e compelled to scramble over the rocks on foot. The effect of
hours of this exercise on muscles unaccustomed to such surprises may
be imagined; yet, owing to the wonderfully restorative air of
Arizona, the next day after this, the severest physical exertion I
had ever known, I did not feel the slightest bad result, and was as
fresh as ever. That there is an element of danger in this trip cannot
be doubted. At times the little trail, on which two mules could not
possibly have passed each other, skirts a precipice where the least
misstep would hurl the traveler to destruction; and every turn of
the zigzag path is so sharp that first the head and then the tail of
the mule inevitably projects above the abyss, and wig-wags to the
mule below. Moreover, though not a vestige of a parapet consoles the
dizzy rider, in several places the animal simply puts its feet
together and toboggans down the smooth face of a slanting rock,
bringing up at the bottom with a jerk that makes the tourist see a
large variety of constellations, and even causes his beast to belch
forth an involuntary roar of disenchantment, or else to try to
pulverize his immediate successor. In such a place as this Nature
seems pitiless and cruel; and one is impressed with the reflection
that a million lives might be crushed out in any section of this maze
of gorges and not a feature of it would be changed. There is,
however, a fascination in gambling with danger, when a desirable
prize is to be gained. The stake we risk may be our lives, yet, when
the chances are in our favor, we often love to match excitement
against the possibility of death; and even at the end, when we are
safe, a sigh sometimes escapes us, as when the curtain falls on an
absorbing play.

[Illustration: STARTING DOWN THE TRAIL.]

[Illustration: A YAWNING CHASM.]

[Illustration: OBLIGED TO WALK.]

As we descended, it grew warmer, not only from the greater elevation
of the sun at noon, but from the fact that in this sudden drop of six
thousand feet we had passed through several zones of temperature.
Snow, for example, may be covering the summits of the mountains in
midwinter, while at the bottom of the Canon are summer warmth and
vernal flowers. When, after two or three hours of continuous descent,
we looked back at our starting-point, it seemed incredible that we
had ever stood upon the pinnacles that towered so far above us, and
were apparently piercing the slowly moving clouds. The effect