We had now reached the lower limit of perpetual snow. There were no more moraines on the surface of the glacier, and no bare rock surfaces large enough to hold a tent. The entire region was snow-mantled as far as the eye could see, except where pinnacles and cliffs too steep and rugged for the snow to accumulate rose above the general surface. A little to one side of the mouth of a steep lateral gorge we found a spot in which a mass of partly disintegrated shale had fallen down from the cliff. We scraped the fragments aside, smoothed the snow beneath, and built a wall of rock along the lower margin. The space above was filled in with fragments of shale, so as to form a shelf on which to pitch our tent. Soon our blankets were spread, with our water-proof coats for a substratum, and supper was prepared over the oil-stove.
Darkness settled down over the mountains, and the storm increased as the night came on. What is unusual in Alaska, the rain fell in torrents, as in the tropics. Our little tent of light cotton cloth afforded great protection, but the rain-drops beat on it with such force that the spray was driven through and made a fine rain within. Weary with many hours of hard traveling over moraines and across crevassed ice, and in an atmosphere saturated with moisture, we rolled ourselves in our blankets, determined to rest in spite of the storm that raged about.
As the rain became heavier, the avalanches, already alarmingly numerous, became more and more frequent: A crash like thunder, followed by the clatter of falling stones, told that many tons of ice and rocks on the mountains to the westward had slid down upon the borders of the glacier; another roar near at hand, caused by an avalanche on our own side of the glacier, was followed by another, another, and still another out in the darkness, no one could tell where. The wilder the storm, the louder and more frequent became the thunder of the avalanches. It seemed as if pandemonium reigned on the mountains. One might fancy that the evil spirits of the hills had prepared for us a reception of their own liking—but decidedly not to the taste of their visitors. Soon there was a clatter and whiz of stones at our door. Looking out I saw rocks as large as one's head bounding past within a few feet of our tent. The stones on the mountain side above had been loosened by the rain, and it was evident that our perch was no longer tenable. Before we could remove our frail shelter to a place of greater safety, a falling rock struck the alpenstock to which the ridge-rope of our tent was fastened and carried it away. Our tent "went by the board," as a sailor would say, and we were left exposed to the pouring rain. Before we could gather up our blankets they were not only soaked, but a bushel or more of mud and stones from the bank above, previously held back by the tent, flowed in upon them. Rolling up our blankets and "caching" the rations, instruments, etc., under a rubber cloth held down by rocks, we hastily dragged our tent-cloth down to the border of the glacier, at the extremity of a tapering ridge, along which it seemed impossible for stones from above to travel. We there pitched our tent on the hard snow, without the luxury of even a few handfuls of shale beneath our blankets. Wet and cold, we sought to wear the night away as best we could, sleep being impossible. Crumback, who had been especially energetic in removing the tent, regardless of his own exposure, was wet and became cold and silent. The oil-stove and a few rations were brought from the cache at the abandoned camp, and soon a dish of coffee was steaming and filling the tent with its delicious odor. Our shelter became comfortably warm and the hot coffee, acting as a stimulant, restored our sluggish circulation. We passed an uncomfortable night and watched anxiously for the dawn. Toward morning a cold wind swept down the glacier and the rain ceased. With the dawn there came indications that the storm had passed, although we were still enveloped in dense clouds and could not decide whether or not a favorable change in the weather had occurred. We were still cold and wet and the desire to return to Blossom island, where all was sunshine and summer, was great. Uncertain as to what would be the wisest course, we packed our blankets and started slowly down the mountain, looking anxiously for signs that the storm had really passed.
An hour after sunrise a rift in the mist above us revealed the wonderful blue of the heavens, and allowed a flood of sunlight to pour down upon the white fields beneath. Never was the August sun more welcome. The mists vanished before its magic touch, leaving here and there fleecy vapor-wreaths festooned along the mountain side; as the clouds disappeared, peak after peak came into view, and snow-domes and glaciers, never seen before, one by one revealed themselves to our astonished eyes. When the curtain was lifted we found ourselves in a new world, more wild and rugged than any we had yet beheld. There was not a tree in sight, and nothing to suggest green fields or flowery hill-sides, except on a few of the lower mountain spurs, where brilliant Alpine blossoms added a touch of color to the pale landscape. All else was stern, silent, motionless winter.
The glacier, clear and white, without a rock on its broken surface, looked from a little distance like a vast snow-covered meadow. We were about a mile above the lower limit of the snow-fields, where the blue ice of the glacier comes out from beneath the névé. The blue ice was deeply buried, and could only be seen in the deepest crevasses. Across the glacier rose the angular cliffs and tapering spires of the Hitchcock range. Every ravine and gulch in its rugged sides was occupied by glaciers, many of which were so broken and crevassed that they looked like frozen cataracts.
Cheered by the bright skies and sun-warmed air, we pushed on up the glacier, taking the center of the stream in order to avoid the crevasses, which were most numerous along its borders. Two or three miles above our first camp we found a place where a thin layer of broken shale covered the snow, at a sufficient distance from the steep slopes above to be out of the reach of avalanches. We there established our second camp after leaving Blossom island, dried our blankets, and spent the remainder of the day basking in the sunlight and gathering energy for coming emergencies.
We found the névé of the Marvine glacier differing greatly from the lower or icy portion previously traversed. Instead of ice with blue and white bands, as is common lower down, the entire surface, and as far down in the crevasses as the eye could distinguish, was composed of compact snow, or snow changed to icy particles resembling hail and having in reality but few of the properties of ordinary snow: it might properly be called névé ice. Usually the thickness of the layers varied from ten to fifteen feet. Separating them were dark lines formed by dust blown over the surface of the glacier and buried by subsequent snow-storms, or by thin blue lines formed by the edges of sheets of ice and showing that the snow surface had been melted during bright sunny days and frozen again at night. The horizontal stratification so plainly marked in all the crevasses in the névé was almost entirely wanting, or at least was not conspicuous, in the lower portion of the glacier, where, instead, we found those narrow blue and white bands already mentioned, the origin of which has been so well described and explained by Tyndall.
The center of the Marvine glacier, as in most similar ice-streams, is higher and less broken by crevasses than its borders. The crevasses at the side trend up stream, as is the case with marginal crevasses generally. In the present instance the courses of these rents could be plainly distinguished on each border of the glacier, when looking down upon it from neighboring slopes. The crevasses occur at quite regular intervals of approximately fifty feet, and diverge from the bank at angles of about 40°. In the banks of snow bordering the glacier similar crevasses diverge from the margin of the flowing glacier and trend down along its banks. The marginal crevasses and the crevasses in the bordering snow-fields, to which no special name has been given, fall nearly in line; but between the two there is a series of irregular cracks and broken snow, sharply defining the border of the moving névé.
The origin of the marginal crevasses trending up stream was explained during the study of the glaciers of Switzerland. The following diagram and explanation illustrating their development are copied from Tyndall:
"Let A C be one side of the glacier and B D the other; and let the direction of motion be that indicated by the arrow. Let S T be a transverse slice of the glacier, taken straight across it, say to-day. A few days or weeks hence the slice will have been carried down, and because the center moves more quickly than the sides it will not remain straight, but will bend into the form S' T'. Supposing T i to be a small square of the original slice near the side of the glacier; in the new position the square will be distorted to the lozenge-shaped figure T' i'. Fix your attention upon the diagonal T i of the square; in the lower position this diagonal, if the ice could stretch, would be lengthened to T' i'. But the ice does not stretch; it breaks, and we have a crevasse formed at right angles to T' i'. The mere inspection of the diagram will assure you that the crevasse will point obliquely upward."29