100 Dr Forry on the Climate of the United States. 



around the earth. The same isothermal curve, according to 

 Humboldt, runs on the western coasts about six degrees of 

 latitude higher than on the eastern ; but to illustrate the 

 law that at this convex point the seasons ai-e most equalized, 

 another table becomes necessary. Thus the annual mean 

 temperature being equal to the fourth part of the total of 

 the winter, spring, summer, and autumnal temperatures, the 

 same isothermal line of 53°-60 shews — 



Winter. Spring. Summer. Autumn. 



At the concave summit in 1 go..gQ_ 32°-00 + 52°-30 + 7j^'60 + 54°-50 

 America, 74° 40' W. Ion. J ~ 4 



At the convex summit in| ^„„.gQ_40°-10 + 5r-80 + 68°-40 + 54''-10 



I 53-60=- 

 At the convex summit m\ ^^^^^ 4r-33 + 48°-00 + 65°-00 + 52°-67 



Europe, 2 20' W. Ion. / 4 



At the coHcaw summit in 1 24°'80 + 54°"70 + { 



Asia, 116° 20' E Ion. / ^'^'^^- T 



'} 5r-i5=- 



America,122°37'W.lon.i ' 4 



The first three results on the same isothermal line are 

 furnished by Humboldt. Unable to obtain the same annual 

 temperature on our Pacific coast, it becomes necessary to 

 take a lower isothermal line (that of Fort Vancouver in the 

 " Army Meteorological Eegister") which, of course, gives a 

 contrast in the seasons correspondently greater. It is thus 

 seen that, on the western coasts, where the isothermal curve 

 rises, or is convex, the seasons are much equalized, the dif- 

 ference between the mean temperature of winter and sum- 

 mer being only about one-half as great as on the eastern 

 coasts, where the line sinks, or is concave. But this may be 

 better illustrated by a tabular ai'rangement. 



T";ntTieim!il T in<^ ^'*'"- ^etw^Pon *feaTi Tcmp. 



isothci mal Line. ^j. Winter and Sumrael-. 



Asia, eastern coast, 53°'60> At depressions, , 55°'80 



America, eastern coast, 53°'60J ... . 43°"60 



Europe, western coast, 53°'60) At Summits^ . 28°"30 



"•15] 



America, western coast, 51°'75j ... . 23°'70 



It may be well to add, that, with the exception of the last, 

 the writer is not aware of the local position of these points 

 of comparison — a consideration which may be supposed to 

 be of some importance, inasmuch as the northern division of 

 the United States presents, oa the same isothermal line, a 



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