Besearches on Existing Glaciers. 257 



certain extent, have been attributed to the influence of the 

 temperature of the external air. I therefore went a second 

 time, in the month of August last, to the same glacier of the 

 Aar on which I had lived during the preceding summer. On 

 this occasion I remained more than a month including some 

 more or less distant excursions (from the 8th August to the 

 10th September), having been accompanied by several friends 

 who were naturalists, some of whom had been with me during 

 the previous years. Messrs Forbes* of Edinburgh, and Heath 

 of Cambridge, likewise spent nearly three weeks with me at 

 the Hotel des Neuchatelois. Afterwards, my friend M. Escher 

 de la Linth, took an active part in our labours. I passed 27 

 days altogether on the glacier, during which time I succeeded 

 in sinking the piercer to a depth of 140 feet. As it is the 

 first time that an attempt has been made to penetrate to a 

 great depth into the interior of a glacier, it may not perhaps 

 be uninteresting for my readers to be informed of the mode 

 of procedure followed, and the results obtained. 



The attempts which I made the previous year, had shewn 

 me that a glacier could not be so easily pierced as one 

 would at first suppose. I looked forward with pleasure to be- 

 ing able this year to observe the phenomena presented by the 

 glacier at its contact with the rock. I communicated my new 

 projects to M. Koehli, engineer at Bienne, and we were con- 

 vinced that we should employ iron piercers like those used in 

 the construction of artesian wells. M. Koehli was good 

 enough to entrust me with his own piercer, which is 150 feet 

 long. It was, he said, the greatest depth which I could reach 

 by piercing with the hand ; while a larger piercer would have 

 required considerable scaffolding, and an outlay of money 

 which would greatly have exceeded my pecuniary resources. 



* Notwithstanding the painful disputes wliich afterwards arose respect- 

 ing certain phenomena in the structure of glaciers, whose discovery was 

 claimed by Professor Forbes, I am far from regretting our residence to- 

 gether on the glacier ; and if any thing could console me for the vexation 

 I experienced on this subject, it is the thought that the visit of that gen- 

 tleman to the Hotel des NeuchAlelois, has contributed to diffuse more 

 widely in England and Scotland the knowledge of the mechani&m of 

 glaciers. 



