802 Report of the Besearches of M, Agassh. 



quently pieces of broken stalactites ; and the walls of the pit 

 were rough to the touch, doubtless owing to the capillary 

 fissures. 



" I should have wished to have remained somewhat longer, 

 to have examined in detail the structure of the ice, and en- 

 joyed the singular spectacle of the blue sky, as seen from the 

 bottom of the abyss ; but the cold obliged me to ascend as 

 soon as possible. On reaching the surface, my friends in- 

 formed me of their anxiety for my safety on hearing my cries, 

 and of the great difficulty they had experienced in drawing me 

 up, though they were eight in number. I had, however, re- 

 flected but little on the danger of my position. Perhaps, had 

 I previously known it, I should not have so exposed myself; 

 for, if one of the sharp-pointed flakes of ice lining the walls 

 had been detached by the friction of the rope, and had struck 

 me in its fall, the danger would have been great. I would, 

 therefore, advise no one to repeat the experiment, unless for 

 some important scientific purpose." 



Like many other natural phenomena, that of these blue 

 bands, in other words, the ribboned structure of glaciers, gave 

 rise to many singular suppositions ; and this tendency to ima- 

 gine extraordinary causes for the explication of facts, which 

 are for the first time observed with attention, is very remark- 

 able. Without doubt, the ice of our lakes and rivers exhibits 

 no appearance of this sort ; and we should not be astonished 

 at this, since the origin of glaciers is wholly different from 

 that of common ice. If we follow one of these bands through- 

 out a more or less considerable extent, we speedily discover 

 that they invariably grow narrower, and become more rare as 

 they ascend towards the neve. It is at their origin, then, that 

 we must examine them attentively, ere we shall be able to 

 distinguish the causes which produce them. In 1841, M. 

 Agassiz expressed the opinion, that the blue bands are bands 

 of ice formed from water, in the midst of the white ice which 

 is the product of the neve ; and he thus conceived that they 

 constituted one of the means by which the water infiltered 

 into the interior of the glacier, and so produced its move- 

 ment. Professor Forbes, on the other hand, in the account 

 of his researches of 1841, simply compared them to the cleav- 



