18 Historical 



temperature. Now the line at which the eternal snows begin cor- 

 responds very accurately with the temperature. 



In our Alps and Pyrenees, about 43°-47° north latitude, this 

 line is a little above 2700 meters; on Etna (38° lat. N.) it rises to 

 2900 meters. In the main mountain ranges of the center of Asia, of 

 Pamir (40° lat. N.), in the mountains of Boutan (27° lat. N.) , it 

 varies between the enormous heights of 4000 to 6000 meters, higher, 

 naturally, in the regions nearest the equator, and also, curiously 

 enough, on mountain slopes facing north; on Gaurisankar, the 

 snow begins at 5300 meters towards the north, whereas towards 

 the south it begins at 4900 meters; the chain of Karakorum is at 

 certain points bare of snow up to 6500 meters (Schlagintweit) . In 

 Abyssinia (13° lat. N.) the line is about 4300 meters, and on Kili- 

 mandjaro (3° lat. S.) it is a little more than 5000 meters. The Cor- 

 dillera, in its long extent from south to north, does not lend itself 

 to an average estimate. At the equator, the volcanoes around 

 Quito have the line of eternal snow at about 4800 meters. Speak- 

 ing generally, this snow line is lower as the distance from the 

 equator becomes greater; at Popocatepetl (19° lat. N.), it is only 

 4300 meters. But in the Andes of Bolivia, and especially in the 

 mountains which edge Lake Titicaca on the west (16° lat. S.), it 

 rises considerably up to 6000 meters: much above the level in the 

 mountains of the east, where it is about 4800 meters. In the Andes 

 of the Chilean shore, on the volcano Corcobado (2290 meters) , in 

 43° lat. S., that is, at the same distance from the equator as Mala- 

 detta, it is only 1800 meters. On Mount Hooker (52° lat. N.) it is 

 2600 meters, on Mount Elias (60° lat. N.) 1500 meters, and on Baren- 

 Berg (2096 meters) on the island of Jan Mayen (71° lat. N.) at 

 only 400 meters. On Tierra del Fuego, on Mount Sarmiehto. (2075 

 meters), in 54° lat. S., the line is at 1100 meters, much lower than 

 on Mount Elias, which, however, is much nearer the pole. 



Living Organisms. The extent of vegetation varies in altitude 

 with the snow line, which perpetually limits it. Whereas in our 

 Alps the timber line is at about 1800 meters, in the tropical Andes 

 the grapevine, the cinchonas, and the oaks extend up to 3000 meters. 

 In the Himalayas, the limit is higher yet, because apricot trees are 

 cultivated at an altitude of more than 3000 meters, and birches 

 and poplars grow up to an elevation of 4200 meters. 



Animals naturally follow vegetation; birds conform to this rule, 

 and if on the sides of Chimborazo the condors sometimes soar at 

 the prodigious height of 7000 meters, that is because 2000 to 3000 



