Fixt Stars are, like tlie Sm^ enobled with their own native 
Lights he fees DO iceonvenience in it to gflSrnij that jhey 
muft affo be fubjeil to the incurfions of (uch SpotSjas the 
Sun iSj which frequently augmenting about them do ob- 
{GurejirBpair^cr quite abfcond theirLi'ght5& rhatfometmc s 
for ^ longjfomerimes for a ihort time5& by turnsjsccoiding 
as the matierjof which they are made up, gathers together 
in great or fmall quantity.And therefore if fuch bodies ups 
on a fuddenmeet about any Starj which for many s'ges^be- 
iog free from fuchdarkning matter,did fliine very bright to 
us, what wonderjit fliould be obfcured.or vanifti altogether? 
Again, if any Star^ which before had alwaies about irfuch 
a quantity of Spots> as that for a long time it was counted to 
be (for example) of the fourth Magnitude^do unexpecSied- 
!y unvail its^facej it will then fhine forth and challenge pofH« 
bly the place of a Star of the fecond orfirfl Magnitude 
Again, if any Star*, having been for many ages confiEi'dto 
a dark prifon amongthefe Spots,do break Prifoa and fliow 
its formerly: reflrainM Light, what wonder^if there appear 
to us a New andnever before feen Star ? And if by a new 
colledion of Spots it return to its former imprifonment 5 
what wonder^if we lole again the Splendor of if ? Laftiyjif 
one only part of the body of any Star lets out its internal 
luftre^ and have a periodica! motion about its own Center; 
you 1 fee it^no lefs than that of BuUialdusVin the Whale^ ap- 
pear at certain determinate times, untill a new mafs of tol- 
levied Spot§3 or a nevi; Opening of the fame do occafion an 
unexpected alteration* 
Thefe our Author propofes as Pojftble Caufes of fuch EC 
fecfts 5 remitting thofej that require Indubitable ones, to that 
QiLucanVhzth\A. X, 
§ltmrite quos agkat Mundi labor ; at mihi femper 
Tu^qp^mnquB moves tamcrebrm Can fa meatus, ' 
*Vt Super i vdmre^ late^^ — • ■ 
So much of this Exercitation. which we confider as mofl 
proper fo^our purpofe. As for the others 5 we fli^ll but 
name 
