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Show Introduction Stimulated by experiments in snow and avalanche research at the Weissfluhjoch ( 6), observations on the creep and glide of the snow cover in the avalanche defenses " Schilt" at Stein, Toggenburg, have been made since the winter of 192 » 6/ z » 7- Since i960 further observations have followed in the defenses " Mattstock" at Amden ( 14), " Kuenihorn" at St. Antoenien, " Ruchli- Schrims" at Pfaefers, " Kneugrat" at Braunwald, and " Wisstannegg and Nollen" at Arth. After a 20- year observation period we deem it advisable to report some of the conclusions on the character and significance of this snow cover motion which so often has disasterous effects on construction and afforestation. The winters of 1965/ 66 and I966/ 67 have demonstrated these effects with especial clearness. The winter of 1965/ 66 was an outstanding l! glide winter". In the community of Conthey ( Wall is) the gliding snow cover tore up about 3 hectares ( 7.5 acres) of forest and carried it down toward Planpra. On the Brienzergrat a 100- meter length of track on the Brienz- Rothorn Railway was destroyed along with the retention wall and carried 30 m toward the valley. In the supporting structures on the Kuenihorn at St. Antoenien- Castels, snow bridges and their foundations were pushed over and broken apart. The structures next to the ridge crest were unable to support a section of cornice involved in the glide motion and the descending snow mass destroyed 144 running meters of the defense. The damage amounted to about 100,000 Swiss francs. In addition, gliding snow sheared off the construction access road for |