and this gave confidence to the
adventurer, who rode more steadily on, and spared no pains to make sure
of there being no possibility of the Indians reaching the top from that
side.

On went Bart, and three-fourths of the way were passed with nothing
overhead but towering perpendicular rocks, impossible for anything but a
fly to scale. The Indians had been left one after the other as scouting
sentries, and at last, when no one was in company with the young
adventurer but the Beaver, the edge of the canyon on this side was well
in sight, and only a few hundred yards of the rock remained to be
inspected.

"We will do this, at all events," said Bart, pressing his cob's sides
with his heels; and he cantered on, for the face of the mountain was now
so perpendicular and smooth that there was no difficulty in determining
its safety at a glance.

Only about three hundred yards more and then there was the canyon,
presenting a barrier of rock so steep, as well as so much higher, that
there was nothing to fear on that side. Only these three hundred yards
to examine, and the dangerous enterprise was almost as good as done, for
every step taken by the horses then would be one nearer to safety. Bart
had ridden on, leaving the Beaver, who had drawn rein, looking back at
the plain, when suddenly there was a warning cry, and the lad looked
over his shoulder to see the Beaver signalling to him.

"A minute won't make much difference," thought Bart excitedly, and
instead of turning, he pressed his horse's flanks and galloped on to
finish his task, rejoicing in the fact as he reached the canyon edge
that he had seen every yard of the mountain-side, and that it was even
more perpendicular than near the gateway.

"Now for back at a gallop," said Bart, who was thrilling with
excitement; and turning his steed right on the very edge of the canyon,
he prepared to start back, when, to his horror, he saw a party of
dismounted Indians rise up as it were from the canyon about a hundred
yards away, the place evidently where they had made their way down on
the occasion of the attack during the salmon-fishing. With a fierce
yell they made for the young horseman, but as Black Boy bounded forward
they stopped short. A score of bullets came whizzing about Bart's ears,
and as the reports of the pieces echoed from the face of the mountain,
the cob reared right up and fell over backwards, Bart saving himself by
a nimble spring on one side, and for