(i.e., Viersat), one of the most picturesque mountains in Switzerland, rises very steeply from the valley of Lauterbrunnen to the height of 13,671 feet. It is one of the ridges of the Bernese Alps, separating the cantons of Valais and Berne. It is in reality a group of mountains, increasing gradually in height, and separated by deep ravines. Of these heights, the Silberhornen, on the W. side, are remarkable for the graceful forms assumed by the snow which covers them. The Jungfrau, like the other mountains of the chain to which it belongs, is characterized by its sharp edge, the summit being not more than two feet broad. As seen from the Wengern Alp in full front, it appears a massive mountain, but as seen edgeways it is narrow and sharp. This, it is said, may be owing to the gneiss rock, of which it is composed, splitting into immense plates. The top of the Jungfrau was long considered inaccessible. In 1811, however, the Brothers Meyer of Aarau laid claim to having reached the summit. In 1828 six peasants of Grindelwald made a successful ascent. On the 28th Aug. 1841, a party of scientific gentlemen, including MM. Forbes and Agassiz, proceeding by the glaciers of Oberaar, Vietsch, and Aletsch, succeeded in gaining the top. While they were there the thermometer fell to six and a half degrees below zero. Lichens were found on the highest exposed rocks.