120 (^liarperitier^s I^i^mj/ on Glaciers, 



epoch in the north of the old continent. The diluvial glaciers 

 of the north, favoured by climate, acquired even greater ex- 

 tension than those of the Alps, and dispersed to still greater 

 distances the debris they carried along with them. Lastly, 

 in proportion as the crevices and fissures created by the dis- 

 location and fracture of the beds became closed up, and the 

 water ceased to penetrate in such great abundance into the 

 interior of the globe, the vapours diminished, and the hygro- 

 metrical and meteorological state of the atmosphere under- 

 went modification. Rain became less freqiient, the rays of 

 the sun became more active, and the diluvial glaciers, at once 

 deprived of water and exposed to a higher temperature, must 

 have melted by degrees and returned to their present dimen- 

 sions. 



As to the considerable time necessary for the formation of 

 these immense diluvial glaciers, M. de Charpentier first re- 

 marks that authors are not much in the habit of hesitating 

 about time in their geological hypotheses. No one refuses 

 to admit very long periods of years, when attempting to ex- 

 plain the formation of thick beds of sandstone or limestone. 

 But his hypothesis does not require much in this respect. In 

 fact, in 1818, the glacier of the Rhone advanced about 150 

 feet ; by supposing a similar annual progression, it would re- 

 quii'e 774 years to extend to Soleure, that is to say, QQ leagues 

 from the bottom of the Valais. Thus, a climate analogous 

 to that which prevailed in Switzerland from 1812 to 1818, 

 continued for about eight centuries, would be sufficient to 

 enable the great glacier of the Rhone, augmented by all the 

 glaciers proceeding from the lateral valleys, again to advance 

 and deposit its moraines on the sides of the Jura, where we 

 now find the debris of the erratic formation. In 1818, the 

 alarm was such among the mountaineers in the valley of 

 Chamouni, in consequence of the considerable enlargement 

 of the glaciers, that no one doubted that if the cold and rainy 

 weather of the six preceding years had continued for five 

 more, all the glaciers would have become united, forming 

 only a single glacier, which might have extended as far as 

 Sallanches, situated 7 leagues from thence. 



