CLIMATE OF ETJKOPE. 87 



would each pass through regions of various temperatures, 

 or what is the same thing, lines made to follow the same 

 temperature would have to make various curves and con- 

 tortions ; such lines have been constructed and are called 

 "isothermal" lines. The causes of this are to be found in 

 the various currents of the ocean, the tides and winds, and 

 in the proximity to the ocean of snow-clad mountains and 

 arid plains. The variation of latitude in these lines some- 

 times reaches as much as seven degrees. 



Europe contains about 3,900,000 square miles of surface, 

 and is separated from Asia by the Caucasus, Caspian Sea, 

 River Ural, and Uralian Mountains. It is about 3000 

 miles long and 2400 broad, about two-thirds being plain and 

 table-land and one-third mountain land. The chief mountain 

 ranges are those which run through Norway and Sweden in a 

 north-westerly direction, and the mountain system along 

 the south part from Portugal to Turkey. This last includes 

 the Pyrenees, which runs from the Bay of Biscay to the 

 Mediterranean, the highest peak of which is Mont Maladeta 

 (11,500 feet) ; the Alps, the highest point of which is Mont 

 Blanc (15,748 feet) ; the Apennines, the highest point of 

 which is Mont Viso (12,586 feet) ; the Carpathian Moun- 

 tains, extending from Presburg in Hungary towards the 

 sources of the "Waag and March, the highest point being 

 Mont Lemnitz (7962 feet) ; and the Balkan range, which 

 may be considered a continuation of the Alps eastward, 

 runs as far as the Black Sea, together with many inferior 

 ranges and branches. 



The climate of Europe embraces a range from the tem- 

 perate to extreme cold. It is bounded by the Arctic Ocean 

 on the north, Asia eastward, the Mediterranean Sea south- 

 ward, and the Atlantic Ocean to the westward ; it contains 

 two great inland seas, the Black Sea and the Caspian Sea. 

 There are three great volcanoes in Europe, Hecla, Vesuvius, 

 and Etna, but the plains of Auvergne contain many which 

 are extinct. 



Asia contains the highest mountains and the most exten- 

 sive table-lands in the world. It is somewhat square, being 

 bounded northwards by the Arctic Ocean, westward by 



