S02 M. Von Buch on Volcanos and Craters of Elevation. 



the flat South Sea islands containing a sea lake has been seen 

 smoking and giving out vapour ; and it is not extraordinary, for, 

 as such a phenomenon only indicates violent volcanic action, and 

 not the existence of a volcano, the effects of the agency of the 

 fire disappear after a short time, and can only be seen by those 

 whom accident has conducted at so transient a moment to such 

 an inland. The solid masses of which it was composed were 

 widely different from those of Ferdinand's island (Graham's 

 island) off Sicily, or of Sabrina, near St Miguel in the Azores, 

 whose solid nucleus did not reach the surface, and whose loose 

 layers of erupted slags and lapilli were speedily destroyed by 

 the sea. In a few years corals surround such South Sea islands 

 as the one we have instanced, they become a resting place for 

 fatigued birds, and are gradually covered by vegetation. 



We may therefore feel assured that discoveries in the great 

 ocean will never be exhausted. Islands will continue to rise 

 from the depths of the seas, and the various conditions of their 

 vegetation will relate their histories. 



That elevation craters rise out of the sea is, however, quite 

 accidental, and does not belong to their internal constitution, or 

 to the conditions of 'their appearance. These relate chiefly to 

 the great restraining covering, which obstructs the extrication of 

 the imprisoned vapours from the interior, and which must there- 

 fore be removed and broken up before the vapours can escape 

 into the atmosphere. Hence craters of elevation can, in like 

 manner, be formed on the solid land, or, on already existing and 

 raised up islands, and of these we have examples, sometimes of 

 the gi'eatest distinctness, in almost every land. The Laacher-See 

 near the Rhine, Cantal, and Montdor, are among the most re- 

 markable elevation craters occurring on continents ; and some 

 which are precisely similar have been actually formed before our 

 eyes. When the island St Marie in the Azores was discover- 

 ed. Prince Henry bestowed it on its discoverer, the navigator 

 D. Vincent Cabral, and it was cultivated and peopled. Some, 

 time afterwards Cabral reached the north-west side of the neigh- 

 bouring island St Miguel. He found a flat productive land of 

 great extent well suited to cultivation, and hence in the highest 

 degree adapted to the foundation of new colonies. Nearly a 

 year was occupied in St Marie with preparations for this new 



