iM Charpcntier'tj Essat/ on Glaciers* 



naturalist of Neufchatel seems to suppose. If the phenome- 

 non is not observable in the elevated neves, this is solely, in 

 M. de Charpentier's opinion, because the melting of the an- 

 nual snows is not completely effected in such places. 



With regard to the crevices so common in glaciers, M. de 

 Charpentier ascribes their origin either to the unequal ex- 

 pansion of the ice, when the congelation of water takes place 

 in the interior of the glacier, or to the dislocations produced 

 by the inclination of the bed of the glacier, or to the inequa- 

 lities of that same bed, &c. When these rents are formed, — 

 and that is usually accompanied with a loud noise, — their width 

 rarely extends to 5 lines, and never exceeds these dimensions ; 

 but if they communicate with the lower face of the glacier, 

 either directly or by the intervention of other rents, they 

 speedily enlarge by the melting of the ice on their sides, oc- 

 casioned by the access of the air or rain-water, until they 

 sometimes acquire a width of 10 feet. When the crevice 

 does not extend to the bottom of the glacier, it becomes filled 

 with water at its termination, and that freezes in winter. If 

 this ice does not continue compact like that of rivers, it is 

 because it is soon subjected to the influence of the expan- 

 sion of the ice formed in the night during summer, when it 

 becomes rent and granular like that of a glacier. These 

 crevices distribute the water produced by rain or melting 

 throughout the whole extent of the glacier, and bring it in 

 contact with the capillary fissures, which absorb it in greater 

 or less quantities ; the rest follows the bed of the glacier, 

 and issues from it in the form of a torrent. These waters 

 are always mingled with a very fine mud, which appears to 

 be the produce of the rocks ground by the friction of the 

 glacier. Accordingly, the waters greatly diminish on the ar- 

 rival of winter, and are then perfectly clear. It is probable 

 that, if the torrents which flow from glaciers are not com- 

 pletely dried up during winter, it is owing to the existence 

 of springs under the glacier, which issue there from the 

 interior of the earth, and not because the glacier melts, even 

 in winter, on its lower surface. In fact, the observation 

 made on the glacier of Getroz by M. Venets, and some other 

 I'acts cited by M. de Charpentier, tend to induce the belief 



