218 



PHYSICAL GEOGRAPHY. 



danger of being swallowed up in one of the dark rents into which often shepherds and 

 their flocks have sunk, never to rise. The day was cloudy, and a strong wind half 

 froze us. The rocks were falling on all sides, and we narrowly escaped destruction. I 

 myself twice saw large blocks of rock pass with dreadful velocity through the line of 

 people, and between two of them not four feet apart. At half-past two I reached the 

 summit." 



The broad and deep depressions in mountainous districts properly speaking, valleys 

 are ranged into two classes, according to their direction in relation to the main eleva- 

 tions. Those which are situated between two principal ridges are termed longitudinal, 

 and those which are at right angles with a great chain, or variously inclined, are called 

 transverse. Valleys also are styled lateral which feed, with tributary streams, a great 

 watercourse ; and by the terms upper and lower valley, parts of the same valley, near 

 and more remote from the source of a river flowing through it, are denoted. The canton 

 of the Valais in Switzerland one of the most remarkable spots upon the globe, combin- 

 ing, within a very contracted area, the productions and temperature of every latitude 

 from the arctic to the torrid zone is a longitudinal valley, the largest in the Swiss Alps. 

 Its axis is parallel to the main chain of Mont Blanc and Mont Rosa on the south, and the 

 ridge of the Bernese Alps, with the grand heights of the Jungfrau and Finster-Aar-Horn, 

 on the north. The Rhone passes through it, rising at its western extremity among the 

 glaciers of Mont Furca, at the height of 5726 feet above the sea, descending to an 

 elevation of 1350 feet before it escapes out of the valley towards the Lake of Geneva. 

 The valley is nearly a hundred miles long, the breadth of the base varying from a quarter 

 of a mile to three miles. It can only be entered on level ground at one point, where the 

 Rhone rushes out of it through a narrow gorge formed by the Dent de Midi and the 





Glacier of the Rhone. 



Dent de Morcles, which rise 8000 feet above its waters. Connected with this great 

 longitudinal valley, there are thirteen lateral valleys on the south side, and three on 

 the north, which bring down the waters of its enclosing mountains. The canton of the 

 Grisons also comprises upwards of sixty transverse valleys, belonging chiefly to those 

 which are longitudinal those of the upper and lower Rhine, and the Inn. These 

 bye-valleys are often nooks into which man seldom pries, and where no specimens of 

 his handiwork are to be found. There are no sights or sounds but those of Nature, 

 exhibiting herself in rock, wood, heath, and mossy flower, and speaking by the rippling 

 rivulet, as if inviting the enquiry 



