me jagged sierras grew purple and then black in the fading
light. Fortunately there was a moon, though the luminary of night was
in her last quarter. However, the silvery light added to the
brilliance of the desert stars, gave them all the radiance they needed
to pursue their way.

The travelers could now perceive the outlines of the Haunted Mesa more
clearly. It reared itself strangely out of the surrounding solitudes,
almost as if it were the work of human hands, instead of the result of
long-spent geological forces.

"Wish we were there now," breathed Ralph, patting his pony's sweating
forequarters, "poor old Petticoats is about 'all in.'"

"It's purty hard to kill a cayuse," rejoined Pete. "I've seen 'em
flourish on cottonwood leaves and alkali water--yep, and git fat on it,
too. Be like a cayuse, my son, and adapt yourself to carcumstances."

"Very good advice," said the professor approvingly, as the desert
philosopher concluded.

As Pete had conjectured, the ponies were far from being as tuckered out
as they appeared, despite their sunken flanks and distended nostrils.
As the cool night drew on, and they approached more nearly to the
upraised form of the mesa, the little animals even began to prick their
ears and whinny softly. The pack animals, too, seemed to pluck up
spirits amazingly.

"They smell grass and water," commented Pete, as he observed these
signs.

Shortly after ten, as had been surmised, they were among the
bunch-grass surrounding the mesa. Striking such a spot after their
long wanderings on the hot desert, was delightful, indeed. Presently,
too, came to their ears the tinkling sound of flowing water.

"It's the overflow from them old-timers' well at the base of the mesa,"
pronounced Pete, listening.

"Yes, and here it is," cried Jack, who had been riding a short distance
in advance, and had suddenly come across a small stream.

The water was but a tiny thread, but it looked as welcome just then as
a whole lake. Cautioning the boys to keep their ponies back, Pete took
a long-handled shovel from one of the packs, and soon excavated quite a
little basin. While he had been doing this, the boys had had to
restrain their thirst, for the ponies were almost crazy with impatience
to get at the water. It required all the boys' management, in fact, to
keep them from breaking away and getting at the water. In the heated
condition of the little animals, this might have meant a case of
f