[ 628 ] 
after or before the contaCt as feen from the center of 
the earth. 
In all the above calculations, I have confidered the 
place of Venus, with refpedt to the center of the 
Sun, both in right afcenfion and declination j and I 
have neglected the fractions of feconds in the refults 
of the parallaxes of longitude and latitude, and I have 
always taken the fecond that was neareft to the frac- 
tional part. 
I take this opportunity of acquainting the Royal 
Society, that I have, by means of an achromic ob- 
jeft-glafs micrometer of 40 feet focus adapted to a 
reflecting telefcope of two feet focal Length, meafured 
the leaf! and greatefl diameters of the Spn, and I find 
the apogeal diameter = 3 1' 28", an4 the perigeal 
diameter = 32' 33 
Cl. Some 
