C ^71 ] 
not fo much as once to lofe the planet out of the 
field. I pronounced that moment (I mean that of 
internal contact) as foon as I faw a lambent light 
{not a well-dejined light) whirl round the opaque limb 
of the Planet j from whence I am inclined to think I 
pronounced that too early by two or three feconds. 
The firfi: part of this rare phenomenon, which I 
beheld, was a kind of penumbra, at 7^ 8' 50". 
I then counted i, 2, 3 to , and plainly difcerned 
the dark limb of Venus make a dent very near the 
vertex of the Sun’s limb. 
At y*’ 26' 34''' I perceived the lambent light above- 
mentioned j at which time the Sun was not above ' 
of a degree above the top of a chimney, 
This is a fimple and faithful relation of what I ob- 
ferved, which 1 had not even copied till this morning, 
after you was pleafed to notify your expedation. 
I am glad of this opportunity publicly to acknow- 
ledge the many obligations you have been pleafed to 
confer on me ; and am. 
Sir, 
(with great refpe<5f). 
Your much obliged, 
and mofi: obedient, 
humble fervant, 
Middle-Temple, 
S June, 1769. 
J. Horsfall. 
Z 2 
XXIII. 
