“that the high tides and violent currents were diminishing the number of the islands:”[11] and I have already shown, on the authority of Captain Moresby, that the work of destruction is still in progress; but that on the other hand the first formation of some islets is known to the present inhabitants. In such cases, it would be exceedingly difficult to detect a gradual subsidence of the foundation, on which these mutable structures rest. [6] Williams’s “Narrative of Missionary Enterprise,” page 31. [7] Kotzebue’s “First Voyage,” volume iii., page 168. [8] M. Desmoulins in “Comptes Rendus,” 1840, page 837. [9] “West of England Journal”, No. I., page 35. [10] Beechey’s “Voyage to the Pacific,” chapter vii., and Wallis’s “Voyage in the ‘Dolphin’,” chapter iv. [11] See an extract from Pyrard’s Voyage in Captain Owen’s paper on the Maldiva Archipelago, in the “Geographical Journal”, volume ii., page 84. Some of the archipelagoes of low coral-islands are subject to earthquakes: Captain Moresby informs me that they are frequent, though not very strong, in the Chagos group, which occupies a very central position in the Indian Ocean, and is far from any land not of coral formation. One of the islands in this group was formerly covered by a bed of mould, which, after an earthquake, disappeared, and was believed by the residents to have been washed by the rain through the broken masses of underlying rock; the island was thus rendered unproductive. Chamisso[12] states, that earthquakes are felt in the Marshall atolls, which are far from any high land, and likewise in the islands of the Caroline Archipelago. On one of the latter, namely Oulleay atoll, Admiral Lutké, as he had the kindness to inform me, observed several straight fissures about a foot in width, running for some hundred yards obliquely across the whole width of the reef. Fissures indicate a stretching of the earth’s crust, and, therefore, probably changes in its level; but these coral-islands, which have been shaken and fissured, certainly have not been elevated, and, therefore, probably they have subsided. In the chapter on Keeling atoll, I attempted to show by direct evidence, that the island underwent a movement of subsidence, during the earthquakes lately felt there. [12] See Chamisso, in Kotzebue’s “First Voyage,” volume iii., pages 182 and 136.