Dr Tilesius on the Volcano Cooshna. 355 
mass of the stones, which seem as it were to have been torn from 
one another, and from the similar direction of the equally ele- 
vated chains of rocks on both sides, which are separated only 
by this channel. 
Krusenstern supposes, that this separation of Japan from 
Jesso, of which the probability deserves to be farther proved, 
by a careful examination of both sides of the coast, during some 
future voyage of Eui*opean navigators through the Straits of 
Sangar, will be established and brought to the evidence of cer- 
tainty. He even believes that this separation has taken place 
simply from the neighbourhood of the high Peak of Tilesius, 
and from its explosions. But the present construction of the 
rocky coast on both sides, with its conical-shaped summits, and 
pillar-shaped walls, which here and there are broken by fallen 
and shattered beds and layers of basalt-shaped materials, betrays 
so many traces of violent separation in the mass itself, and af- 
fords such distinct characters of a volcanic rock, that the cause 
of the separation may easily be found in the stone itself, and 
need not be sought for in the neighbouring volcanoes. When 
a person has seen the volcanoes of Kamskatka; those of Japan 
and the Kurile islands ; those of the Marquesas or Mendoza 
islands, especially Nuckahuva; those of the islands of Tenerilfe 
and St Helena,-— with their volcanic construction, as we have 
seen them, — it is not difficult to recognise the volcanic construc- 
tion of a group of rocks, even at some distance, and by the help 
of the telescope, and to become satisfied as to the general charac- 
ter of volcanoes which are without craters, or whose craters have 
fallen in, or which have become extinct. We must proceed, 
however, to a further consideration of the geographical position 
of the two volcanic islands Coosima and Oosima. The direc- 
tion of both these islands is N.W. and S.E., and the channel 
between them is twenty miles in breadth. The western entrance 
into the Strait of Sangar cannot be missed, even when stormy 
weather might prevent our observation of the latitude. From 
the south, the first landmark that appears is the Peak Tilesius, 
which rises white above all the surrounding rocks, and which is 
distinctly pointed out by its height, and by its everlasting snows. 
Cape Greig, from which the direction of the coast to Cape San- 
