518 Europe : — a popular Physical Sketch. 



At Kasan, on the latitude of Copenhagen, mercury freezes 

 occasionally, which in western Europe only happens in 

 Lapland. Also in the south of Russia the winter is pro- 

 portionally severe ; the sea of Asov is frozen every year along 

 the coast, and so is the mouth of the Volga in the Caspian 

 sea. 



Too few observations exist upon the annual quantity of 

 rain, which, on a plain, generally at a great distance from 

 the sea, may be supposed to be trifling. At St. Petersburg 

 it amounts to 21 inches. Snow is much more common, and 

 remains much longer on the ground, than in the same lati- 

 tude in western Europe, and the thus protracted sledge 

 communication increases the inland trade. From observa- 

 tions during one century, the river Neva freezes across at 

 St. Petersburg on the 11th of November, and is freed from 

 ice on the 9th of April. The river Volga at Kasan (on the 

 latitude of Copenhagen) is frozen from the end of October 

 till the commencement of April. 



In St. Petersburg westerly winds prevail, (yet not to such 

 a degree as in western Europe,) so also at Moscow and 

 Kasan. Whether this also be the case on the southern part 

 of the plain, is not known, for want of observations upon the 

 subject. 



The northern and central part of the east European 

 plain possesses many forests, whereas the southern part has 

 none. These barren districts are, as far as they are uncul- 

 tivated, called ' steppes,' the soil of which towards the Cas- 

 pian sea contains salt ('salt-steppes'). The predominant 

 forms of trees are, fir, pine, larch, birch, oak, lime, and elm. 

 The larch, which does not appear in a wild state in Scandi- 

 navia or the North European plain, is common in the north- 

 ern and north-eastern part of Russia. The lime tree is more 

 common on the east European plain than in any other part 

 of Europe. The north frontier of these trees may thus be 

 fixed : — 



