424 SOUTH AMERICA— THE ANDES REGIONS. 



seaboard. A glacier descending from the spurs of the neighbouring Mount San 

 Valentin penetrates far into the interior of the lacustrine basin, its sparkling 

 surface offering a striking contrast to the dark cliffs of the rocky gorge through 

 which it falls a height of over 300 feet down to the lake. Here it glides along 

 the bottom at a depth of over 650 feet, until broken into fragments by the upward 

 thrust caused by its greater relative buoyancy in the denser waters of the reservoir. 

 An incessant thunder produced by the crash of the yielding blocks is re-echoed 

 from the surrounding cliffs, while the tempanos, or icebergs, some as much as 100' 

 feet high, drift away with the current setting towards the Rio de los Tempanos. 

 Through this emissary they float northwards down to the Elephant Gulf, where 

 the fresh water of the melting masses mingles with the marine floods. 



The bed of the lake is steadily silting up with the deposits of shingle and 

 glacial muds, which are brought down from the uplands, and which have already 

 created the Isthmus of Ofqui, enclosing the lake on the south side. A much 

 larger glacier than that of the lacustrine basin descends from the same heights to the 

 southern part of the isthmus, which is traversed by the sluggish Rio San Tadeo, 

 draining these moist alluvial plains southwards to the Gulf of San Estevan. The 

 discovery of this curious glacial region is due to the missionary Garcia, who ia 

 1766 passed from one gulf to the other b}^ the Ofqui Isthmus, which might easily 

 be pierced by a navigable canal. 



Wellington and Southern Groups. 



South of the Taytao Peninsula, which curves round south-westwards like a crab's 

 claw, the sea is clear of islands for a distance of about 60 miles. Beyond the break 

 the insular system again begins under various names, nearly all taken by the English 

 Admiralty surveyors from British celebrities. First comes the group of Wellington 

 Islands, separated from the Magellanic mainland by the Messier Channel, and 

 farther on by a narrow passage winding like a river, and in some places, especially 

 the English Narrows, contracting to a width of 300 or 400 feet. At Saumarez 

 Island a superb prospect is presented by the steep granite and schistose cliffs, where 

 the ships glide along the base of lofty mountains washed by tides swift as 

 impetuous rivers. 



A peak 3,840 feet high, at the southern extremity of the Archipelago, has 

 received the name of " The Cathedral," from its dome, belfries and turrets, carved 

 by the hand of time, and decorated by the falling moss with white lines, cornices 

 and parapets. The recent German expedition of the Albatross and that of the 

 Chilian hydrographer Serrano, have decomposed the Archipelago into several 

 separate groups, which were formerly regarded as forming the single large 

 island of Wellington. A navigable inner channel was also discovered, far less 

 dangerous than the Messier passage. 



All the more recent explorations in the insular groups farther south — Madrede 

 Dios, Duke of York, Hanover, Queen Adelaide — have similarly increased the 

 number of known islands studding the inlets which wind amidst the mountains. 



