Report of the Researches of M. Agassiz. 177 



transported immense boulders to the opposite slopes of the 

 Jura. There were others, again, who entirely denied the alli- 

 ance supposed to exist among some of the phenomena which 

 had been associated in the theory of glaciers, and especially as 

 regarded this polish upon rocks, and the various striae and 

 grooves which it was alleged had been produced by their enor- 

 mous pressure. 



All these different opinions, interpreting so variously the 

 phenomena which had been accumulated, made the acquisi- 

 tion of new and more detailed observations altogether indis- 

 pensable : and it was important that these should be made as 

 much as possible upon the glaciers now existing ; in fact, that 

 their current operations should actually be watched. Besides, 

 the observation we had made the previous year concerning a 

 constant limit of the polished rocks, was of such paramount 

 interest that it merited peculiar attention. 



Thus the immensity of the field was evident. And how- 

 ever important may have been the results of the researches 

 of late years, much still remains to be accomplished ; espe- 

 cially when we consider that here, as in every new science, 

 the solution of one problem only gives rise to the consideration 

 of another, and that what appeared at one time sufficiently 

 established, is presently involved in doubt by discovery of new 

 facts which may oblige the observer to undertake a new series 

 of investigations. If innumerable difficulties which are met 

 with in conducting researches, apparently simple, cause our 

 progress to be slow, it is no less true that the slightest obser- 

 vation, and a single fact needing confirmation, require long and 

 arduous journeys ; and withal, nature in these elevated regions 

 is so capricious, that we must almost steal her favours that we 

 may profit by the slightest circumstances of time and place. 



We have no intention of entering into the details of all the 

 observations which were made at the Hotel des Neuchatelois 

 during the last two years. These will appear in a separate 

 volume which M. Agassiz is now preparing as a sequel to his 

 Etudes sur les Glaciers, and of which notice will subsequently 

 be taken. The object of this article is only to exhibit, in 

 a summary manner, the sojourn of M. Agassiz and his com- 

 panions at the lower glacier of the Aar, pointing out the 



VOL. XXXV. NO. LXIX. ^JULY 1843. M 



