2 Account of a visit to Barren Island. [No. 1, 



er in the direction of the spectator, the upper circumference of this 

 valley is seen in the shape of an oval ring, formed by the crest of the 

 surrounding ridge. In the middle of this ring, the upper part of a 

 regular cone is visible, from the apex of which small white vapour- 

 like clouds emanate. It is also distinguished from the surrounding 

 darker masses by its grey colour, and some large white marks on it, 

 like fields of snow. An entrance is not discernible. 



The slopes towards the sea are generally covered with shrubby ve- 

 getation, presenting however some bare patches towards the upper 

 edge ; small trees grow about the base, where large rounded stones 

 are washed by the sea. 



Turning now to the S. and S. W. the enclosing wall is higher than 

 the cone and the crest of the opposite ridge, and both therefore dis- 

 appear from the view. On this side the vegetation down the spurs 

 to the sea may be called rich, and consists of different forest trees of 

 moderate height, interspersed with graceful palms ; and where the 

 descent is rocky, the rocks are frequently covered with ferns. 



Passing to the westward of the centre of the island, and continuing 

 the survey towards the northern end, one of the first turns discovers 

 a large gap in the circular wall, extending quite down to the base of 

 the island, through which the interior of the valley, with the cone 

 in the middle, opens at once into full view. 



The sides of this gap or fissure in the circular wall form a regular 

 cut or short transverse valley through it, opening towards the sea 

 into a small bay, and on the other side into the circular valley, to 

 which it is the only way of access. Opposite this entrance, in the centre 

 of the valley, rises the cone of grey ashes, and surrounding its base the 

 bottom of the valley is filled with black masses of cold lava, which 

 are continued like a congealed stream through the gap, breaking off 

 abruptly when they arrive near the water's-edge. At its termination 

 the steam is about 10 or 15 feet high, and its breadth seems less than 

 farther up. It looks like a black perpendicular wall drawn across the 

 entrance and facing the sea. 



The lava consists of a black basalt mass (matrix) throughout which 

 are disseminated innumerable semi-transparent little crystals of a 

 variety of common felspar (orthoclase), and also many bright green 

 granules of olivine. The lower part of its thickness is homogeneous, 



