152 Report of the Researches of M. Agassiz. 



tions which were made during the night, at the bottom of the 

 shaft ; so that it really appears that this is truly the lowest 

 temperature to which the glacier is subjected. 



That this observation may not rest isolated, M. Agassiz has 

 taken measures whereby it may be verified. Before quitting 

 the glacier in 1842, he again introduced two of Bunten's ther- 

 mometrographs, and a small horizontal alcohol minimum 

 thermometrograph into the glacier, at different depths. These 

 two thermometrographs are in the same bore, — ^the one at the 

 depth of fifteen feet, the second eight ; the thermometer is at 

 seven feet below the surface. We may hope thus completely 

 to confirm next summer the observation of the last. 



Observations upon the presence of Water in the interior of 

 the Glacier. — The presence of water in the interior of the gla- 

 cier constitutes one of the essential postulates of the theory of 

 infiltration. It is clear that a quantity of water is continually 

 engulphed within the glacier, as is proved by the numerous 

 streams and rivulets which are nearly all lost in the crevasses 

 previous to their having attained the extremity of the glacier. 

 This, however, does not amount to a proof that this water 

 quite penetrates throughout the mass, as it would do through 

 a sponge. On the contrary, it appears more natural, at the first 

 glance, to suppose that it would always flow straight on, and 

 especially when we consider how exceedingly compact the ice 

 everywhere is, when defended against the action of external 

 agents. It was, therefore, a matter of great importance to 

 determine, by direct experiments, that water was to be found 

 in the interior of all ice ; and the more so, as many scientific 

 men, maintaining that the water did not penetrate beyond a 

 certain depth, founded on this belief an objection against the 

 theory of infiltration. Mr Hopkins was one of these, support- 

 ing his opinion in his learned memoir, entitled, Theoretical 

 Investigations on the motions of Glaciers. The bores which 

 were opened in the ice by M. Agassiz supplied a rare and 

 happy occasion for making direct experiments upon this sub- 

 ject, previous to his determining to make experiments by 

 means of the infiltration of coloured liquids. The results ob- 

 tained by M. Agassiz, and detailed by him in Jameson's Jour- 

 nal, vol. xxxiii. p. 262, have been confirmed in the most satis- 



