"We'd be sausage meat if we landed on those," declared Chunky.

"You are likely to go through the machine if you don't pay closer attention to your business," answered Dad.

Carefully, cautiously, laboriously they lowered themselves one by one over the steep and slippery rocks, down, down for hundreds of feet until they stood on the ragged edge of nowhere, a direct drop of several hundred feet more before them.

The guide knew a trail further on, so they crept along the smooth wall of the Canyon with scarcely room to plant their feet. A misstep meant death.

"Three hundred feet and we shall be there," came the encouraging voice of the guide. "Half an hour more."

"I could make it half a minute if I wanted to," said Stacy. "But I don't want to. I feel it my duty to stay and look after my friends."

"Yes, your friends need you," answered Ned sarcastically. "If they hadn't I never should have pulled you out of the hole in the crater."

"I was just wondering how Chunky could resist the temptation of falling in here. He'll never have a better opportunity for making a clean job of said Walter.

"He has explained why," replied Tad. "We need him. Of course we do.

We need him every hour-----"

"And a half," added Ned.

The roar of the river became louder as they descended. Now they were obliged to raise their voices to make themselves heard. The Professor was toiling and sweating, but making no complaint of the hardships.

He was plucky, as game as any of those hardy boys for whom he was the companion, and they knew it.

"Hold on here!" cried Stacy, halting.

All turned to see what was wrong.

"I want to know---I want to know before I take another step."

"Well, what do you want to know?" demanded Tad.

"If it's all this trouble to climb down, I want to know how in the name of Bright Angel Trail we're ever going to be able to climb up again!"

"Fall up, of course," flung back the guide. "You said this was mountain climbing backwards. It'll be that way going back," chuckled the guide.

"And I so delicate!" muttered the lad, gazing up the hundreds of feet of almost sheer precipice. But ere the Pony Rider Boys scaled those rocks again they would pa.s.s through some experiences that were far from pleasurable ones.

CHAPTER IX

CHUNKY WANTS TO GO HOME

Instead of a half hour, as had been prophesied, a full hour elapsed before they reached the bottom of the trail that was practically no trail at all. Tad was sure that the guide couldn't find his way back over the same ground, or rather rock, to save his life, for the boy could find nothing that looked as if the foot of man had ever trodden upon it before. He doubted if any one had been over that particular trail from the Garden on.

As a matter of fact, Dad had led them into new fields. But at last they stood upon the surer foundation of the bottom of the chasm.

"Anyone needs to be a mountain goat to take that journey," said Tad, with a laugh.

"No, a bird would be better," piped Stacy.

"I'd rather be a bug, then I wouldn't have to climb," spoke up Walter.

"Hurrah! Walt's said something," shouted Ned.

By this time Nance and the Professor had walked along, climbing over boulders, great blocks of stone that had tumbled from the walls above, making their way to the edge of the river.

The others followed, talking together at the tops of their voices, laughing and joking. They felt relieved that the terrible climb had come to an end. As they approached the river, their voices died away.

It was a sublime but terrifying spectacle that the Pony Rider Boys gazed upon.

"This is more wonderful than Niagara," finally announced the Professor.

"The rapids of the Niagara River would be lost in this turbid stream."

Great knife-like rocks projected from the flood. When the water struck these sharp edges it was cleanly cut, spurting up into the air like geysers, sending a rainbow spray for many yards on either side.

What puzzled the lads more than all else were the great leaping waves that rose without apparent cause from s.p.a.ces of comparatively calm water. These upturning waves, the guide explained, were the terror of explorers who sought to get through the Canyon in boats.

"Has any one ever accomplished it?" asked Tad.

"Yes; that intrepid explorer, Major J.W. Powell, made the trip in the year 1869, one of the most thrilling voyages that man ever took. Several of his men were lost; two who managed to escape below here were killed by the Indians."

"I think I should like to try it," said Tad thoughtfully.

"You won't, if I have anything to say about the matter," replied Dad shortly.

"No one would imagine, to gaze down on this stream from the rim, that it was such a lively stretch of water," remarked the boy. "It doesn't seem possible."

"Yes, if they had some of this water up on the plateau it would be worth almost its weight in gold," declared Nance. "Water is what Arizona needs and what it has precious little of. Speaking of the danger of the river," continued Nance, "it isn't wholly the water, but the traveling boulders."

"Traveling boulders!" exclaimed the boys.

"Yes. Boulders weighing perhaps a score or more of tons are rolled over and over down the river by the tremendous power of the water, almost with the force and speed of projectiles. Now and again they will run against snags. The water dashing along behind them is suddenly checked under the surface. The result is a great up-wave, such as you have already observed. They are just as likely to go downward or sideways as upward. You never know."

"Then that is the explanation of the cause of those up-waves?" asked the Professor.

"That's the way we figure it out. But we may be wrong. Take an old man's advice and don't monkey with the river."

"I thought you said Dad's beloved Canyon would not hurt him," said Tad teasingly.

"Dad's Canyon won't. The river isn't Dad's The river is a demon. The river would scream with delight were it to get Dad in its cruel clutches," answered the old man thoughtfully, his bristling whiskers drooping to his chest. "Are you boys hungry?"

The boys were. So Dad sought out a comfortable place where they might sit down, a shelf some twenty feet above the edge of the river, whence they could see the turbulent stream for a short distance both ways. It was a wonder to them where all the water came from. The Professor called attention to his former statement that the river drained some three hundred thousand miles of territory. This explanation made the matter clearer to them.

Coffee was made, the ever-ready bacon quickly fried and there in the very heart of the Grand Canyon they ate their midday meal. Never before had they sat down to a meal amid such tremendous forces.

The meal having been finished and Dad having stretched himself out on a rock after his dinner, the boys strolled off along the river, exploring the various crevices.