[ 6, + ] 
judged of the contact when there was no light be- 
tween the limb of Venus and that of the Sun, others 
did not imagine the contadt to happen, till they loft 
a part of the circumference of Venus: I fhall there- 
fore fet down the difference between the obfervers, at 
the fame place, that an eftimate may be formed of 
the limit of this error. 
Ob fervers at Greenwich - 3 Difference in obfervation = o 
at Bologna - - 4 - -- -- -- - 6 
* at Paris - - - 6 - - - - - - ~ 16 
at Sherburn Caftle 2 - -- -- -- =4 
at Cambridge - 2 - -- -- -- - 7 
at Stockolm - -2 - -- -- -- =3 
at Upfal - 3 - -- -- -- - 6 
at Tornea - - 2 - = 14 
at Cape of G. Hope 2 - -- -- -- =4 
at Carlferona - 2 - -- -- -- - 6 
The mean, therefore, of all thefe comes out to be 
= 6 ", 6, an error that may be committed in judging 
of the contadt, even at the fame place. 
After having computed the parallaxes of longitude 
and latitude, on the fuppofition that the Sun’s paral- 
lax was = 8" 4., for each of the above places, I 
compared the obfervation at each place with the ob- 
fervation at the Cape of Good Hope, and deduced the 
Sun’s parallax from each, as may be feen more fully 
in the following table. 
* M. de la Lande, in a letter to Mr. Mafkelyne, fays that 
M. de la Caille obferved with a Telefcope of Mr. Dolland’s 
conftru<ftion, which was not well fitted up ; it may, therefore, 
be prefumed that there is fome miftake in the obfervation of 
M. Maraldi, becaufe his obfervation is later than that of M. de 
la Caille, and differs fo confidcrably from the reft. 
I. 
