170 Report of the Researches of M. Agassiz, 



thus a strong motive to visit these elevated regions, and 

 observe the temperature of the air, and the state of the ice.* 



Temperature. — Previous to the time when M. Agassiz de- 

 voted himself to the study of the glaciers, absolutely nothing 

 was known concerning the temperature of these icy masses. 

 Nevertheless, it was very generally admitted that it must be 

 very low. The first experiments were made in the year 1840, 

 at the lower glacier of the Aar, where they indicated a tem- 

 perature which was nearly constant, oscillating between 32 F. 

 and 31°. 5 F. But these observations having been made at a 

 depth of only 25 feet, it might be feared that they were not 

 completely independent of the external temperature. Hence, it 

 became necessary to repeat them at different stations, and still 

 more, at greater depths. It also became important to exa- 

 mine more in detail the relation of the external melting with 

 the temperature in the shade and in the sunshine, to study 

 the influence of nocturnal radiation, and to observe the action 

 of the heat upon the water contained in the baignoires and 

 the different cavities of the ice. 



The phenomena connected with moraines are of primary 

 importance in reference to the question of the transportation 

 of boulders ; hence these moraines have been studied in all 

 their aspects ; and their origin, formation, transport, their 

 combinations, compositions, and different characters, have been 

 described and figured with great care in the work of M. Agas- 

 siz ; and we might have supposed that, in these points at least, 



* The year 1842 has been fertile in ascents, and thus the impulse given 

 by the study of glaciers has greatly advanced the limits of our know^ledge. 

 The Finsteraarhorn has been scaled by M. Sulger, a citizen of Bale, towards the 

 end of the month of August. The Strahleck also has been frequently traversed. 

 The Dent-du-Midi has been escaladed for the first time by seven natives of the 

 Valais. The Jungfrau has again seen adventurous travellers risk their safety upon 

 its snowy ridge : MM. Studer and Burky accomplished its ascent in August, con- 

 ducted by five guides from the Grimsel, two of whom accompanied us the pre- 

 ceding year ; and I have thus enjoyed the satisfaction of M. Studer's confirming 

 in all respects the description I had previously published. Finally, I have my- 

 self scaled the Shreckhorn, along with my friend M. Escher of the Linth. An 

 equally remarkable ascent has been accomplished in the Pyrenees. A Russian 

 officer, M. de TchihatcheflF, has scaled the peak Nethon de la Maledetta ; and it 19 

 interesting to remark that his observations, relative to ice and snow, correspond 

 precisely to those we have made among the Alps. 



