280 



TIERRA DEL FUEGO. 



June^ 1834. 



mass in its downward course. They have been aptly com- 

 pared to gigantic icicles. The lower limit of glaciers^ must 

 depend on that of the parent snow^, greatly affected by the 

 form of the land : in Tierra del Fuego the snow-line descends 

 very low^ and the mountain sides are abrupt ; therefore we 

 might expect to find glaciers extending far down their 

 flanks.* Nevertheless^ when on first beholding^ in the mid- 

 dle of summer, many of the creeks on the northern side of 

 the Beagle channel terminated by bold precipices of ice 

 overhanging the salt water, I felt greatly astonished. For 

 the mountains from which they descended, were far from 

 being very lofty. Captain FitzRoy from angular measure- 

 ments considers the general range to have an elevation 

 rather under 4000 feet, with one point called Chain Moun- 

 tain rising to 4300. Further inland, there is indeed a more 

 lofty mountain of 7000 feet, but it is not directly connected 

 with the glaciers to which I now allude. This range, which 

 exceeds by so little the height of some mountains in Britain, 

 which yet sends down in the middle of summer its frozen 

 streams to the sea-coast, is situated in the latitude of the 

 Cumberland hills. 



I was much interested by observing the great difference 

 between the matter brought down by torrents and by gla- 

 ciers. In the former case a spit of gravel is formed, but in 

 the latter a pile of boulders. On one occasion, the boats 

 being hauled on shore, within the distance of half a mile from 

 a glacier, we were admiring the perpendicular cliff of blue ice, 

 and wishing that some more fragments would fall off, like 

 those we saw floating on the water, at a distance of more 

 than a mile from their source. At last, down came a mass 



* In the Alps, Saussure gives 8793 feet as the mean of the lower 

 limit of the snow-line. At Mont Blanc the glacier of Montanvert is said 

 (Encyclo. Metropol.) to descend 12,000 feet below the summit of the 

 mountain, and this will make its base 5160 feet lower than the line of 

 snow. In Norway (See Von Buch) where a glacier first comes down 

 to the water's edge (lat. 67°), it is 3800 below the same line : in Tierra del 

 Fuego the dilFerence must be very nearly the same as in the last case. 



