CHAPTER XXIX

IN THE CAVE

Steadying themselves against the swaying motion of the anchored airship, our friends crowded to the windows to look out. They beheld a terrifying and wonderful scene.

Almost the whole of the island was under water. Only the high middle part, with its tower of rock, was out of the flood. Securely held by the anchor ropes, the _Comet_, as light as a chip on the surface of the waves, floated on the bosom of the flood. Her very lightness, due to the fact that the gas bag was partly filled, and the strength of the anchor ropes, had saved her. Then, too, the fact that she rested on hydroplanes, or pontoons, was in her favor. These were a new feature of the airship, which had only recently been added.

“Say, it’s lucky you thought to let the hydroplanes down,” spoke Bob, as he looked out at the flood sweeping past them.

“If he hadn’t, we’d probably be wrecked by this time,” was Ned’s opinion. The hydroplanes, I might explain, were light hollow boxes, made water tight, and attached to the _Comet_ by long toggle-jointed arms. They could be raised or lowered at will, and allowed the _Comet_ to float on the surface of water. If you boys have ever seen a water-spider, or bug, skimming along on the brook or lake, as you doubtless have, you will get a good idea of how the hydroplanes worked by recalling to mind the insect.

“Well, what are we going to do?” asked Ned, as he looked at the flood sweeping past. On the surface of the water floated all manner of débris, including much driftwood, and even whole trees. “We can’t stay here,” went on the lad, “for we may have a hole punched in us any minute.”

Even as he spoke there was a grinding sound, and a log scraped along the side of the _Comet_.

“Yes, we’d better get out,” agreed Jerry.

“I’ll get breakfast right away,” said Bob briskly, “and then----”

“No, you don’t!” cried Ned. “No breakfast until we’re out of danger. Why, we might be wrecked, and then I’d like to know how we could ever get out of this canyon,” and he looked up at the towering cliffs on either hand--cliffs that no mortal could scale. On each side--all around them--was the raging flood, in which no craft, save one as light as an airship, could have lived for a moment.

“It all depends on the airship,” agreed Jerry. “We must get away while we can.”

The words were hardly out of his mouth before there came a crash, and the craft trembled from end to end. There was a splintering noise, and Jerry sprang toward the stern.

“What’s the matter?” asked Ned.

“We’ve been hit! One of the hydroplanes is smashed and a bicycle wheel crushed! We’ve got to go up right away! Start the gas machine, Ned. Bob, you come in the pilot house with me, and help. Professor, you see that the motors get plenty of oil; will you? We’ll need all the power we’ve got.”

Instantly the interior of the _Comet_ was a scene of activity. The effect of the damage was at once apparent, for the craft had settled on one side. But as soon as the gas began flowing into the bag she began to lift, until she was once more on a level keel.

“All ready now?” called Jerry to Ned, in the motor room.

“All ready--let her go! But what are you going to do?”

“I’m going to land on the high ground near the tower of sandstone. I can see a good level place there, and the water can never get as high as that. Besides, I want to make some repairs before we try to make the mainland, and we can make ’em there. We’ll stay on top of the hill until the flood goes down. Give me full speed, Ned. Tell the Professor to use lots of oil.”

As Ned turned to convey the request to the scientist, Uriah Snodgrass, who had been looking from a side window out on the flood, uttered a cry of delight. The next instant he caught up a small fish net, attached to a long handle, and thrust it out of the window, into the swirling water. Then he cried:

“I’ve got it! I’ve got it! Oh, you little beauty! I’ve got you almost at the last minute, when I least expected you. Oh, what a rare find!”

“What is it?” cried Ned.

“The two-tailed toad! I saw it floating down on a log, and I made a grab for it. I have it!” and holding out the net he displayed a queer-looking object--a hideous toad, covered with “warts,” but having two unmistakable tails.

“Ugh! What a creature!” cried Ned.

“A most valuable acquisition to science,” declared the professor proudly.

There came a shrill whistle through the tube leading to the pilot house.

“What is it?” asked Ned.

“Aren’t you going to start?” Jerry wanted to know. “The river is still rising, and more logs are coming down! Get a move on!”

“Aye, aye!” answered Ned, and he yanked over the electrical switch. Instantly the propellers whizzed around, and the _Comet_ strained at the mooring ropes.

“Now’s the time!” cried Jerry to Bob, who had been provided with a light, keen hatchet, for the purpose of severing the lines. “Cut!”

The little axe came down as the _Comet_ lifted her dripping hydroplanes out of the water, and, freed from the holding cables, she soared aloft. Jerry directed her toward the big hill in the middle of the island, where there was room to land. Fortunately there was scarcely any wind to sway the craft, though the rain came down in torrents.

Well aloft now, over the raging flood of the Colorado, the _Comet_ was more like herself, and, with Jerry to guide her, there was comparatively little danger.

“You’ve got to be careful how you let her down,” suggested Ned, when, having set the machinery to working automatically, he joined his tall chum in the pilot house. “You don’t want to smash that hydroplane and wheel any more than they are.”

“Sure not. We’ll be down in a few minutes, and then we can get right to work.”

“What about the radium?” asked Ned.

“Oh, we’ll look for that, too, as long as we’re in no immediate danger. I hope we find it. The Professor got what he wanted, and it’s up to us to make good, too.”

It was but a short distance from where the flood had floated the _Comet_ to the place where Jerry proposed to anchor, and, a little while after arising, the airship came gently down. It required no small skill to make a landing without further damaging the broken parts, but Jerry managed it.

“Make fast the ship! All hands out at anchor work!”

The professor rather disliked to leave off making notes about the two-tailed toad that the flood had brought him, but he finally put the specimen away, and joined the boys in the work of making their craft secure.

They had landed on a small plateau, which was, in a manner, cut in the side of the hill. Back of it arose a steep cliff of sandstone, while the surface of the shelf was covered with trees, grass and bushes.

Ned, taking one rope, walked off to the left to fasten it to a big stump that he thought would hold. As he came near it he glanced behind a bush, and, as he did so he uttered a cry:

“Fellows, look here!” he shouted. “Here’s a big cave leading right into the hill!”

Through the rain, splashing over the soaked ground, came Bob and Jerry, the professor following. They stood grouped about a hole in the slope--a hole large enough to permit a man to enter upright.

“Let’s go in and see what’s there,” proposed Bob.

“I guess it’s safe,” came from Jerry. “There are hardly likely to be any bears on this island.”

Together they advanced into the cavern. It was dark, but their eyes soon became somewhat accustomed to the gloom.

“It’s too big to explore without a light,” remarked the professor. “This may be a place for valuable relics. Let’s fasten the airship, and then come back with electrical torches.”

They turned to go, but, as they did so there came a sound which startled all of them. It was the sound of a human voice and, in cracked tones, as if the speaker had not used his vocal cords for some time.

“Who are you? What do you want?” was demanded in hollow accents. And then there came a faint glimmer of light, and in the rays of it they beheld a man--apparently a very old man--with matted beard, tangled hair and hollow, sunken eyes, who stood staring at them from the depths of the cave.