SOUTHERN DISTRICT. 



317 



The foregoing tables express the average temperatures and the average quantity of rain 

 with great accuracy, as the records were generally made hy good observers. Many of the 

 differences in temperature which appear in the taljles, are due to differences in height. 

 Many of the places are situated in vallies, and are surrounded by elevated land : some near 

 large bodies of water, which temper the atmosphere botli winter and summer ; and hence, 

 in either case, they can not be compared with other places whose position is relatively 

 different. The same place exhibits some anomalies in temperature. Pompey, for example, 

 gives an average temperature of 44°-06 for ten successive years, beginning with 1826 and 

 ending in 1835 ; for the next ten years, beginning with 1836 and ending willi 1845, it is 

 only 41° -45, a difference which is rather remarkable, considering the time during which 

 the observations were made. Differences equal to this are rarely found to prevail in other 

 places : for example, at Cherryvalley the average temperature for the same periods re- 

 spectively are found to have been, for the first, 44° -83 ; for the second, 43° -28. If we 

 compare the several years with each other, we shall discover that at Pompey there is less 

 constancy or evenness of temperature than in most places. In 18-26, the average was 

 45° -97; in 1836, 40° "IS; in 1827, 43° -50; in 1837, 40° -02; in 1828, 47° "33; and in 

 1838, only 40° '27. Something of the same fitfulness may be observed as it regards the 

 quantity of rain. The average for 1836 was 23-84 inches; in 1837, 30-30 inches; in 

 1838, 23 "21 inches; in 1840, 33-79 inches. The variation, according to these tables, 

 amounts to about ten inches of rain. The temperature of a large extent of inhabited ter- 

 ritory, however, is not represented. The high grounds of Allegany, and the country 

 situated upon the ridge dividing the waters of the Genesee and the Susquehannah and 

 Allegany rivers, must be considerably colder than Pompey. If the supposition is true, it 

 would reduce the temperature of the district. 



The vegetation of the high grounds consists of pine and hemlock, and hard wood inter- 

 mixed, as represented in the woodcut on page 306. In the vallies, the hard timbers, 

 maple, beech, oak, ash, hickory, etc. abound. The vallies are narrow, but pleasant, and 

 furnish some fine scenery. In the cultivated vallies, the spreading branches and depressed 

 heads of the trees indicate a greater tendency to a lateral extension ; and long branches, 



