366 ASSINNIBOINE AND SASKATCHEWAN EXPEDITION. 



three degrees warmer than the summer at Toronto, 

 and with this excess of temperature there occurred the 

 unexpected difference of 21*74 inches of rain in favour of 

 Eed Eiver during that year. 



It must be borne in mind, however, that the results of 

 one year's comparison are not of much value in estimating 

 the relative climatic adaptation of regions far apart ; nor 

 do they afford sufficient data for a fair estimate of the 

 climate of the locality where the observations were made. 



The small difference between the temperature of the 

 spring at Toronto and Eed Eiver is an interesting fact. 

 While the summer shows an excess of 3°, the spring 

 gives a deficiency of 2°, so that the mean of the spring 

 and summer months at Eed Eiver was nearly one de- 

 gree higher than the corresponding months at Toronto. 

 No feature in the meteorology of this distant region is 

 likely to excite so much interest as the extraordinary fall 

 of rain during the agricultural months. It is well known 

 that the cause of the sterility of a vast region on the east 

 of the Eocky Mountains, within the limits of the United 

 States, is traced to extreme aridity. The great American 

 desert, which places so vast a barrier between the Missis- 

 sippi Yalley and the west flank of the Eocky Mountains, 

 derives its barrenness from the absence of rain during the 

 summer months. A fall of thirty inches in the Valley of 

 Eed Eiver during the summer of 1855, with a corre- 

 sponding fall of 8 -76 at Toronto, shows a remarkable 

 difference in the humidity of the two places, and one 

 which report states is generally maintained in other years. 



The following comparisons refer to corresponding 

 months of the same years, and are of course liable to 

 those annual fluctuations to which the climatic elements 

 of all countries are subject. It is very probable that- 

 more extended observations will reduce the extremes. 



