246 Professor Agassiz on the Glacier Theory. 



our walk. At three o'clock we were up, and while Jacob pre- 

 pared the coffee, we examined our thermometers, and saw, to 

 our great disappointment, that the cold was far from being so 

 intense as we imagined ; for, as during the previous summer, 

 we had on serene nights, seen the thermometer descend to 

 -5° and 6° ( + 23° and 21°.2 F.), we expected to find it now at 

 -12° or 15° (+10°.4 or 5° F.), or even lower. Tn place of 

 that, the temperature of the air was -2° ( + 28.4 F.), and the 

 therm ometrograph which was sunk in the snow indicated — 3° 

 ( + 26°.6 F.). To what cause are we to attribute this singular 

 state of the temperature ? We asked Jaun if it happened 

 often that the nights were so mild, and he replied, that, for a 

 long time past, it had not been so cold as formerly. Notwith- 

 standing this temperature, the snow bore us while we de- 

 scended the declivity which leads from the Hospice to the 

 bed of the Aar. We now looked forward to the prospect 

 of proceeding with light steps over the hardened crust, and 

 of scaling the edge of the glacier with equal facility ; but 

 we had scarcely advanced a few paces in the valley, when 

 we arrived at a place where the crust gave way under our 

 feet. Under this superficial crust the snow was very fine, 

 dry, and powdery, and we sank sometimes with the one 

 foot, sometimes with the other, generally up to the knee. 

 We attempted to regain the flank of the valley, but this 

 was still worse. It was necessary for us, nolens volens, 

 to be satisfied with advancing very slowly. We had to 

 endure a double punishment ; in tlie first place, on account 

 of our impatience, which could not be reconciled to such a 

 mode of progression ; and in the second place, owing to our 

 knees, which suffered from the constant repetition of the shock 

 against the superficial crust, each time we went down. In 

 the mean time, day made its appearance, after having been an- 

 nounced by a sensible diminution of the temperature ; and the 

 sight of the summits becoming gilded one after the other, still 

 further augmented the provoking annoyance caused by our de- 

 testable path. There is nothing more painful for a man who 

 is conscious of possessing a certain degree of energy, than to 

 feel himself yielding to the pressure of physical obstacles. I 

 was conscious of my strength becoming exhai\sted at every 



