ated fields, and--see! human beings in motion, who
are--"

"Kicking up a great old bobbery, just as though they'd sighted us, and
wanted to know--I say, uncle Phaeton, how would it feel to get punched
full of holes by a parcel of bow-arrows?"

With a quick motion the air-ship was turned, darting lower and off at
a sharp angle to its former course, for the professor likewise saw what
had attracted the notice of his younger nephew.

Scattered here and there throughout that secluded valley were human
beings, nearly all of whom had sprung into sudden motion, doubtless
amazed or frightened by the appearance of that oddly shaped air-demon.

Brief though that view had been, it was sufficiently long to show the
professor houses of solid and substantial shape, cultivated plots, human
beings, and a little river whose clear waters sparkled and flashed in
the sunlight.

It was very hard to cut that view so short, but the professor had not
lost all prudence, and he knew that danger to both vessel and passengers
might follow a nearer intrusion upon the privacy of yonder armed people.
Yet his face was fairly glowing with glad exultation as he brought the
aerostat to a lower strata of air, shutting off all view from yonder
valley, as it lay amid its encircling hills.

"Hurrah!" he cried, snatching off his cap and waving it
enthusiastically, as the air-ship floated onward at ease. "At last!
Found--we've discovered it at last! And all is true,--all is true!"

"Found what, uncle Phaeton?" asked Waldo, a bit doubtfully.

"The Lost City of the Aztecs, of course! Oh, glad day, glad day!"

"Unless--what if it should prove to be only a--a mirage, uncle Phaeton?"
almost timidly ventured Bruno, a moment later.

CHAPTER XV. ASTOUNDING, YET TRUE.

The professor gave a great start at this almost reluctant suggestion,
shrinking back with a look which fell not far short of being horrified.
But then he rallied, forcing a laugh before speaking.

"No, no, Bruno. All conditions are lacking to form the mirage of the
desert. And, too; everything was so distinct and clearly outlined that
one could--"

"Fairly feel those blessed bow-arrows tickling a fellow in the short
ribs," vigorously declared the younger Gillespie. "Not but that--I say,
uncle Phaeton?"

"What is it now, Waldo?"

"Reckon they're like any other people? Got boys and--and girls among
'em, I wonder?"

"I daresay, yes, why not?" answered Featherwit, scarcely realising