PIPER ISLETS.

After having anchored once for the night under the lee of reef e of King’s chart—­one of the most extensive we had hitherto seen, being fourteen miles in length—­on September 26th, the ship anchored under the largest of the Piper Islets.

This group consists of four low bushy and wooded islets, situated on two reefs separated by a deep channel.  The larger of the two on the south-eastern reef, off which the ship lay, is about half a mile in circumference.  The trees are chiefly a kind of Erythrina, conspicuous from its light-coloured trunk and leafless branches; one of the most abundant plants is a Capparis, with long drooping branches, occasionally assisted by a Cissus and a Melotria, in forming small shady harbours.  In the evening, vast numbers of white pigeons came over from the mainland to roost, and of course, all the fowling-pieces were put in requisition.  Some deep pits dug in the centre of the island were perfectly dry, and are probably so during the latter half of the dry season, or after the month of July.  On this island we observed the remains of a small establishment for curing trepang—­a large seaslug found on the reefs and in shoal water, constituting a valuable article of commerce in the China market, where in a dried state it fetches, according to quality, from 5 to 200 pounds a ton.  This establishment had been put up by the crew of a small vessel from Sydney, and several such have at various times made voyages along this coast and in Torres Strait, collecting trepang and tortoiseshell, the latter procured from the natives by barter.

YOUNG ISLAND.

September 28th.

On our way to the northward today, we passed Young Island, of King, which had been previously examined in one of our boats, and found to be merely a reef covered at high-water.  Twenty-nine years before it was an embryo islet with two small trees upon it.  And as the subject of the rate of increase of a coral reef, and of the formation of an island upon it, is a subject of interest and of great practical importance, I give below in a note* two records of the former appearance of Young Island.

(Footnote. “...Passed at about three-quarters of a mile to the northward of a small rocky shoal, on which were two small trees.  This particular is recorded as it may be interesting at some future time, to watch the progress of this islet, which is now in an infant state; it was named on the occasion Young Island.”  Narrative of a Survey of the Intertropical and Western Coasts of Australia, performed between the years 1818 and 1822, by Captain P.P.  King, R.N., volume 1 page 226.  Its appearance in 1839 is described as “an elevated reef, with one small mangrove growing on the highest part.”  Stokes’ Voyage of the Beagle volume 1 page 57.)

September 29th.

Passing inside of Haggerstone Island, we rounded Sir Everard Home’s group and anchored under Sunday Island, where the Bramble joined us after a month’s absence.  This is a small, high, rocky island, of flesh-coloured compact felspar.  On one side is a large patch of brush with some mangroves and a coral reef.