Climbing the "Chute," west side of Gibraltar. Here the guides cut steps in the ice.
These hints of the almost inconceivable mass of a glacier, with its millions of millions of tons, suggest how much of the Mountain has already been whittled and planed away. But here we may do better than speculate. The original surface of the peak is clearly indicated by the tops of the great rocks which have survived the glacial sculpturing. These rise from one to two thousand feet above the glaciers, which are themselves several thousand feet in depth. The best known of them is the point formed by Gibraltar and the ridges that stretch downward from it, Cowlitz Cleaver and Cathedral Rocks, making a great inverted V. Eastward of this, another V with its apex toward the summit, is called Little Tahoma; and beyond, still another, Steamboat Prow, forming the tip of "The Wedge."
Spines of rock like these are found on all sides of the peak. They help us to estimate its greater circumference and bulk, before the glaciers had chiseled so deep.
Looking from top of Gibraltar to the Summit. Elevation of camera, 12,300 feet. In distance is seen the rim of the crater. The route to this is a steady climb, with 2,000 feet of ascent in one mile of distance. Many detours have to be made to avoid crevasses. Note the big crevasse stretching away on right—a "Bergschrund," as the Swiss call a break where one side falls below the other. The stratification on its side shows in each layer a year's snow, packed into ice.
But they do even more. Wherever lava flows occurred in the building of the Mountain, strata formed; and such stratification is clearly seen at intervals on the sides of the great rocks just mentioned. Its incline, of course, is that of the former surface. The strata point upward—not toward the summit which we see, but far above it. For this reason the geologists who have examined the arêtes most closely are agreed that the peak has lost nearly two thousand feet of its height. It blew its own head off!
Such explosive eruptions are among the worst vices of volcanoes. Every visitor to Naples remembers how plainly the landscape north of Vesuvius tells of a prehistoric decapitation, which left only a low, broad platform, on the south rim of which the little Vesuvius that many of us have climbed was formed by later eruptions, while a part of the north rim is well defined in "Monte Somma." Similarly, here at home, Mt. Adams and Mt. Baker are truncated cones, while, on the other hand, St. Helens and Hood are still symmetrical.
Like Vesuvius, too, Rainier-Tacoma has built upon the plateau left when it lost its head. Peak Success, overlooking Indian Henry's, and Liberty Cap, the northern elevation, seen from Seattle and Tacoma, are nearly three miles apart on the west side of the broad summit. These are parts of the rim of the old crater. East of the line uniting them, and about two miles from each, the volcano built up an elevation now known as Crater Peak, comprising two small adjacent craters. These burnt-out craters are now filled with snow, and where the rims touch, a big snow-hill rises—the strange creature of eddying winds that sweep up through the great flume cut by volcanic explosion and glacial action in the west side of the peak. (See pp. [14], [27], and [52].)