Prof. V. Ball— Volcanoes in Bay of Bengal. 407 
letterpress appears to be founded on previous accounts, it is not of 
much value. 
The more important dimensions of this Island which have now 
been definitely ascertained are as follows : 
Maximum diameter of Island 2. .:. .... ... ... ... about 2) miles: 
Circumference ae Roth. 6d. LODACU Ret AIRE npr nae A ope Ny 
Height of outer Crater... BE Sess. skcedice Jee em lelOOneets 
Estimated height of or iginal Cone oso 600" 800) 060, 600 BAND) gg 
Height of inner Cone . SCORE ciel set. dear’ aoe OO OMe 
Angle of slope of Cone a0. | ono. lob 32° 
Narconpam, Lat. 15° 26’; Long. 94° 15’. 
The account by Mr. Mallet of this volcano is, in some respects, of 
greater value, though less interesting than that of Barren Island. 
This is due to the fact that it had never been so thoroughly examined 
as the latter has, and because the total information regarding it was 
vague and incomplete. 
We now know that its highest peak rises to 2330 feet above the 
sea, that it retains no remnant of any crater, and owing to the 
absence of clearly marked alternations of lava and ash, such as 
occur in Barren Island, there is some probability that it never had 
one. In other words that it may, as Mr. Mallet suggests, owe its 
origin to the “extrusion of viscid lava without the accompaniment 
of crater-forming materials,” like the domite Puys of Auvergne. 
The lavas of Narcondam, unlike those of Barren Island, are of a 
very uniform character ; felspars, both triclinic and orthoclinic, occur 
in them, causing them to be of a very pale colour, and they include 
both hornblende and augite—the latter in a subordinate degree ; 
they are in short, according to Mr. Mallet, hornblendic andesites, 
and are distinctly more acidic than are those of Barren Island. 
Certain agglomerates consisting of rounded and angular fragments 
of lava embedded in a finer matrix are largely developed on the 
coast. They appear to have been formed by pluvial action, as no 
trace of marine organisms has been observed in them. 
My observations on Narcondam having been limited to the neigh- 
bourhood of one small bay, I could only speak as to the absence of 
any evidence there of recent volcanic action. Mr. Mallet has, how- 
ever, confirmed this for the whole island, and there is no record, so 
far as is known, of the volcano ever having been observed in a state 
of activity. 
Colonel Yule’ has, however, suggested a Sanskrit derivation for 
the name, Naraka-Kondam =<‘ a pit of hell,” as being possibly con- 
nected with a period when the volcano was active; but Mr. Mallet 
has collected evidence from old charts which tends to prove that 
there was confusion between the two islands, and that the name 
Narcondam may have been at one time applied to Barren Island—to 
the form of which the title “a pit of hell” would not be inappro- 
priate, and with the probability of this being the true explanation 
Colonel Yule’ has expressed his concurrence. 
1 Marco Polo, bk. iii. ch. 13, note. 
* Anglo-Indian Glossary, art. Narcondam. 
