happen to come across a few shrubs they must be loaded on top of the
water-kegs, for the mule that carries them is getting to have a precious
light load, and he deserves a heavy one for causing us all that trouble
yesterday."

A very short time after they were going straight for the mountain--the
great peak forming their goal, and the doctor taking its bearings by
compass so as to know their route if mist should hide it, and when
darkness came on.

To the surprise of all, both ponies and mules stepped briskly and well,
the pasture upon which they had been busy having had a wonderfully good
effect. The hardy beasts seemed now to need no water, and made light of
their loads, while as the stiffness suffered by the riders passed off
with movement in the warm bracing air, the difficulties and perils of
the past seemed to die away.

Griggs proved to be right, too, before they had been two hours on the
way, for first one or two, then a covey of the large partridge-like
birds that haunted the open appeared, and as the day went on several
plump additions to their stores fell to the guns.

But the wood was so far wanting, and it was not until evening was
approaching that they came upon a scattered patch of trees, which grew
for a long distance in a meandering way, just one here and there, and
from which a sufficiency for their purpose was obtained; but the pasture
was no more plentiful, and they kept on, till all at once Griggs slapped
his hand down heavily upon his leg.

"Got it!" he cried.

"Got what?" exclaimed the doctor, and the boys stared.

"That idea. Can't you see, doctor? These trees have been all along on
our right for quite a time."

"Yes, that's plain enough," was the reply.

"And they go right on as far as we can see, wandering in and out, but
getting thicker."

"Yes, I can see all that, but I confess that I don't see what it has to
do with your excitement."

"Don't you, doctor?" cried Griggs. "Well, it means this: there's been a
watercourse here some time or other, and there's enough moisture
underground to keep these little scrubby trees alive."

"I see. It is possible."

"As it gets farther from the hills there are fewer trees, but as we
follow it up you can see they are getting thicker, and I believe that if
we keep on far enough we shall come upon grass and water, perhaps a
pool."

"Then we'll keep on," said the doctor, "certainly; and may you prove to
be right."

Griggs did prove to