C 9-3 ' 
portion of the edge of the excavation, between the 
nucleus and the eye. 
Thel'e views, which now prefented themfelves, 
I remember to have communicated, that afternoon, 
to my fon; when I then told him, that, if they 
were well founded, there would be room to verify 
them, if the fpot fliould again return upon the op** 
polite fide of the difc. I was however uncertain, if 
it would laft fo long upon the fun’s body, as to be 
again vifible after the time of half a revolution-; a 
circumftance which I wilhed to take place, as I 
was aware, that my prelent obfervations might 
juftly be deemed infufficient, for eftablifhing fo lin- 
gular an opinion concerning the nature of this 
fpot ; and that, notwithstanding all which I had 
feen, we might ftill imagine, that thefe changes 
were produced by certain phyfical alterations of 
the fpot itfelf. 
Thefe confiderations made me attentively wait 
its return. At laft, on December i ith, I again dis- 
covered it, on the oppofite fide of the difc, it having 
by that time advanced a little way from the eaftern 
limb, being diftant from it i' 30". And now I 
could only perceive three fides of the umbra, 
namely, the upper and under fides, and that to- 
wards the limb, which was the fide that formerly 
had vanifhed. The fide towards the center of the 
difc was not as yet vifible j but I concluded, upon 
the fame grounds as formerly, that it was hid from 
my fight, by its averted pofition only, and that, af- 
ter the fpot had advanced a little further, it would 
make its appearance. Accordingly, the next day, 
being December 1 2th, at ten o’ clock, it came into 
Vol. LXIVo- : L C . . view 9 
