Now came the most wonderful display of his mountain-craft. Had I been alone at the feet of these crags I should have said, "It can't be done," and have turned back down the mountain. But Muir was my "control," as the Spiritists say, and I never thought of doing anything else but following him. He thought he could climb up there and that settled it. He would do what he thought he could. And such climbing! There was never an instant when both feet and hands were not in play, and often elbows, knees, thighs, upper arms, and even chin must grip and hold. Clambering up a steep slope, crawling under an overhanging rock, spreading out like a flying squirrel and edging along an inch-wide projection while fingers clasped knobs above the head, bending about sharp angles, pulling up smooth rock-faces by sheer strength of arm and chinning over the edge, leaping fissures, sliding flat around a dangerous rock-breast, testing crumbly spurs before risking his weight, always going up, up, no hesitation, no pause--that was Muir! My task was the lighter one; he did the head-work, I had but to imitate. The thin fragment of projecting slate that stood the weight of his one hundred and fifty pounds would surely sustain my hundred and thirty. As far as possible I did as he did, took his hand-holds, and stepped in his steps. But I was handicapped in a way that Muir was ignorant of, and I would not tell him for fear of his veto upon my climbing. My legs were all right--hard and sinewy; my body light and supple, my wind good, my nerves steady (heights did not make me dizzy); but my arms--there lay the trouble. Ten years before I had been fond of breaking colts--till the colts broke me. On successive summers in West Virginia, two colts had fallen with me and dislocated first my left shoulder, then my right. Since that both arms had been out of joint more than once. My left was especially weak. It would not sustain my weight, and I had to favor it constantly. Now and again, as I pulled myself up some difficult reach I could feel the head of the humerus move from its socket. Muir climbed so fast that his movements were almost like flying, legs and arms moving with perfect precision and unfailing judgment. I must keep close behind him or I would fail to see his points of vantage. But the pace was a killing one for me. As we neared the summit my strength began to fail, my breath to come in gasps, my muscles to twitch. The overwhelming fear of losing sight of my guide, of being left behind and failing to see that sunset, grew upon me, and I hurled myself blindly at every fresh obstacle, determined to keep up. At length we climbed upon a little shelf, a foot or two wide, that corkscrewed to the left. Here we paused a moment to take breath and look around us. We had ascended the cliff some nine hundred and fifty feet from the glacier, and were within forty or fifty feet of the top.