Actions of Volcanoes. 293 
and it is evident that the action which produced the greatest, is 
also capable of accounting for the least, of these. 
Now, although it may be said that no volcano exists in 
Eeooa, and that such a cause cannot therefore be admitted, it 
will be sufficient to shew that volcanoes have in other instances, 
and in this sea, exerted that very action, and in such a manner, 
that the coral rises upon the sides of the volcanic mountain ; 
proving, in these cases, what may safely be inferred in the 
others, that it is not only capable of producing the required 
effects, but that, in these instances, it has actually produced 
them. That force, therefore, which has exerted its action, so as 
entirely to erupt the volcanic matter, may well be allowed to 
have also exerted that much less one, which was sufficient, as in 
the case of earthquakes, to alter the level of the submarine land. 
It is possible that the volcanic action may here have been 
exerted under Eeooa itself, as the nature of the summit of the 
hill is not described by Cook. On other occasions he has neg- 
lected to notice volcanic rocks where we now know that they 
exist ; and this is a subject which did not excite the attention 
of Mariner. But whether this be the case or not, the presence 
of a volcano in this group of islands is established. Toofooa 
contains one which is always burning, and this island is only 
seventy miles distant from Tongataboo. The small island Kao, 
about three miles from Toofooa, is also described as a cone, so 
that it is probably also of the same nature. 
There is indeed reason to think that a volcanic force has 
been exerted very extensively in this part of the south Pacific 
Ocean. In Cook’s arrangement, upwards of 150 islands are 
associated under the term Friendly Isles, and of these thirty-five 
are hilly. Otaheite, in the same sea, is of this form, and so are 
Bolobola and Eimeo. Though he has not mentioned volcanic 
rocks among these islands, it is now known that they occur in 
many places, and there are three burning volcanoes even in the 
Friendly Isles. 
In further confirmation of this view, Eap, which lies to the 
westward of the Caroline Islands, is a seat of volcanic energy. 
Earthquakes are here frequent and violent, according to 
Kotzebue. He further remarks, that when Ulea trembles, all 
