MR. BLACKWELL ON THE GLACIERS IN WINTER. 271 



very faint and nearly horizontal at *, where the surface of the stream 

 is nearly so too. I left Gateshead without having an opportunity of 

 getting a sectional view of this stream. I can get no real Stockholm 

 pitch in Glasgow, else I should have made the experiment you have 

 incited me to attempt here. I am, etc. 



" LEWIS GORDON." 

 " GLASGOW, January 31, 1845." 



APPENDIX, No. V. 



EXTRACTS from a LETTER from E. BLACKWELL, Esq., containing 

 Observations on the Movement of Glaciers of Chamouni in Winter. 

 Communicated with remarks by Professor FORBES.* 



" The accessibility of the glaciers, even up to a considerable height, 

 is at this season a question of mere physical force. I have made 

 within the last few days two excursions into the region of perpetual 

 snow. The first of these was on the 6th of January, and was to the 

 summit of the glacier of Blaitiere, several hundred feet above the point 

 where I had noted the line of the neve in September and October ; 

 the second was on the 13th, when I succeeded in reaching the junction 

 of the glaciers of Bossons and Tacconaz, near the Grands Mulcts. 

 This junction is exactly at the commencement of the neve, as I re- 

 marked between the months of August and October, on six different 

 occasions, when I passed there on my way to and from Mont Blanc, 

 the D6me de Goute, etc. In both these expeditions I was struck by 

 the excessive power of the sun ; the greater apparent warmth, even 

 in the shade, as compared to the valley of Chamouni ; and the sudden 

 chill which followed sunset. There was also much less snow at these 

 heights than in the valley, and I have no hesitation in saying that in 

 winter very little snow falls upon the higher summits. The snow-falls 

 in the valley are invariably brought by a low creeping fog, which 

 comes up from Sallanches. It seldom overtops the Col de Voza, and 

 the Aiguilles appear bright and sunny in the gaps of the cloud. It is 

 in spring and autumn that these higher peaks are powdered by every 

 storm ; now the dispersing clouds leave them as dark as before they 

 gathered. I fancy this winter is unusually cold ; every one is crying 



* [Proceedings of the Royal Society of Edinburgh, 5th February 1855.] 



