192 Correspondence—Professor J. Milne. 
one is the highest. It was the two smaller ones which erupted 
this year. 
Tturup.—At the south-west end of this island there is a mountain 
which was seen to give off steam for the first time in 1879. 
Simusir.—At the south end of this island there is a mountain which 
gives off steam. 
Ushishir.—F rom this island a little steam is given off. 
Rashua.—This island also gives off a little steam. 
Shaiskotan.—Not only does steam issue from the north-east end of 
this island, but it also issues at the south end. The state of activity 
appears to be greater than on Simusir, but less than it is on Chirnoi. 
Kharim Kotan.—This island gives off a little steam. 
Onekotan.—A little steam is given off from the mountains at both 
ends of this island. 
When I wrote about the Kurile Islands, I only mentioned nine 
mountains, which were seen to be giving off steam. ‘The numbers 
of such mountains will now be increased to 17. Of well-defined vol- 
canic peaks I saw fifty-two. Forty-three of these were at that time 
(1878) apparently extinct. From Mr. Snow’s observations we now see 
that several of these shortly afterwards, that is, in 1879, became active. 
The number is in fact variable, and, for aught we know, the number 
of active cones in the Kurile Islands may at the present moment be 
different from what it was when I was there, or when Mr. Snow was 
there. We have in fact in the case of the Kurile Islands a remarkable 
example of the futility in attempting to enumerate the number of 
active cones in any given area. ‘The number is ever changing, but on 
the whole it is probably growing less. It may roughly, perhaps, 
follow some law analogous to a rate of cooling. For any one short 
period we may perhaps determine the number approximately, and it 
is only in this way that we can regard enumerations like the oft-re- 
peated lists, as, for instance, those by Humboldt, which tell us that 
there are only 225 active volcanos in the world. 
As to what is a voleano, whether it is active, dormant, or extinct, 
and how volcanos are to be enumerated, are questions which require 
discussion, and upon which I hope to offer a few remarks in a con- 
tribution which I am preparing upon the volcanos of Japan. 
In conclusion, I may remark, that through the kindness of Mr. Snow, 
I have obtained a few more specimens of rocks from the Kuriles. 
These are like those which I obtained before, namely, Andesites,—a 
class of rock which seems to be as characteristic of the Pacific area as 
Basalts are of the Atlantic. J. Mite. 
YeEpo, JAPAN, Jan. 11, 1880. 
MISCHLBLANHOUS. 
GEOLOGICAL SuRVEY OF JAPAN.—Reports of Progress for 1878 and 1879. By B. S. Lyman. 
Tokei, 1879. These reports give a short statement of the work carried on in the field during 
1878 and part of 1879- Besides descriptions of the metalliferous deposits of gold, silver, and 
lead, attention was paid to the extent and yield of the coal-fields of Yesso; it appearsthat the 
productive coal-fields as at present ascertained occupy about 350 square miles. The chief aim, 
however, was to finish the survey of the oil lands of Japan, to complete the reconnaissance of 
the whole country that had already been begun, and to ascertain what places most needed detailed 
surveys. The reports are accompanied by a small map of the eastern part of Asia, to show the 
position of the productive coal-fields of Yesso, Japan, and geological and topographical maps of 
the Kayanoma, Nuppaomanai and Bibai coal-fields. Tables are also given of the principal facts 
in regard to the oil wells of Akita Ken, and of all Japan.—J. M. Fa a 
