The Pbaßs ofJupiter ; byDr. Hook.n. 14- p- 245*

F'i- n?-

The Revolutiones Jupiter äs-en his Axis ;by S. Cam-pani. n. I, f .5

By Dr. Hook.h.

By S. Divini;

n. 12 , p. 20A.

( )

I fhall only sdd that the Proportion o 5 the Squares of the Times of tKePeriods to the Cubes of the Diflnnccs , ( which is propofcd as probable byKspltr, but now demonstratively found true by Mr. Newton, ) gives us nice-4 y the Proportion of the Diflnnccs of thefe Pinnets front the Center of Sa-turn ; and iüpposing the Satellite of Ilugens four Diameters of Saturn's RJnydistant from him, we fhall find by the Periods, the Diflnnccs as follows.

Periodus.

Diflantia.

d.

h.

/

Diam.

Intimi -

I

z 1

18F

O, 964

Z

17

i' -35

M edi i -

4

'3

4/4

1, 740

Penextimi -

i)

u

4 1

4, oco

Extimi — — ■-

79

7

54

11, 6z 1

Thele Diflances may be used, as more accurate than thosc obtaincd byObfervation, which yet dister but little therefrom.

LXXXII 1 . An. 1 666. Jun. t6. between z and 4 of the Clock in theMorning, I oblerved the Body of Jupiter through a 60 Foot Olafs, andfound the apparent Diameter of it through the Tube, to be somewhat morethan two Degrees, that is about 4 times as big as the Diameter of the Moonappears to the naked Eye.

I law the Limb pretty round, and very well defined without Radiation.The parts of the Phasis of it had various Degrees of Light. .About a, and/, the North and South Poles of it, somewhat darker, and by degrees itgrew brighter towards />, and c, two Belts or %°nes , the one of which, b, wasa lmall dark Belt croi-fing the Body Southward; Adjoining to which was a(mall Line of a somewhat lighter Part; and below that again, Southwards wasthe Great black Belt c. Between that, and c, the other smaller black Belt,was a pretty large and bright Tpnc, but the Middle d, was somewhat darkerthan the Edges.

LXXXIV. 1. 5 . Campani affirms that, by the Goodnefs of his Olaffes, hebath Oblerved certain Protuberanccs and Inequalities of Jupiter .- and he isnow Obferving whether they do not change their Situation.

z. An. 1664. May 9. about 9 a Clock at Night, Mr.Hoo 4 .with an Ex-cellent ii Foot Telelcope Oblerved a (mall Spot in the biggest of the threeObscurer Belts of Jupiter, and Oblerving it from time to time, he found thatwithin two Hours after, the laid Spot had moved from East to West, abouthalf the Length of the Diameter of Jupiter.

3. F.uflachio de Divinis pretends, that the Permanent Spot in Jupiter bathbeen iirst of all disoover’d with his Olaffes; that Ps Gctignics is the first that

bath