( 4040 ) 
ference : which makes us believe^that they are flat,aad fuper- 
Among thdfe Spots of the fecond fort there is none fo /en- 
iible,a$ one that is fcituate between the two Bchs,which in the 
difque olfupiter are ordinarily feen eKtendcd from eaft to weft^ 
the largeft of which is between the Center and the Northern 
iimb.and ihe narroweft is beyond the Center toward the Sou- 
thern hnib.This Spot is alwaies adhering to the Smthern Belt i 
itsdiacaeter is about the tenth pare of that of Jupiter --^ and at 
ehe time that its center is neareft to that of J^^puer^ it is diftant 
from it about the third part of the femi-diameter of thatPlaoet, 
Signor Cajfmi, afcer'he had made many Obfervations of this 
Spot during the Summer of the year i66;5found5 that the pe- 
riod of its apparent revolution is of nine hours znd fifty fix mi' 
mutes • and havii^g taken an Epoeha of the time^when it arrived 
at the middle of the Belt, he calculated Tables and Ephem^rids 
of its motion forthe end of the faid year i66s,and for the be- 
ginning of i666.He continued to obfcrve it until the beginning 
of 1 6665when '^npiter approached to the beaqas of the Sun^and 
the Obfervations were found conform enough to his Ephe- 
merids. But after it was got free of the fun-beams^tbisSpot was 
difficult to be difcerned z And as this gave ground to believe, 
chat it might be of the nature of the Spots of the Sun^which^af- 
ter having appeared for a while^difappear for ever,Signor Caf- 
^ni ceirfed at length to obfer ve them. 
But jf^fw. 19. of this prelent year 1^72, f ft. nj when he ob- 
ferved Jupiter at 44 a clock in the morning,he perceived in the 
fame place of his difque the Figure of the fame Spot^adhering 
to the fame Southern Belt. It was already gone beyond the 
moiety of this Beltjand he fa w it advance little by little towards 
the Weftern limb,to which it fcemed to be very near at 6| a 
clock : But it then appeared fo (mall and little^and fo little fen- 
fible^that he was obHged to ceafe from obferving it. 
By the Celerity of its motion near the Center, and by the 
place where he had begun to fee it, he judgedjthat it might 
have been in the midft of the Belt at 4 a clock and gf min^ in 
the morning And as he prepared himfelf to make Ephemerit 
des of its motion for this prefent year i Sja^he perceived^ that 
mthofe, he had made for the year 1666, by goodluckjthis 
%oc had been in the midft oi Jupiter the fame day, namely 
