k they started down the trail that led from Grand
View into the depths of the fearful dip. And as they descended,
following their guide, Bob found himself realizing the colossal size of
everything connected with the rainbow-hued canyon walls.

Nor was his mind made any easier when Frank took occasion, half an hour
later, to bend toward him, and say in the most natural manner possible,
though in low tones:

"They're on the job again, Bob--Abajo and Eugene--because I happened to
see them watching us start down the trail; and they had some one along
with them, perhaps a guide; so we'll have to take it for granted that
they mean to dog us all the time, hoping to steal our thunder, if we
make any lucky find!"

CHAPTER XIV

THE HOME OF THE CLIFF DWELLERS

Although Bob had anticipated such a thing, still the knowledge that it
was actually coming to pass gave him a thrill. For some little time he
did not say anything; but Frank could see him look uneasily up at the
walls that now arose sheer above their heads some hundreds of feet.

Frank had studied the situation as well as he could, both from a map of
the canyon which he found in the little guide book, and his own
observations. All the while he kept before him that admission on the
part of the old Moqui whom they had befriended, to the effect that the
Westering sun shone full in Echo Cave. So he expected to find the home
of the hermit-scientist high up in the wall on the Eastern side of the
Grand Canyon.

First he intended heading toward the East, and going just as far as they
could. Days, and perhaps weeks, might be spent in the search for the
strange cave that had once been the home of those mysterious cliff
people, which cavern Professor Oswald was occupying while studying the
lives and customs of the long departed people who had dug these
dwellings out of the rock.

At noon they had made good progress; but when the tremendous size of
that two hundred mile canyon was taken into consideration, with its
myriad of side "washes," and minor canyons, the distance that they had
covered was, as Bob aptly declared, but a "flea-bite" compared with the
whole.

And Frank declared time and again it had been a lucky thought that
caused his chum to suggest that they bring the field glasses along. They
were in almost constant use. Far distant scenes were brought close, and
high walls could be examined in a way that must have been impossible
with the naked eye.

Of co