298 Report of the Researches of M. Agassis. 



composed of two kinds of ice, the one (that of the furrows) 

 still snowy and softer, the other (that of the laminae) more 

 perfect, crystalline, glassy, and more resistent ; and that it 

 was to the unequal resistance which they offered to the action 

 of the atmosphere, that was due the hollows of the furrows, 

 and the projections of the harder laminae. After having tra- 

 versed them many hundred yards, I reached the margin of a 

 great cleft, from 20 to 30 feet wide, which, cutting perpendi- 

 cularly in the direction of the furrows, and discovering the 

 interior of the glacier to the depth of 30 or 40 feet, allowed 

 us accurately to distinguish the structure of the ice in a most 

 beautiful transverse section. As far and deep as my view ex- 

 tended, I saw the mass of the glacier composed of a multitude 

 of minute strata of snowy ice, separated every one from its 

 neighbour by one of the icy laminae above alluded to, and 

 forming a regular stratified whole, not unlike to certain schis- 

 tose limestones. They corresponded on the two sides of the 

 cleft, exactly like the strata on the opposite sides of a trans- 

 versal valley.'' 



All who had any accurate knowledge of glaciers were aware 

 that this phenomenon was strictly allied to the superficial fis- 

 sures which I have alluded to above ; at the same time, as 

 they were ignorant of the cause, they were content to register 

 it among those numerous facts which still required elucida- 

 tion. M. Agassiz, in his Etudes sur les Glaciers^ speaks of it 

 only casually ; nevertheless, our attention was often directed to- 

 wards these remarkable appearances during the sojourn we 

 made upon the glacier of the Aar, in the month of August 1840 ; 

 and we were often astonished at their regularity, remarking, 

 that they scarcely commenced sooner than at a league above 

 the extremity of the glacier. I well remember, that often, 

 when walking with M. Nicolet in the neighbourhood of our 

 hut, I used the blade of my knife to satisfy myself that the 

 fissures had really in the interior that remarkable continuity 

 which characterizes them upon the surface of the glacier. 



In 1841, the epoch at which we commenced to study in de- 

 tail the different phenomena which the glaciers present, the 

 longitudinal fissures, and their actual relation with the bands 

 mentioned by M. Guyot, could not fail to attract our attention. 



