August 6th.

We passed out to sea to the southward by a wide and clear channel between the Duperre and Jomard Islands.  The former are five in number, all uninhabited, small, low, and thickly covered with trees.  They extend over a space of about six miles on the northern margin of a large atoll or annular reef extending eleven miles in one direction and seven in another, with several openings leading into the interior, which forms a navigable basin afterwards called Bramble Haven.  Inside the greatest depth found was twenty fathoms, with numerous small coral patches showing themselves so clearly as easily to be avoided—­outside, the water suddenly deepens to no bottom with one hundred fathoms of line, at the distance of a mile from its edge.

WESTERN ISLANDS OF THE LOUISIADE.

For several days we continued making traverses off and on the line of barrier reefs extending to the westward, obtaining negative soundings, and occasionally communicating by signal with the Bramble, which was meanwhile doing the inshore part of the work.  The next islet seen was Ile Lejeune of D’Urville, situated in latitude 10 degrees 11 minutes South and longitude 151 degrees 50 minutes East, eight miles to the westward of the nearest of the Duperre group, with a wide intervening passage.  The sea-face of the barrier now becomes continuous for twenty-one miles further, its northern side broken into numerous openings, leading into shoal water.  It is, in fact, an elongated, almost linear atoll, with islands scattered along its sheltered margin.  After this, the barrier becomes broken up into a series of small reefs, with passages between, still preserving a westerly trend, until it ends in longitude 150 degrees 58 minutes East.  Several small, low islets are scattered along its course; of these the Sandy Isles come first, three in number, two of them mere sandbanks, and the third thinly covered with trees, apparently a kind of Pandanus.  The neighbouring Ushant Island (supposed to be that named Ile Ouessant by Bougainville) is larger and densely wooded, and still further to the westward we saw the two Stuers Islands, also low, and wooded.  All those islets hitherto mentioned as occurring along the line of the barrier reef are of the same character—­low, of coral formation, and generally wooded—­and so are two others situated a few miles to the northward of the reef, and unconnected with it.  These last are Kosmann Island, in latitude 11 degrees 4 1/2 minutes South and longitude 151 degrees 33 minutes East, and Imbert Island, situated thirteen miles further to the westward.

August 11th.

Today we came in sight of two groups of high rocky isles, very different from the low coral islets in the line of the barrier reef, which here ceases to show itself above water.  These are the Teste and Lebrun Islands of D’Urville, the latter two in number, and of small size (the westernmost, in latitude 10 degrees 53 minutes South and longitude 150 degrees 59 minutes East) the former, a group of four, of which the largest measures two and a half miles in length, while the smallest is a remarkable pyramidal projection, to which the name of Bell Rock was given—­this last is situated in latitude 10 degrees 57 1/2 minutes South and longitude 151 degrees 2 minutes East.