THE ALPINE REGIONS.
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three feet in height, by the slow yet resistless onward pres-sure of this giant ice-plough. In passing we may also noticethat here and there deep fissures run up into the ice. In thisglacier, however, they are not so large, or so remarkable asin many others; as for example at Grindelwald or Rosenlaui,where they extend for a considerable distance into the glacier.In the latter the pure blue of its glassy walls has an almostunearthly beauty. The cause of these fissures we will pre-sently explain; let us now mount upon the ice, choosing aplace where the slope is as gentle as possible, and wherethere are no nicely poised blocks above, threatening a suddenfall. Cutting a step here and there with our axes, where theslope is steepest or where an inconvenient fissure obliges usto turn aside, we find ourselves in a few minutes on the sur-face of the great ice-stream. Making our way as best • wecan among these fissures, which for the future we will callcrevasses (their local name), we gain a convenient spot, fromwhich we can survey a good extent of the glacier; and seatingourselves on a fallen rock, let us look around.
Above, and on each side of us, is the ice, rent in all direc-tions by crevasses, to thread whose intricate labyrinths will beno easy task. Fantastic enough are the forms of the brokenice cliffs; towers and pinnacles, strange shapes like weather-worn statues, here rise on high, there seem nodding to a fall;here a knife-like ridge divides two chasms, there a blue archspans a yawning gulf; all around the blocks which are travellingdownward lie poised on the slippery slopes. Of those that starton this journey comparatively few arrive at its end uninjured;the rest fall into these abysses, and are crushed to powderbetween the glacier and its rocky bed. What then is the causeof these crevasses? The glacier, as we said, is not at rest, butin constant motion. It is literally a great ice stream; thoughnot a fluid, like water, nor a viscous mass, like honey, which canreadily adapt itself to any inequality in its rocky bed. Hence