Coral Reefs

Page 90

BEVERIDGE Reef, 20 deg S., 167 deg W., is described in the "Naut. Mag." (May 1833, page 442) as ten miles long in a N. and S. line, and eight wide; "in the inside of the reef there appears deep water;" there is a passage near the S.W. corner: this therefore seems to be a submerged atoll, and is coloured blue.

SAVAGE Island, 19 deg S., 170 deg W., has been described by Cook and Forster. The younger Forster (volume ii., page 163) says it is about forty feet high: he suspects that it contains a low plain, which formerly was the lagoon. The Rev. J. Williams informs me that the reef fringing its shores, resembles that round Mangaia; coloured red.


PYLSTAART Island. Judging from the chart in Freycinet's "Atlas," I should have supposed that it had been regularly fringed; but as nothing is said in the "Hydrog. Memoir" (or in the "Voyage" of Tasman, the discoverer) about coral-reefs, I have left it uncoloured.--TONGATABOU: In the "Atlas of the Voyage of the 'Astrolabe'," the whole south side of the island is represented as narrowly fringed by the same reef which forms an extensive platform on the northern side. The origin of this latter reef, which might have been mistaken for a barrier-reef, has already been attempted to be explained, when giving the proofs of the recent elevation of this island.-- In Cook's charts the little outlying island also of EOAIGEE, is represented as fringed; coloured red.--EOUA. I cannot make out from Captain Cook's charts and descriptions, that this island has any reef, although the bottom of the neighbouring sea seems to be corally, and the island itself is formed of coral-rock. Forster, however, distinctly ("Observations," page 14) classes it with high islands having reefs, but it certainly is not encircled by a barrier-reef and the younger Forster ("Voyage," volume i., page 426) says, that "a bed of coral-rocks surrounded the coast towards the landing-place." I have therefore classed it with the fringed islands and coloured it red. The several islands lying N.W. of Tongatabou, namely ANAMOUKA, KOMANGO, KOTOU, LEFOUGA, FOA, etc., are seen in Captain Cook's chart to be fringed by reefs, in several of them are connected together. From the various statements in the first volume of Cook's "Third Voyage," and especially in the fourth and sixth chapters, it appears that these reefs are of coral-formation, and certainly do not belong to the barrier class; coloured red.--TOUFOA AND KAO, forming the western part of the group, according to Forster have no reefs; the former is an active volcano.--VAVAO. There is a chart of this singularly formed island, by Espinoza: according to Mr. Williams it consists of coral-rock: the Chevalier Dillon informs me that it is not fringed; not coloured. Nor are the islands of LATTE and AMARGURA, for I have not seen plans on a large scale of them, and do not know whether they are fringed.

NIOUHA, 16 deg S., 174 deg W., or KEPPEL Island of Wallis, or COCOS Island. From a view and chart of this island given in Wallis's "Voyage" (4to edition) it is evidently encircled by a reef; coloured blue: it is however remarkable that BOSCAWEN Island, immediately adjoining, has no reef of any kind; uncoloured.

WALLIS Island, 13 deg S., 176 deg W., a chart and view of this island in Wallis's "Voyage" (4to edition) shows that it is encircled. A view of it in the "Naut. Mag." July 1833, page 376, shows the same fact; blue.

ALLOUFATOU, or HORN Island, ONOUAFU, or PROBY Island, and HUNTER Islands, lie between the Navigator and Fidji groups. I can find no distinct accounts of them.


The best chart of the numerous islands of this group, will be found in the "Atlas of the 'Astrolabe's' Voyage." From this, and from the description given in the "Hydrog. Memoir," accompanying it, it appears that many of these islands are bold and mountainous, rising to the height of between 3,000 and 4,000 feet. Most of the islands are surrounded by reefs, lying far from the land, and outside of which the ocean appears very deep.

Charles Darwin

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