M. Von Buch on Volcanos and Craters of Elevation, 201 



north to south. The slope sinks rapidly, and at a short distance 

 the depth is very great. The island is rising, says Virlet, like 

 a vast graft out of the sea. 



Thus islands of elevation and craters of elevation are quite 

 a general consequence of volcanic activity ; but they are not 

 volcanos, though, nevertheless, as it would seem, they exercise 

 a much more important influence than the largest volcanos on 

 the alteration, and especially on the increase, of the surface of 

 the earth. Such islands are doubtless still rising from the sea. 

 It has been frequently conjectured, that all coral islands of the 

 South Sea which contain a shallow lake (lagune) in the middle, 

 may be regarded as islands of elevation ; and a new and extreme- 

 ly remarkable account given by Poeppig in the excellent and ta- 

 lented narrative of his journey, presents us with an example in 

 which Nature seems, as it were, to have been surprized in the 

 very act of forming such an island. 



Captain Thayer, of the American schooner Yankee, visited 

 the haven of Talcahuano in Southern Chili. Poeppig saw him 

 there, and obtained permission to examine his journals. It ap- 

 peared from this authentic source, and from the relation of the 

 Captain, that, on the 6th September 1825, in south latitude 

 30° 14)', and east longitude 178° 15' from Greenwich, an entirely 

 unknown small island was descried from the ship. A thick 

 smoke rose from the middle of the island. Boats were sent to 

 examine it. As they approached a completely barren rock was 

 seen, which rose only a few feet above the surface of the sea. 

 It consisted of a broad ring which included a small pond, and 

 which, being broken at one point, seemed to admit the sea. 

 The sailors sprang out into the water in order to drag the boat 

 over the shallow, but in an instant they sprang back in the 

 highest degree alarmed, because the hot water had burnt their 

 feet. The smoke was seen to issue from several fissures which 

 traversed the surrounding ring. Only at one point sand was 

 found ; all the rest consisted of solid rock. The crater had a 

 diameter of 800 paces, and sloped so rapidly externally that at 

 a distance of 100 fathoms no bottom could be reached. Never- 

 theless, at a distance of four English miles the temperature of 

 the sea water was 10° to 15° higher than had previously been 

 remarked in these latitudes. This is the first time that one of 



