234 Mr Edward Collomb on the 



out meeting with large masses, except on the southern slopes 

 of the Rothenbach ; and at this season of the year the move- 

 ment was not perceptible. At the same time, the beds of 

 snow were stratified, and had passed into the state of neve ; 

 but the part of neve resting immediately on the ground, had 

 not been converted into ice. The alternations of heat and 

 cold were not sufficiently great in the month of March to 

 produce the circumstances favourable for converting the in- 

 ferior neve into ice. There were thin layers of ice inter- 

 posed, but they did not touch the ground. The sections we 

 made in the mass presented the following successive layers : — 



Neve. 

 Ice. 

 Neve. 

 Ice. 

 Neve. 

 Ground. 

 The layer of ice lying between the neve was very compact 

 and compressed almost like plate-glass, from 5 to 10 mm. in 

 thickness. This layer no doubt corresponds to the time of a 

 fall of snow followed by verglas. I account for this phenome- 

 non in the following way : An excessively thin superficial 

 layer of clear ice being formed, a new fall of snow took place, 

 then this snow partly melted in order to be transformed into 

 neve ; but during this operation, the verglas did not act as a 

 filter, but, on the contrary, arrested the waters of infiltration ; 

 the latter became frozen, and formed a layer of ice from 5 to 

 10 mm. in thickness. May we not find in this the origin of 

 the blue and white veins of the large glaciers, respecting 

 which so much discussion has taken place \ 



Two months later, on the 10th May, the Drumont still re- 

 tained, near its summit, a series of spots of snow, some metres 

 in thickness, leaning against a slope of 30 or 35 degrees. 

 These snows were in motion. The fact was evident ; they had 

 pressed strongly against the trunks of the trees that stood 

 in their way. The stratification of these snows was in a 

 very advanced state, the part resting on the ground being 

 completely transformed into ice. By cutting sections in this 

 mass, the followings beds were noticed : — 



