HISTORY OF MAURITIUS. 
38 
u At six in the morning, Mercury came forth from the clouds which hovered 
over the mountains, when it had attained an altitude of 7°'§. He then observed, 
with a telescope of three feet in length, that it had but just entered on the Sun’s disk, 
and was near a spot, when the sky became cloudy, and it rained copiously till 40' past 
eight. 
<f When the weather was cleared he made his observations with the horizontal and 
vertical lines, which form, in the focus of the glass of his quadrant, a radius of three 
feet. He had already verified their position by the horizon of the sea, as well as that 
of the line of collineation. The times which he gives in his tables are the true ones, 
and the altitudes are corrected only by the quantity with which the quadrant had 
increased them, &c. 
" Art. 4.—Opposition of Saturn to the Sun. 
“ Art. 5.—Passage of Mars through its nodes. 
" Art. 6.-—Opposition of Mars to the Sun. 
u Art. 7.—Observations to ascertain the altitude of the Pole, and the obliquity 
of the Ecliptic.* 
“ I determined the elevation of the Pole from the place where I made the obser¬ 
vation, by the mean of four stars which pass near the Zenith; and served at the 
same time to verify the position of the axis of the teleseope of the sextant, in regard 
to the first point of the division, and by the means of the distance of the two tropics 
from the Zenith. In June, 1753, by five observations from y of the female Hydra, 
reduced to the 1st of January, 1750, I found its distance from the Zenith to be 
i° 39' 38",8, on one side, and by five others, reduced to the same, of i° 42' 22 // ,o, on 
the other side of the first point of the division; from whence it follows, that the error 
of the position of the axis of the telesope was 1' 21",6; that the real and corrected 
distance from the Zenith of i",2 of refraction, was i° 41' i",6; and that, supposing 
the declination of this star on the 1st of January, 1750, to be 21° 50'43",8 south, 
as in my catalogue, the elevation of the Pole was 20° 9' 42",2. 
“ In the same month of June, the reduced distance of s of the Crow, from the 
Zenith, was, by four observations on one side, i° 5' 22 // ,o, and by four on the other, 
i° 2' 42",7; the error of the sextant was therefore i' 19",7 : and supposing o",8 of 
* The following observations being very important to the cosmographic and maritime situation 
of the Isle of France, we have thought it necessary to insert them at large, as they have been 
related by the Abbe de la Caille. 
