glow of
sunshine right in front, as if it came round an elbow of the way. A few
minutes later Griggs led the party into a vast amphitheatre walled in by
towering walls that were on the whole perpendicular, but seamed with
rifts running up to natural terraces or breaks in the strata of which
the vast walls were composed.

The change from the gloom of the zigzag ravine along which they had made
their way, to the sunlit amphitheatre, was almost painful, and the party
stood in a group shading their eyes, gazing about in silence, till Chris
suddenly snatched off his hat, waved it in the air, and with a shout
startled the mules into the beginning of a stampede.

But this was nipped in the bud, and as soon as the animals were calmed
down, the boy cried excitedly--

"I didn't mean to do that. But, I say, we've found the old city at
last."

"Nay," cried Griggs, shaking his head. "This don't go on all fours with
our map."

"But it's a city," cried Ned eagerly. "It's precious old; but look all
along there, and up yonder, and down that bit--everywhere, there are
houses with doorways and windows. Why, there's quite one side of a
street along at the back of that shelf."

"Yes, boys; it's a city, sure enough," said the doctor almost as
excitedly as the lads. "Why, Griggs, this must be one of the old
pueblas that the Spaniards talked about."

"Yes, sir, that's it, sure enough; a city cut out of the rock-faces of
this great shut-in place. Why, it must have been a regular stronghold
where thousands of people lived, and we've hit upon the way in. I
shouldn't wonder if there's no way out."

"Oh, there may be at the end yonder. How far is it to where that great
rock-wall closes in?"

"Mile and a quarter, I should say," replied the American.

"Then at the widest part yonder it must be nearly half-a-mile across,"
cried Bourne.

"Hardly, sir; say quarter, and here and there not half that."

"But the cliffs seem about the same height," cried Chris, "just as if
they had been cut level."

"Nature cut them then," cried Griggs, laughing. "Seems to me that it's
just one great fault in a bit of tableland."

"But how could it come so regular?" said Wilton thoughtfully.

"Who knows, sir? Earthquake perhaps, or shrinking. Anyhow, here it is,
regular rock city such as we've read about; and the old folks made it by
cutting away. Chopped it out of the stone and by filling up and
securing the openings."

"But look at the t