[ 187 ] 
h 
f 
tf 
External contad 7 3 234! 
Detachment of the ligament 7 22 i2i-‘ 
I have llkewlfe obtained from my brother, Mr. 
John Horfley, a minute of his obfervation made at 
Greenwich with an excellent refrador of Mr. Dol- 
lond’s, which magnified, however, only 50 times. 
My brother afTures me, that he did not fee the liga- 
ment which I have defcribed, though it was feen by 
Mr. Mafkelyne and by others, at Greenwich. He 
has fet down, however, two different dates of the to- 
tal ingrefs. One, which he calls clofe contad with- 
out any light, appearing between the limbs of Venus and 
the Sun, at 28'' 15^', apparent time at Greenwich. 
Another, which he marks thus, “ a thread of light, 
fine as you can imagine, appearing between,” at 
7^ 29' 28^^ Here is an interval of 73'' between the 
clofe contadl and the appearance of light. The time 
of the appearance of the light being reduced to mean 
time, and to the meridian of Oxford (reckoning the 
meridian of Oxford 5' 4 ' weft of Greenwich, as it 
is ftated in Mr. Mafkelyne’s Tables), was 7^ 22' 9'', 
which is only 3'^ earlier than my obfervation of the 
detachment of the ligament. Now from hence I 
conclude, that the magnifying power of the telefcope, 
which my brother ufed, was too fmail to JJiew him the 
JJmpe of the ligament, yet the ligament had its effed 
with refped to obftruding the Sun’s light, which he 
perceived about the fame time as others, who ufed 
glaftes of greater force ; which feems to be a ftrong 
confirmation of the reality of what we faw : or that 
there adually was a part of the Sun’s diflc, which 
}3 b 2 remained 
