740 /. H. OGILVIE 



but only in one instance, the side of the lUecillewaet, was it evident 

 among glaciers of the second type. 



Thus all the conditions affecting rate of motion are in favor of the 

 glaciers of the second type. They have greater slope, more snow- 

 fall, and less retarding load. According to the very meager statistics, 

 their rate of motion is about five times as rapid as that of the glaciers 

 of the first type. 



CONDITIONS AFFECTING WASTE 



Since, therefore, the glaciers of the second type are retreating with 

 much greater rapidity than those of the first, more waste must be 

 looked upon as the cause. The factors which affect rate of waste 

 may be summed up under (i) amount of rainfall; (2) daily and annual 

 range of temperature above the freezing-point; (3) altitude of the 

 snow-line; (4) topography; (5) amount of sunhght and of air received 

 by the ice. 



Rainfall. — The records at the Glacier House show an annual 

 rainfall of 12.98 inches. This amount is too small to be a large 

 factor in wastage, especially when contrasted with the great snowfall. 

 The only records kept in the Rocky Mountains localities are notes of 

 the number of rainy or showery days. These notes show consider- 

 able variation in different years, but afford no data for comparison 

 with the western region. 



Range 0} temperature. — For the past seven years records have 

 been kept at the Glacier House. From the end of October until 

 the beginning of March the maximum temperature is below freezing. 

 In March, April, September, and October the average temperature 

 is near the freezing-point, either above or below. In the summer 

 months it is above, with an absolute maximum of 86°. The daily 

 range is 10 to 20°. 



At Banff records are kept in the office of the Rocky Mountains 

 Park of Canada. There is much more variation in temperature here, 

 and the daily range is greater, and sometimes involves a rise above 

 the freezing-point in winter. In midwinter temperatures of 4-40° 

 are not uncommon. The daily range is from 20 to 40°, and sudden 

 intense cold may be followed by warm Chinook winds. 



The two climates are in a general way similar. Winter has 



