HISTORY OF MAURITIUS. 325 
" To resolve a problem of this nature, I had recourse to the variations, of which 
there is a sensible progression in these seas, in steering from east to west: with this 
view I traced all the courses of the vessels, whose error, between their points of de¬ 
parture, which were correctly known, such as the Isles of France and Bourbon, and 
the land-fall on the coast of Malabar , were of little consequence. I took care to 
mark the variations which had been observed, and having drawn the lines of a con¬ 
siderable quantity of them, I discovered that these lines cut the meridians in an 
angle of from 31 0 to 32 0 from north to west. 
“ As I could rely on the exactness of the observations made by M. Morphey, I 
referred to them for the intersection of the variations which he had observed, with 
the parallel of latitude of those isles, and I found that the two last were in 49 0 30', 
and answered, on the old charts, to Aldabra ; the isle of the Assumption in 44 0 55' 
longitude, and the middle of Cormoledo in 46°. I consequently traced them on my 
chart. 
" The correctness of this operation was confirmed to me about four months after, 
and before my chart could possibly have reached the isles, by a letter from M. 
Grandmaison, who had fallen in with the isle Aldabra , three days after his depar¬ 
ture from the Isle of Anjouan. The position, according to his reckoning, is pre¬ 
cisely the same as that which I had given to it. 
“ This method of determining the situation of the isles, and dangers of this Archi¬ 
pelago, by the variation, in default of astronomical observations, has appeared to 
me to be preferable to that of the track of vessels in this sea, where the currents are 
continually changing their direction. 
“ The Isle Natal , which is seen to the north of Aldabra , was observed by M. Barri, 
who commanded a ketch, in his passage to India, after having seen the Cape 
d'Ambre. The latitude is the same as is given in the Portuguese charts. 
“ The English ship the Atham, in 1758, discovered a sandy island, with several 
breakers, in 6° 57' south latitude, and thirteen leagues east from the Isle of Zan¬ 
zibar. The ship ranged along the sandy island to the westward at the distance of a 
league. 
“ The bank of Patram was seen in 1758 by the ship Pitt; when it was found 
to be in 4 0 30' south latitude, and 50' to the east of the meridian of the Isle of 
Cornmore. 
6t It is supposed also that there is a sand bank in 3 0 57' of south latitude, and 2 0 5' 
