C 156 ) 
tioDS,whiift the Earth approached Jupiter by more rhan 
the Radius of its own Orb ; and the difference of the fe- 
cond ifiquationsof the Firjl Satellite being according to 
Caffwi 8'. 30'', the faid difference in the Fourth ought to 
be i^-io'i inftead of 18 |; whence the Interval of thefe 
t'No Emerfions would be according to his Precepts, bur 
8}^ i6^*-46', inflead of i^^- if^- /s^?>\ obferved. And 
whereas i8^i nnay ftem too great a difference,- it muft 
be noted, firft, that Monfieur Romer had dated the whole 
I'econd Equation ^^^ 00'', ( vide PhiL Tranf Num, 136.) 
which Monfieur Ctf^;?/ has dirainiflied to i4'.io";fo that 
inftead of 8^1, Monfieur Romer allows above 13' ; and Ic- 
condly,that in the firft of thefe Obfervations, being about 
half an hour before Sun-rife,the brightnefsof the Morning 
might well hinder the feeing of this fmalleft and flowell 
Satellite, till fuch time as a good part thereof was e- 
merged. 
But I have exceeded the Bounds of my intended DS- 
courfe, and (hall only Advertife, That thefe Tables are 
not Printed with the ufual Care of the Imprimerie Roy ale 
a Paris, That the Tabula Revolutionum primi Satellitis 
Jovis in Amis loo.pag.i''^ ^ is faulty in thefe Years, 
^6, 39, 55, 98 & 99; as is alfo the Epocba for the Year 
1700, pag, 99. where pro Num. I. 1 853 lege 1873, and 
pro NumALioo^y lege 1 10,4 ; And that the Number of 
Revolutions of the Second Satellite in 100 Years, />j^.6o, 
61 ; of the Third 76,77 ; and of the Fourth, /dg.90, 
91, are by a grofs miftake of the Calculator, all falfe 
and erroneous, and muft be amended by whofoever 
would ufe them. Which yet ought not in the ieaft to 
be attributed to the Excellent Author, but rather to the 
Negligence of thofe employed by him. The Reader 
hereof is defired to amend thefe following Errata^ which 
were difcovered when it was too late. 
ERRATA. Pag. 138. 14. pro 5°- 30'. % y^- 
31'. 40". lin. 2 y. pro &^'x6'l leg. 8°-28' I 
' 111 A 
