It was not until the dark had really come and the stars were shining brightly that the boy awakened to the consciousness of a trail and felt that he could speak. He turned to the assistant. "And that's been going on every day for years!" he said, struck by the wastefulness of such a sight to so few eyes. "For thousands upon thousands of years that went on before any man saw it," replied Black, smiling slightly, "and it will go on when the present civilizations are deemed but musty antiquities." The night was well advanced when the party reached the crest of the Canyon on the north side. The journey, as Masseth had said, was one devoid of special risk because of the numbers of the party and the known trail, though, in truth, it needed a keen eye at times to discern that such apparently impassable ground was intended for a trail. The top reached, however, a hasty camp pitched, the packs and saddles taken off, the mules and the animals hobbled to graze on the rich herbage of the Kaibab plateau, Roger sank to sleep without loss of time, and it seemed to him hardly ten minutes before the cook aroused him for the camp breakfast. "You know something about the work of a rodman, and of the handling of the tape?" asked Masseth, after breakfast, referring to the 300-foot steel tape used in measuring distances in wooded areas. "Yes, indeed, Mr. Masseth." "Of course you realize that the tape is generally impracticable in such a country as this, and that all the work must be done by the computing of angles with continual astronomical verification. As topographic aid you can learn as much as you are able of the use of instruments, at such times as you are not carrying out levels." And Masseth, questioning closely, elicited the mathematical ability of the lad. The boy had always hated arithmetic and its kindred studies, not realizing the value of the higher branches, but with the incentive before him, he found his chief's teaching markedly interesting. The next day a semi-permanent camp was pitched, and there the supplies were kept. The head packer, who became a teamster as soon as things were settled, immediately left for the village of Kanab in Utah, over a hundred miles away, where a heavy wagon was in waiting, and whence the provisions were to be drawn for the party during the two months it should be on the north side of the Canyon. As it was a three days' journey there and the same returning, the teamster was a busy man, having but one day comparatively free and camping on the trail five nights out of seven.