GLACIERS OF THE CANADIAN ROCKIES AND SELKIRKS. I? 



Numerous factors conspire to prevent the movements of glaciers from 

 being exactly coincident with the corresponding climatic phases. For the 

 Swiss glaciers Heim found that, ordinarily, an advance began from 3 to 6 years 

 after the opening of a damp-cool phase and reached its maximum in 4 to 10 

 years, bvit in the case of the longest glaciers the maximum position might not 

 be reached until the close of the cycle itself. These facts partially explain the 

 anomalous behavior often noticed in neighboring glaciers. When the lUecille- 

 waet Glacier was first visited by the Messrs. Vaux, in 1887, it was standing 

 close up against a small moraine, which it had just formed, or more probably 

 assisted in forming during this period of halt. Since 1887 this glacier has been 

 in constant retreat at an average rate of 33.2 feet per annum. In 1905 the 

 retreat was found to have been reduced to 2 feet and the inference is that the 

 glacier is preparing to advance. So far as we may judge from a study of this 

 one glacier, the best known of the series, a damp-cool phase of the precipitation 

 cycle closed in the early Bo's, and was followed by a dry-warm phase, which lasted 

 for 16 to 18 years, ending somewhere near the close of the century. The follow- 

 ing quotation from Dawson furnishes confirmatory evidence of the existence 

 of the preceding wet phase of the cycle, which was itself preceded by a dry phase. ' 



"Evidence of a remarkable character has been found, which tends to show 

 that a somewhat rapid increase in the total annual precipitation, has taken 

 place during late years, and deserves to be recorded here. The evidence referred 

 to is that afforded by the abnormal height of small lakes, without outlets, occur- 

 ring in regions characterized by moraine hills. These serve as natural gauges, 

 but instead of measuring the actual rainfall give- a result, dependent on this and 

 the counteracting effect of evaporation. The abnormal character of the rise 

 of the water in these lakes is shown b}^ the facts that it has killed a belt of trees, 

 some of large size, and at least fifty years in age, along parts of the margins of 

 some of these lakelets. Both the Douglas fir and the yellow pine — the latter, 

 never naturally growing even in damp soil, — have been found in numbers thus 

 killed. The condition of the trees shows that they have been killed within a 

 few years, and their size indicates that the waters of the lakes in question have 

 not been for any considerable time dtiring a period of 5 o years or more, at the present 

 high level. These observations were made in both 1883 and 1884. The lakelets 

 observed to be so affected were numerous and scattered over a belt of country 

 along the western part of the range [Rockies] for a length of about 140 miles." 



Looking to the records of the Canadian Meteorological Service for still 

 further evidence of the periodicity of the climate of the region, we find that only 

 three of the stations have records sufficiently continuous and reaching far enough 

 back to be of help. These stations are Agassiz, Banff, and Calgary and their 

 averages are more nearlj^ the real, but still unknown, normal. Average annual 

 temperatures and precipitation for the mountain stations, based upon observa- 

 tions made between 1880 and 1897, will certainly be found later to be too high 

 for the temperature and too low for the precipitation, while those averages 

 based upon observations taken since 1897 will prove to yield too high a pre- 

 cipitation and too low a temperature. In table iv we place side by side the 



' Geological Survey of Canada for 1885, p. 32 B. 



