it was solid enough to knock a hole in us,” said Tom. “It must have been here right along.”

Captain Sprowl’s rejoinder was an astonishing one.

“Now d’ye know, I ain’t so all-fired sure of that,” said he.

“You think it is of volcanic origin?” asked Mr. Chadwick.

“No sir-ee, not by a jugful. You see, we are somewhere’s off the mouth of the Amazon River. A bit to the south maybe, but the drift sets south. Did you ever hear of the floating islands of the Amazon?”

“Yes,” rejoined Mr. Chadwick, while the others said nothing, “but I always thought that they were more or less of a myth.”

“Not so’s you could notice it,” was the reply. “I’ve heard tell of bigger ones than this. They get detached from the upper reaches of the river during floods and are carried out to sea. They’ve been met with much further out than this, and a dern sight bigger, too. They’re perfectly good islands, they say, except for one thing.”

“What’s that?” asked Jack, for the captain had paused as if he expected someone to put a question.

“Why, they’ve got a mighty oncomfortable habit of sinking. You see, they ain’t much more than a sort of big door mat held together by twisted roots and so forth, and when they get good and soaked through—down they go.”

“Blitzen! Den you dink dot dis island may go py der bottom?” gasped the little professor.

“Wa-al, it wouldn’t surprise me,” rejoined the captain, producing a pipe and filling it leisurely. When it was lit and drawing, he supplemented this remark:

“We’ve got to get ashore, gents.”

“That’s plain enough,” said Mr. Chadwick, “but unless some ship picks us up, how are we going to do it?”

“Why, as I onderstand, these boys here have a sort of fly-with-me-swim-with-me boat, ain’t they?” asked the captain. “What’s the matter with our using that?”

It was odd, and goes to show how confused the average human mind may become in a big emergency, but up to that moment not one of them had thought of the Wondership. Her awkward bulk was still secured on the top of the midship cabin house, and as far as could be seen she was undamaged.

“But the rent in the gas bag?” objected Mr. Chadwick.

“I guess we can fix that,” volunteered Jack. “Some canvas and pitch will make a patch that will hold.”

“Plenty of those aboard,” said the captain. “Now, I tell you what we’ll do. We didn’t have much of a breakfast, and we’re all as empty as a whale that ain’t struck no fish. Hungry folks can’t do good work. Give me a crew with full stomachs and I’ll take a lumber raft across the ocean. I’ll turn to with Dick here, and cook up a good meal. The boys kin overhaul their Johnny-jump-up, yonder, and the professor and Mr. Chadwick can get to work selecting supplies and so on to stock the thing with. For we may land, if we land at all, in some place where they ain’t got no hotels to welcome shipwrecked strangers.”

The captain’s suggestions met with unanimous approval, and while Jack and Tom clambered up to inspect the Wondership, the others scattered on their various tasks. As they worked, Jack and Tom from time to time took a look at the island on which the yacht rested. It might have been that their imaginations were quickened by what the captain had said, but it appeared to them that the bushes at the water’s edge were gradually subsiding into the sea.

If this actually were the case, there was need for quick work, for the floating island was all that was keeping the Valkyrie above water. If, as the captain feared, the island subsided, the yacht would go with it to the bottom beyond the shadow of a doubt.