x ii PREFACE. 



where the slopes are steep. The ice-caseade of the Geant 

 has suffered much from the general waste. Its crevasses 

 are still wild, but the ice-cliffs and seracs of former days 

 are but poorly represented to-day. 



The great Aletsch and its neighbors exhibit similar 

 evidences of diminution. I found, moreover, this year, 

 that the two ancient moraines mentioned in paragraph 

 364 are parts of the same great lateral moraine which 

 flanked the glacier for a long period, during which its 

 magnitude must have remained practically constant. The 

 place occupied by the ancient ice-river is rendered strik- 

 ingly conspicuous by this well-preserved boundary. 



During my residence at the Bel Alp this year, a 

 catastrophe occurred which renders, for the time being, 

 the description of the Margelin See given in § 50 inap- 

 propriate. In company with two young friends I had 

 descended the glacier and passed through the gorge of 

 the Massa. On our return to the Bel Alp we found the 

 domestics of the hotel leaning out of the windows and 

 looking excitedly towards the glacier. From it pro- 

 ceeded a sound which resembled the roar of a cataract. 

 The servants remarked that the Margelin See must have 

 broken loose. This was the case. For a time, however, 

 the water flowed beneath the glacier; but at a point 

 about midway between the Bel Alp and the ^Eggisch- 

 horn, it broke forth on the ^Eggischhorn side, and formed 



