[ 47 ° ] 
Few obfervations of Venus near the inferior con- 
junction with the Sun on OCr. 31. 1751 were made, 
on account of the unfavourable weather here in Eu- 
rope. By an obfervation made at Greenwich on OCt. 
25, the mean horizontal parallax was 9", 8 ; but 
according to the obfervation made at Paris on the fame 
day at the Royal Obfervatory, that parallax was 
1 1 ",4. On OCt. 27, by an obfervation made at 
Paris, the © ’s mean horizontal parallax was 9^,8 5 ; 
but by an obfervation at Bologna on the fame day it 
was found to be By the obfervation at 
Paris on Nov. 17, the Sun’s mean parallax was 10", 5. 
By a mean of all the obfervations of Venus, the 
Sun’s mean parallax is 10^,38 ; and if we rejeCt 
the Paris oblervation on OCt. 25, that parallax is 
io' v ,i3*. 
We fee then that,according to thefe obfervations, the 
Sun’s mean horizontal parallax is not lefs than 8", 94. 
If we take a mean of the whole, that quantity is 
10,09: But if we rejeCt the obfervations that differ 
moff in excefs, the Sun’s mean horizontal parallax will 
be found to be 9^,92 a determination in which every 
affronomer might readily acquiefce, when he con- 
fiders the accuracy of the obfervers and the nice 
agreement of almoft all the obfervations. 
And fuch was the ftateof the Sun’s parallax as de- 
duced from the lateft and beff obfervations, when 
the approaching tranfit of Venus in 1761 engaged 
the attention of the curious of all nations. Dr. Hal- 
ley, in Philofophical TranfaCtions, N°. 348, had pro- 
pofed a method of determining the Sun’s parallax 
* See the Abbe de la Caille’s Introduction to- his Ephemerides 
Celeftes from 1765 to 1774. 
by 
