Already considerably shaken in nerve, I tried to dissuade Clark from attempting his slide. Replying that the stunt was a part of his daily routine for keeping his wits on edge, he "corduroyed" off up the side of the canyon, which at that point has a slope of about forty-five degrees. When he was perhaps a hundred feet above my head, he laid hold of a sapling, swung quickly around, and shot full-tilt for the icy brink. I was sure he intended to kill himself, just as so many cracked inventors do. A sudden numbness seized me. The roar of the fall grew deafening, and I involuntarily closed my eyes. There was a thud and a crash, a shower of fine snow flew over me. Then the roar of the fall resumed. When I mustered up the courage to open my eyes, it was to discover my mad companion cautiously drawing himself back from the brink. He had stopped, as usual, by throwing himself on his side and digging the edges of his ski into the frozen snow. Although he wouldn't admit it, I am certain he kept going an inch or two more than was his wont, for one long strip of hickory was swinging free beyond the icy edge and the other held by only a thin ridge of hard snow. While he was still thus poised on the brink of Kingdom Come, or rather the Falls of the Yellowstone, Clark insisted on explaining to me the principle of a parachute cape he had devised for use in such an emergency. He reckoned that it would not only help in checking his momentum at the proper moment, but would also have a tendency to make his landing much less painful in the event he went over. I am wondering tonight if all inventors are like that. Clark is the first genius I have ever known, so I can't be quite sure. Grand Canyon Station, April 10. Clark and Smith took me out for a ski-jumping lesson this morning. Clark seems to be rather a star performer in all departments of ski work, but he claims that he is better at jumping than at anything else. What the long, straight drive, hit cleanly from the tee, is to the golfer, what the five rails, fairly taken, is to the cross-country rider, what the dash down a rocky-walled canyon is to the river boatman, the jump is to the ski-runner. But what the foozle is to the golfer, the cropper to the rider, the spill in midstream to the boatman, the fall at the end of the jump is to the ski-man. I saw both the jump and the fall today. Or rather, I saw the jump and _felt_ the fall. If I saw anything at all, it was stars.