Hot and Thermal Springs. 375 



near MUllinen, are to be seen among others the same rolled stones 

 which are now carried along by the Kander, some hundred feet 

 lower. To this action of the deepening of the beds of glacier 

 streams must be added the immense pressure sustained under the 

 glaciers. 



Let us suppose, that in a certain time the destruction of the 

 rocks under a glacier proceed to a depth of 115 feet, the glacier 

 will thus be brought down into a region in which the mean 

 temperature of the soil is 2°.25 higher than before. It will now, 

 therefore, be melted more rapidly ; and, if more is not supplied 

 from above than before, it must suffer a decrease in size, nay, in 

 a certain time it will disappear altogether. That many glaciers 

 have actually decreased to a considerable extent in progress of 

 time, is evident from the heaps of detritus (Gandecken), which 

 are often found at a considerable distance from their present 

 lower extremity.* 



I am inclined to consider these evident signs of the former and 

 present extent of glaciers, as more decided proofs of their de- 

 crease than the mere tradition of the formation of new glaciers 

 is of their increase. However, I do not mean, by the above 

 train of reasoning, altogether to deny that glaciers may also in- 

 crease, and that new ones may sometimes be formed. It is only 

 the universality of the phenomenon that I am calling into ques- 

 tion. With regard to the second of the two causes given above, 

 as acting in opposition to the increase of glaciers, viz. the falling 

 in of high points of rocks, it is self-evidtnt that glaciers must 

 disappear, when the mountains covered with perennial snow, 

 from which they are supplied, are destroyed. The hypothesis 

 of Ebel,t that the northern side of the Gemmi to the Dauben lake 

 was formerly covered with glaciers, is therefore certainly cor- 

 rect ; for we have evidence of this in the enormous fallings-in 

 which have there taken place, probably in consequence of the 



" For the sake of example, we may mention the Gandecke, already cited 

 above, near the upper Grtndelwald glacier ; that of the lower glacier, which is 

 now covered with trees ; as well as that of the present Rhone glacier, which 

 lies at a distance of 2404 paces from it. May not the heaps of detritus which 

 are found in valleys at a great distance from any glacier, also have been for- 

 merly Gandecken ? 



t Part in. pp. 30 and 338. 



