C s 44 3 
eftimates to be, 9 hows and $6 minutes- 
For as Kepler did before con jedure, from the motion of 
die Primitive Planets about the Sun as their Center? that the 
Sun moved about its own Axis, but could not prove it, till 
by Galileo and shiner the Spots in the Sun were difcovered 5 
fo it hath been thought reafonable, from the Secondary Pla- 
nets moving about Jupiter } that Jupiter is alfo moved about 
his Axis; yet, till now, it hath not been evinced by Obfer- 
vation, That it doth fo move? muchlefs, in what Period of 
Time. And the like reafon there is to judge fo of Saturn % be- 
caufe of the Secundary Planet difcovered by Monfieur H«- 
gens de Zulichem to move about it 5 (though fuch motion be 
not yet evinced from Obfervation :) as well as that of the 
Earth , from its Attendant the Moon, 
Whether the fame may be alfo concluded of the other 
Planets, Mars> F<?»#/,and Mercury , (about whom have not 
yet been obferved aby Secondary Planets to move, ) is not 
fo evident. Yet there may be fomewhait of like probability 
inthofe. Not onely, becaufc it is poflibje they may have 
Secundary Planets about them, though not yet difcovered ? 
(For, we know, it was long after thofe of Jupiter , before that 
shout Saturn was difcovered ; and who knows, what after 
times may difeover about the reft. 0 But becaufe the Primary 
Planets being all in like manner inlightned by the Sun , and 
( in all likely hooef) moved by it ; it is likely that they be 
moved by the fame Laws aud Methods; and therefbre,turn 5 d 
about their own Axis, as it is manifeft that fome of them 
are# 
But, a? for the Secundary Planets , as well thofe about 
Jupiter , as that about Saturn 5 it is moft likely that they have 
no fuch Rotation upon their Axis* Not fo much, becaufe, 
by reafon of their fmalnefs, no fuch thing hath been yet ob- 
ferved/or, indeed, could be, though it were true ? ) But he- 
caufe they bring Analogical to our Moon , it is moft 1 ikely 
that they are moved in like manner. Now, though it be 
true. 
