We turn again to the left into a sort of stairway in the mountain side, and cautiously tread the stony defile downward; at places over loose boulders, at others around or over the points of shelving rock, where one false step would send horse and rider a mangled mass two thousand feet below, and more rarely over ground covered with bushes and grade moderate enough to afford a brief rest. It is impossible to repress fear. Every nerve is tense; the muscles involuntarily make ready for a spring, and even the bravest lean timorously toward the mountain side and away from the cliff, with foot loose in stirrup and eye alert, ready for a spring in case of peril. The thought is vain; should the horse go, the rider would infallibly go with him. And the poor brutes seem to fully realize their danger and ours, as with wary steps and tremulous ears, emitting almost human signs, with more than brute caution they deliberately place one foot before the other, calculating seemingly at each step the desperate chances and intensely conscious of our mutual peril. Mutual danger creates mutual sympathy—everything animal, everything that can feel pain, is naturally cowardly—and while we feel a strange animal kinship with our horses, they seem to express a half-human earnestness to assure us that their interest is our interest, and their self-preservative instinct in full accord with our intellectual dread. We learn with wonder that of all the five thousand who have made this perilous passage not one has been injured—if injured be the word, for the only injury here would be certain death. One false step and we are gone bounding over rocks, ricocheting from cliffs, till all semblance of humanity is lost upon the flat rock below. Such a route would be impossible to any but those mountain-trained mustangs, to whom a broken stone staircase seems as safe as an ordinary macadamized road. At length we reach a point where the most hardy generally dismount and walk—two hundred feet descent in five hundred feet progress. Indeed half the route will average the descent of an ordinary staircase. Then comes a passage of only moderate descent and terror, then another and more terrible stairway—a descent of four hundred feet in a thousand. I will not walk before and lead my horse, as does our guide, but trail my long rope halter and keep him before,—always careful to keep on the upper side of him, springing from rock to rock, and hugging the cliff with all the ardor of a young lover. For now I am scared. All pretense of pride is gone, and just the last thing I intend to risk is for that horse to stumble, and in falling strike me over that fearful cliff. At last comes a gentler slope, then a crystal spring, dense grove and grass-covered plat, and we are down into the valley. Gladly we take the stage, and are whirled along in the gathering twilight.