The Use of the Globes. 263

p ^-IV. A Parallel Spbere is that whose°^ es co-incide with the Poles of the Ho-

rizon,

"slieP P erioc hcally, its Period being equal to 333 Days.to (j hasnomena of this and the like Stars are supposed.ti^g 6 ° w mg to the Spots on their Surface, which foine-tie r S ‘^crease, and sometimes decrease, in the Man-S Un aS We have observed they do on the Surface of our

^ 0r that the Stars are really Suns, and have each(> e ' ter n of Planets, &c. about them, like ours, cansofjj ° ^°ubt to those who understand the Rules of Rea-tightly, as I have before observed, Annot.Ajfj S " 1 - And therefore, as they revolve about theirtr e ’ those Spots may cause a great Alteration of Luf-I'hj'j. ?t>d sometimes wholly obscure them for a Time.

no Wonder if Bodies at such a Distance shouldUs, Appearances produced by Causes quite unknown toj ^^e more on this Head in Dr. Longs Astronomy.hq. ■?.* -^ s to the Distance of the Fixed Stars, we hadley Hopes of any Estimation of it, till Dr. Brad-

so y e S an his Observations on them with an Instrument1:^ y exaS, as that he is of Opinion, if the Paral-a Star amounted to but one single Second, heUiUst nave observed it; and therefore that such a StarS Usl ^e above 400000 times farther from us than the

its if S represent the Sun, X the Earth, ATB

Ui at thit, and R a Star at such a distance S R or T R,a 'i A E Semidiameter of the Orbit S 1 stiall subtendse |v gle XRS — 30'"', or half a Second, then we find^ . htance S R by this Analogy :

Is ^Tangent of the Angle TRS = 30"— 4. 371914S 0 ^ Radius 90° = 10.000000

l he Snn’s Distance SX— I — 0.000000

__

*^ e distance of the Star SR en 424700 =?. 5.628086.

Patsies ^ Ut the Distance of the Sun SX = 20000 SemU■ s of the 'Earth (fee Annot. CXXXIV.) ; andS 4 supposing

PlateLXIII.Fig. 4.