This rock is the most general of any in this range of islands, at least as far as we had opportunities of examining them. The islands on this coast are very numerous; they lie in great clusters along a line of three degrees and a half of latitude. The islands vary in length from five or six miles to as many yards, and are of all forms. We saw none that were remarkably high, and none which seemed volcanic. As our stay on the coast was only nine days, and as the ships were almost always under weigh except at night, it was quite impossible to make any careful or valuable geological observations. It offers a splendid field to future voyagers.
GREAT LOO-CHOO ISLAND.
1. Grey stratified lime-stone without shells. This specimen was taken from the north end of the island, where the ranges of hills were mostly composed of it: the strata being highly inclined. The hills rise to the height of four or five hundred feet, and present nothing interesting.
2. Fawn-coloured, cellular, granular lime-stone. The cliffs at Napakiang are composed of this rock; it also appears to stretch along the whole of the south-west and south parts of the coast. In the narrative, this rock has been erroneously called coral. These cliffs are curiously hollowed out into horizontal caves, which have all the appearance of having been worn by the dashing of the waves; but as it is obvious, that in their present situation the sea can never have reached the face of the cliffs, it seems probable that the whole coast may have been raised up, by a gentle movement, without dislocating the strata, or disturbing the horizontal position, in which it seems probable that these caves were formed.
The variety of coralines which girt the shores of this island was very great, and large collections were made, as well of these as of the numerous zoophites which filled up every part of the reefs below high-water mark. This collection, of which unfortunately no duplicates were kept, was afterwards lost.
SULPHUR ISLAND
Lies in latitude 27º 5' north, and longitude 128º 25' east. An accurate representation of it is given as a frontispiece.
We attempted to land, but the surf broke every where so high against the rock that this was impossible. There is a crater on the left side with white smoke issuing from it; this has a strong sulphuric smell. The sides of the crater are stratified. The south end of the island is about four or five hundred feet high, and is formed of a dark dingy red rock distinctly stratified; at several places it is cut vertically by great dykes, which being more durable than the strata which they intersect, stand out from the face of the cliffs to a considerable distance.
FOOTNOTES:
[Footnote 19: Specimen 7, infra.]