The lads shook their heads.

"That's a water marker. When a traveler across the desert finds a sink he indicates it either by a heap of stones, which he sticks in the ground, or by any other means at his command. For instance, this pile of stones tells me there is a water hole somewhere near by, and the arm points the way to it."

"Where is it, then?" wondered Walter. "I don't see any signs of water."

"Nor do I. We'll follow the direction indicated by the arm and see if we don't come up with a water tank somewhere close by," replied Parry.

With the guide leading the way, the others following in single file, they trailed away to the westward until, finally, they came to a slight depression in the ground.

"It should be near here," the guide informed them. "There it is. See that dark hole?"

The boys bounded forward, dropping on their knees by the opening into which they peered inquiringly.

Suddenly they uttered a yell, and, springing up, ran back as fast as their legs would carry them. As they did so, some dark object bounded from the water tank and leaped away into the sage brush.

"Goodness me, what was that?" cried Walter, after the boys had pulled up and faced about.

"Come back, come back. That was only a badger," laughed the guide.

"In the water?" asked Tad, who had stood his ground.

"No; so much the worse for us! There is no water there. No need to look. The tank is empty. Some wandering prospector has emptied it to save his burros and fill his canteen," announced the guide.

"What are we going to do, then!" queried Ned.

"Do without it. We shall have to give the stock a very little of our fresh supply, saving only enough out of it for our own breakfast and a canteen full apiece to take with us on the morrow. I think I shall be able to find a river about ten miles below here, providing it has not changed its course or gone dry. The water here in this country is as fickle as the desert itself."

"What if we should fail to find any?" breathed Tad.

"Well, you know, neither man nor beast can travel far on the desert without it. But we'll find some to-morrow. Don't worry," soothed the guide, though in his innermost heart he was troubled. That this water hole should prove to be dry did not promise well for those that were to follow.

CHAPTER IX

THE BOYS DISCOVER A RIVER

"Where's that river you were talking about?" demanded the lads when the outfit pulled up at noon next day.

"Don't you see it?" smiled Parry.

"Not a river," answered Ned, gazing about him, then allowing his glance to rest on the face of the guide to determine if Parry were making sport of them.

"I am not sure myself. I know where it should be. Whether it's there or not is another matter. Fetch the shovels and we'll soon find out."

"Finding a river with shovels!" muttered Stacy. "Huh! Who ever heard of such a thing?"

But as soon as the boys had returned with the digging implements, Parry swung the tools over his shoulder and strode confidently to the left of where they were encamped for the noonday rest.

The boys followed him full of curiosity.

Finally the guide threw down the tools and began to run his hands over the hot, yellow soil.

"Guess the sun's gone to his head," muttered Ned, as he squatted down to observe more closely what the guide was doing. The other three lads followed his example. In a moment they were on all fours, hopping about like so many quadrupeds.

Parry was shaking with laughter as he observed them.

"Bow! Bow wow!" barked Chunky, jumping on hands and feet, snapping his teeth together suggestively.

The boys looked at each other and burst out laughing. They had discovered all at once what a ridiculous figure they were making.

"Sun gone to your head, too, Chunky?" chuckled Ned. "Oh, no, I forgot; it's dog days," he added maliciously.

"Your master had better get a collar and chain for you, then, Ned,"

laughed Stacy, in high good humor with himself.

The guide's voice put a sudden end to their merriment.

"Here's the river," he cried. "There is plenty of water in it, too."

The boys gathered about him quickly.

"I don't see any river," averred Walter.

"There isn't any," answered Ned, in a low voice.

"I'll show you whether there is or not," snapped Parry, who had overheard the remark. "You boys think I have gone crazy, don't you?

You'll find there is something to learn about this old Nevada Desert--some things that you never even dreamed of. Hand me a shovel, please."

All at once Stacy began pushing his companions roughly aside.

"Here, here, Fatty! What are you trying to do?" the others demanded, beginning to struggle with him to prevent being bowled over.

"I'm saving your lives," cried the fat boy.

"Saving our lives?" cried Ned. "Go shake the alkali out of your eyes."

"Yes, you'll fall in and drown."

"In what?"

"In the river. Don't you see the river right there in front of you?"

queried Stacy, his eyes fairly beaming with importance.

"No, I don't. If there was a river there you'd be the first one to fall in, and don't you forget that."

"What's this? What's this?" inquired the Professor, approaching.