Professor Forbes on the Leading Phenomena of Glaciers. 225 



fore advanced up the glacier, but again the storm thickened, 

 and as we got to the foot of the rock on which station E was 

 fixed, David Couttet (who had hitherto been the chief en- 

 courager of the expedition) said quietly, " Nous allons faire 

 une betise,'' and proposed to return, for we were half blinded 

 by the snow. I begged, however, that we might at least stop 

 and take shelter as before. We did so, and profiting by a few 

 minutes* pause in the drift, I fitted up my theodolite, and took 

 an observation of the motion of the glacier since my last visit 

 with due care and deliberation. We then returned nearly as 

 we had come, fortunately without accident, and reached the 

 Montanvert after nine hours' absence. What struck me most 

 in this expedition was, that even at the highest station, which 

 is 7900 feet above the sea, and in this severe weather, the ice, 

 far from being frozen to a great depth, appeared charged with 

 water as usual, except at the surface. The stick which marked 

 the point of the glacier observed, and which I expected to find 

 firmly frozen into its place, was standing in water in its hole 

 in the ice, and of course quite loose. The surface of the gla- 

 cier generally was dry, — ^there was not a rill of water in the 

 Moulins, or elsewhere : yet the congelation had scarcely pene- 

 trated at all. Couttet and Balmat were all the time afraid of 

 treading into a watery hole, and thus getting their feet frozen, 

 an accident which I thought very unlikely to happen ; but they 

 both did get their feet wet in the course of the day. Hence 

 there can be no doubt, that, as Couttet very distinctly express- 

 ed it, the snowy covering kept the glacier warm, just as it 

 does the ground, and that the cold penetrates extremely slowly 

 even when winter arrives. I may add, that near the Tacul I 

 found no difficulty in obtaining a draught of water by break- 

 ing the crust of ice formed on a pool in the glacier under a 

 stone. It was on this excursion that I observed the blue 

 colour of snow, previously mentioned, which was most dis- 

 tinctly perceptible by transmitted light, whenever the snow 

 was pierced by a stick to a depth of six inches or more. It 

 was at one part of the glacier that this was most evident, 

 which I attributed to the particular degree of aggregation 

 which it had there, neither very dry nor very moist. 



From the incidents just related, I think it seems to be de- 



