GLACIERS OF THE CANADIAN ROCKIES AND SELKIRKS. 29 



minimum period of flow. During the spring and fall the flow is very greatly 

 reduced and must be very scant, or nothing, in the winter. Mr. Robert Camp- 

 bell informs me that he has seen water in the stream, however, beneath the 

 snow and ice of winter. 



e. Water temperatures. The temperature of the water at the main exit 

 was found to vary from 32.0° F. to 32.4,° at various times of the day. Near the 

 site of the camp, just outside of the older of the two great block moraines, and 

 some 2,000 feet from the exit, a series of observations was made upon the temper- 

 ature of the water in the west branch of the drainage brook. The observations 

 were made between Jt:ly 2 and 27, 1904, and in the early morning, near midday, 

 and in the evening, but not at any stated hours. Most of them were taken 

 between 7 and 8 a.m.; 12 and 2 p.m., and 8 and 9 t-.M. Of 56 observations, 

 those for the morning averaged 35.4°, for midday 41.4°, and for the evening 

 35.2°. A small amount of drainage was received from Mt. Whyte, which must 

 have materially affected the temperatures. Upon July 18, 1904, simultaneous 

 observations were made at the glacier, camp, and at the delta, one mile below. 

 The maximum temperature for the day was 51.7° F. and the minimum 34.8°. 

 The results were as follows: 



Time. Glacier. Camp. Delta. 



9:00 A.M. 32.4° 35.2° 35.8° 



6:00 P.M. 32.4° 34-o° 36.0° 



By the time the water has moved across Lake Louise to the foot, its tem- 

 perature has been raised some 6° to 12°, the temperature ranging from 42° to 

 48°, during the summer months. The temperature of the Bow River at Laggan, 

 into which Lake Louise is drained, was found to be 54.9° F., Aug. 15, 1904. 



5. Forward Movement. 



o. Measurements. Long before the attention of scientists was directed 

 to glaciers as suitable subjects for investigation, the Swiss peasants had dis- 

 covered that the}^ possessed a forward, down-valley movement and that they 

 slowly transported boulders and other objects left upon their surface. In 1841 

 the Bishop of Annency, M. Rendu, published his remarkable work, Theorie 

 des Glaciers de la Savoie (edited by George Forbes, 1874, translated by 

 Alfred Wills), in which he shows a surprising insight into the laws of 

 glacial motion. "Between the Mer de Glace and a river," he writes, "there is 

 a resemblance so complete that it is impossible to find in the latter a circum- 

 stance which does not exist in the fonner" (page 85). Since this was written, 

 in 1839, glacial investigation has done much to justify, if not to actually verify 

 the generalization. Streams of ice and streams of water have many character- 

 istics in common, as well as important differences. All are agreed that the 

 cause of the movement is, in both cases, the force of gravity, acting upon the 

 mass itself, or some other mass in contact with it. As to the nature of the ice 

 movement, those' wh(«e opinions should carry the greatest weight are not yet 



