them, none taking effect, because accurate aim was not
possible while they were in motion. And now a concerted movement was
apparent to surround the wagon. Over one hundred warriors were counted,
and among them certain chiefs, recognized by their distinctive
headdress.

"Go for the river, Harry," was the Professor's injunction.

The yaks were now beyond all control. Several of the arrows found their
marks in the poor animals, and they were now vying with the foremost
savages in making speed. Eventually the flanks of the attacking party
outran the team, and the Professor made his way to the front, leaving
George and John to take care of the rear.

When one of the prominent chiefs, who was leading the flanking party,
presented a fair target, the Professor shot, and had the satisfaction of
seeing him fall, and this temporarily checked the pursuit on that side.
Grasping Harry's gun, he fired into the party on the opposite side, with
good effect. The opening shot by the Professor was a signal for George
and John.

And now began one of the most exciting running duels between the
contending forces. The Professor knew that if the river could be reached
they would have only one side to defend, but they were fully three miles
or more from the crossing point of the stream, and to make matters
worse, the team was beyond control, and was traveling to the northwest,
whereas the direct course to the river was to the north or northeast.

There was no help for it. They must keep cool, and reserve their fire.
After each shot the weapon of each would be reloaded, so that they
always had a reserve force of guns. The arrows came spasmodically, and
only a few of them from the trailing members of the band came near. The
danger was from those who were attempting to encircle the wagon.

John was requested by sign to go to the forward end, and he promptly
responded, and at every shot one of the pursuers went down. The main
object was to keep them away from the team a sufficient distance to
prevent injury to the yaks, and this required the greatest energy and
watchfulness.

The attacking party began to have a wholesome fear of the guns, and kept
at a distance, which prevented them from effectively using the arrows.
This pace was kept up for two miles, and the effect was now apparent on
the poor animals. Harry noticed it, but he kept up a brave front, and
did his share in the firing.

But now there was increased activity in the ranks of t