Prof. V. Bali— Volcanoes in Bay of Bengal. 405 
days at Barren Island and four at Narcondam. The results have 
been published by Mr. Mallet,! and his paper gives a most interesting 
account of both islands, which is accompanied by several valuable 
maps and sections, all of which may be said to supersede what has 
been previously published. 
In referring to the subject again, I desire to point out, in the first 
place, that I quite agree with Mr. Mallet that the crater at the 
summit of the cone on Barren Island as he saw it in 1884 was 
practically in the same condition as when I saw it in 1878, and that 
consequently there has been no active eruption during the interval 
of eleven years. 
Unfortunately I cannot now definitely account for the fact that 
there is a difference in the bearings of the larger sides of the crater, 
as given by Dr. Playfair and myself, from those ascertained by the 
recent survey. It is possible that I may have quoted Dr. Playfair’s 
bearings either by mistake or because my own memorandum had 
been lost. Be that as it may, the elliptical hollow as now described 
and represented corresponds in all its details with my recollection of 
what it was when I saw it. 
We may indeed, I think, with perfect safety, push back the period 
of the quiescence of the volcano still further. There is before me 
an original copy of a photograph taken by M. Mellitte for Dr. Mouat, 
whose signature it bears and the date, Dec. 1857. It represents the 
cone with its characteristic points exactly as it is shown in the 
lithograph from a photograph which is given in Mr. Mallet’s memoir. 
During this period of 27 years, that is to say, up to 1884, the only 
observed manifestation of internal action has been afforded by the 
outpouring of steam and sulphurous vapour from a portion of the 
edge of the crater. 
In the Bombay Times, during July, 1852, the volcano is said 
to have been described “as very active.” I was unable, when in 
India, to verify this statement by reference to the original. Possibly 
the paragraph itself might show whether this was only an exagger- 
ated way of describing the issue of steam from the summit. If the 
voleano was really in a violent state of eruption in that year, there 
should be, one would suppose, abundant record of it in the logs of 
passing vessels. 
Nothing can be more conclusive as to the cooling down of the 
lower parts of the lava which occupies the valley between the old 
outer crater and the cone, and perhaps it may be added the 
exhaustion generally of the energy of this volcano, than the records 
of the temperatures of the hot spring as observed during the period 
from 1832 to 1884. In 1882 it was described as almost boiling; 
in 1857 (Drs. Mouat and Playfair) it was too hot to be borne by | 
the hand, their thermometer was only capable of measuring up to 
140° F.; in 1858 (Dr. Liebig) almost boiling; in 1862 (Rev. C. 
Parish) scalding hot; in 1866 (Andaman Committee) 158°—163° ; 
in 1878 (Y. Ball) 130°; in 1884 (F. R. Mallet) 106°—116°. These 
observations are not sufficient to establish the rate of cooling, though 
1 Mem. Geol. Survey of India, vol. xxi. pt. 4. 
