1805.
September.
of fresh water, called the Grand Bassin; its situation is more elevated than Vacouas, and except the ridges and tops of mountains, it seemed to be in the highest part of the island. This basin is nearly half a mile in diameter, of a form not far from circular, and is certainly deep; but that it should be 84 fathoms as was said, is scarcely credible. The banks are rocky, and appear like a mound thrown up to keep the water from overflowing; and the surrounding land, particularly to the south, being lower than the surface of the water, gives the Grand Bassin an appearance of a cauldron three-quarters full. No perceptible stream runs into it, but several go out, draining through hollow parts of the rocky bank, and forming the commencement of so many rivers; the Rivières des Anguilles, Dragon, and du Poste fall into the sea on the south or south-east parts of the island; the R. des Aigrettes before mentioned, and the R. Noire which runs westward, rise not far off, but their asserted subterraneous communication with the basin is doubtful. No great difference takes place in the level of the water except after heavy rains; when the supply, which must principally come from springs in the bottom, so far exceeds the quantity thrown out, as to raise it sometimes as much as six feet.
On the western bank is a peaked hill, from which the Grand Bassin is not only seen to much advantage, but the view extends over great part of Mauritius, and in several places to the horizon of the sea. It was apparent from hence, that between the mountains behind Port Louis and those of La Savanne to the south, and from the R. Noire eastward to Port Bourbon, not one-half, probably not a third part of the primitive woods were cut down; and this space comprehends three-fifths of the island, but excludes great part of the shores, near which the plantations are most numerous.
The elevated bank round the Grand Bassin consists partly of stones thrown loosely together; though porous, the stone is heavy and hard, of a dark grey colour, and contains numerous specks of what seemed to be feldt spath, with sometimes particles of mica and