THE, SOU RCE OF THE NILE, 635 
fible, both at the zenith and horizon. With a brafs qua- 
drant of three feet radius, by one meridian altitude of the 
fun’s upper limb, all neceflary xquations and deductions 
contidered, I determined the latitude of the place of obfer- 
vation to be 10° 59’ 11”; and by another obfervation of the 
fame kind made on the 6th, 10° 59’ 8”; after which, by a 
medium. of thirty-three obfervations of flars, the largeft and 
neareft, the firft vertical, I found the latitude tobe 10° 59’ 103. 
a mean of. which being 10° 59’ gf”, fay ro* 59’ 10”; and 
if we fhould be fo unneceflarily {crupulows as toadd 15” for 
the meafured. diftance the place of the tent was fouth of 
the altar, then we fhaltl have: 10% 59’ 25” in round num- 
bers, for the exact latitude of the principal fountain of the 
Nile, though the Jefiuts have fuppofed it, 12° N. by a random 
guefs; but this being nearly the latitude of Gondar, the- 
eapital from which they fet out, fhews plainly they knew: 
not the precife latitude of either of thefe places.. 
On the-7th of November I was fortunate enough to be 
in time’ for the obfervation of an immerfion of the firft fa- 
tellite of Jupiter, the laft vifible here before that planet’s. 
conjunction with the fun. My fituation was very unfa- 
vourable, my view. of the heavens being every way inter- 
rupted by a thick grove of bamboo canes, with high and. 
_fhady trees growing upon the head of the precipice. Jupi- 
ter was low, and the prodigious mafs. of that beautiful 
mountain of Geefh, bade fair to hide him before our bufi- 
nefs was done; I was. therefore obliged to remove my tele- 
fcope up. to the edge of the cliff, after which, the weather 
being perfectly favourable, I had as fair and diftinct a view 
of the planet as I could defire, and from that obfervation I. 
did conclude unalterably the longitude of the chief foun- 
tal: 
