Concerning the Distance of the Fixed Stars. By the Honourable Francis Roberts, Esq; S.R.S.Author(s): Francis RobertsSource: Philosophical Transactions (1683-1775), Vol. 18 (1694), pp. 101-103Published by: The Royal SocietyStable URL: http://www.jstor.org/stable/102440 .

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( IOt )

Ifj ConterfZ?g tte DiJnce of tSt fed har^., Ey tbe Honaxrdble Francis Robcrts) ; S.R*S

fT*H E Ancicat ̂flr0n3tCts7 xvho had no ot11er t rvaSr of COmputlng thv DtEtan-eseS the Heavenly

Bcdkes but iDy tlleir i?aralI&x tv tIze Sc,nidiatnerer of tle E>Arths and bPing rlever able to dikoszer any in t11e fiXt Starss did lrom ti<ence rghtly enough nfer tlat vlleir IDiRonce wsas very greatX and tnucll exceeding that of ehe Planets, lut could go no firther otherwitc tIlan by uncertatn guesJ

slnce ttz^ Pythagereaa SyStem of the World has £?eca revlved by CoWeratruw, ( and now by all Matllematicians accepred for the trat ctat ) tl<ere Seemed groutzd to itnaO gine that tile Diameter of the Earth's Annual Couri (wI;h according to our beR A-Llronomers is at 1cal 4oooo times LSigger than the Ss¢ff+sidiamerer of the EarLh) might give a fenfible Parallax tO the Ext Stars, though -the other could norX and tilereby determine their Viw Rance more preciily.

But thougtl we have a Foundatton to buiNdon--So vaRly excceding-that of the AnctentsX there are ime C9n6de4-

rations may make us liuEpeA ttlat even this is not lar enough for our purpofet

Moileur Hagens ( who ts very exaR in lzts ARrona micalObSere7ations) tells us, he could never diliover any vifible Magnitude in the &xt Stars, though he lifed GlaScs which Magntfie the apparent Diaemeter above

.

IOQ ttmes. Now, {;nce in all likelihood- the fxt Stars are Sn5s

( perhaps of a dtirent Magnitude ) W7e m$y as a rea-

tonable Medixm prefime they are generally ab3ut the bigneSs of our Sun

Jet

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( iQX ) Let us then ( for Example) fuppoNe the Dog-Star to

be fiQ The DsRance fromt us to the Sun betng abow

X X times the Sun s Diarneter f as ts demonttrabins fi c;n bt SunS I)iameEer being 3t Pdinutes) it is tvident thaw rtRe Angle under wI->ich the DsgXstar rs Seen in Mr Hggerss lseleScopet muft be rlear tIe m it;-l tht

X7ate (3f its Parailax to the Sun s DillanceX ar Sernsiw

diameter of the Earthns *4nnual C8ourS S So that the Pa rallas to the wholc Diameter can b-e but doubae fuch a guanttys as even to IVIr. Hggens s rlice ObEervatton is

altogether inSenfible. ltho Dil:lance therefore of the fixt Stars Seems 11ardly

within the reach of any of Q2 Nletlaads to determineX but from what llas been laid dowt ve may draw feme Goncluf1ons tha-t will m«uch illufirat: ti Prodigious vaRneS of it

x0 Tlaat the Diamerer of the- EarthSs Aarsual Orb ( which contains at led I 60 Msllions of hfiles ) is blut as a Point in comparifon of it o Xt leaR it muR be above

60oo times theDiRance of the Sun: For if a Star {hould appear through the aforefaid Telefcope half a M;nate

broad ( which is a pret£y fcntible Magnitude ) the trale

epparent Diameter would not exce-ed x^8 3d. Minutes,

which is IeSs than the 60sotI. part of the apparent D=

merer of the Sung and conEcquently the Sun's DiRance nor the 60O0th. part of thv lliRance of tlle Star.

^. TIat could we advance towards the Stars 99 Parts

of the zthole Diflanceg and Ilave on3y XtQO Part remairx ingy the rStars svould appear little bigger t0 us than they do 11ere: For they would {hew no otherjwSe thar} they do tilrough a TeleNcope, which Magulfies-an EIunF dred fiold.

* That at leaft Nine Parts in Ten of the Spa£e be tween us and the tixed Stars Gn rective no greater

IFight trom the Sun, or any of the S2rs, than what we

have from the Stars in a clear Nigl}tv

* That

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( ro3 ) 4. That Light takes up mOre time in travelling from

the Stars to us, thatz we in making a Wel?-IndiaVt-yage ( W}liCil iS ordinarily perS7rmcXd in fx Wceks.) That- a vSound svould n^st arrivc tO US fr()tn ttlCnt't iN S°°O°

}ears, nor a Cannon*[3u11ct in a mucll longer time. This is caGly C0mJpLlt£32> by allowing (according to Ddr.Mewtan) TenMlrutts for tl1*t JurneyfDf light from t11c Sun hithcr > and tlat a Stund moves abc1t

. {8 .

X 3C)o o° ;n a occona s _ n s

III. Sn iMccount of a Stone of a Prodigiom J;z-> extraSed by SeSion out ef a Ufo}>t4S's Bfast- ger) nom liSvixg) ox the Etgbtb daw qf Nso vember, 693 by Mr. BaSi Wood ) Sz* gean.

H E PerSon who performed ttlis) being prevclt^d s upon by 53me rricnds to give tileCurious ar-

Atcount of the extratrdinary bigrae§;s and {hapP of ttlis Stone has communiated it to the Publier G -the>fs TranEaftionsX in thv H)llowing words.

This StonF was taRn from Mtrs. Hetchman, a Widow (ien.tlewomans of ttf4itX Abe of about 0k7e and Fty Yrars > who Ltdges in fLings-HeadFf oart in Molborno [ts {llape is not very unlil<<) to a fort of SprirgPurSe (aS ti1ty Are callFd 3 w^l><h many Pec>ple uSe; attx2 tts (1M7f,ira IS iTlt3i5e>CtR.t8.2S} lTnosth) excepring ouly tat ttzFr ;Wre wrour PretXab>-><ancrs; eacll of wllich is a1)Out t}lC

ZC °; a 41ZCt_NllVt; ttt5>-(^e f( em to have been t rrA 4t 14.sL <jl0n'v)3 w ich {aal ng into tllc bladd>vr a. er t int

trX grF>?it StOnez was atmoR g¢O*3vn tf) itS (1+ll; t-3ig^eE

r r< re > v;7ero Joye-vd to lts firR lDy ad hf (in) aZl( at ]aXz;

UPcame aI1 ono Buy rith it. It is aIrO £:fy prot->ablc that

( ro3 ) 4. That Light takes up mOre time in travelling from

the Stars to us, thatz we in making a Wel?-IndiaVt-yage ( W}liCil iS ordinarily perS7rmcXd in fx Wceks.) That- a vSound svould n^st arrivc tO US fr()tn ttlCnt't iN S°°O°

}ears, nor a Cannon*[3u11ct in a mucll longer time. This is caGly C0mJpLlt£32> by allowing (according to Ddr.Mewtan) TenMlrutts for tl1*t JurneyfDf light from t11c Sun hithcr > and tlat a Stund moves abc1t

. {8 .

X 3C)o o° ;n a occona s _ n s

III. Sn iMccount of a Stone of a Prodigiom J;z-> extraSed by SeSion out ef a Ufo}>t4S's Bfast- ger) nom liSvixg) ox the Etgbtb daw qf Nso vember, 693 by Mr. BaSi Wood ) Sz* gean.

H E PerSon who performed ttlis) being prevclt^d s upon by 53me rricnds to give tileCurious ar-

Atcount of the extratrdinary bigrae§;s and {hapP of ttlis Stone has communiated it to the Publier G -the>fs TranEaftionsX in thv H)llowing words.

This StonF was taRn from Mtrs. Hetchman, a Widow (ien.tlewomans of ttf4itX Abe of about 0k7e and Fty Yrars > who Ltdges in fLings-HeadFf oart in Molborno [ts {llape is not very unlil<<) to a fort of SprirgPurSe (aS ti1ty Are callFd 3 w^l><h many Pec>ple uSe; attx2 tts (1M7f,ira IS iTlt3i5e>CtR.t8.2S} lTnosth) excepring ouly tat ttzFr ;Wre wrour PretXab>-><ancrs; eacll of wllich is a1)Out t}lC

ZC °; a 41ZCt_NllVt; ttt5>-(^e f( em to have been t rrA 4t 14.sL <jl0n'v)3 w ich {aal ng into tllc bladd>vr a. er t int

trX grF>?it StOnez was atmoR g¢O*3vn tf) itS (1+ll; t-3ig^eE

r r< re > v;7ero Joye-vd to lts firR lDy ad hf (in) aZl( at ]aXz;

UPcame aI1 ono Buy rith it. It is aIrO £:fy prot->ablc that

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