towards the middle of the Belt. From 9 a clock % minutes 
and 40 fecondSjUntill 9 aclock and 8 minutes^they faw it in the 
midftof theBelt* At 9 a clock and 15 minutes it was paffcd 
the middlc,and was come nearer to the Occidental limb. And 
^little after the Heavens being over caft, he could Ehen ob- 
4ervc it no further. 
This Obfervation being taken for the Epo^hn^ it iseafic to 
'find hereafter the times^when this Spot fhall return to the midft 
of the Belt* Ftjr you are only to add alwaies 9 hours and ^6 
tninutesjand^for greater precifenes*/ fake^notto omit the or- 
dinary Equation of days, that depends from the inequality of 
themotionof theSun in refpeft of the Equinodial, nor the 
•particular Equation, that depends from the iuequaHty of the 
motion of Jupiter according to the diverfity of the diftance of 
the Sun ana his Apogee. 
This R^evolution being the fwifteft and the moft regular that 
i% hitherto known in the Heavens, a Traveilour alone , even 
"without having any correfpondcncc with other Obfervers., 
«aay makeufe ©f it to find the Longitudes the moft remote 
places of the Earth. We (hall hereafter cxamioe^ to what 
precilcnels^e may arrive by this way* 
Obfervatiom a New Comtt^made Paris in the J{pjinl Oiferva' 
tory bySigmr Gaffini* 
THere now appears a Comet,which feeras to be near the 
end of his Appearance,and which might have been feen 
above a month fince^ if the weather had beenf favourable* But 
he being very fmall^and ha ving been a long while obferved by 
the beams of the Sun^to which he was nigh, and afterwards by 
the Moon,which was greatly advanced in her light, befides 
that the Heavens in thefe parts have often been over-caft^ wc 
have not obferved him but lately* 
The Mathematicians of la Flef(^ perceived him from the 
5 5 of March, and gave us here at Pari$ the firft notice of it. 
l^hofe of the College of C/^rm(?7?^ being advertifed of it, faw 
bim the 2 %tb of the fame month. And upon notice given of 
it to the R. Academy of the Sciences by P. Par die Profeffbr of the 
j^ Mathematicksin the College of C/^rwff»^, Signor hath 
cif er:£nce beeu pbferyiBg him as snuch as the weather did per- 
