^he Use of the Globes.

Xy 'J J

^ose" Qblique Sphere is that, one of

e Poles is above the Horizon, and

j Hi IV 0 ' Ve their constant Twinkling ;

"tl

tk- " — uifi

Line between

the Star

h' A.nH^ ^ ^ a V e alread y begun in a former Annota-

OTrlpr fn ii ndi=»rfl-'2rt/d fhf* T^r\rr*f» /if Ar.

, ln order to understand the Force of the Ar-n Lpt c showing Representations are necessary,hfr fo>Hi o ' 3e fo e bun, AB C D the Earth’s Orbit;- n. “ suppose a Perpendicular erected, as S P,

i ( S. though a*Star at P

V’heV 5! H

„ __ . Nov/ if the Spectator were

^ould view the Star in the fame Perpendicu-

.» ?0,

0e esteemed perpendicular to the Plane of the“la > ->-> J nt ^ be directed to the fame Point in thef M^-'fothe Perpendicular S P, as to Sense. SoOafe the Star P would ever appear in thefo’gbt were propagated in an Instant.

°cit

!n this very Cafe, in which the £§ht be propagated in Time or with ;’ en as the Earth describes its Orbit

Spec-

tator

the

the very small apparent Magnitude of the

,, - r 0 ; ----- v---- -.-6 , for being but

, every Qpake Corpuscle or Atom floating

r ' v ill be big enough to cover and eclipse them,

<thj a thev ' ^ ‘■'‘e-'

b- betr § et ln the right nine uuuvccu me a tarjjS S v e 5 which Alternations of momentary Occul-^ Apparitions make the Twinkling of theI speak of.

Otic here give a fuller Account of the small

i.a > ? a . rent Motion of each Star about its true

si!

fe' v ifibl ,n 0 lts ue Place P, projected in the Points inJ be Ie “u r f ace 0 f rhe Heavens. But if the Specta-cle jy^fod about the Sun in the Circle ABCD,, Ms a ‘atneter is sensible at the Distance P, or sub-Pf Ml s len fobl e Angle A PC, then in the Position APbœnonienon P in the Right Line A P <?,'t B p fok Point a. For the same Reason in tne^ill f e ’ D, the Star will appear in b, e, d; so that

Plate

LXIII

h'g-Ss

7.

» -> to have described the little Circle abed.

6 t)ia,. ® e Distance of the Star S P be so great, that

un, ' J laiV|p, "‘-“moc ui uie out u i w* 6

(,, c 5pp e ter of the Earth subtends no sensible Angle,(? c< *be as a Point, then will also the small CircleL;, tha„ C c me insensible : and all the Lines A P, BP

s V be ..—