[ 574 2 
LIII. T^he ^iuantity of the Sun s Parallax, 
as deduced frotn the Obfervations of the 
T^ranft of Venus, on June 3, 1769 : 
By Thomas Hornfby, M. A. Savilian 
Profef hr of Af rono 77 iy m the U 7 uverfiy 
of Oxford, and F, R. S. 
Read Dec. 19, ^ | HRE uncertainty as to the quantity 
1771- Jl^ Sun’s parallax, deduced 
from the oblervations of the tranfit of Venus in 
1761 (whether it arofe from the unfavourable pofi- 
tion of the planet, fo that a fufficient difference of 
time in the total duration of the tranfit was not, and 
indeed could not be, obtained from obfervations 
made at different places; or fiom the difagreement 
of the obfervations of different aflronomers, which 
were to ferve as terms of comparifon) feems now to be 
entirely removed : and from the obfervations made 
in diftant parts by the aftronomers of different na- 
tions, and efperially from thole made under the pa- 
tronage and diredlion of this Society, the learned 
of the prefent time may congratulate themfelves on 
obtaining as accurate a determination of the Sun’s 
diftance, as perhaps the nature of the fubject will 
admit. 
