jESuy^iktler's Essay on Glaciers. Itf 



tance and hei^t from which these blocks have come, the in- 

 clined pkiin could only have had a slope of 1*" 8' 50". What. 

 moreover, can have become of the removed formations, and 

 what agents can have transported them to another place \ 



Others have fancied a kind of rafts formed by the ice of 

 glaciers, and transporting the blocks on the waters of a sea, 

 whose level reached the highest elevation tliat they have at- 

 tained. M. de Charpentier replies that, according to the facts 

 observed, the shores of this pretended sea, far from having a 

 horizontal surface, must have sometimes had an inclination 

 from the Upper Valais to Vevey, sometimes a curve with a 

 double descent, from Chasseron on the Jura, to Soleure and 

 Gex. Some geologists have thought that the blocks, enclosed 

 in the masses of ice proceeding from glaciers, have been car- 

 ried forward by currents of great velocity, or else, having 

 fallen on the ice which covered the great lakes, which are 

 supposed to liave existed in successive stages in the valleys of 

 llie Alps, they had been transported by the masses of ice re- 

 sulting from the breaking up of this ice on the retm-n of heat. 

 De Luc imagined that an eruption of gas had projected the 

 erratic blocks, but this hypothesis, so little in accordance with 

 what has been since observed in the circumstances attending 

 these ]>locks, can no longer be adopted by any one. 



Many geologists have ascribed the transportation of the 

 erratic matters to currents of water. Some, like Saussure and 

 and De Buch, conceive that these currents have been owing to 

 a sudden movement, or a rapid retreat of the ocean ; others, 

 like Escher de la Linth, to an instantaneous bursting forth of 

 the vast lakes, which may have existed in the interior valleys . 

 of the Alps ; and lastly, others, such as M. Elie de Beaumont, 

 to the sudden melting of the ancient glaciers, a melting pro- 

 duced, at the period of the rising of the principal chain of the 

 Alps, by the action of the gases, to which he attributes the 

 origin of the dolomites and gypsum. The latter remarks that 

 the Alps, having been formed by many different acts of eleva- 

 tion, must have had snow and glaciers accumulated upon them 

 at tlie time of the last catastrophe which gave them their pre- 

 sent relief, while the Pyrenees, raised by a single movement, 

 do not, according to him, present us with any en*atic forma- 



