On low ground one may be in the clouds, but not above them. But as we look down from mountains and see the clouds floating far below us, we almost seem as if we were looking down on earth from one of the heavenly bodies. Not even in the Alps is there anything more beautiful than the "after glow" which lights up the snow and ice with a rosy tint for some time after the sun has set. Long after the lower slopes are already in the shade, the summit of Mont Blanc for instance is transfigured by the light of the setting sun glowing on the snow. It seems almost like a light from another world, and vanishes as suddenly and mysteriously as it came. As we look up from the valleys the mountain peaks seem like separate pinnacles projecting far above the general level. This, however, is a very erroneous impression, and when we examine the view from the top of any of the higher mountains, or even from one of very moderate elevation, if well placed, such say as the well-known Piz Languard, we see that in many cases they must have once formed a dome, or even a table land, out of which the valleys have been carved. Many mountain chains were originally at least twice as high as they are now, and the highest peaks are those which have suffered least from the wear and tear of time. We used to speak of the everlasting hills, and are only beginning to realise the vast and many changes which our earth has undergone. There rolls the deep where grew the tree. O earth, what changes hast thou seen! There where the long street roars, hath been The stillness of the central sea. The hills are shadows, and they flow From form to form, and nothing stands; They melt like mist, the solid lands, Like clouds they shape themselves and go.[42] THE ORIGIN OF MOUNTAINS Geography moreover acquires a new interest when we once realise that mountains are no mere accidents, but that for every mountain chain, for every peak and valley, there is a cause and an explanation.