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 was that of looking up from the bottom of a gigantic well.  Instinctively I asked myself if I should ever return to that distant upper world, and it gave me a memorable realization of my individual insignificance to stand in such a sunken solitude, and realize that the fissure I was exploring was only a single loop in a vast network of ravines, which, if extended in a straight line, would make a canon seven hundred miles in length.  It was with relief that we reached, at last, the terminus of the lateral ravine we had been following and at the very bottom of the Canon rested on the bank of the Colorado.  The river is a little freer here than elsewhere in its tortuous course, and for some hundred feet is less compressed by the grim granite cliffs which, usually, rise in smooth black walls hundreds of feet in almost vertical height, and for two hundred miles retain in their embrace the restless, foaming flood that has no other avenue of escape.