1000000030

hiJ

a:ill/::f¡

",ill,~

giwn ;

ftl/(l I·j¡ ¡IJce

:h:

,cíip–

t~c,

11·(

d.;

I h(

monlh, od

"lile

Ih" d! . Ihollgh

1"'J

h./J ,dI br<ll lll ,-Rdllfy

Ihe gloSe for Ihe Ittiludo

l nd zenilh, and fn Ihe

~ uad

r.nt

of alti lude

Ihe givt1l

l l'mulh inIbe horiloo ;

k~~oin"

il there, lurn Ihe

gl~be

(>11

ils axis until Ihe ecliplic 'cu;s

Ih~

qu.drlnl ia Ihe gi–

reo

altilude: Ih' I poinl of Ihe ecliplic whieh CUISIbe

~nadrant

Ihere, will be the fua's place; aod Ihe day of

the

01001"

anfwfring

therel~,

lI'ill be fonnd over the like

lace of the fu n on Ihe wooden horilOn.

Keep Ihe

quadranl of oltitude inIhdt pofilion; and, having broughl

Ihe fun's plJce to Ibe brafen meridiJn, and thehour-indcx

XII

at noon, lurnbaek Ihe glube, unli! Ihe fun's

pl.ce

cuts the quadraot of

allilud~

osain, and Ibe illJex will

fnelV th: hour.

Any

111'0

POinl! of the ecliptic, which are equidifianl

from the beginoing of Cancel'

01'

of Capricoln, will h" 'e

the fame altitude and az;muth al the fame

h~ur,

thonbh

Ihe months be difIeren!; and therefore it reqaires fome

care in this problem, not lOmlll,ke bOlh Ihe mooth and

Ihe day of the monlh; lOaroid which, obferve, thdt

{rom Ihe 20th of M.reh tO the 2111of June, that part

of the ecliptic which is .(Jelween lhe beginning of Aries

and beginning of Canea is lObe ufcd: from the 2In

cf June

the 23d of September, belw,eo Ihe beginning

of Caneer and beginning of Libra : fromIhe 23d of Sep–

tem~er

to the 21fl of December,

b~tween

the beginning

.of Libra and Ihe beginning of Capricorn ; and from the

21fi of December to the 20th of March,

belw~eo

tbe

beginning of Capricorn and beginaiag of Aries. And:u

one can oever be at a lors

knowinwhat quaner of lhe

year he takes Ihe fuo 's altilude aod alimuth, the abol'e

caution wilh regard to the quaners of Ihe ediptic will

keep him right as to the mOnth and day lhereor.

PROB.

XXV.

To¡ nd

11"

/wg/h o[ /h, /ongej/ day

al an; givw plaa .-I f

the place be on lhe nonh fide of

me equator (fi nd ilSlatitude by Probo

l.)

and elevate Iho

nonh pole to that latilUde; lhen, bring the beginning

Cancel' to the bUlcn meridian, and fet the hour,in–

dex to

XII

at noon. But if the given place

on the

fomh fide of Ihe equalor, elel'ate Ihe fouth poleto its la–

titude, and bring the beginniog of Capricom to lbe

brafs meridian, and lhe hour-index lOXI I. This done,

turn lhe glob. wdlward, unlil the beginning of Cancel'

or Capricom (as lhe laliludeis nonh or fou lh ) comes to

the horizon; and the index will Ihea point out the lime

of fun-fetting, for it lI'ill have gone over all the after.

noon hours, betweea mid-day aod fun fet; whichlength of

time being doubled, will give the ",hole lengthof tbeday

from fun- rifi ng tOlun-felllng. For, in aUI.Hiludes, lbe

fun rifes as long befure mid day, as he fets after it.

PRono

XXVI.

To find ill 'Wha / IIIlillldr Ihd Mg–

tjJ

d.1!

iI,

,¡

afIJ giv,n I"'glh, lifi //'."

houn.- If

Ihe I"ilude be oonh, briog lhe beginning of CatÍce,

the b,.f.n meritlan, and devale the nonh poie lOa–

bout

('6~

degrlcs; hut if tI,e lalilude be fou[h, bling lhe

be~inning

of Cap' icorn 'o tlle meridian, and elevm ,he

{oulh poi. to abollt 66{ degrees; becaufe Ihe loogell day

in r.orth lalitude is, wlren lhe fun is in Ihe fidl poinl of

Caneer; and in fomh Idtilude, ",hen he is in the firfl

p~jtU

of C.pricorn. Thcn fel ule hour-inJtK to XIl at

no,r., an,1turn thc globe \VeflwarJ, untu tbe¡odex poinl1

al h, lf

tlr~

nUll1ber 01 hou,s giyeo; which done, k<tp lhe

~¡"be

from turning on ils aXIS, and Rid. lhe lIItrrdiolJl

down

lbe nOleh", unt il the

aforef.id

poiot of the e.

cl'Plic

(,.iz.

Caneer O( Cap' icorn) comel to Ihe horizon;

[hen, Ih. demioo of the pole \ViU be equallo Ihe lati.

tude ,equired.

Pr.OB

XXVII.

Tlu lalitud,

an, plaa, nol rr–

mding

dtgrm, brillg givrn:

fi~d

in 'Whal cli.

mate th, place

ÍJ.- Find Ihe length of [he loogell d,y at

the gil'eo place, by Probo

XXV.

aod, whatever be the

number of hours whereby il exeeedelh lwelve. doubie

llrat number, and tire fumwill give the'climate io whieb

the place is_

PRO Bo

XXV lIl.

The lalillldr, alld Ihe da, of lhe

1IIM/h, kú ng

gi.rn

; lo

f.nd

16,

ha/lr o[ Ih, do, 'When

Ih,

fin

jhimJ

.- Sel the woodcn borizon truly level, and

the b,afeo melidian due oonh and fOUlb by a m.,incr',

eompafs: Ihen, having retli6ed the

globe,

fiiek a fmall

f.IViog-otedle iotO tbe fun's rlace in lhe ecJiplic, perpen–

dicul" to lhat pan of lhe furface of theglobe : this dooe,

turn lhe globe

ils axis, un,il the needle comes lOlhe

brafeo moridian, and fel the hour-index toXII at nooo

then, tum the globe on ils axis, until the needle poinlS

exatlly towards the fun (which it wiU do wheo il cans

fhadow

t~e glo~e),

and the iodex willlhew Ihe hour

of the day.

r ile Ufo

o¡

Ihe Celeflial G/obe.

H AV' NC

done for the pr& nt with the terrellri.I

globe, we fhall proceed to lhe ufe of me celellial ;

-6d1

prelllifing, that as the equalor, ecliptic, lropies, polar–

circles, horiloo, aod brafen meridiao, are exatlly aIike

on both gloues, all the former problems coneerning tbe

fuo are folved Ihe fame way by bOlh globes. The me·

thod alfo of retlifying [he celellial globe is the fame as

reélifyiog Ihe terreflnal.

N..

The fuo's place for aoy day of the year lIand,

dirdtly over thal day on thehorizonof the celefliaJ globe,

as it does on that of the ,errellrial.

T he

lalitud,

and

longilude

of the flars,

01'

of all o·

ther cdellial pheoomeod, are reckoned in a , ery differ.

enl manoer from the latilude and longilude of places

the eaTth : for all terrell rial laliludes are reckooed from

the equalor; and longitudes from the meridian of fome

remarkable place, as of Loodoo by the Britifh, aod

Dí

Paris by the French. But the allronomers of all na–

tions agree in reekooing lhe lalitude! of tbe moon, flm,

plaoets, aod comel!, from Ihe ecliplic; and lheir loogi–

tudes from the equinotlial colure, in lhat femi circle of

it whiehCUlSIheecliptic at the beginoing of Aries; and

theoce eafiward, quile rouod, tOIhe fame feOli-circle a.

gain. Confequently thofe lIars ,,·hieh lie bttlVeeo Ihe e·

quinotlialand Ihe nonhernhalf of lhe ecliplie, hal'eoOltl.

decl lnation aod foulh lalitude ; Ihofe which lie betlVCCll

tire equi notlial and the foulhern half of ,he ediptie, have

fouth declioalion and nonh lalilude

and ,11 tlrofe ...hieh

!ie between the lropies and poles, have their dcclinalion.

and lali ludes of Ihe f,me denomin"ion.

Tbere are fiKg1'<al circks UII ,he edefiill

~Io~e,

whicl,