COLUMBIA RIVER. 



147 





6 A. M. 



2 P. M. 



6 P. M. 





BAROM. 



THERMOM. 



BAROM. 



THERMOM. 



BAROM. 



THERMOM. 



June .... 

 July .... 

 August . . . 

 September 



30-71 in. 

 30-40 

 30-28 

 30-28 



51° 

 61 



60 

 53 



30-27 in. 

 30-36 

 30-27 

 30-25 



63° 



87 

 86 



78 



30-30 in. 

 30-37 

 30-29 

 30-30 



62° 



72 

 70 



58 



This gives the mean standing of the barometer and thermometer, 

 during the day hours, at 30 32 in., and 66-33° for the summer 

 months. 



The state of the weather, during the period of one hundred and six 

 days, was as follows : 



Fair, 



Cloudy, . 

 Rain, 



76 days. 

 19 " 

 11 " 



106 



In my inquiries of the residents, I am inclined to the opinion that 

 the above is a very fair estimate of the weather, though they almost 

 all differed in their statements : some spoke of the season as a very 

 bad one, others thought it was very fine. The crops of all descrip- 

 tions of grain were good, which I supposed to be the best criterion. 



The climate of the western section, throughout the year, is mild ; 

 and they neither experience extreme heat in summer, nor severe cold 

 in winter. I am disposed to believe this to be owing to the constant 

 prevalence of the southwesterly or ocean winds. It certainly is not 

 owing to the influence of any warm stream setting along its shores. 

 The current near the coast sets to the southeast, and is of a cold 

 temperature : it would rather tend to lessen the heats in summer, 

 than the cold in winter. There have been no observations kept by 

 the missionaries in this lower section of the country. It is liable, 

 from the experience of our parties, to early frosts, owing to the 

 proximity of the Snowy Mountains. Frosts sometimes occur in the 

 latter part of August, which check all vegetation at that early season. 



The southwest winds are caused by the vast extent of the sandy 

 and arid country, lying east of the Cascade and Californian range 

 of mountains, which, becoming heated, rarefies the air, and causes 



