i?8 DESCENT OF GLACIERS. [CHAP. xr. 



in height, namely, about 9,000 feet, between the snow-line on the 

 Cordillera behind Chiloe (with its highest points ranging from onlj 

 5,600 to 7,500 feet) and in central Chile* (a distance of only 9 ol 

 latitude), is truly wonderful. The 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 other hand, 

 a little northward of Concepcion, the sky is generally clear, rain does 

 not fall for the seven summer months, and southern European fruits 

 succeed admirably; and even the sugar-cane has been cultivated.! 

 No doubt the plane of perpetual snow undergoes the above remark- 

 able flexure of 9,000 feet, unparalleled in other parts of the world, 

 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 upper 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 astonished when I first saw a range, only from 

 3,000 to 4,000 feet in height, in the latitude of Cumberland, with every 

 valley filled with streams of ice descending to the sea-coast. Almost 

 every arm of the sea, which penetrates to the interior higher chain, 

 not only in Tierra del Fuego, but on the coast for 650 miles northwards, 

 is terminated by " tremendous and astonishing glaciers," as described 

 by one of the officers on the survey. Great masses of ice frequently 

 fall from these icy cliffs, and the crash reverberates like the broadside 

 of a man-of-war, through the lonely channels. These falls, as noticed 

 in the last chapter, produce great waves which break on the adjoining 

 coasts. It is known that earthquakes frequently cause masses of 

 earth to fall from sea-cliffs : how terrific, then, would be the effect of a 

 severe shock (and such occur here): on a body like a glacier, already 

 in motion, and traversed by fissures ! I can readily believe that the 

 water would be fairly beaten back out of the deepest channel, and 

 then returning with an overwhelming force, would whirl about huge 

 masses of rock like so much chaff. In Eyre's Sound, in the latitude of 

 Paris, there are immense glaciers, and yet the loftiest neighbouring 



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

 ceedingly 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 23,000 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 33, but not in sufficient quantity to make the manufacture 

 profitable. In the valley of Quillota, south of Ingenio, I saw some large 

 date palm-trees. 



J Bulkeley's and Cummin's " Faithful Narrative of the Loss of the Wagtr,* 

 The earthquake happened August 2510, 1741. 



