Coral Reefs

Page 93

Bennett, in a letter to the Editor of the "Singapore Chron.," alludes to the REEFS on its shores. It may, I think, be safely inferred from these passages that the shore is fringed in parts by coral-reefs; coloured red.--SANDWICH Island. The east coast is said (Cook's "Second Voyage," volume ii., page 41) to be low, and to be guarded by a chain of breakers. In the accompanying chart it is seen to be fringed by a reef; coloured red.--MALLICOLLO. Forster speaks of the reef-bounded shore: the reef is about thirty yards wide, and so shallow that a boat cannot pass over it. Forster also ("Observations," page 23) says, that the rocks of the sea-shore consist of madrepore. In the plan of Sandwich harbour, the headlands are represented as fringed; coloured red.--AURORA and PENTECOST Islands, according to Bougainville, apparently have no reefs; nor has the large island of S. ESPIRITU, nor BLIGH Island or BANKS' Islands, which latter lie to the N.E. of the Hebrides. But in none of these cases, have I met with any detailed account of their shores, or seen plans on a large scale; and it will be evident, that a fringing-reef of only thirty or even a few hundred yards in width, is of so little importance to navigation, that it will seldom be noticed, excepting by chance; and hence I do not doubt that several of these islands, now left uncoloured, ought to be red.


VANIKORO (Figure 1, Plate I.) offers a striking example of a barrier-reef: it was first described by the Chevalier Dillon, in his voyage, and was surveyed in the "Astrolabe"; coloured pale blue.--TIKOPIA and FATAKA Islands appear, from the descriptions of Dillon and D'Urville, to have no reefs; ANOUDA is a low, flat island, surrounded by cliffs ("'Astrolabe' Hydrog." and Krusenstern, "Mem." volume ii., page 432); these are uncoloured. TOUPOUA (OTOOBOA of Dillon) is stated by Captain Tromelin ("Annales Marit." 1829, page 289) to be almost entirely included in a reef, lying at the distance of two miles from the shore. There is a space of three miles without any reef, which, although indented with bays, offers no anchorage from the extreme depth of the water close to the shore: Captain Dillon also speaks of the reefs fronting this island; coloured blue.-- SANTA-CRUZ. I have carefully examined the works of Carteret, D'Entrecasteaux, Wilson, and Tromelin, and I cannot discover any mention of reefs on its shores; left uncoloured.--TINAKORO is a constantly active volcano without reefs.--MENDANA ISLES (mentioned by Dillon under the name of MAMMEE, etc.); said by Krusenstern to be low, and intertwined with reefs. I do not believe they include a lagoon; I have left them uncoloured.--DUFF'S Islands compose a small group directed in a N.W. and S.E. band; they are described by Wilson (page 296, "Miss. Voy." 4to edition), as formed by bold-peaked land, with the islands surrounded by coral-reefs, extending about half a mile from the shore; at a distance of a mile from the reefs he found only seven fathoms. As I have no reason for supposing there is deep water within these reefs, I have coloured them red. KENNEDY Island, N.E. of Duff's. I have been unable to find any account of it.


The great barrier-reefs on the shores of this island have already been described (Figure 5, Plate II.). They have been visited by Labillardiere, Cook, and the northern point by D'Urville; this latter part so closely resembles an atoll that I have coloured it dark blue. The LOYALTY group is situated eastward of this island; from the chart and description given in the "Voyage of the 'Astrolabe'," they do not appear to have any reefs; north of this group, there are some extensive low reefs (called ASTROLABE and BEAUPRE,) which do not seem to be atoll-formed; these are left uncoloured.


The limits of this great reef, which has already been described, have been coloured from the charts of Flinders and King. In the northern parts, an atoll-formed reef, lying outside the barrier, has been described by Bligh, and is coloured dark blue.

Charles Darwin

All Pages of This Book