c 338 r 
them a Intoft in contact with the limb ; that is, 
hot § of a lecond of time diflam in palling a wire, 
for 1 have no micrometer; I think they can fcarcely 
be in fuch a hollow, below his ihrface, as the dodfor 
defcribes. To me, indeed, by the brighter light 
often adjoining to them when near the limb, they 
have rather put on the appearance as if they were 
in the crater of a volcano on the top of an 
eminence, which then turned its fide towards us ; 
and if fo, the fpot would appear fomewhat nearer to 
the limb than it addually was. I have, indeed, 
never feen any protuberance on either limb of the 
fun, as I have on the moon ; but I have many times 
obferved, near the eaftern limb, a bright facula juft 
some on, which has the next day fhewn itfelf as a 
fpot ; though I do not recoiled to have feen fuch a 
jacula near the weftern one, after a fpot’s dif- 
appearance. Yet, I believe, both thefe eircum- 
fiances have been obferved by others; and perhaps 
not only near the limbs. 
As to the nebula ; they are certainly not always, 
though they are ufually, quite round each fpot, of 
each clufter of fpots ; neither are they always ex- 
ternally convex. The fpot, fig. IV. which I faw 
Nov. 13, nearly in the centre of the fun, is a re- 
markable inftance of the contrary. Nothing there- 
fore can be concluded from that circumftance. Be- 
fides, fpots are fometimes quite without any nebula » 
at all ; or none that I could perceive with any 
power of my glafs. 
What, the fpots, or their n&bula , are, I pretend 
not to gueft. To me they appear as if they were 
adjoining to the fur face ; though, that, is doubted by 
better 
