Perched up here, the constant struggle of the clouds from the humid south to reach the interior was interesting to watch, and one readily understood that Denali and his lesser companions are a prime factor in the climate of interior Alaska. Day by day Karstens and Walter would go up and resume the finding and making of a way, and Tatum and the writer would relay the stuff from the camp to a cache, some five hundred feet above, and thence to another. The grand objective point toward which the advance party was working was the earthquake cleavage--a clean, sharp cut in the ice and snow of fifty feet in height. Above that point all was smooth, though fearfully steep; below was the confusion the earthquake had wrought. Each day Karstens felt sure they would reach the break, but each day as they advanced toward it the distance lengthened and the intricate difficulties increased. More than once a passage painfully hewn in the solid ice had to be abandoned, because it gave no safe exit, and some other passage found. At last the cleavage was reached, and it proved the most ticklish piece of the whole ridge to get around. Just below it was a loose snow slope at a dangerous angle, where it seemed only the initial impulse was needed for an avalanche to bear it all below. And just before crossing that snow slope was a wall of overhanging ice beneath which steps must be cut for one hundred yards, every yard of which endangered the climber by disputing the passage of the pack upon his shoulders. [Illustration: A dangerous passage.] [Sidenote: The Primus Stove]