[ 2 +5 ] 
c'ulation j then, at the internal contact, the fide S 
being the femidiameter of the fun, leffened by the 
femidiameter of Venus, is given, and alfo vl y the 
obferved difference of declination ; from whence may 
be found, by plain trigonometry, the angle -uS/; 
from which, if the angle Q^S C be fubtraded, there 
will remain the angle vS d- } from whence, with Sv, 
may be found S d, the difference of longitude, and 
y the difference of latitude from the fun’s center, 
in any other pofition, as at «, there will be given Sb, 
the difference of right afcenfion, and nb , the dif- 
ference of declination ; from whence may be found 
the angle u S h, and the fide S n : if from the angle 
b t the angle QS C be fubtraded, there will re- 
main the angle u S n ; which, with the fide S u y be- 
fore found, will give S the difference of longitude,, 
and un , the difference of latitude from the fun’s cen- 
ter. At the conjundion in right afcenfion, S V is 
the obferved difference of declination, and the com- 
pliment of the angle QSC is — the angle VSa; 
from whence will be found the difference of longi- 
tude S a, and the difference of latitude V a, from the 
fun’s center. 
I. If a mean be taken of the 4th, 5th, 6th, and 
7th of Mr. Hornfby’s obfervations, and alfo of the 
times at iy h 56' 46", the right afcenfion of the cen- 
ter of Venus will be i".2 before the fun’s center, 
and the declination of it 10' 10V6; from whence 
the vifible conjundion in right afcenfion was at 
*7 h 5 ^' 3 j// > ar] d { be vifible declination fouth of the 
fun’s center io' 10V4: the vifible longitude was, 
therefore, 1' 5" .5 before the fun’s center, and the 
vifible latitude fouth of it io 7 6 /7 .^, From the com - 
puted 
