GLACIERS OF THE CANADIAN ROCKIES AND, SELKIRKS. 27 



escape for the surface stream. This is well shown in plate ix, figure t, the small 

 stream entering the nearly healed crevasse from the right. As the ice moves 

 valley ward the drainage area of the stream may be enlarged, the amount of 

 water correspondingly increased, and our glacial well, or "moulin, " may be 

 indefinitely enlarged both in diameter and depth. Since the water is introduced 

 from above and escapes below, they are more like wells, turned wrong-side up. 

 The}^ may be found in variovis stages of development, the younger in the region 

 of the open crevasses, the mature examples in the lower course of the glacier, 

 where they have been caiTied by the general forward movement of the ice, 

 and into which the surface torrent plunges with a sullen roar to unseen 

 depths. 



The main drainage stream of the Victoria Glacier starts near the nose of 

 Mt. Lefroy, to the west of the medial moraine, and passes somewhat obliquely 

 downward to a moulin, opposite the oblique ice face (plate iv, figure i, and 

 plate III). This stream drains that portion of the glacier over which the 

 surface melting is the greatest. A second drainage stream originates near the 

 above, but in the depression between the medial moraine and the Lefroy tribu- 

 tary. This stream collects the surface waters from the tributary and extends 

 for one-quarter mile down the deep depression between the medial and right 

 lateral moraines and disappears in a system of crevasses that cut this portion of 

 the glacier. 



Two short, btit rather deep, drainage channels occur upon the western side 

 of the glacier, lying upon the inner side of the left lateral moraine. One of 

 these has incised the ice to a depth of i8 to 20 feet. Since these streams have 

 probably occupied their present sites for many years it is rather remarkable that 

 they have not completely cut through the ice to the rocky bed beneath. From 

 the fact that they have not done so we are forced to conclude, either that the 

 rate of cutting is surprisingly slow, or else that the glacier thickens in such a 

 way that the bottoms of the streams are elevated with reference to the base 

 of the glacier. It is possible that the longitudinal compression to which the 

 glacier is subjected in its lower half may be sufficient to secure this result. 



c. Marginal drainage. Upon the eastern side of the lower Victoria, along 

 the base of Mt. Aberdeen and Castle Crags, there is no visible marginal drainage 

 at present, but water may be heard trickling amongst the rocky debris. Just 

 at the head of this depression, however, where the tributary joins the main 

 Victoria, there is evidence of earlier drainage here, in the fonn of an abandoned 

 lake bed, with a length of 500 to 600 feet. A small gravel delta was formed 

 at the head, while the rest of the bed is filled with silt. A still smaller lakelet 

 existed for a short time at the nose of Mt. Lefroy, in the depression between 

 this side of the tributary and the Victoria. Upon the western side of the glacier 

 there occurs a similar marginal lakelet, between the glacier and Mt. Whyte, 

 fed by a mountain stream and a discharge stream from the glacier itself (plate ix, 

 figure 2), which cascades over the lateral moraine from a dozen different places. 

 The lakelet has an elevation of 6,554 feet, is largely filled with fine silt, and 



