198 EFFECTS OF FOBEST TEGETATION OS CLIMATE. 



abstract of Lis work. This forest lies not far from Orla, and is 

 bounded by the old frontier of Poland and Lithuania, where it 

 is about 25 miles in circumference, being seven geographical 

 miles in length and six in breadth, lying in latitude from 52° 29' 

 to 52° 51' N. 



It is flat and sandy with lakes ; the Ahies^ncea occupies with the 

 JPinus sylvestris four-fifths of the soil, of which the proportion 

 of humus to the sand is as 1 to 4. The other trees are Taxus 

 baccata, Quercus robur, Carpinus betulus, Betula alba, Alnus 

 glutinosa, A. incana, Salices, Tilia parvifolia, T. grandifolia, 

 Populus nigra, alba and tremula : Pyrus mains sylvestris : P. 

 pyraster, Cerasus padus, Acer campestre, A. pseudo-platanus, 

 XJlmus campestris, Praxinus excelsior. There are also some 

 shrubs which are enumerated in Grilbert's Flora Lithuanica 

 (1781). 



Here, then, we have a country of forests without mountains, 

 and its climate peculiarly cold and severe. All the region north 

 of the Carpathians, as far as the Baltic, is exposed to the cold 

 and dry north winds from the swampy forest plains of the 

 deserts of Eussia and Tartary, whilst to the south of the moun- 

 tains grow the grapes of Hungary and the fruits of the south. 

 The mean temperature of Lithuania is about 4:4° P. Its 

 weather is stormy, now cold, then intensely hot ; warm by day in 

 summer, cold at night. Near the forest of Bialowieza the cold 

 is greater, and the harvests later by eight or ten days than at 

 some distance from it. So much so, that sledges are used on 

 the snow, whilst the peasants a few miles away are preparing to 

 till their land. 



IS'ow, here we come into relation with the river-producing 

 power, like that of mountainous regions. It is t}iefo'rest which 

 causes the waters of the heads of the Narew and Bug that 

 belong to the great basin of the Vistula. The Narewka and 

 Biala bear vessels even in t\iQ forest. And thus we find that high 

 mountains and glaciers are not essential to the formation of 

 rivers. 



Humidity and vegetation act reciprocally on each other, and 

 the leafy trees which have the greatest share in the action upon 

 the atmosphere grow in the marshy and damp spots of the 

 Porest of Bialowieza. 



The value of this example will be seen if we refer to such 

 principles as have been maintained respecting climate by such 

 waiters as Lyell and Daubeny. Malte-Brun also argues that 

 the west winds in Poland, which blow for three-fourths of the 

 year, are humid, the north are also moist though cold as are 

 the south, and the east the coldest of all. Globes of fire, par- 

 helia, falling stars, the Aurora borealis, and violent storms 

 characterise Poland. 



