200 Europe : — a popular Physical Sketch. 



As the sky is clearer in the south than in the north, so it 

 is also clearer in the east than in the west, where the vapours 

 of the sea frequently produce fogs and clouds. 



The north limits of some of the most common trees form 

 lines that bend to the southward in the western part of the 

 north of Europe, thus indicating the vicinity of the sea being 

 unfavourable to forest vegetation. The different trees, how- 

 ever, offer remarkable modifications in the latter respect. 

 The north limit of the beech is much curved towards the 

 south in the eastern part of Europe. 



The northern limits of the most important cultivated plants 

 are explained by the lines which also serve to explain how 

 corn and vine cultivation depend upon the mean temperature 

 of the summer, while that of the olives and oranges upon 

 the mean tempeature of the winter.* 



Taking into consideration the wild plants as well as the 

 cultivated, Europe might be divided into the four following 

 zones, provided all the mountains, the lower temperature of 

 which of course change matters, be excepted : — ■ 



1. — Northern Zone, The Zone of the fir and birch. The 

 uncultivated Zone. Here are either no forests at all, or birch 

 and pine forests; some mountains; plants, none; or very little 

 grain cultivation, (barley,) no fruit tree. The occupations 

 followed here, are fishery and breeding of cattle. Iceland, 

 Far-islands, Scandinavia north of 64°, Russia north of 62°. 

 Most of these regions are mountainous. 



2. — First intermediate Zone, Zone of the beech and oak. 

 Zone of the grain. Forest partly of pines,f partly of 

 beech and oak, some heaths with heather ; much grain, par- 

 ticularly rye ; northern fruit trees ; considerable breeding of 

 cattle. The British isles, Scandinavia south of 64 s , Finland, 



* The isothermal lines and the limits of several kinds of vegetation 

 and cultivation are laid down in Professor Schouw's original sketch 

 in various Maps, &c, which we are unable to introduce here. — Ed. 



t Original " Needle Trees," which arc probably Pines, — Ed. 



