C ^38 ) 
compleated ; or elfe that fome Invention of fliorter Telefcopes 
manageable on Ship-board, may fufBce to (hew the Eclipfes of 
the Satellites at Sea, at leaft thofe of the Third Satellite^ v* hich 
fall at a good diftance from the Body of Jupiter^ being near 
three times as far from him as the firft. 
Tlie laft but moft confiderable Treatife of this CoUedion gives 
the aforefaid Tables for computing the Motions of Jupiter $ So- 
teliites, but more efpecially thofe, for fpeedy finding the Eclipfes 
of the firft or innermoft. Wherein Monfieur Ca^ffi !)as cm- 
ployed his Skill to make eafie and obvious to all Capacities the 
Calculation of them, which is otherwife opcrofe to the Skilful, 
and not to be undertaken by the )efs knowing, who yet per- 
haps would be willing to find the Longitude of the Places they 
live in. 
Thefe Tables have for Principles, That the innermoft Satellite 
revolves to the Sun in i**- i8^- x8'. 36''. fo precifely, that in 100 
Years the difference is not finfible; That in the timr c ^ fhc 
Revolution of Jupiter to his Aphelion^ which he fuppofes in 
43 3x^' 14^* 5x'. 48'', this Satellite makes exaSly 2448 Months 
or Revolutions to the Sun : and dividing theOrbite of Jupiter 
into 1448 parts, he has in a large Table of ^Equation ibewn 
what is the inequality of the Motion of Jupiter in each Revo- 
lution reduced to Time, afTuming 7^^W/y,rhe greateft i^^quation 
of Jupiter f^- 30'. v/hence the hourly Motion ot \ht Satellite from 
Jupiter being 8^^- X 6' it follows, that the greateft inequality 
( Jupiter pafTing the Signs of Cancer and Capricorny ) amounts 
to 39'. 8^'. of time, to be added in Cancer^ fubftrafled in Capri^ 
torn, Laflly^ As r o th;: Epocha or beginning of this Series o[ Re* 
volutionsjhe has determined the Aphelion of Jupiter about i t De-^ 
gree forwarder than Aflrommia Carolina^ and above 2 Degrees 
more thm tht Ruelolphine TahleSy viz. precifely in 9°- of Lilra^ 
in the beginning of this Century, which perhaps he finds the 
proper Morion of Jupiter about the Sun at this time to requires 
and the number of Revolutions fince Jupiter was laft in PeriheliM 
is here ftiled Num. I. i 
