“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: