24> 



PROF. E. HULL, ON GENEVA AND CHAMOUNIX 



lias "been iti 13 years 96*76 and in 57 years 242*72 feet. These 

 ^tre the alterations of level since 1850 within the memory of 

 the present inliabitants. But Mons. Yallot goes a step farther 

 back and compares the present levels with those of the period 

 of maximum high level of the Glacial period, showing enormous 

 shrinkage since that epoch. He has observed the glaciated 

 rocks at the foot of the Aiguille du Dru and at the head of 

 TrelaportOi positions higher up than those above-named on the 

 side of the Mer de Glace. There can be no doubt the ice 

 reached these glaciated rocks, and has left its well-recognized 

 marks and polished surface, and these he finds to be 400 metres 

 (1,312 feet) higher than the actual moraines now at the base of 

 the cliffs. At this altitude the glacier has left no lateral 

 moraines analogous to those of the present day, and he con- 

 cludes that the Glacial Epoch does not present so long a period 

 of equilibrium as is generally supposed. He infers, on the 

 contrary, that the rise and fall of the ice was comparatively 

 rapid, not allowing time for the formation of a lateral moraine, 

 which can only be accumulated during a prolonged period of 

 tranquillity. 



On the above facts M. Vallot remarks : — " When we consider 

 that the life of a man has sufficed to see the ablation of 

 50 metres of a glacier (that is to say, of one-eighth of the total 

 thickness of 400 metres) disappear since the Glacial Epoch, 

 •one asks if all that has been said regarding the length of that 

 period has not been considerably exnggerated ? " Bat here 1 

 would observe that we must recollect tiiat whatever the length 

 of that period may have been it was sufficient to allow of the 

 bed of the Atlantic Ocean being raised to a height of over 

 6,000 feet above its present level, and the extension of the 

 continental river valleys to that depth below the present 

 surface, and the subsequent subsidence of the sea-bed to about 

 its existing level.* 



Vlsit to the Glacier des Bossons. — My next visit was to 

 the Glacier des Bossons, which descends from the snows of 

 Mont lilanc and is easily visible from Chamounix. Its valley 

 is clothed in forests of pine, and its lower end disappears beneath 

 the trees, leading one to suppose that it is easily accessible on 



This is on tlie assumption tliat the cold of tlie Glacial Period has 

 been brouf^ht about by physical changes such as the elevation of the sea-bed, 

 and adjoining continents, and the consequent diversion of tlie Gulf 

 Streanj, all of which I have endeavoured to show took ])lace in my 

 essay, " Another possible cause of the Glacial Epoch." Trans. Victoria 

 Institute, vol. xxxi, p. 141 (1805). 



