and Longitude of the Royal Ohfervatory at Greenwich, j 
zenith diitance of the equator, affected only by the mean refrac- 
tion. 
I (hall now give the apparent zenith diffance of the equa- 
tor, and the true latitude of the Obfervatory, refulting in this 
manner from my obfervations of fix years, from the autumnal 
equinox of 1765 to that of 1771, in which I allowed o",g for 
the correction of the error of the line of collimation, additive 
to the obferved zenith diftances, as I found from a revifion of 
my calculations of the zenith diftances of (tars taken with the 
mural quadrant, compared with the like taken with the zenith 
fe&or in 1768. 
Years of the obfervations. 
Number of days of 
obfervations. 
Apparentzenith 
diitance of equa- 
tor, taking the 
fun’s horizontal 
parallax 8", 8. 
T rue latitude of 
the Obfervato- 
ry, according to 
Dr. Br adley’s 
refractions and 
the fun’s hori- 
zontal parallax 
8", 8. 
0 in 
0 / // 
Autumnal equinox of 1765311(1 vernal of 1766 
, 5 2 
51 27 28,6 
5 1 28 40,1 
Autumnal equinox of 1 766 and vernal of 17 67 
33 
3°>4 
41,9 
Bo : h equinoxes of 1768 — — 
46 
3 2 >2 
43,7 
Both equinoxes of 1769 — — 
48 
28,7 
40,3 
Both equinoxes of 1770 — — 
20 
2 9’3 
40,8 
Both equinoxes of 1 77 I — — 
42 
2 9>7 
4 D 3 
Mean from fix years obfervations — 
— 
5 1 2 7 29,8 
51 28 41,3 
Mean found by Dr. Bradley, with O ’s hori - 1 
zontal parallax Io"y - — 
J 
51 27 28 
5 1 28 39’5 
But if i",2 be added to reduce them to 
the -» 
O ’s horizontal parallax 8", 8, Dr. Brad- z 
51 27 29,2 
5 1 28 40,7 
i.fv’s refill f will he rlmncred to — 
Differing from my determination above only 
0,6 
0,6 
In further confirmation of the latitude of the Obfervatory, 
I fhall now adduce eight years obferved zenith diftances of the 
fun in the folflices, being deduced from a< number of obferva- 
tions taken at and near the lolftices, and corrected for line of 
collimation, refraClion, parallax, and nutation. 
Years 
