"You come next, and see," was the reply. "Now, gentlemen, I'll lead; please follow in single file."

Griggs sent his pony forward at a walk towards the far end of the amphitheatre, holding the fir-pole well-balanced and low-down in front, while, rising in his stirrups, he bent forward, lancer-like, keeping his eyes fixed upon the ground before him, over which he guided his mount.

In this way he advanced, still keeping at a walk, avoiding every dangerous-looking spot, keeping to the open, and wherever there was the possibility of a lurking enemy being at hand the tuft at the point of the pole was lowered to the ground and used as a beater to drive out any reptile that might be there.

At the commencement the mustang seemed disposed to start and shy, but a few soothing words calmed it, and as if divining the object in view, it stepped out finally, only uttering a snort or two when the green head of the spear was rustled about, the snorts sounding as if given to help scare any danger away.

"Don't seem to be any, Griggs," said Chris.

"Not yet, my lad," was the reply. "You see, I'm picking out the least likely bits; but one never knows."

"There goes one," shouted Chris the next moment, and he raised his piece to his shoulder.

"Don't fire; he's got well into cover," cried Griggs. "It was a snake, but I don't think it was a rattler, for he didn't talk with his tail."

"No; I didn't hear him rattle. Why did you tell me not to fire?"

"Because you wouldn't have hit the brute, only wasted a cartridge."

There had been no check, and they rode slowly on and on till the end of the depression had been reached, Griggs's plan resulting in starting off altogether five dangerous-looking serpents from the spots where they lay ready to scuttle in amongst the growth at the first movement of the extemporised weapon--the last of the fleeing reptiles proving its dangerous nature as it hurried away by giving off a harsh, dull, rattling sound with its quivering tail.

A careful examination was made to the left without effect, and another to the right, but everywhere they were faced by the precipitous wall of cliff, carved-out and terraced, and here and there offering facilities for climbing up more or less high, the stones from above having fallen from the weakening and decay of time till a glacis-like slope had been formed; but after the reptiles that had been started in the less likely places, there was no present temptation for ascending the stony slopes, bathed in the hot sunshine and looking thoroughly suited for the home of the dangerous creatures.

This exploration of the lower part of the amphitheatre, ravine, or depression tempted farther search, the party riding on, and after examining cautiously the sides, visiting the upper portion near the zigzag gorge by which they had entered; but only to find that there was no other means of access to the city unless by a descent from the tableland in which the place seemed to be formed.

"And snakes seem to be the only inhabitants," said Chris to his companion. "Why, Griggs, we can't stop here."

"Not unless we can find water," said the American.

"And not even then," replied the boy, "with the risk of getting bitten."

"If there are no more than we started we're not going to give up for that," said Griggs coolly. "Why, they're quite scarce."

"But we haven't been upward on those terraces. They may be swarming there," cried Chris.

"Yes, and there may be none. We don't want to go up there to-day. What we want is water. Now, where is it?"

"Nowhere, seemingly."

"Oh, that notion won't do," said the American. "Here, it is plain enough that once upon a time this was a big place with no end of people living in it."

"Yes; so my father thought."

"Very well, then; I dare say it was just such a dry, hot place as it is now, and they must have had water close at hand, or they wouldn't have settled here."

"They got it out of the gully through which we came."

"No, that won't do," cried Griggs. "This was the old people's stronghold, where they could be safe and set all their enemies at defiance. Everything points to that. Don't it?"

"I think so," said Chris grudgingly.

"Well, then, it isn't likely that they would depend on a fall of water from which the first enemies who attacked them could cut them off and leave them to die of thirst."

"I never thought of that," said Chris, as, separated now from the rest, they allowed their ponies to pace slowly on, nibbling off such juicy shoots as came in their way.

"It isn't likely," said Griggs. "There must be water somewhere--a fine fall that comes down from the plain up above, or they wouldn't have chosen this spot."

"Perhaps there used to be one, and it has dried-up."

"Nay; the place is too green. Water must come on the high ground somewhere and find its way into this great hollow. Anyhow, it's out of sight, so it's underneath somewhere."

"Then we shan't find it."

"I don't know about that, my lad," replied the American, with a little laugh. "There's other senses besides seeing."

"Yes, smelling," said Chris, with a smile; "but we can't find it that way."

"Don't you be in too great a hurry, my lad. We're going to have another good hunt round at the bottom of these great cliffs, and if that comes to nothing we might try smelling."

"Ah! Nothing but a dog would be any use there."

"In a hurry again, boy. I'd back something else to find water before a dog."

"A fish on dry land?"

"Tchah! No. What was it found the lake for us the other day?"

"The mule," cried Chris.

"Got it again," said Griggs, laughing. "I don't say he would, but I shouldn't at all wonder, if we brought old Skeeter round, as like as not he'd smell out the place."

"Buried under some of these great stone slides that have come down?"

"To be sure, my lad. Now, that's a likely place."

Griggs pointed to a huge gap in the cliff away to their right where the carved-out openings running along behind a rough terrace a hundred feet up the vast wall suddenly ceased as if broken off, and commenced again at about the same height on the other side of the gap.

"Let's go and look, then," said Chris; "but it doesn't seem very likely, for it's all one bank of piled-up stones."

"That have run down from up yonder like those avalanches we read about.

Mind how you come, for it's a snaky-looking bit. Go on, old chap; I'll sweep the way for you with my fir-pole."

Chris felt a creepy sensation at the allusion to snakes, and his eyes looked very wide open as he followed close behind his companion, whose pony picked its steps with the greatest caution, the way growing more and more enc.u.mbered with stones as they neared the slope which filled up the gap.

"It looks as if there had been an earthquake. What a roar there must have been when these stones came tumbling down!"

"More likely that water had been coming down in a regular stream for hundreds and hundreds of years till all the earth and small stones had been washed away and made a great hollow underneath which held up the cliff as long as it could, and then gave way all at once."

"You're talking as if a torrent ran down from the top of the cliff yonder."