110 THE ICE AGE IN NORTH AMERICA. 



Almost every arm of the sea which penetrates to the interior 

 higher chain, not only in Tierra del Fuego, but also on the 

 coast for 650 miles northward, 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 pro- 

 duce 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 neighboring mountain is 

 only 6,200 feet high. In this sound about fifty icebergs were 

 seen at one time floating outward, and one of them must have 

 been at least 168 feet in total height. Some of the icebergs 

 were loaded with blocks of no inconsiderable size, of granite 

 and other rocks, different from the clay-slate of the surround- 

 ing mountains. The glacier farthest from the pole, surveyed 

 during the voyages of the Adventure and Beagle, is in latitude 

 46° 50', in the Gulf of Penas. It is fifteen miles long, and in 

 one part seven broad, and descends to the sea-coast. But even 

 a few miles northward of this glacier, in the Laguna de San 

 Rafael, some Spanish missionaries encountered "many ice- 

 bergs, some great, some small, and others middle-sized," in a 

 narrow arm of the sea, on the 22d of the month correspond- 

 ing with our June, and in a latitude corresponding with that 

 of the Lake of Geneva ! 



In Europe, the most southern glacier which comes down to 

 the sea is met with, according to Von Buch, on the coast of 

 Norway, in latitude 67°. Now, this is more than 20° of lati- 

 tude, or 1,230 miles, nearer the pole than the Laguna de San 

 Rafael. The position of the glaciers at this place and in the 

 Gulf of Penas may be put even in a more striking point of 

 view, for they descend to the sea-coast, within 7£° of latitude, 



