1000000030

Dorthero hemifpherc, \ViII be callcd ,he

1J0rlh/,ole

Ihe

jpbrrr;

aod ,hal whieh is in lhe middle of

,~e

fou,hero

hemifphm, Ihe

flulh pole.

If anolher greal eirele be draIVn upon lhe (phere, in

{ueh a manner as 10 cut lhe

equin,,~lial

at an angle of

23-t

de¡;rees in IWO

0~por,le

poin,s, ir

"Al

reprcfen, lhe

cditlic,

or eirele of I,le fuo's

app~renl

anrrual mal ion:

cne hall' of whieh is on lhe nonh fide of Ihe equinoé!ial,

Wld

Ihe olber half on Ihe fOUlh .

a large llud be made10more ea(!ward io lhis eeliplie,

io fuch a manner as 10 go quile round il, in rhe lime lhat

me fphere is turoed rOllnd IVe(!warJ

366,

limes upon ils

axis; Ihis nud l'Iill reprefenl Ihe/un, ehanging his place

every day a 36SI h pan of lhe celiplie; and going round

weflward, lhe fame way as Ihe Ilm do; bUl Wilh amo·

tion fo much nower lhan Ihe motion o¡ Ihe llars, lhal

they IVill make

366

revolulions abOUl lhe axis of lhe

{phere, in lhe time thal Ihe fun makes only

;65 .

Du·

ring one half of lhefe revolulions, lhe fun IVill be on rhe

nonh ficle of lhe equinoé!ial; during rhe olher half, on

th~

fouth; aod at lhe end of each hJlf, in lhe equinoc–

élial.

IVe fu ppofe lhe rerrenrial globe in lhis maehine 10be

abour one inch io diaméler, aoa lhediam :ter of lhe Ilarry

{pllere 10beabout five or r,x feer, a fmall iofea 00 lheglobe

wo'Ula fee only a very linle ponioo of its (urface; bUl

il would fee one half of Ihe flarry (phere; the coovexily

of rhe globe hidiog rhe olher half from ilS view.

Ihe

{phere be luroed \VenIVard round rhe globe, aod lheiofeé!

could judge of rhe appearaoees which arife from rhal mo–

tion, it ",ould fee fome flars rir,ng rO its vieIV in lhe

caflero fide of lhe fphere, whilll orhers IVere fening on

Ihe weflero: bUl as alllhe Hars are fixed to Ihe fphe,e,

Ihe fame n2rs1I'0uld always rife in rhe farne poinls of I'icw

onlhe eafl fid e, and fet in rhe fame poinls of view on the

wefllide. Wilh lhe fun il 1V0uld be olhcrwife, becaufe

the fun is not

fixed

ro .ny point of lhe fphere, bUl moves

1I0IVly aloog an oblique cirele in ir. And if rhe infeé!

tltould look rOIVards lhe fourh, aod call1har poinl of tbe

globe, whcre the equioollial in rhe fphere feems 10eUl it

on lhe lell lide, lhe

e.ifI p.i/JI;

and where it CUlS lhe

¡¡Iobe 00 lhe right fide, lbe

'W'¡¡

poinl;

rhe little animal

\\'ould fee lhe fuo rife nonh of lhe eafl, and fet nonh of

tbe \Vell, for

182t

revolutions ; afler which, for as

nlany more, lhe fun would rife fOUlh of lhe can, aod fel

fOlllh of Ihe \Vefl. And io the whole

365

rerolutions,

fhe fuo would rife only rwice in rhe ean poinr, aod fel

lwice in lhe \Ven. AH th& apI,earances would be lhe

{ame, if rhe flarry fphere nood flill (lhe fun only moviog

iD rhe eeliplie) and the eanhly globe \Vere turned ,ound

lhe axis of lhefphere eaflward. For, as lhe infeé! would be

carried round Wilh Ihe globe, he would be quileinfeofible

of ilSmOlioo; and rhe fun and flars \Vould appear 10

move wefhvard.

We may imagine as many cireles defcribed upon lhe

eanh as IVe picafe ; and we may imagioe rhe plane of any

cirele defcribed upon lhe earrh rO be conlioued, unlil il

marb a cirele in the concave fphere of lhe hea.eos.

The

horizon

is eirber

flnjiblt

ralional.

The

flnjible

horizon is that eirele \Vhich aman flanding upop a large

rlane obfer,es 10 lerminare his view all around, where

lbe beaveo

and

eanb fcem tO meer. Tbe

pl~oe

of our

fenGble horizon conrinued la lhe he.v"-n, di,'ides il

,oto

1\1'0 hemifpheres ; one vifible rO us, lhe orher hid

¡be

convexily of rhe eanh.

The

pl.ne

of rhe

rolional horizon,

isfuppofcd parallel

10 lhe plane of Ihe feoG¡'le ; (o pafs rhrough rhe centre

of lhe

e.nh

, and 'o be conlioued ¡O lhe heavcns. And

ahhough rhe plane of lhe fcnr,ble horizon rouches lhe

e.nh

in lhe place of lhe obferver. yer

IhiJ

plaoe, and

lhar of the mional horizon, \\ ill feem10 coincide in lhe

he.ven, bec.ufe lhe whole earth is bur a poior comparcd

10 ¡he fph ere of lhe hea"en.

The eanh being a fpherical body, rhe horizon, or li.

mir of our vicw, mun ehange as we change our

p~ee.

The

po'"

Ihe Mrlh,

are rhofe rwo poinls on il!

furface in IVlrich ilS axis termi natrs. The one is called

lhe

lIorlh

1,le,

.nd ,he orher the

flu lh p,le.

The

p./u.o[ Ihe he.v,n,

are thofe I\VO poinrs in which

lhe eanh's axis produced

lermin~res

in Ihe heavcn; fo

lhal lhe

norlhpole

of lhehea"en isdireé!ly over lhe oonb

poleof the

e.nh

; and lhe

jóulh1'01,

of rhe heaven is di–

feé!ly over the fomh poIe of

rh~

eanh.

The

'qual"

is a grear cirele tlpOOrhe eanh, every

pa" of \Vhieh is equaHy diflanl fromeilher of rhe poles.

divides ¡he eanh imo llVO e9ual pam, calJed Ihe

IIOr–

,her"

and

fi'i1hm, h'l/Iijphem.

lf we fuppofe lhe plane

of Ihis eirele 10 be eXltnded ro rhe heaven, il wi11 mark

lhe

(quino{/ial

thmio, and will di,ide the heaven ioto

rIVO equal pans, called lhe

/Jorlhern

and

flulh,m

hemi–

fploercs of ¡oe heaven.

T he

IIIcridi.n

of any place il a greal cirele paffiog

lhrough rhal place and lhe poies of the eanh We may

imagine as maoy fueh rneridians as \Ve pleafe, becaure aoy

place lhal is ever fo linle to lhe eafl or \Yefl of any olher

place, has a dilfercnl me'1dian from lhal place; for no

ooe eirele cao pafs rhrough any two fuch plaées and rhe

poles of rhe eanh.

T.he

IlIeridian

of aoy place is divided by lhe poies io–

la t\Vo (cmicircles: rhar \Vhich paffes lhrough lhe place

is called rhe

g,ogrephicol,

upp" lIuridialJ;

and rhat

whieh palfes lhrough lhe oppofile place, is called lhe

lo'Wtr lIIeridian.

When the rOrarion of lhe earlh brings the plaoe of lhe

geographical meridian ro rhe fU.n. il is

nOM

lIIid-da}

la lhat place ; and when the lower meridian comes rOlhe

fuo, il is

mid.nighl.

Al! places Iying undrr rhe fame geographical meridiao,

have rheir noon ar Ihe fame lime, and confequently al!

lhe orher hours. Al! thore places are raid 10 have rhe

fame

IOllgilude,

bccaufe no one of ¡hem lies either eall·

ward or we(lward from any of rhe refl.

IVe imagine

femieireles, one of whiclr is lhe geo–

graphical mcridian ora gi"en place, ro mm al rhe poles,

and ro divide the equalOr ioto

equal pans; eaeh of

lhefe meridians wi11 come rouod rOtite fun iD

hours,

by lhe earrb's equable motion rouod il! axis in rhar rime.

And, as lbe e9uaror cootains

360

degrees, lhere will be

degrtes contaioed hetweeo any lWO of lhere meridians

which are nearefl rOone aoorher : for

rimes

360.

And as lhe carrh's mOlion is ealtward, Ihe fun's appmnt

motion will be weflward, al lhe fale of

degrees eacn

bour. Therefore,

They whofe geogmphical

mefiJi~o

degrm ufl·

ward