Page:The Geologist, volume 5.djvu/97

Rh that no influence of weather on these towers of rock can ever have so modelled and gnawed them down. . ..

"Most of what is called granite in the central Alps is granitic gneiss, called in the people's language 'Gaisberger,' because the highest mountains climbed by the goats (Gaisen) are formed of it. It is the substance from which the atmospheric influences carve those strange towers of rock and picturesque ornaments, which in Chamouny are significantly called Aiguilles, from their sharp points. From this so-called 'primeval mateterial' are formed the wondrous spikes of stone which ornament the summits of different mountains, or strike up here and there like outposts through the far-stretching wastes of névé. We should see many more of these slender rock 'needles' if many of them were not engulfed in the perpetual snow. Here the Achilles-heel of the apparently indestructible 'urgestein' betrays itself. Gneiss is, as already stated, of stratified tabular structure. In the elevation of the Alps, the strata of gneiss were raised, and often placed vertically on the edges of the fracture, as the immediate envelope of the granite. The mass must have been of various hardness at different places. At any rate, whilst particular parts have withstood the action of the weather without injury, others have been over- thrown, gnawed into, and destroyed by the atmosphere to such an extent as quite to have disappeared, and left only isolated points behind. Examples on a large scale are the Aiguille Verte, the Aiguille du Moine, the strangely shattered Aiguilles de Charmoz, the Aiguilles Rouges, all the mountains on both sides of the Valley of Chamouny, the Schreckhörner, and Grindelwald Viescherhörner in the Bernese Alps, the whole southern wall of the Bergell in the Grisons, etc., etc.

"But a different kind of atmospheric action attracts our attention in the Alps, and that in the most singular manner, and in places where the explanation is not at once obvious. This appears in the so-called 'Devil's Mills' or 'Seas of Rock' on the highest points of many isolated mountains. The Sidelhorn, close to the Grimsel, is one of the most visited points of view in the Bernese Alps. It is easily reached from the Hospice in two or two and a half hours. The nearer one approaches to the summit, the more do the vast rock ruins accumulate, piled wondrously over each other, till at length the highest point is covered with a perfect chaos of such loosely massed granitic blocks of gneiss. At times a certain disturbed stratification may be observed, something like plates laid upon each other; then again, in other places, a tolerably regular step-like formation, but in general they lie without recognizable order. This phenomenon, which frequently occurs on summits, is the result of a weathering of the granite, but of that kind in which more or less the scaly structure was once predominant. The brothers Schlagintweit represent in their atlas such disorganized scales of gneiss. As the fanciful Jean Paul employs the beautiful picture 'graves are the mountain-tops of a far new world,' here in reality the mountain tops are graves of a past world. The grandest and most imposing masses of granitic rock are only to be found in the central Alps. There they often tower in such fearful sublimity, like vertical walls of rock palaces above the deep valley-hollows, that one is startled at their greatness. He who has never seen the dusky pyramid of the Finster Aarhorn from the 'Abschwung' on the Aar Glacier, as it rises in naked sublimity from the snow-beds to the clouds; he who has not journeyed round the south-east of Mont Blanc, and seen its central mass from the Cramont or the giant rocky brows of the Grand Cornier, Dent Blanche, and Weisshorn, from the depths of the Einfischthal, will hardly