y the missionary ship _John Wesley_ in
August 1857; its appearance had been heralded some years before by a
strange agitation of the sea and by fire and smoke ascending from the
water. This new volcanic island lies about midway between the two other
volcanic islands of Tufoa and Late.[6] A third new volcanic island seems
to have been formed to the south of Tufoa in 1886.[7] Another new island
was thrown up from the sea about the beginning of the twentieth century;
it was partly washed away again, but has again materially increased in
size.[8] It is noteworthy that the volcanoes, new or old, all occur in a
line running roughly north and south at a considerable distance to the
west of, but parallel to, the main body of the Tongan archipelago. They
clearly indicate the existence of submarine volcanic action on a great
scale. Even in the coralline islands traces of volcanic agency have come
to light in the shape of pumice-stones, which have been dug out of the
solid coral rock at considerable depths.[9] In the lofty island of Eua
an extensive dyke of basalt is found inland underlying the coral
formation.[10]

[6] T. West, _op. cit._ pp. 92-93.

[7] I infer this from the entry "Volcanic island, 1886," in Mr.
Guillemard's map of the Pacific Islands. He does not mention it
in the text (_Australasia_, ii. p. 497).

[8] George Brown, _Melanesians and Polynesians_, p. 6.

[9] T. West, _op. cit._ p. 94.

[10] George Brown, _op. cit._ p. 4.

These facts lend some countenance to the view that the whole archipelago
forms the summit or visible ridge of a long chain of submarine
volcanoes, and that the islands, even those of coralline formation, have
been raised to their present level by volcanic action.[11] That very
acute observer, Captain Cook, or one of the naturalists of the
expedition, noticed that in the highest parts of Tongataboo, which he
estimated roughly at a hundred feet above sea-level, he often met with
"the same coral rock, which is found at the shore, projecting above the
surface, and perforated and cut into all those inequalities which are
usually seen in rocks that lie within the wash of the tide."[12] Again,
on ascending the comparatively lofty island of Eua, Captain Cook
observes: "We were now about two or three hundred feet above the level
of the sea, and yet, even here, the coral was perforated into all the
holes and inequalities which usually diversify the surface of this
subst