270 Meteorological Reguterfor 1823-^5, Jcept at the 



the trouble of tedious calculations. In order to ascertdn the 

 means for the several years, as given in the last table, the ex- 

 treme stations are taken, and as many intermediate ones, at the 

 north and south respectively, as are found to be equi-distant 

 from them, or nearly so. Thus in 1822, Fort Snelling is the 

 extreme northern, and Cantonment Clinch the extreme south- 

 ern post; Council Bluffs is 3° 28' south of the former, and 

 Fort Johnston 3° 36'' north of the latter, &c. The aggregate 

 of these should give the mean of the centre of the district of 

 country in which the observations were made ; and the result 

 appears to be near the truth. For the latitude of the city of 

 Washington is 38° 53^, and the average mean temperature is 

 56.56 ; the centre of the several stations at which these obser- 

 vations were made is in latitude 38° 13', and the average mean 

 temperature is 56.52. In comparing the eastern and western 

 posts, those in about the same latitude are of course taken ; 

 thus. Council Bluffs is 24° 25' west, and but 0°05' north of 

 Fort Wolcott ; Fort Snelling is 26° 04' west, and but 0° 09' 

 north of Fort Sullivan. To prevent the constant repetition 

 of the terms east and west, the numbers only are stated ; it 

 being always understood that the first relates to the east and 

 the second to the west; thus, in January 1822 the means are 

 stated to be 22.20 and 16.25, that is, 22.20 at the east, and 

 16.25 at the west. 



" In 1822 the aggregate mean temperature of the year was 

 57.06; the highest degree 108; the lowest — 29; and the range 

 1S7. The proportion of winds was N. 5.07, S. W. 4.95, 

 N. W. 4.93, S. 4.60, S. E. 3.39, W. 3.10, N. E. 2.67, E. 

 1.71. The proportion of weather, fair 18.90, cloudy 5.0S, 

 rain 5.63, snow 0.85. At Fort Snelling, the most northern 

 station, the mean for the year was 44.32 ; the highest degree 

 92, the lowest — 29, and the range 121. At Cantonment 

 Clinch, the most southern station, the mean for the year was 

 68.97, the highest degree 93, the lowest 20, and the range 73. 

 On comparing the eastern and western posts, it appears that at 

 the former the mean temperature of the winter months is much 

 higher, and that of the summer months much lower than at 

 the latter. Thus in January it is 22.20 and 16.35, February 

 27.40 and 26.40, March 35.52 and 41.10, April 42.31 and 



