80 LIFE OF HORACE BENEDICT DE SAUSSURE 



relief to logic, in which he gave a successful course of lectures. In 

 March of the year 1764 he found a further distraction in a third 

 excursion to Chamonix, where he saw the landscape under snow and 

 studied the glaciers in a new aspect. He notes that in the valley 

 the snow was so hard that laden mules did not break the surface, 

 and so deep that the palings between the fields were buried. 

 This, however, can only have been the case at the head of the 

 valley, as at Chamonix there was only eighteen inches. De 

 Saussure's remarks on the aspect of the scenery in its winter garb 

 are interesting. He wrote : 



' It was more wonderful than pleasing. The uniformity of white 

 surfaces of enormous extent reaching from the tops of the mountains 

 to the bottom of the valley, broken only by a few rocks where cliffs 

 could not hold the snow, by forests of a dull grey hue, and by the Arve, 

 which wound like a dark thread through the centre of the picture ; 

 this combination, lit by the sun, had, in its grandeur and its dazzling 

 purity, an element of death and infinite sadness. The glaciers, which 

 so well ornament the landscape when their background is a beautiful 

 green, made no effect in the middle of all this white, although when 

 near at hand the ice-pyramids, whose sides remained bare, shone 

 like emeralds under the fresh and white snow that capped their tops.' 

 [Voyages, 730.] 



De Saussure added that his excursion had proved to him three 

 things the formation of glaciers by the melting and refreezing of 

 snow, their forward motion, and the permanence of the streams 

 that issue from them. 1 



Three months later de Saussure gave an audience at the 



1 It may be convenient to take this opportunity to refer to recent observations 

 os to the true origin of glacial streams in winter. 



Up to the present time it has been generally believed that the winter outflow, 

 the perfectly clear water issuing at that season from the foot of the glacier, is the 

 result of a continuous melting of the ice caused by the warmth of the earth. It 

 seems strange that the fountains which break out from under the snow on bare 

 slopes in winter, when all else is frozen, did not suggest either to de Saussure or 

 to any of his scientific successors that the permanence of the glacial streams might 

 be due to similar sources in the bed of the glacier. This somewhat obvious fact 

 was not recognised until, in 1904, 1 pointed it out in an address to the Geographical 

 Section of the British Association at Cambridge. It was subsequently observed 

 independently by Professor Collet, formerly director of the Service des Eaux of 

 the Swiss Government, and now Professor of Geology in the University of Geneva. 

 Professor Collet has verified my observation and placed the matter beyond doubt 

 by a careful analysis of the waters issuing from the ice at different seasons of the 

 year. (The Academy became a University under Napoleon.) 



