22 V. Ball — Volcanos of the Bay of Bengal. 



General Description of Barren Island. — Seen from any side but the 

 north-west, Barren Island appears as a nearly flat-topped hill with 

 numerous spurs running down into the sea. From some aspects, 

 however, the top of a central cone with a column of smoke rising 

 from it is discernible. 



As the north-west side opens up to view, it is first realized that 

 the island consists of a circular ridge forming a huge amphitheatre, 

 which is broken down at one side for a distance of perhaps 150 

 yards to the level of the sea. The view obtainable through this 

 entrance discloses a bare cone which rises from the centre of the 

 island. Except at a sort of shoulder not far from the top, and at 

 two peaks close to the summit, no rocks are seen on this cone, its 

 smooth sides being covered with grey ash and occasional strings of 

 shingle. Towards the top some whitish patches are seen, these are 

 due to the presence of gypsum mixed with the ash. 



The accompanying illustration, it will be observed, is somewhat 

 diagi'ammatic in its character, being rather of the nature of a bird's- 

 eye view, than a representation taken from an actual point of view. 



The total diameter of the island is, on the authority of Lieutenant 

 Heathcote, 2,970 yards. The circuit of the island, from the time it 

 took us to row round, I estimated at about six miles. 



The high encircling ridge is formed of somewhat irregularly de- 

 posited layers of lava, ash, and conglomerate, which dip away from 

 the centre. A section of these may be seen on the left hand of the 

 gap or entrance, and others at various points on the sea-face, no two 

 of them corresponding exactly in character. 



These beds or layers generally clip at angles of 35° to 40°, which 

 inclination appears to be continued steadily under the sea, as bottom, 

 except at one place, has not been found with a line of 150 fathoms 

 at one-quai"ter of a mile from the shore. This steepness has been 

 unfavourable to the formation of a fringing reef of coral of any 

 magnitude, such as we find surrounding some of the islands of the 

 Andaman and Nicobar groups. The elevation of this outer ridge 

 varies somewhat in places, but it probably nowhere is much in 

 excess of 1,000 feet. Its highest points are towards the south and 

 west. 



The appearance presented by the inner scarped face of this amphi- 

 theatre is very peculiar. In several places cornice lines mark the 

 position of particular beds, but a purplish grey, or in places brownish, 

 ash spreads over the steep slopes, except towards the south-west and 

 west, where there are some trees and shrubby vegetation. To the 

 north, south, and east a few tufts of grass — generally arranged in 

 long vertical lines, the first being a sort of protection to those below 

 it — are the only plants which have managed to establish a footing in 

 the loose ash. The outer slopes facing the sea are for the most part 

 covered with a luxuriant vegetation, in which large forest trees may 

 be discerned. These latter attract considerable numbers of fruit- 

 eating pigeons (Carpopliaga bicolor). 



From its composition and character, it is evident that this ring of 

 cliffs is the remnant of the original cone which gradually rises from 



