HISTORY OF MAURITIUS. 
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opportunity oF pursuing fresh researches; and now it was that he first attempted to 
determine the longitude at sea, by the distance of the moon from the stars and sun ; 
a very bold attempt, which, from a want of proper instruments, was not so suc¬ 
cessful as it has since been. It appears that Appian was the first who conceived the 
idea of making the observations of the moon subservient to the determination of 
the longitude at sea. Gemma Frisicus, and Kepler, adopted his views: but it was 
reserved for the age in which we live to realize, by practice, the theories of these 
astronomers. 
“ M. Halley, convinced, from his own experience, of the insufficiency of the 
common methods employed by seamen to find the longitude, proposed to determine 
it by the motions of the moon, and the occupation of the stars occasioned by 
that planet: but the honour of having first employed this method belongs solely to 
M. D’Apres de Mannevillette. 
" On the 21st of October, 1750, he departed again for India, on board the ship 
le Glorieux, to the command of which he had been appointed by the Company; 
by whom he was instructed to determine, in a more exact manner than had hitherto 
been done, the position of the Cape of Good Hope, and the Isles of France and 
Bourbon. He was also ordered to examine the eastern coast of Africa, from Laurent 
Bay to the Cape of Good Hope. He received on board his ship the celebrated 
Abbe de la Caille, whom the government sent to the Cape of Good Hope, to make 
observations of great importance to the improvement of astronomy, and to measure 
a degree of the meridian. 
“ M. d’Apres put into Riode Janeiro on the 25th of January, 1751, and arrived 
at the Cape on the 30th of March following ; from whence he proceeded to fulfil the 
object of his mission, and accordingly steered towards the Isles of France and 
Bourbon. He determined, with the utmost precision, the position and form of those 
islands; and he detected an error of about nine leagues in the extent of the Isle of 
France from north to south, which he fixed at eleven leagues two-thirds, while the 
old surveys had given it twenty-one. 
" Two years after, the Abbe de la Caille received the orders of government to 
visit both these islands, and to repeat the same operations; and the calculations of 
the geometrician were in exact conformity to those of the navigator. M. d’Apres, 
on examining in his turn the survey which the Abbe de la Caille had made of the 
