428 
1805. 
September. 
\ 
A VOYAGE TO {At Mauritius. 
of fresh wafer, called the Grand Bassin ; its situation is more ele- 
vated than Vacouas, and except the ridges and tops of mountains, it 
seemed to be in the highast part of the island. This basin is nearly 
half a mile in diameter, of a form not far from circular, and is cer- 
tainly 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, par- 
ticularly 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, drain- 
ing through hollow parts of the rocky bank, and forming the com- 
mencement of so many rivers ; the Rivieres des Anguilles, Dragon, 
and du Paste 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 com- 
munication 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 
