130 STUDIES, SCIENTIFIC AND SOCIAL 



contours extend to at least a thousand feet higher, above 

 which level the mountains rise in sharp peaks or serrated 

 ridges. The descent towards the Grimsel Hospice is very 

 grand, owing to the enormous surfaces of smooth ice- 

 ground rocks of the hardest gneiss, which plunge down 

 at a very high angle for nearly a thousand feet into the 

 curious little enclosed valley, with its two small rock-basin 

 lakes, in which the hospice is situated. Here we see an 

 example of the effects of a kind of eddy in the old ice 

 streams to which I think sufficient attention has not been 

 paid. The torrent from the Aar glacier comes in from the 

 west, but before reaching the Hospice turns off abruptly 

 through a narrow gorge into the main valley, running at 

 first nearly north. But looked at from above, this gorge 

 is invisible, and it seems as if the valley from the glacier 

 continued through the two small lakes further to the east. 

 It is evident that when this district was buried deep in 

 ice very little of it could escape through the gorge, but 

 must have flowed over the higher slopes, while the por- 

 tion in the valley, fed by ice-streams from nearly opposite 

 directions, would acquire a slow eddying motion which 

 would greatly aid its grinding power, and thus account for 

 the land-locked valley and the two small rock-basin lakes. 

 Proceeding down the valley we see on all sides precipi- 

 tous slopes of ice-worn rocks, some of which are so smooth 

 and so extensive that steps have had to be cut in them to 

 form the old mule-path, the new road here going on the 

 opposite side of the valley. Usually the valley is narrow 

 or V-shaped, but in several places, where it widens out, 

 as a little below the Grimsel gorge, above the Handeck 

 fall, and especially at Guttannen about half way to 

 Meiringen, there is more or less of flat valley bottom, 

 suggesting filled-up lake-basins, and showing that in these 

 places the valley is of the U-form, which is held to be the 

 characteristic result of glacial erosion. Why this form is 

 not more general seems to me to be due to the character 

 of the pre-existing valleys. Where these were narrow and 

 precipitous, with the features of ordinary mountain gorges, 

 the greater part of the weight of the ice would rest upon 

 their slopes, which would be ground or split off as the ice 



