110 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [DcC. 5, 



In the higher valleys, both in Switzerland and in the mountainous 

 parts of Great Britain, I have often been struck with the great accu- 

 mulations of rounded blocks and pebbles in places where there were 

 no torrents which could be supposed to have rounded them or 

 brought them to their present position. I particularly noticed a very 

 large collection of such blocks near the top of the Splugen on ascend- 

 ing from the north, where there were no lateral valleys down which 

 they could have been brought : they lay very thick at the elevation 

 of about 6000 to 6500 feet, reaching nearly to the top of the Pass, 

 covering the sides and filling up the bottom of the valley in irregular 

 hillocks, without forming any regular terrace, such as we see at lower 

 levels. These accumulations are doubtlessly formed out of the 

 destruction of the beaches of these early oceans, which, owing to the 

 steepness of the sides of the mountains, have been carried by the 

 slipping of the snow and by the gradual action of the weather to the 

 first resting-place below the level at which they were formed. 



Lines of Water-level traceable in the Excavation of Valleys. 



In ascending any alpine valley, we usually find the ascent tolerably 

 gradual until, on reaching the head of the valley, the ascent suddenly 

 becomes steep, and we have to climb some winding or fatiguing path 

 for a considerable height ; after this we often find ourselves in an- 

 other upper valley, which, like the lower one, is but moderately in- 

 clined until we reach its head, where a second steep ascent must be 

 climbed on to another higher level. The valley of the Engadin is 

 an example of such a structure ; from Martinsbruck we ascend the 

 Inn gradually to Zernetz, situated at the head of the lower Engadin, 

 4910 feet above the sea; we then ascend rapidly about 250 feet on 

 to the level of the upper Engadin ; then for nearly thirty miles the 

 ascent is so slight as to be imperceptible to the eye, until above the 

 lake of Sils, at an elevation of 5900 feet, we again find a steep ascent 

 to the Pass of Maloggia. 



More frequently we find lateral valleys at a different level from the 

 main valley, into which they empty themselves by a cascade : thus 

 the valley of Linththal rises very gently to and ends abruptly at an 

 elevation of 2500 feet ; but, if we climb a steep zigzag path by the 

 side of the falls of the Fatschbach, we come about 2000 feet above 

 the Linth to the level valley of Urnerboden, which ends, at a height 

 of 4700 feet, at the precipitous ascent to the Klausen Pass. 



A more familiar illustration may be found in the Valley of Cha- 

 mounix, which rises gently to the village of Le Tour, 4274 feet above 

 the sea ; a little above this commences the ascent to the Col de 

 Balme. But the lateral valley of the Mer de Glace ends some 1 700 

 feet higher than the Valley of Chamounix ; the glacier then rises 

 moderately ; from its termination below the Montanvert there is a 

 gradual ascent to a height of above 9000 feet at the head of the 

 branch called the Glacier de Lechaud*. The head of the Glacier 



* These heights are taken from Prof. Forbes's * Travels,' &c., chap. i. 6. 



