SECT. XXVI. EXCESSIVE CLIMATES. 261 



ing upon the distance of the place from the neutral iso- 

 thermal line. These results are confirmed by the ob- 

 servations of M. Kupffer of Kasan during his excursions 

 to the north, which show that the European and the 

 American portions of the isogeothermal line of 32 of 

 Fahrenheit actually separate, and go round the two 

 poles of maximum cold. This traveler remarked, also, 

 that the temperature both of the air and of the soil de- 

 creases most rapidly toward the 45th degree of latitude. 



It is evident that places may have the same mean an- 

 nual temperature, and yet differ materially in climate. 

 In one, the winters may be mild, and the summers cool ; 

 whereas another may experience the extremes of heat 

 and cold. Lines passing through places having the 

 same mean summer or winter temperature, are neither 

 parallel to the isothermal, the geothermal lines, nor to one 

 another, and they differ still more from the parallels of 

 latitude. In Europe, the latitude of two places which 

 have the same annual heat never differs more than 8 or 

 9 ; whereas the difference in the latitude of those having 

 the same mean winter temperature is sometimes as 

 much as 18 or 19. At Kasan in the interior of Rus- 

 sia, in latitude 55-48, nearly the same with that of 

 Edinburgh, the mean annual temperature is about 37-6 ; 

 at Edinburgh it is 47-84. At Kasan, the mean sum- 

 mer temperature is 64-84, and that of winter 2-12; 

 whereas at Edinburgh the mean summer temperature 

 is 58-28, and that of winter 38-66. Whence it ap- 

 pears that the difference of winter temperature is much 

 greater than that of summer. At Quebec, the sum- 

 mers are as warm as those in Paris, and grapes some- 

 times ripen in the open air : whereas the winters are 

 as severe as in Petersburgh ; the snow lies five feet 

 deep for several months, wheel carriages cannot be used, 

 the ice is too hard for skating, traveling is performed in 

 sledges, and frequently on the ice of the river St. Law- 

 rence. The cold at Melville Island on the 15th of Jan- 

 uary, 1820, according to Sir Edward Parry, was 55 

 below the zero of Fahrenheit's thermometer, only 3 

 above the temperature of the ethereal regions, yet the 

 summer heat in these high latitudes is insupportable. 



Observations tend to prove that all the climates of the 



