"Guess you'd better get off!"
Roger slipped from his saddle, and going to the mule's head started to walk beside it.
"Go in front, you chump," called the other. "If the trail's none too wide for one, how do you suppose two can go abreast?"
"But I can't help him then!" protested Roger.
This speech was greeted with a hoarse chuckle.
"Any old time a mule needs a tenderfoot to teach him where to put his feet," he said, "I want to have a front seat to watch it. Don't you ever worry about that, I guess he can walk anywhere that you can, but on a shelving bank a rider makes a beast topheavy."
Down they went into the chasm, climbing over heaps of fallen rock, pitching down slopes which seemed almost perpendicular to the boy, and as they descended the sun rose higher and the air seemed to become less tenuous and almost visible. Roger had been expecting the wonderful radiance of the valley to become tenfold richer under the noonday sun, and was surprised to note all the color fade out of the rocks and the air become as it were so solid as to refract the light of the sun. The whole atmosphere seemed to be glowing with a metallic luster which was most confusing, because of the way in which it changed the whole environment. Lines of strata became distorted and even disappeared, the buttes appeared to flatten, the minor shadows to diminish and the darker shades to turn an inky black, till, when the halt was made at noon, the boy realized that he could not have made his way back one mile by reason of the chaotic look of the abyss under the direct light of the noonday sun.
After the march had been resumed and the afternoon was drawing to a close, however, the true witchery of the scene struck deep into Roger's mind. As the evening clouds began to gather and the twilight shadows deepened, the Titanic temples and cloisters seemed to awake and stretch themselves to meet the expected vesper. Little by little the atmosphere lost its density and the rocks behind began to glow, the colossal buttes assumed their due proportions; while a thousand bizarre forms, that had not been observable in the intense light of day, thrust themselves forward into an uncouth prominence. Then the sun disappeared from the view of the travelers, though still shining on the rocks above. Black cantered up beside the boy.
"Now watch," he said: "here's where you see the greatest display of color in the whole world."
"But how can it be brighter than it is now?" queried Roger, on whom the bold and striking scene was creating a profound impression.