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MICtOCOfY RISOIUTION TBT CHAtT 
 
 [ANSI and ISO TEST CHART No. 2) 
 
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 : 112 12.0 
 
 I.I 
 
 II 
 
 1.8 
 
 &mi^ 
 
 A APPLIED ItvMGE In. 
 
 '6S) EasI Morn SlrcO 
 
 ('16) 492 - OJOO- Phofie 
 (716] JSa - ^989 -fo. 
 
pamphlet Casa No. >-«? 
 
 ^ Rhprintki) Fkom TiiK Tkansactions Of 
 l,VY HK TiiKoNTo Astronomical 
 
 I J SociKTv For Thk Year ISKIl. 
 
 NEXT APPARITION 
 
 HALLEY'S COMET 
 
 JOSEPH POPE, C.M.G., r B 1 r Etc. 
 
900504 
 
Ni;XT Al'I'AKITIOS 
 
 HALLEY'S COMET 
 
 JOSICPH I'DPIC, CM I 
 
 i;ii. 
 
 IIAFMIV'S Ojmkt. 
 
 I-cyers „f astl,.,u„„i„,l sci.„«- wh„ are still i„ ,„i,|,n^. ,jf^ 
 ..u,„o, ,a,l .„ have „„.u.,l .ha,, as regards the n.anifes „, I 
 
 '""^ "■•""""' ''"^- "■» ><■."».. as c,„„ets. thev have Ce 
 
 ^s^.av„., than ,l,e «e„eratio„ i„„„e.l,atelv ,.«■„.„« o„; .l^ 
 
 " « at. hers „ the sk^■, a,„: with i„„,r.>ve,l ,„e.,„s „f oKsc-rvatio,, 
 ." -ery l,a,„l. the ac.„al „,„„ber of k„ow„ ..m.ets has ll 
 
 ;rt ™r'"" """"' '"^ "" '■"'' ™""^>— ' i"~ 
 
 I refer, however, t„ those .pleu.li.l u|.i,aritio„s which, fro,,, 
 llab..K„„„„Kof recorded hi.story. have ,«rio<licallv excit„l the 
 wo„der a„c. „,terest of ,„a„ki„d, „ is ,,'ow „earl>- twe.Uy '.!': 
 
Ilnlliv't l,mi,l. 
 
 M 
 
 since a rt-iilly xn-iit .■.iim-t (Intuoil in mir nkiis ()„r fiilliir^., |kt 
 liu|»i I slmulilHiiv mir ^r.mM. li.r-i, win- n...rf IcntuiiaU' in tlitir 
 ilay. Til ll'.-ni «:i> uivi-n to Ulmi,: llu' y.rvM innut i.r |s| I, nni' 
 of till' niriM lirilliatil nf nii«liTii tini.'.. wliicli, cnnlniry to ilie 
 rfpnlmiiinofiointtsiiijjiiural. v.:iH.iltin,'nilliyl»iuntirnlli;irvf»ts, 
 iiliiinilunt vinl:i>;is. ami a ni-ni-ral plmty, imlndi .y,. il i> s „|. „„ 
 umisual nnnihcr "f liviiis Imm lliat yrar. 
 
 In IH.;.-, a^lrnni.nurs win- ulailili ni-il l>y tin riiipinaranci' 
 cf the ininct kndwn a^ llalUy,, „l «l,iih ni.w liirtaltir. 
 I'ik'llt yi-ars later l.riiin;lit tliu >;r<at ..niu-t (if |s|:l, |,.rha|is the 
 most spliTHli<l cilijict of its class cccr prcsi'iitcd tri the eye of man. 
 Its tail extended over seventy decrees of heaven, and its l.rilliaiiei' 
 was such as to .ender it distinctly visible to the naked eye at 
 niHin. Ilonati's coinei in |N.-|S was the next im|ior,in); vis lor. 
 and the specncle aflorded liy its transit over Aptnnis formed a 
 Iwamifnl and impressive sit;ht. Once mole, in Isill, ,, i.,r(;c 
 comet made its ap|)earance. and thiitien years later another, 
 known as l' ia's. traxersed onr skies. Then followed the 
 comets of Is- ,tid |ss^', since which latter date no comet of 
 striking apjieariiice has liecii se-n. It is therefore not siir|>risiiiK 
 that on tiie threshold of the twentieth century we should lieRin 
 to realize the dearth of these' pheiumicna in our own times, and 
 to eiKiuire how s<Kin we may exiwct to lie a(;aiii favoured with 
 the Kloriolis spcitacle of a (jreat comet lilazillK in the heavens. 
 To this i|iie.stion science can furnish no |i<)sitive answer, Tl e 
 iiumlier of comets is lej;ioii. Hut all insiKiiificant fraction of this 
 nnmlier is known to us. The apparent size and lirilliancy of 
 these olijects ilepeud largely lipiu the nearness of their approach 
 to our Klolie. It is ipiite possible that one of the myriad wan- 
 derers in the realms of sp.ace may dash i ito our system' at ally 
 time, and in its headlong journev to the sim may cross our path 
 at a jxiiiit siifl"iciclitly near the earth to cause it to outvie in niaj; 
 uitude and splendour all | .vious apparitions. .-Vpart from such 
 a sudden and unlooked for coutiiiKellcy we shall ha\e to possess 
 our .souls in ;i;;tieiice for some years to come, for of nearly all 
 the noted ohjeets that liave iipjieared ill recent times, either their 
 \-Krm\s are infinite or are of such duration as to preclude the 
 
M 
 
 //,;//,! 
 
 |ii>t<tilitlit\ 
 iin'rt:il liif 
 lik.' :!Hlll Mar 
 
 ■ ilir lnhdliliin, ilicii, ii^uiii, .„ .„|y f,m. 1,1 ,|,j, 
 riK KriMl >,,iiul 1)1 |sl| liii«ii uriiKl i.f .iiimihiilit 
 rii.it „f im:; Hill „„, ri.-\i,n our »kiv» ln-f<iri- 
 Dr. >:„M „t III.- J 111, ,..„t„r>. „n.l a cull- in„r ihm-. a» unai 
 niu>t K„ ruiiii.l UC.ri- l)„„ali.. ,„„iit .„,m^ aKaiii »illil,> hailiiix 
 dlHtancf „t the i-arth. Tliu> all „. ,ai. ivir I,,,,*. ,„ Li„„v 
 of tlK-*' l,«iii., i, already rwnrik-,1 jfi „„r lihrarii.. of 
 tlu-tii the fiiliirv lla^. iiaiiKliI iti store for u», l-ortunatvlv the 
 orlnts of all the t-reat eoinel. are not traced on «uh ample lines 
 One-thai a»M»i.iti-d with the illnstnous name of llalley— is 
 kn.iwn to complete its elliptic c-onrse within the span allotted to 
 hinnan life. II last visii,,| „„r scsu,,, i,, ,1,^. ^,„,r |s:i,-, ,„„| |,^ 
 
 reapiicarance in llHO is .-.aifidently ked forward to. 
 
 As llalleys is the solitary known example of a cons|,i,nous 
 ccmiet with a fixisl uri.Kl „f less than a centurv, and as we all 
 t-njoy a reasonahle ex|«vtation of UholdinK it with onr own eves 
 It may not l>c ont of place todevote a few niinnles to a c-o.isidera- 
 tioii of Its past history and approaching; visit. 
 
 < tne sometimes meets with the rellection Ihat the development 
 of astronomic-al seience has had the elTcrt of u.v.nfmK the hnman 
 race-that in the liuhl of the knowlcsl^e whuh a jnst c-onception , 
 of the nniverse- reveals, man shrinks to ahscdnte insimiineance 
 and in his pniiy state is eomparal.le only to a niierosc-opic insivt 
 erawlniK on the rind of an oranne. 1 confess that the impression 
 
 which astronomy pr.«lnees o y mind is nither the reverse of 
 
 this. It is of course' true that si-ie-nce aopiaints us with the fact 
 that our v;lol,e is but one of a host of worlds, and that „ forliofi 
 the dwellers thereon must, hotli in re.s|»ct of their physical size 
 and the shortness of their duration, ,K-cupv hut an ntterlv iiisin- 
 uihcant relation to the sum of tllhlKs. Hut hnillanitv, I take it, 
 IS not to lie jjauned by pounds ,r:vi,di,fH:h. ■ The minds the 
 measure of the man,' ami 1 snljiiiit that, jndned In inan's 
 intellectual cajiacity , the disparity we are consideriiiK is hs no 
 means so oyerwhclminK as some of onr lHK.-ts ami phil,».ophers 
 are Kivcn to re|)resent. The niiaided intelliKeiice that has rea- 
 soned out the plan of the iiniverse-that has measured and 
 weighed the earth we live oii and the snii round which it moves 
 
Ilall.y, I, mi, I. ,-,;, 
 
 -tliiit l.„> ■l.unni.K-.l tiK- ri-lmi>. ,„sii„m, „r Hk. v:,ri,.,„ „I.„ki, 
 ■""I u.,l...k„l tl,.. „n.u.ri.., of ilKir >„,„|,l„ ,, ,i„„, -,|,„ 
 
 n„w..,.. .„« ,1,. ,H„„„i, „f „,. „ ,,,,.,„ ,,,„ .^.^,,,,,1 ,„^. 
 
 |.rol,„„„U>t ,kpll,« „l ,|...... ,„„1 pnKlai,,,. ' ilu- „.,.„r. .„>,1 .„„,. 
 
 |««iti..ii ..1 th.,«- .lisi,,„t ,|,|„r., whid. r..ll i„ 11,,. rta)ni» ..f tl,. 
 ■i.l.lut.- ,,,..„k, I., „,. rall„.r .,f ,|,.. «,.l c .,Hnl„„.., ,„■ ,|,, 
 Kriut tr.„i„r il,„„ „)■ i),i. l„iinl.l.,i v,,„k,„i His l,.„,.l \„,1 
 
 '.-umll,,,,,, ,1,, :,„„ „,m,kTf„l ,„ „ , i,„,lkrt„al lri„,„,.l„ 
 
 X afr,.r,U-,l ,„ „s hyhin, « , «iv,„ „i» „.,„,,., ,|,a, „„„, 
 
 ..,„„„. ul all c,„i,i.t>. „, ,l„. ,„,, ,v„rui.cc nf ,v[,„l, «v an- alrca.lv 
 lit-Kllinilli; In I,„k fiirH-aril. 
 
 At the tit„i «l,i.„ N,.„t„„ „a, i,,«aKc.,l i„ ,Uvvl„pi„K hi» 
 llK.Mx „f «rav,tatiu„ a hrillia„t nui.ct appiarul, whid,, l>,„„ it, 
 M/c- a„<l ^,Ju„l,M,r. i.xdti.l „„„.„al i„tcr.>t, S .l.lclv na,„i„K 
 mt,. new, it ,n,v.r>..,l th. hvav.-ii, with aln,„>t ir,c„„« .vahll! 
 rap-lity .is s,,,..- cxcx«li„K at ,<rihdi.„. .i: iniu-s ., s,r.,>„l 
 A,>,,r„ad,„.K' >l.c- s„„ withi,, half Ilu. clistan., the „„»„, fr,„„ 
 M,f larth ,t swi,„K r.„„„l that l,„„i„ar.v {„ iw.. „„„rs, a,„l throw- 
 inn "fr a tra.n „f light .iu,ri- tha„ a h„„,lri,l ,„illi„„ ...ik-s j,, 
 K-.,nth swt.pl „„twanl.s i„l„ spac- a„.l ha. iicv^.r >i„.„ l,,.,.,, s„.,. 
 
 1 his n,ysti.n„„s ,,,rai,Kir arristi.l thi' attii,iio„ of thv pri.i 
 "I P "l<».>rh.rs hin,.sdf, whn s„„Kl,t t„ a>avtai„ whether it i, ■ 
 m.«h. „<,t prove to he olK-,lie„t ,o the eo„trol]i„« pri„eiple whic . 
 I he ha.1 lalel, t,„„„l , reK„late-l the solar sv ste,„. Its a,„a,i„u 
 vdcK-ity, however. re,><lere,l it „„ „„s„ital,le ol.ject for his 
 researches a.,,1 it was re-servwl to a„otl,er ill„strio„s ];,>nlish„,a„ 
 -l-..ln,u,„l Ilalley-to eol„plete the applicatioi, of the law of 
 iiinversal Krav,tatio„ to the eo,„etar> world which Newt.,,, had 
 Ileum, 
 
 I" Ills-', the year foll.,wil,K that which the co„let ..hservc-d 
 hy .Newt..,, d,sapiieare.l, another canie int.. view, nflor.li,,.- Ilallev 
 the .,p|«.rt,n,ity for which he had lwe„ waiti„K. llavi,ij; ..hserved 
 Us ,>os,t,o„ a,„l co,„pare,l its orhit with great care, he re>„arke,l 
 that ,1 showe.! a strifci„K resel,.hlai,ce t.. the comets of l,",.!! .„,d 
 IMl., ,11 fact their ele„,el,ts were „earlv i,le.,tical. I.„rther 
 iiivest.Kat,,,,, led hin, t.. extend his co,„pariso„ to the co„,ets 
 wh,ch apiieared i„ U.M) and lliso. All the i„for,„atio,. he co„ld 
 
M 
 
 Ifalkv'a L'omef. 
 
 gather of these earher apparitions led him to suspect that they 
 were but reappearances of one and the same comet. His inference 
 did not rest merely in the correspondence of the intervals. 
 •' Many things. " he tells us, led him to believe that the comet of 
 l.'i:!l . observed by Apian, was the same as that described by Kepler 
 in lliilT, and which he himself saw in HiH2. The comet of 14r,lt 
 was not observed astronomically, but the chronicles of the period 
 record its motion being retrograde. Now, it is a peculiarity of 
 Halley's Comet that with. I think, one eNception, and that 
 unknown to Halley, it is the only comet having an elliptical path 
 and a period of less than a century, whose motion is from east 
 to west. Struck by these coincidences he set about tracing the 
 comet back to its fin t recorded appearance when it signalized the 
 birth of Mithridates, KtO B.C., on which occasion it is said to 
 have lieen visible twenty-fonr days and to have surpassed the 
 sun in brightness ; its tail extended forty-five degrees and it 
 occupied four hours in rising and setting. Halley noted its 
 successive visits in the years :i2:!, :«lll, .V>(), !i;iO, KKM;, 10S2, 
 11.')."), 12:i0, l:!0.-), l:)S(l, i4.-,(i^ and so up to his own times which 
 witnes.sed the twenty-fourth return from its first recoriled appear- 
 ance. He found it moving in a plane but little inclined to the 
 ecliptic and in an ellipse of a very great eccentricity approaching 
 the sun within about ">.'),(Hin,(KKI miles and receding therefrom 
 more than twice the distance of the planet Neptune. Becoming 
 mce and more convinced of the identitj of the comet he was 
 observing with those whose appearance I have mentioned, he set 
 himself to work to compute its next return, and after long and 
 laborious calculations announced that it would re-appear about 
 the close of 17.').'< or the Ijcginning of 17.')ll. He was then a 
 young Ulan and outlived his prediction, made in 17(1.'). nearly 
 forty years. He could not. however, hojjc to see its realization 
 and his words on this head are almost pathetic. 
 
 ■■ Wherefore if it should retuin ;ircordins lo our prediction about the 
 year 17!;8, iinjiarti;-! |jostcrity wit] not refuse to afknoivlcdfjc that this was 
 first discovered by a i F.nglishman," 
 
 A,s a matter of fact he had been dead seventeen years when 
 his i>redietion was fulfilled. 
 
/fal/iv's Comet. 
 
 As tlif time for the vfrificjitinii of this aniKuuicemt'iit drew 
 , near, much interest prcvailL'<l in the astronoinical world, and 
 
 efforts were made to fix the date with j^reater precision tlian 
 j Halley had attempted. That eminent man realized that tlie 
 
 I iniponderal)le, ahnust spirittia] textnreol" a comet must lie jjower- 
 
 1 fnlly swayed by the attraction of the UirKer jjhuitts, but know- 
 
 ledge of the law of j^ravitation was in its infancy when Halle\ 
 ; toiled over the problem as to the exact amount of perturbatiitn 
 
 1 his comet would he subjected to froui this cause, and it was 
 
 j reserved for later in\-estigators to solve it witli that rij;orons accur- 
 
 i acy in which astronomers delight. The skilled l-"rench niathe- 
 
 j niaticians. Clairaut and I.ahnide. undertook the task, which 
 
 I was one of enormous magnitude, involving the computatit)n of 
 
 I all the perturbations the comet had undergone throughout a 
 
 \ period of two revolutions, or I"iO>ears. At length the laborious 
 
 task was completed and the ainiouncement madt that the comet 
 would be retarded .')]S days by the influence of Jupittr.. and 1(10 
 by Saturn— Clairaut fixing the date of its perihelion passage for 
 the i;>th April, 17-V.), with a margin of thirty days for jHJssible 
 error. 
 
 These results were comnnniicated ti> the Academy of 
 Sciences on the 14th November. 17')N. and on the "'"ill ! iiplumbm ^^'* • y. 
 following the comet was seen b\- one (leorge Palitsh. a Saxon 
 peasant in the environs of Dresden. It arrived at perihelion on 
 the Kith March, IT')!*, just thirty days earlier than the date of 
 Clairaut's prediction, but within the limits of error which he had 
 assigned. 
 
 This certainly was a wonderful intellectual feat, and of a 
 nature to make us jin ud of our race. The intervals between the 
 comet's previous re-appearance had not been luiifonn. Con- 
 siderable discrepancies existed. This \-isit was '(-^(i days longer 
 than the previous revolution, which makes the triumph of the 
 astronomer all the greater. In a burst of enthusiasm I.alande 
 exclaims : 
 
 " What arc tliirly-two (i.iy 
 / one two-lmndredth part - 
 
 iin iiitcrviil of more than i 
 i'hirh obscrvatif^ns were 
 
 ) yens, durin^j 
 [ule. the comet 
 
nX 
 
 /Mln's Lomii. 
 
 Iwinu-mit "( sii'lil "11 'lit- ■•■-t"' Ilie '""<■' ^^'i-i' ■"' lliiitytivci ihy« (.ir 
 ^ill the mlirr .itlriic li.ins (,f llie -. I;ir .y~i™i wliidi h.nr ii.it lic.n inrhidril ; 
 fnr iill the r.iiiifti.. iIk- ^iliLitinii .iiul iii;i-ms r.f wliidi iirc unkintwn Ki us ; 
 foi thf it?>ist..ii(e tA Ili« rtlif:e:il inedilliii. wliirh we .ire unable even to 
 eMiiiiate, mix) 1.11 .ill til. se .|ii:ililies ulii. Ii "( lHles^ily li.i\e heen neulerteil 
 in the .i|iprii\iniati.ins if the ciileiiliitieii .' ... A ililTeremc of 586 
 (lavs lictw.en the revolutions of the siiiiie comet, a ihffeieme |irochued tiy 
 the distuiliint; artion of Juiiiler and Satuin, affords a liii.ie strikiiif; (U-iiion- 
 strati.in ..f the jtreat jirini iple of attrntion than we rould have daied to hi.( e 
 for. ami |j|ai es liiis la« aiii.ii(;-t the iiuiiii>er of the fundamental tiuths iif 
 I'hysirs. the realitv of vviiiih it is nii rule [.Cssihle to d.inbt than the existenee 
 of the hollies wliii h |irodliee it." 
 
 I.al.iiKle's Kratificiitioii is all the more legitimate when it is 
 colisitleretl that at the lime when these iiredictiiiiis were made, 
 the existence nf neither Uranns nor Neptune was known. Yet 
 the comet's jiath cuts the orliits of hoth these jilanets ami conse- 
 quently is more or less jierttirbed by them. 
 
 Ill the interval between IT-'i'.l ami l^o-'i, the rtate of the next 
 appearance of Ilalley's comet, Rreat strides had been made in 
 the science of astronomy. The planet rranns had been discovered, 
 the mas.ses of the larjter planets were more accurately ascertained, 
 and the methods for computinj; perturbations largely improved. 
 TakiiiK the perihelion passage of IT-V.I as the ]xiiiit of departure, 
 and followiuK iu the steps of Clairault, two French savants, 
 Messrs. Damoiseau and I'ontecoulaut. indeiielldetltly undertook 
 the necessary calculations anew. Their results agreed within a 
 few days. Mr. Damoiseau fixint; the date of the comet's jierihelion 
 passage for the 4th November, l-S:!."!. and Mr. Poutecoulanl ten 
 days later. Two other astronomers. Messrs. I.ehuiaun and 
 KosenberRer, respectively, fixed the dates at November llth and 
 •itlth. On this occasion not only was the perihelion passage 
 computed, but the exact path of the comet anions the stars 
 mapped out, and the precise point indicated at which it would 
 first be seen. The last of these piedictions was published 011 the 
 l-'.'ith July. lf*:!.">. On the eveniuK of the -"ith August Mr. 
 Duiiiotichel. of the Observatory at Komc. directed his telescojic 
 to the prescribed simH, and there, within a degree of the place 
 fixed by Rosenlierger, was the comet, as yet but a faint .stain of 
 
//tflliv's Coimi. 
 
 50 
 
 I a 
 ion 
 ten 
 iiid 
 md 
 ase 
 :ars 
 iild 
 the 
 Mr. 
 o]ie 
 
 I sice 
 
 II of 
 
 li;;l,t on the .k-ep blue c,f th.- \.ei.ve„s. It arr■^■e,l :.t ,»r,l.el,.,n 
 on llK- Mlth NovcinhtT, tlit- ,i;rfere,.ce l»:t«i-i.n the ol.senrf and 
 the naan of the c.nn,n.ted <h.tes hein^ less than three .lays. On 
 the '.th Ma;-. ls:;C., it finally eeased to lie yisllile. 
 
 Once more, and xvith Kreatly in.proved facilities, astronomers 
 acldressed the.nsehes to the task of Iracinu this ^van<lere. m Ins 
 mi«htv pil«rin,as;e. The <h.ra.i,>n of the last ,,er„„l was fonnd 
 totseventv-six years and \X< days. An e,|ual jx-nod jvo dd 
 brinir the next jwrihelion passawe to March 'I'Mx. I' -. It "a* 
 been ascertained, however, that the next retnrn »dl he son.e- 
 what accelerated 1>V the attraction of Jnpiter, and that the ,*r,„d 
 of the rev<,l«tion which the comet is now perK.rnnnK wdl be 
 nearly two years less than on the previous occasion, and shorter 
 than any l.i'therto predicted. According to the best .anthont.es 
 thenexi perihelio.i passage will take place on the ■.>4th May, 
 1111(1.* 
 
 Accounts of past appearances of Halley's con.et vary c.nsidera 
 blv in respect of its si/.e an.' brilliancy. These discrepances tnay 
 no doubt l>e accounted for to a consi.lerable extent by a con.pan- 
 son of its .listances from mn Kh.be at successne v.sus. These 
 necessarily ranged between wide linn.s. I.. !««•. the comet 
 approached the earth within fonr and a halt nulhon nules. 
 Doubtless there have been .«asions when the earth was on the 
 far side of its orbit at the tin.e the con.et cr.>ssed the echpt.c, u> 
 which event it would be separate.l bv- a nu.ch greater n.terval 
 than in Is:!.",, and consc'.iuently present a less conspicuous 
 appearance. 
 
 Apart, h.,wever, fr.m. the apparent effect due to chauK«s in 
 relative p..siti.,..s, Halley's come, is renu.rkable for sm^ular an. 
 sudden changes of aspect. I.nrinK some tin.e l>elore an. alter 
 its ,.-riheli,>u pa.ssaKe on N.nenrber ir.th. ISIL. >t ap,*ared .im.e 
 des'titute of tail. Vet in the preccliuK October ,. ha.l a .1 
 extending twentyfour degrees, which Bessel .lescrd«s as aung 
 been produced by emanations at first issuing Iron, the comet in 
 » 1 have alsi. seen ,;.c date sive" as the .6th May, 
 
m 
 
 tile dirt-ction of the 
 
 //iMy.< Ouiiii. 
 
 sun, anil Ijeiiij; swept niiniti as it' hv snnie 
 rt-pulsivi- forre. Ajrain, in tlie twenty fonr hours from tlie L'.inl 
 to tile LMth January, \><:'.l\, the liriRhtness of its nncleiis inerease.1 
 twenty fold. 
 
 These clianges indicatiiiR as the>' <lo the oiieratioii on a 
 vast scale of iiiiKlity forces unknown to man, add to the interest 
 with which we look forward to tlie next retnrn of Hallev's 
 Comet. 
 
-z^