THE SMITHSONIAN INSTITUTION. 203 



and, consequently, the river may not be much affected thereby until 

 the warm rains of spring. 



From the '^Tth to the close of the month the weather remained 

 clear and cold, with the wind steady from north and northwest, with the 

 exception of a part of the day of the oOth, when it veered to east and 

 northeast, the barometer nearly all the time remaining stationary at 

 about 30.15 inches, and never attaining the maximum it previously 

 reached on the 9th, 13th, 14th, 16th, and 17th, The mean temperature 

 of the four last cold days of the month was 34°, being 5° plus the 

 mean temjierature of the four coldest days, from the 19th to the 23d 

 January, 1854. The mean of all the highest readings of the ther- 

 mometer by day was 56.04°, and of all the lowest by night 44.03° : 

 the 'mean dail.y range of temperature during the month was, there- 

 fore, 12.01°. The mean degree of humidity was 0.818, complete 

 saturation being represented by 1,000. 



