52 Flora of Narcondam and Barren Island. 
the amphitheatre that results, and therefore about a-quarter of a mile 
to the north of the centre of the island, a newer perfect volcanic cone 
rises to a height of 1015 feet. At the top there is an ovoid crater, 
somewhat straighter along its northern than its southern edge, and 
somewhat higher on these edges than at either extremity. The edges 
mentioned are nearly 80 feet above the bottom of the cup which is 
itself sub-divided into two parts. The western, somewhat irregular, is 
full of loose lava fragments, and has its floor nearly 40 feet higher than 
the other, which is an almost perfect circle, about 20 yards wide, with a 
floor of smooth soft sand. At the west end the rim of the crater is 
about 40 feet lower than along the north and south edges, and is thus 
very little above the floor of the minor western depression. In the 
middle of this dip the rim carries a huge lava block, about 20 feet long, 
10 ft. wide, and nearly 20 feet high.* This block forms a striking 
object on the cone as seen from the landing-place. At the eastern end 
of the crater the rim dips even more, and is about 60 feet below the 
level of the northern and southern edges, or just over 20 feet above 
the floor; the edge is here narrower than elsewhere. In and about the 
crater are several solfataras with crevices whence steam escapes. 
The cone itself consists of volcanic ashes, fairly firm on the south, 
east and north sides, but loose and friable on the western face. The 
slope is very uniform, being about 30° on every side. The valley be¬ 
tween the cones contains, at the base of the inner, two lava streams 
that have flowed to the sea through the breach in the outer; of these 
streams the northern overlies the southern. There has also been a 
third flow to the east, this does not, however, come in contact with either 
of the others. The sea, it may be remarked, does not enter the breach 
in the outer cone, the breach, as well as the valley between the cones, 
being filled to above sea-level by the products of the newer volcano. 
The seaward slope of the outer cone is much steeper in the northern 
than in the southern part of the island, and is furrowed by many nearly 
meridional ravines, diflB.cult of access where they enter the sea, but more 
easily traversed further up. The slope of this half of the ancient 
crater towards the newer volcano is, on the other hand, even and 
rounded, consisting for the main part of bare, loose black ash, derived from 
the inner cone. The inner slope of the southern half of the original 
volcano is, on the other hand, except at its base, steeply precipitous ; the 
seaward slope of this half, besides being much more gradual than that 
* The measurements (Mallet: Memoirs of the Geol. Survey of India, xxi, 267j 
are:—Length, 22 feet ; breadth, 11 feet, height, 13 to 19 feet. The greatest height 
is at the west end, where it is also narrowest ; its most striking aspect is to the 
spectator on the beach at the landing-place, to whom it looks like a huge tooth. 
266 
