1903] Soirees. 243 



The lantern-views of the evening, selected from the Bickmore 

 collection, kindly placed at the disposal of the lecturer by Professor 

 Penhallow of McGill University, and from the likewise valuable 

 (commercial) collection of E. R. Shepard of Minneapolis, were, 

 for the most part, Intended to illustrate the natural sculpturing of 

 the rock-formations exposed to de-<tructive forces so soon as those 

 masses have become elevated to mountainous heights. The 

 influence of running water in cutting out valleys, the importance 

 of streams of rock debris or rock-waste in explaining the wearing 

 away of the mountain massifs, the destructive activity of snow 

 and ice, especially in the form, respectively, of avalanches and 

 glaciers, were outlined and explained by reference to views from 

 southern British Columbia and Montana. It was pointed out that 

 the actual ridges, domes, peak and cliflFs seen during a journey 

 through the Canadian Cordillera, are more directly due to Nature's 

 sculpture controlled chiefly by these agencies, than to upheaval of 

 the earth's crust. The proximate cause of the individual moun- 

 tains is, in reality, the excavation of the intervening valleys, sunk 

 as these are in rock-piles once mu h higher than the mountains of 

 to-day. 



The colouring ot mountain s^'enery is of course partly to be 

 referred to the natural pigments characterizing the constituent 

 rocks, but, in general, still more to the influence of the sky, of the 

 clouds and of the atmosphere itself, and, again in important 

 degree, to the forest and to the artificial changes incident to man's 

 inhabiting, clearing and cultivating valleys and higher slopes. 

 The coloured Bickmore slides served to illustrate this third part of 

 the lecture. The special control of the subjective element in 

 scenery exerted by the presence or absence of man and his works 

 in mountain-landscape was touched upon by the lecturer, and a 

 comparison drawn in that regard between Switzerland and the 

 Cordillera of America. 



After the lecture the Report of the Geological Branch wa 

 read. 



