Laughingly the lads pulled their ponies down to a walk; then halted
entirely to enable the burros to catch up with them. By this time the
pack animals had become so familiar with their work that little
attention was necessary on the part of the boys. Now and then one more
sleepy than the rest would go to sleep and pause to doze a few minutes
on the trail. This always necessitated all hands stopping to wait
until the sleeper could be rounded up and driven up to the bunch.

Juan had disappeared. They were discussing the advisability of sending
one of the boys out after him when he was seen returning. But at what
a different gait! His burro was dragging itself along with close to
the ground, while Juan himself was slouching on its back half asleep.

"You must have a motor inside that beast," grinned Tad.

"Him go some, señor?"

"Him do," answered Stacy, his solemn eyes taking in the sleepy burro
wonderingly.

"Better not waste your energy performing," advised the Professor. "We
shall need what little you have. We will make camp here, as I see
there is a spring near by. Help the boys unpack the burros."

"Si, señor," answered the guide, standing erect and permitting his
burro to walk from under him.

With shouts and songs the lads, in great good humor, went to work at
once, pitching their camp for the first time on the plains of New