1834.] DESCENT OF GLACIERS. 245 



be determined by the extreme heat of the summer, ratlier thai' 

 by tlie mean temperature of tlie year, we ought not to be sur- 

 prised at its descent in the Strait of Magellan, -where the sum- 

 mer is so cool, to only 3500 or 4000 feet above the level of the 

 eea; although in Norway, we must travel to between lat. 61^ 

 and 70^ N., tiiat is, about 14^ nearer the pole, to meet witli 

 perpetual snow at this low level. The difference in height, 

 namely, about 9000 feet, between the snow-line on the Cordil- 

 lera behind Ciiiloe (with its highest points ranging from only 

 5600 to 7500 feet) and in central Chile* (a distance of only 9' 

 of latitude), is truly wonderful. Tlie land from the southward 

 of Chiloe to near Concepcion (lat. 37^), is hidden by one dense 

 forest dripping with moisture. The sky is cloudy, and we have 

 seen how badly the fruits of southern Europe succeed. In 

 central Chile, on the o-ther hand, a little northward of Con- 

 cepcion, the sky is generally clear, rain does not fall for the 

 seven smnmer months, and southern European fruits succeed 

 admirably ; and even the sugar-cane has been cultivated. | Iso 

 doubt the plane of perpetual snow undergoes the above remark- 

 able flexure of 9000 feet, unparalleled in other parts of the 

 -;\'orld, not far from the latitude of Concepcion, where the land 

 ceases to be covered with forest-trees ; for trees in South America 

 indicate a rainy climate, and rain a clouded sky and little heat 

 in summer. 



The descent of glaciers to the sea must, I conceive, mainly 

 depend (subject, of course, to a proper supply of snow in the 

 uppcT region) on the lowness of the line of perpetual snow on 

 steep mountains near the coast. As the snow-line is so low in 

 Tierra del Fuego, we might have expected that many of the 

 glaciers would have reached the sea. Nevertheless I was asto- 

 nished when I first saw a range, only from 3000 to 4000 feet in 

 height, in the latitude of Cumberland, with every valley filled 



* On the Cordillera of central Chile, I believe the snow-line varies ex- 

 ceetlingly in height in different summers. I was assured that during one 

 very dry and long summer, all the snow disappeared from Aconcagua, 

 although it attains the prodigious height of 2;?,0l)U feet. It is probable that 

 much of the snow at these great heights is evaporated, rather than thawed. 



t Miers's Chile, vol, i. p. 415. It is said that the sugar-cane grew at 

 Ingenio, lat. 32^ to So'^. but not in sufficient quantity to make the manufacture 

 profitable. In the valley of Qulllota, south of lugeuio, I saw some largo 

 date palm-trees. 



