CEHM Microfiche Series (l\/lonograplis) ICIMH Collection de microfiches (monographles) Canadian Institute for Historical Microreproductions / Institut Canadian de microreproductions historiques Technical and Bibliographic Notes / Notes techniques et bibliographiques The Institute has attempted to obtain the best original copy available for filming. Features of this copy which may be bibliographically unique, which may alter any of the images in the reproduction, or which may significantly change the usual method of filming are checked below. n n n D D n D D D Coloured covers / Couverture de couleur Covers damaged / Couverture endommag6e Covers restored and/or laminated / Couverture restaur^e et/ou pellicul^e Cover title missing / Le titre de couverture manque Coloured maps / Cartes g^ographiques en couleur Coloured ink (i.e. other than blue or black) / Encre de couleur (i.e. autre que bleue ou noire) Coloured plates and/or illustrations / Planches et/ou illustrations en couleur Bound with other material / Reli§ avec d'autres documents Only edition available / Seule Edition disponible Tight binding may cause shadows or distortion along interior margin / La reliure serr^e peut causer de I'ombre ou de la distorsion le long de la marge int^rieure. Blank leaves added during restorations may appear within the text. Whenever possible, these have been omitted from filming / Use peut que certaines pages blanches ajout^es lors d'une restauration apparaissent dans le texte, mais, lorsque cela ^tait possible, ces pages n'ont pas 6t6 film^es. L'Institut a microfilm^ le meilleur exemplaire qu'il lui a ^t^ possible de se procurer. Les details de cet exem- plaire qui sont peut-^tre uniques du point de vue bibli- ographique, qui peuvent modifier une image reproduite, ou qui peuvent exiger une modification dans la m^tho- de normale de filmage sont indiqu^s ci-dessous. Coloured pages / Pages de couleur I I Pages damaged / Pages endommag6es n D D n Pages restored and/or laminated / Pages restaur^es et/ou pellicul^es Pages discoloured, stained or foxed / Pages d^olor^s, tachet^es ou piqu^es Pages detached / Pages d^tachees rri Quality of print varies / Showthrough / Transparence Quality of print varies / Quality inegale de I'impression Includes supplementary material / Comprend du materiel suppl^mentaire Pages wholly or partially obscured by errata slips, tissues, etc., have been refilmed to ensure the best possible image / Les pages totalement ou partiellement obscurcies par un feuillet d'errata, une pelure, etc., ont 6X6 film^es k nouveau de fa^on t obtenir la meilleure image possible. Opposing pages with varying colouration or discolourations are filmed twice to ensure the best possible image / Les pages s'opposant ayant des colorations variables ou des decolorations sont film^es deux fois afin d'obtenir la meilleure image possible. \^ Additional comments / Commentaires suppl^mentaires: Pagination is as folloNs: p. [137]-151. This Hem is filmed at the reduction ratio checked below / Ce document est film^ au taux de rMuction indiqu^ ci-dessoua. lOx 14x 18x 22x 26x 30x J 12x 16x 20x 24x 28x 32x Tha copy filmsd h«r« has baan raproducad thanks to tha ganarosity of: National Library o£ Canddd L'axampiaira filmi fut raproduit grica A la 9*n4rosit* da: Bibliotheque nationals du C a n ada Tha imagas appaarmfl hara ara tha bast quality possibia considaring tha condition and lagibility of tha onginal copy and in kaaping with tha filming contract spacilicaiions. Las imagas suivantas ont ata raproduitas avsc la plus grand soin. compta tanu da la condition at da la nattat* da l'axampiaira filma. at an conformit* avac las conditions du contrat da filmaga. Onginal copias in printed paper covars ara filmad baginning with tha front covar and andmg on tha last paga with a pnntad or illustratad impraa- sion. or tha bach covar whan appropriata. All othar original copias ara filmad beginning on tha first paga with a printed or illustrated impres- sion, and andinfl on the laat page with a printed or illustrated impression. Tha last racordad frame on each microfiche shall contain the symbol -^»- (meaning 'CON- TINUED"!, or tha symbol V (meaning "ENO'l. whichavsr applias. Maps, plates, chaas. etc.. may be filmed at different reduction ratios. Those too large to be entirely included in one exposure ara filmad beginning in the upper left hand corner, left to right and top to bottom, as many frames aa required. The following diagrams illustrate the method: Las axamplairas originaux dont la couvartura an papier est imprimoe sont filmas »n commencant par la premier plat at en terminant soit par la darniAre paga qui compona une empremte d'impression ou d'illustration. soit par la second plat, salon la cas. Toua las autras axamplairas originaux sont filmOs an commandant pa: la premiere paga qui compona une empremta d'impreasion ou d'illustration at en terminant par la darniOro paga qui comperta una talla •mprainta. Un das symbolas suivants apparaitra sur la darniAra image da cheque microfiche, selon la cas: la symbolo — ^ signifia "A SUIVRE", la symbola ▼ aignifio "FIN". Las canaa. planches, tableaux, etc., peuvent atra film*s A das taux da reduction diffarents. Lorsqua la document att trop grand pour atra raproduit an un saul clich*. il att filma 4 partir da I'angia supOrieur gauche, de gauche i oroite. et da haut en bas. an prenant la nombre d'imagas nacessaira. Las diagrammas suivants lllustrent la mAthoda. C^ .H.^-^-i; fiwv > n >: ; .- I 'r>»4[ LTBI.KATIO.NS .\'^: dominion ^Istropljpsical ObsfiUatorp \ K IDKi \ \nL I, \,,. 7 / / i )r^T^.,iN(, \ aim \i;i.i; r (»i'im( III. i;s \ ri.i'i;( ri.\i wd iw iHivcoxi,- in .1, 1'1.\--KKI 1 i-\ I IKiDI ( TION 111 licicniiii illiij the iir IiiimI rlrllirlil- lit a ~|), 11 in-ci incasmTiiitMils of the imiI III' I 111' rclalivi' orliit, il ipii- liii iar\ III 1111 a -{•viv- il rMilial M'liinl v. u< ran ii-iiall.\ nlilain llic iiciiml. the iTrcnlricil \ ic iiiaxiiiiuni iirliilal \r|iii'ily, ll.c \clocily nt' ihi- iriitii- nl nia— nt llic >>st('iii, and tile lonnitiuli' ami t iiiir III |M'ria>tniii. The ilicliuatidli iif the plain' nf llii' nrliit in liii. plaur laiii^nil lit llir rrlc-lial -iili is indctciiniiiahlc ami ciiiiscinu'ntly, thdiinh lonnulu iml t 1- an' available ni\iliii tin- >('ini-a\i~ major ami the mass, these hoili appear a< limcli(in< of the sine i.| the iiielinatinii. ami their actual values musi remain imknoun >o lonu a> the imiiiiat ill respect to the i xpiession Un- the ma-s oi' t ratio of tlie masse- of the two limlie^ ami unle.-^ ihi- i- '• the eom|)arati\(>ly few insta ion 1- uiikiiow II. I'lirlher, le -\>tem. it appears as a function of the le I'.l^c olll\ in i- known, which i.- l! nces when the .--pcctr:! of both components are pie-cni. neither the nia.ss of each nor the total mas< of the >ystem. .-il-.'.ay- ap|M arinj; uitli the fmi'-tion of the inclination attaehed. can he determined. It is only in two spc'ial ca-e-^ thai ll whose orbital elements have heen determined and in erlip-ini; \ly:ol xari.ibii - ,if which imliiialioii can lie nblalind : m \ |sii;ii binaries the lijiht 1 ir\( iratelv kiiowi III the case of visual hinaries. with the inciin.alioii and the rela;i\e radial \eloeiti -e~. the dimeii~ioii< ot wo >tal-. of the two co;'i|)onents known, we can e\ideiilly obtain the ma> ihe orbit, and the parallax, lint not the diameter and deiiMties of the I III the other case, the one under consideration. wIhic the spectroscopic biiiar\ re',oKes ilia plane so nearly in l!ie line of ^ijrht that the >tar- muluallv eclipse .me another twice in theperiud. then, if an accurate linht curve is available, not only the inclination hut the relative dimensions of tin iwo bodies in terms of the ma.ior axis of the sv-t , i .m be deteriniiied. When, in addition, both spcci,-;, can be measured, complete ii iniation ean he ohtained about 'he aeliial diameters, masses, densities, and distance apa:l of the two bodies. This is of importance in view of ihi' small miniber of stars for which we have sueli data. i:w I Ml IxiMIMitN \>ll!i>l'll\>|i \l, iiu.>| l:\ \li)|!S V|( r.i|!l \ III 111.' llilrriTliit- to tHMli-iii-i'il lii'iv li.illi -|>(rll;i hiiv.- Im'CII iil.xTM'tl ill \ ( »liliillclii Miiil 1! S XuIiicuIm'. in \\tiirli il.if :iii in tlii- f!i>c imi>t ilclHiiil u|){. :.•:. >p...-iiai tvp.' Hit' wa- placed iiii.liT .il.-cn alioii for la.jial v.'lofily on Mar. lit, l'.ll!». and ol)>..rvatinn- were fontinii.'il until .lunc 1. In all IS plal.- ueiv (.l.lain.Ml n( wliirli H «vic ii-^iilt tlial tlicir vclocilic- arc iiiircliaMc aiit . Ilu> latter prohalilv due to the Mipcrpositioii of the continuous spectrum of the one star on the ahsorption line- of the other. One plate. No. I'lSli, ol.taincd at principal iiiiniiiuiin allows the spectrum with single lines. This sp.'ctnini is princi|.ail.v. hut not wholly, as it i- only a jiartial cciip-e. of the fainter star, and hence (jives a truer idea of the character Miid type. I'rom thi- si.ectrum the type sliouhl he classed as H.".. hut is rather almornml in the hreadtii of the hydrogen lines. In all ".» doiihlc lines have been measured Uy. 115; He 4472. 4:?SS. 414 t, lOJtl. C 42C.7: Mn 44S1 : (a. K. :i!i:54. (Iwinn to the la.'k of con- trast and the dilTu-eiicss of the lines, the measiiri- arc .litlicult and iieccssarilv not of very hi'nh aceiiracv. In many cases s,„ue of the lin-s of the weaker spectrum could only he recognized ani;i!V.\Tll>N.- <>l I nl'llltCIII i'l;.l. •viunli'l l):ll.' .IuIk.u Dm- I'.M'I 171-'. \l.l ,1 -J ■J.o.-,l IIJ'J ITTti 7 ■.'.ii.-,ii '.171 isii,-, l:; J.IHVJ "'"■'> islis 1 1 ■.mm;:! i\\'.< l"ll.'l Js ■.MI77 '.i;;."i I'.MI J,( ■J u7s '.'7- I'l:; - M \ '-'l 'J.IWJ s7i. m.V.' 1 •-MKl Slid I'.is:! 1'. ■JAXi HS.'. ■jmni I'.l ■J.nds SS| ■jn.v; :ui •-•.Kl'.i '.111 ■J)7-' ,lui 1. -J lMIJ s71 ■'OS! :! •J.lt:i ■ S7I1 •JOilT t ■Jilt SMI V.l...ii> i'l,:i-(' ItricliM II i'.lij I'.iii :> ■ 17'.i :; 1 ■>_• - lis 1 ■_*'J_* 1'. II -"i7J l.".i. 7 . i.-,'.i :; (1 tils lis -J • IJs s u l;is 171 7 .'i:. 1 1 it:. ■ l:l'.i 1 I.-.II -1 II :il7 I'll J ■ I'll .' 1 :;:;7 1 I'l I'.il s II mill Lir. 1 1 ■.•:.', 1 . isj 7 ■J III J 11 .-.11 - 170 t - I7l:i II l.VJ US 1 ■r 7:1 7 1 1 is i-l.Vi 1 -2111 1 II |s| -1.S7S + 1111! s N., nf I!,-i.lii;.!-(l C l.iii.- I'allil.r jilitllllc-r l';lillt<'r I'.l J II 11 I I Hi J ■J 1 7 1 J :i . 1 I li : i:t 1 + I r, V 1(1 - I :i 1 ■J 1(1 ■J ■ ).» s s 11 i:i ;i It i'> 1 JS 1 2 1 l> 1 • • s; »- I III -ri ' 1 1;' i-i • I'll iiLT.i I - 111 1 1 i.ir-iM. \ \i!i \i;' \m III ihi' .ili'i'.i- l.iMi' llii' lil-l lliivi' n.jiiiiih- ui.i- ill'' |il:ili iMiMlr.i ,■• il:il" .iinl .luiiaii .l;ilc 111 ihr III. II \ :il|i I1-. 'ill' liillllli ciil'iMili u'lM - I'li'' plia-r (liil'i |'lilii,il> ' iilllillMllii "1 l!ii- IiiiuhiMiillir "I'lif .•.ipiji'ili^il liMiii ll„. Iiiitvil I l,:i-i ,' l> Ml> iljli Ttt.i uilli fill |mtiih| I Ii77:!l7t) '\:t\-. ri.i- IiM'i ;iliii islli ■ iihiii ii- ui.. li I ,1, II .1 \ , |.,. ili(- jii'l ill I iiililli .■mil iiiiilli llir ic-ii|n:il- iVmii ll.f liiiiil ml.il nl li ■ l.nuhi. r .imi l.iiiil'T riiiii|)iinini - |i-|)CiMi'. fl\ . ulill" llii' I'M Mill iiilunili i'"iil:,iii- ihr nun iiri •'{ .Imililiil lilic^ iiii;i-lll '•' I nil cHcli I'hilr. willi llii' lAi clirmli 111 philr l'.l^:i, i-li ^^llH li -.\ ■tiitlc I;im- wire liica-ilii-il. A' ihr plii.liimiirir iirliil ilm- linl -liuw :iii\' illipl li'ii ' ainl a- llii .il'-i'|-\ a.tinli- -fcni Id t'lijlnw -iln' riiivc a- ii(i-i'l\ a- rail ill' cNprrlnl. i|,c nil.il ua- ;i--i|ii|i'i| 'n lii' I'll'inlai anil niii-iMii|riill\ iin!\ K. lln' liali aui|il'.nitlr ami -j ili< \rl.ii'il> ui tin' -\-li'iii. I'l'ii.-iiii III 111' (li'lirniiliril. i- ruin -iiimil li riir\ i-^ ilKn\ li llirminii I In' iili~i| \ al imi- \\, 'va- a --in 1 ivj (I l^iii., l\ UKMl Iviii. ami 7 IJ n k\,>. Till' M'loril.v al ilMV lilia-i- " i- uivrli ii> \ -, K -in " an'l In a|i|ii.\ lia-i -iplaii - rol'l'iTliiili- \vi' ii'iM' 6\ - (') 7 ■ 1/ l\ -111 li. \ii i'|ilirini'ii- anil I'li-i r\aliiin i'i|Ual|i'ii- wrri' I'linnril, ii'-nllliii; ill tin' iiui'ina! ri|iialiiin- ■_'(iH li-, J : ill I oK Id I'Jl ."iK wlin-i' -iiliiliiiii ii;a\(' ?iy - +-U .". ami tlir tilia! I'Irini'lit- K,, - IT'.t > - -2 7*) km. K, = Jill tl _':;iii iK; ill r.'i .ii\ rtK,,- -2 -2 2\ ''<^ n ."i.'ill'l u oKf = 11 ■J 70 km. 1 ss km. while tlic pi'iilialilr I'l'i'iir i>f a -iniilf plati' fur r.'nii -|ii'c!inm w.'i- llir -anir aiiil I'liual In i- S-:{ km. < ' ' i<-'.u • till' rhai'ai'Irl- nf llu' >|M'i'triiin ami llir ililliriilly iif mi'a-ilirmi'lil these re-iilN a' ' 'v. the imcei'laiiity uf K ainI ('i)iiM'inielill.v nl' ihc ilimi'ii-imi- ol" th-' sy-tem ' '■■: -lii;lillv <<\cv mii' fier rriil. .\|i|)lyiiiK ti, .iile- I'V liic ui'ii-knnwii immilia'. \m- have a,, -in i - 1.1 17.IHI(I km. a, sill i - l.71><.niMI km. (iii,,+ 111,1 sin i :- '.I S'.M) In Sliaple\'- |iiiiitiini('li-ii' nfliil* ihier -nliil iuii- {iri- nlitaiiii'il. tw.i .'i--immi(j imili irmly illuminateil ilisr- ami a tliinl pnsliilaliiiii liaikriiiiin inwaiils the limli. Shaple> 's -irdiul tiiiil thinl snlutiiiii- I'.re aiiplii'il iiere. one iiniliiini. mie ilarkeiieil. '1 lie-e ti.i\i' imlinat imis uf S.'>'' 4'2' anil s:; ."is' respn'ti',! Iw ami make the railm- uf eaeh >ta'' It -."I'J o\ liie -emi a\i- of the relative urliil in eaeh -ulutiuii. The ilimeii-iuii>. mas-es, ami ileiisities uf tin system at unee fulluw. •Contribiiliim.- fnnu iii>' 1'riiiii''iiii i >li-.rv:iliir\ N" o. p sl. T1.17:i- i; on«>?e;7<<) I III |iM\!lNh.\ N-llii |M|\«|( \l nli>M:\ \lUI\ l):.lk. IM'I 1 -.tlU ,l\l- !• hitlM ctllm „, ■• liimliti-- -iMi- ti III I. iiii- I'l i.iihn- Ml -lih ,,. I mIu.-I.ipJ .1-1:1. I. ■■ f.aiiifi Hi. lit;!--..^ tintilih I -i:ir ir " '';HI»I» r ,■ .li li.|l\ linulili 1 -l;ll . Vltl IMMI ^. ||.-. INMI I l."iS.(KNI 1 i;i).iNiii 1-.' 7s IJ HJ ■| ^1 ,". St) :i :2 :i 'Jil ;, .!i .1 v ; :, :ii, 1 1,1. 1 71 II jii is 11 !■> II II, ■n„. MilniHi- III Ihr -tai- Miv iMinputiMl ,--uinii,u tl Ili|.ti.".l l.-niis Kiv. 11 l.> iIm' |iliiilii|Hrllir "rliil ;illil vi,lun,..|in;:l.-r^t:ir -''-^ -""' M,luM,nViMtiT-l:„' -''■•■-^ -"■•"■ ami \Uv Inlal M.'acr area nl Imtl- -lai-^ l^'^^ I '■'''- 111! I r Uplum-lii If wr a--u,nr lli. MU'fa.T inl-'n-i'v of a H.". star to U' --'■:. nuignitudcs.' the sun's alisolul.- inapiituai' to Im' I sil, the ah-ilut,' inatrnitu.l." of llx" brighter ronipoiifnt of A-ll.,|.liN-l. i.l.l..ulliil HI. I' 11:., IVIl. nil -I'l ( ri|n-( iil'li o|tlltl-ii| I 1 1 ll'>IN'. K M:I \HI I,: III I tlpliliKlii "li"- i|.|Ml.lil lliauiillu.lr 1- li :•..".. 1- It I'.l :iihI lirii.-.^ ill.- |mImII:.\ i- II ' tHiM* \ m-iiph -linuint ilic -111.' rurv- |..f lli.- t\M , onipoii.nl - uiih tlif \.lo,iti.- ivpi. - -1 llli'il liV .iptll illrli- I- -llown III lnj. I /,' ,N' I ,//,,-.r,./.l Tlir .•-lipsiliK VMl-lMlilr I! S \ nlp.rnl:i oll'lilil tn. ■ -'-' K'. I'""' l^i ^ vi-. iiiiiu. : .VI Wii- pl"..'.vl miil.T ol.--iA;,ti..u \i.nl _'|-. I'll''. MM. I It.. Ii-i plair n-.-il n, ,1,, pnnripal .nl.il ^^,l- ..I1M111..I mi I'.: • •-'H. 1! J. \ Im. maih'-.l -i-.l -■•; |.!atr un- ,,l,t;,iM.'.l "11 .liilv :»'• Mii.l n-i..| for thr -. ml -p.-.li.;n,, r..nitr, n pl.-il.'- vmiv oM.'.ii,. I 111 llii- iiil.Tv.il. all i.t wl.i'li lia\f l"'.ii iii..:i-iltv,l .umI u-mI. Tin- •pfilinn, 1- .1 ispi- T.^ iii-lriti'ar- n.ii-|i|.Ta!il> luinlitrr Mian ui\.M l'> Nillaml an. I Sl.'Uail. 'I'lii- l.iiiarv 1- c-pcciai.'. ini.i. -lint: on a.T.,;itii ol ;!,.■ um-.U .li-|.ai ii> in •!/.■ ..I ll.-' us n,pon..nl-, t|„' laml. • -t.,r i. :iii; lis .■ mi,. - tlir i|ini,i.'liT..I 'ii. l.nulit.r an.l niii. inilli^ a- Initilil. Il «"il''l ■•i>li-«>.|il.'nllv l.r .•Xi'i-I.'.!, v\lii'ii itn' I ■ ■' -'ar- ai.- ..1 ii.arl.s ,.,,ual l-iiulilii'-. iliat l!..' -1 -nil I ^'■•'■•'■"in «'m!.l ii- plainly vi-iMi'. Imt it ran iilv \.<- „,,.„ anil a-iii-nl with Ktval .lilil.aili > . ali.l It 1- ,-t iina^'.i L. I fniilx al.ont ..ti,-l. .n- I li t|„. inl.Mi-ity i.r il,rl.iii£litrr-p 1- ..lilv tl :n that oi ll,.- I.tml.t. r :, lit-'al, r ilitT.TcliiT ill nia-r. wh. 11 l.olii .p.-. M.i .1 pp. .a r than ha- pivvMU^Iy l.i-.n loiin.l. Whytli.- , ,„,1 >p,.rlflllii ^lioilM 1..' s.) ivlalivly faint wlwli th.. tu.. -tal- ,ai.' u( ifaily .M|llal l)iiM;h.lf<'^-> i> ii-'l appaivnt. ll may l- that. allli..ii«li tlio .•..nlimion- ii.iti «i th.' -p.'.-tia :u f nearly iMjual int. ■n-ity.tli..al.-.iipli..n lin.-..f lli.' n.ll.o.U aiv faint. t than th..-.. „r the iH-iiiiaiv f.-ii.i.Tint; tli.'in .lilli.iilt u< -.■■■ vnIi.ii iI. .•..iHinii.iii- -p.'.'tiiiin ..f llic •man is sii|)ri-p..>c.i. Or. atiain. a ni..iv iilM'ly .•\plaiiati..n i> that th.' Iin.- aiv ui.l.'ii.'.l M. iiiii.'li hv th,' r..tali..ii .4 th.' laru.' .liam.'t.'r faint ->ar a- I., h.' mail.' i.'lali\.'ly \.ry faint. On.' plate wa- mad.' al".iit .' ' '...ut- ;ill.'r [.riiiiary minimum, uhi.h. a.'.'..r.liiik t.. St..wart'-.irbii*,\v..iil.ll.i' al.oul an 1 im.'i ih.' I.it.-il pha-.'. -. that altli.mirh ii w.nil.l n'.'eiv.' m..>t ..f th.' liuht from the t ..i.'r .'..^Mp.in.nt . al.out ..ii.'-liflh u..iil.i .'om.' fr..tii th.' hritlht.'r. Thi- -!..'.-( nii.i ha- nei. h ti..' -am.' --hara.t.'r a- th.' ..th.'t-. .'\.'.'pt that the line- are mil. 'h w.'ak.'r aii.| ilm- 1- in as-'n .-.lU'iit with th.' .'ih.i^e h\pothe-i-. 1 u th' ;• an a.l(liti..nal i)lal.' wa- ..l.taine.l on .lulv ;!0 ,,i. .>,'..,l •_•:; .'imil-ion an.l llu- liii.'r Krain .•na..l.- the sec.n.l s|)e<'lnitM i" !><• m.'ie iva.iily ami .'.'riaiiily ni.'a-iir.- 1. <>n fir- jilat.' the enlian.'e.! line »:.»'.• i- plainly .loul.l.'.l. th.' iiiL'ti-it;, ..f th.- -.'.'..ihI -i-.-.-inim h.'im: r.'latively niiieli stn.nner than in the oth.-r lim'- Fiirth.T. !h.' Mli.-oii pair ll'-'s. 4i:il -le.u tairly stnmn .'onipunmn-. wiiih' the -.•e.'ii.l -p.-. .im m th.' hy.lmu.'n ami lu'lium hie- 1- >.-i\ weak. This w.ml.l mak.' it app.-ar a- n th.- faint .l.tTii.-.' .- palU' a w.'ie ..f I'yp.' H'.l with relativi'lv wak liv.ir..tie.i aii.i h.'lium Iin.-. wl ..' th.' '.nsiht .1. n-.' -tar i- !'.> ..r.'V.'ii earlier. Tli.' r.'lativ inleiisiti.-> ..f ih.' .i.-'.l'ie.l lim- l-".!'-'. H^H- i r> ar.' nior.' n-'arly •.V-lr..pli.v-i.al .l..wi-ii:.l. l-V :il-'.. I*"-"' .„,„„1 U.u, -.Iv Ml".nt l,:,lf .^ .•:.n>,.:u..l ^M'l. ..n.-l. m tl... I.x.lrn«..., mh.I '"■'"""'""'" II lit II I1-- \|t,,t.ll,.r II lih.- Iia\.- (..■■■l. ii»a-Utv.l ni llir|„,)HMn .|»rlMnn,lh ' > .S 11- H,.. i;s> iltl 11 M loju, h-r, l.-.l',., \lnllM. < I-''.: . , K.:i'»:!l:„.aHMl,.'i,.,rm., 1 |,h,.. >. n 's n;n, ll... lux- ar.. m „„K la.i .|'l:'l"> '"' Hi.:,Mn,.Mu-nl, MlllMMmh mil-l, l,..,„.r ,l..n 1 Mml. in I OplMiuIn, Im. ili- mrMMiv ,„ ■..■rth.l. - m,v -a.i-lurl.nlv ....n.nhinl. ilw i.rol.r.l.ir ■ t M„.M-i,r. - ..I tl,.. |.r,M-.A -|"""ui a |.la.. I., iiiu '^uU In ihi.' '"l!li.'!i''''l-Tva - ui .-n l..l..u lolu ■•,, ,,„- (!.■ rial.- iiuiulMr. .■..luinii- ■. 1 ,1 ,!,• iii.l .lulial, .lat.- ..I III.. ..l.-.rNali..li, an.l .•-.luinii I Ui.' |ilia-.. In-.n piiinan luini- ",„„„ .U..-.1 1, .h.. -iw-.al iiha-. .•.H"..i:,j 'M>:\ uri, a |..n.Hl ui I I77:v.'.-. .luv- ,, ^„.«a,r- i,l,..t..n,.inr m,I„i.* C.luiiin- .V «■. .■miau. ti..' ^,U^\u- "I H-' pniiian ,,„! -,v„„.l„A -lar-. a ..1 -•nlunni- V '.' il.- ,v-i.l..aN m it,.' ••.■n- al.MT, ,■,! i- r..M.pu.,-.l ,.,,„„ ,|„. ,,,,,,,1 ,,,1,1,. c,,!,,,, . 7 ...miaii.- tlu' uuhiIht of Im.- ni.'a-ur,.,| iii \' I. I'll I lAK IM:ll. Nlliril" 1 Hal' ,ll,l.-.l. 11 l!,-|.|lKil- II f llnutii.r liiiii. I'H'i l"-»^ .\|.iil'Jti |,,|._. .. ■..„ I'l^T M iv (i . . JJI.l .liil% 1 •jjivi ■' :! ■J'.".i> " T ■.';tni •■ > •j:;."i(i .Ml'T •Jli'.MI ■Jil'.' 'I i:i II i:. is I'.i .17.'. '.•^1 II 7Mi ..> A uTs ",ts^ .\- 7','''' • •-'■.' ■.' lis.'. '.Ui'.l 1 XlN li.i -J ttl'.NI.i 1 llJt ■ 11 -J ll;;-'Hi:i 1 ,-.17 TO 7 1 lTs>'! 1 II.VI - 7i.'.i Us- '.10.' .' a..'i -ii'.il ii"»;ii .; 0.17 * 'J7 ■ .". l.Yi.Ms .' .'lOT ' ~ ■'> l.M-77.1 . l.tl r-JH ■.' 1,-..". ->7s II IKMI --■'.1 l.'sV' .; lii-.i t ■_'* i ■ S l.'.'.l Vf.' ; lilt 111 l.'.l)-7-J7 n I'.J 111 1711 7..II ! .MO i'i7 - 1 ;■-• " 1 1 to 1117 1 s III 1 iiji - s l(.:t 7 10 J ..o • I.; J 1 J>< :i JO f 7 > -■ II .' 'IS II .". o '.i iit „„.■.■ MM.., thai thr ..ll.ll WH< ll.il .-iivular. allli.iusjli tia' ,,t,.it.'inrt i ir orl.U iI.h- nn: >1.- ,.,.,-,.utn,ilv, hut tlii- vi'Mn..iit i-iM '.Illy larrly !'.• .il.taiiu.'l with a....|ira..y Inmi t':.. ,,. .- |-,.,.lii„i,iaiv ,.|..-,i..nl- ..l.laiii'.'i ^'ni|,hi.ally u.-n. ..i-mi.i.il a>lol!iiw- iuctn<. .ili^i.|\al i.iii- , ..(.(.(.Titnritv K halt' atiiplitiiili' \ 'I'li'iiy ■) \f|ii(.it>- .if >y-l..iii u.. I.mnilii.lr III ,-ip-<' . T tiMi.. "I pii -ir.'ii no.'. .".I 11 km. •_'2ii."i km. !tlt I '.»).', ilav- I'niM .niiiiiiiuiii. •A-in.|.li\-i.:.l.l"on,:.l. iJ. 1'., I'.il.'.. nil »l'|. Ml"'-, nl'l. milllT-' Ml I, ril'MSi. V \l:lMiH - I t:i S„ .,,1... n- HM.I .,l,-..,.at,„M .•.,....."- .mLmI;....,! I,> :.n- o, I,.l,„u.., hll..- ...lu,. n«,n« ... ,1,.. - 11 ^..M ■.•.•....,.,. ^;'•';7''7^;7 ;:;.;:;; , ciirri'i" " ,11- lur Ihi.1i iial...ii- all' ui'-.'.i "'1 ll i,. lullnuilii: lal.l.-, vli.'tv \, \. /, .1 Ims.- .la' \ allM- \ 0*; > oK / K .'i. H KA HI II IJ l:'. I I TM'.ll, III ..I I \ MItiN I-.;. Ml.'N- l:- \' .1'" ' I ^1 1 IKOx ■.'S'^-, IKll 1 ' » i> 1 . II '.1 II i IHH) ilH. • t* H . . '.Hit • 1 ll > '7'. .. ' |.'i<' 1 S.l 1 l»»l 1 IHHi ., ,., i|.* ' t- .If.' ■-' -■ r»* ■ i ItJ I IHMI 'Hill 1 •** i.« 1 ■* 1 1 IKHI '''' ■'7'* ,■..'. 1 ) ( 1 1 IHHI Vi^ 7.'^ TN 1 ■..'. T'»^ S VI I IKMI •T.' 1 1 )i M t iir. M 1 ',i:n'i J IT I IHMI ;.ii •1^1 vm .', ^it 1 II' HI s. i- i.'i^ .■.(■« " 1 IHHI 'I'.;. ilj'i ■ lifi • ll .'._' t IHHI '«U 1 iiln 1- ol'i II "^ - j ", ,' Hit) »i J.'i 1 IHHI It '..'i 1,',,„„ ,h..-i. „li-.'rvaniii. .•.|..M.i-.i- .111' t'.ll'.v^i'>i£ ""i"'''>- "'''• ■■'"•'"""' II I'll II Ml - 1 1 ;!i " K ,-,IHi - '.t JU-.' 1. iMl.-,s . It 714 - <» I limiv t lIMTv 7 J II. I •_'7'.t/ !•-':{ I i; ii7i. II 'I'licii' -iiliiti.iii t:a\<' X _ -fll 111 y -^ 4(1 its z = -t-li i:.7 „ ^ -:{ 5:«i 5 7 - . M> .ll a K -= fi> '.'^ a, = +0 iiivj!" S »• = - :< 7 1 11 .III 11.71.1 I ' m II si ihi' liiial i'li'iMfii.> , = (I ii.-):< • 111.". K,, -- .M''.is •- " "'•' ^ = -•_>'i't)4 >^ t> .'.ll u; = '.'lili-'Jli ■ '. ^1 r 1 I UK! tla.\- K, 17.-. '.I 1(1 nil iinMIM.iN \s,i;nniN>ll. \ nra|.li n| !!„■ ,,rhil wiih lla' ,.l.s,Tvatioi,< ..f 111.' l-riliripal sp,..'- iniiii ivprc-i'iilc I li.v iai<-li- i- -liow ii in I' ij£. -'■ r,i: J i; s \ui|..,.„h,. Applyinu' ilir aliovc ,,i..it- wcolilaiii l>y llic well known tornuiia' ■A, -in 1 ;v:t('uarr- i.holomclric mIiiI* fi\\v< two solutions, a nniform. an. Th.' .liiHcnsion-. ma-.- and arn-ilifs in lUc orhit follow. I'or (•,MM).aris,.ns tlic dinicn- -ion- fn.n. Sliapl.y-- .larkcncdorKit' arral-oi:i'..n ami it app.'ars that further i)h(il..- mi'irii work on tlii- -lar i- ili-ir.-iMr. I l,i|,„i!l l),ilkrl...l >ll:l|>l.'X ;, -rinl :!M- rrl:ilH.' .'|I>,I .,, ■■ Mllilt lillttlil' 1 -l.ir :, Ml 1' rm- "'■ -nil'- '-iili'i- 1 r^iliii- l.ntilii.'i -':ir I ■• r:init--i ■■ i,,„ 111.1- l.i-mliir, •■ II, ■■ l:,il,trl M iMlill Illi-- ,,, ,1. n-iv hv..;litrr -<:« ,„ ■■ i.ii.. 1 1,-, |ii(i iiiiii i.',,.iiKi.iKMi ii.-Mnimii ;;.,i|ii,iHiii :;.i.tl.uiKi :'. :isu,iK"' .-. I'l 1 '.111 '.I SI .'. Jil I r.t I, '111 II TO II i«M7 -"- 110 _. n:, Ill '_'.'• \\\ O't 71 nils •\-lni|.li>-.-.l .1 11. . I l-V >;!■"■. I"l-"' ;C..l,lilliilli..li- fiMlli I'nn.-rl.in I lli-nv.il.ii \ . %■■ '■'■■ V '«> im; si'i.ciiiiisi Mi'ic oiiitns oi i,( i.ii'^in(; \ \i(UHi,i> 14."> If we iissimic tli<> s.ulm'c iMtcii>it.v of a Un Mar In \»' - -' J* inanniludr^ aii.l \W Min's alisul.itc iiiauiiitu.lc to \ iMauiiiHi.lr uf ihr l.iiirl.t.T (•oiiip..ii..nl ,,f |{ S VulprnilM', witli appaivnt ina-i.it u.l.' 7 T.V i> ^ 1 !«' m.mI tli.' parallax i-O" (IPJi;. T W l)riiiiiiii< •n„. <..'lip.Mnu varial.lr TW Dracnnis ,n l.-.h :V2 »iM., 5ftil IV. HMI(I: vis. nmu 7-4.-,; spcrlral tvp.' B'.li wa- lirM ..l.-.^rvcd mi .Vpril IM. HH'.t. an.l ihc laM plalr oliIaiii.Ml ,m .lillv 17. During; lliis interval 14 plat.- wcrr ..htai 1. all "f wliich arc u-.m! in tlir ,,|.|,il. ' Tl.cv aiv nut -.. well ,li>l ril.ut.Ml a- in It S \ lilprcuhe. owilli; to the (l.M'lli of priniarv iniiiiintuti. when \U<- Mar fall- to '.• S n,a|iiiitua... iiiakinn it iiM|.rarti<'al.l.' to .ihtaiii plalc- at tin- .•poMi. The coiiiparativ.' faiiiliii— of the -..conilarv. it- li^jlit li.aiitr (lllo of till' -y-tcin. of conr-c naidcr- it- -pci'truiii iiiiolwrvahlc. Thr -pcrtrmii clasM'il a- !«• is in ivality \:i ,in.i)iiii«: by the iclativc -trrnntli of hy.lroK.'n ana K an.l tlif niMMh.'r an.l int.ai-il> ..f tli.' in.Mallic lin.>. an.l in .■..nM^.iucn.M' -h.Mil.l 1... .'apaM.' .if a.M'urat,' in-asiiivm.'nl. \lth..ujjh lli.- i lann.'ni.'nt aiu..nn ll"' lin.- i- fairlv k.-.mI. tlu' vcl.i.Mti.- ..f tlu- plal.'s aiv .lisa|ip.>intii>s:. ih.' ivsi.hial- .uifxp.rt- ,.,llv liinli. iv-ultiiiK in a plat.' .•rr.,r ..f r2ti ki 'r -.■.-..n.l. Thi> i- pr..l.al.ly .In.' t.. \Uv ratii.M- ui.l.' an.l.lifTns.' rliara.-t.a- of ih.' m.'talli.- lines, inakinMI tlie s..ttinf;s une.'tlain. •riial th.' lin.'s are wi.le sh.ml.l n.it l.e a .'ause lor -urpri-.' when «<• .•..n-i.l.'r the nearness ,,f the iw.. h.Mli.'s an.l th.' i.rol.al.l.- rapi.l r..lati..n of tli.' hri-ht h.Mly in th.' p.'ri."l .-f t h.- \-tein. Th.' .lata .if th.' ..hs.rvation- are tiiven in Tahle 1\ . wIh'IV .-.ilumn 1 .■..nlani> the ,„„„|„.|. ,,|- ,1„, plat... .■ohnnn- -' an.l :! the .lal.' an.l .Inlian .late ..f th.' ..l.servation. ( olunin 4 eonlains the phas.- fr..in primary iniinnunn .■oinpnt.Ml fr.Mn initial pli..l..in.'trie phase •.>,41S,'.t()ti-4:>:< with perio.l 2 SIIC..->4 .lay> an.l .■..hiinn .'> th.' vel.ieity .letennine.l from measures ..f th.' miinher ..f lin.- in .'..Inmn »'. » 'oUmm 7 I'onlain- th.' r.'si.luals in th.' sens.' ..hserv.'.l niiinis .'.impiit.'.l fr.>m th.' tinal .>rl'it. i\ ni.K |\ .pHs1.1!\ \ii.iN.s "l- I' \\ DliACtiMs / I'l:,!. N.in,l..i Isaj \,.i Ml 1.: iss:; -itt I'M.'.. \l;i ■_".. I'.ls.' .' JJ 1 7 .lui ic :>.i \ 1 ':;.t.s I'M'i No III l{.M.|i|:d- lll:ih |):.lr I'l ll.W \rl...il> I.IIH- II (• Ijj ......' sr HI 1 -St) . ."ill s IJ ■J :;:; iiT.'t st'J II s"J ."i .i;i 2 L'll 11 7i*' n7s '.ijj 1 1 17s is 7 17 • ;i i.i'.i Ovj sill ■j I'HI 1-1 i'J 2 IJ :( I'.i IIS.", S('t,'( ■J Ills 1 .".1 I 1.' 1 17 111! 7:il 1 1 17 :;7 , ;; 17 J 111 m 7J1 ■_' l;il r l>7 .1 11 • J 1.1 1 fj 71.1 I) :"ij_' - 17 1.1 7 J 71 llti 7;'.:; 1 .';!'_' . is r. i:; t 1 ■'■<• 117 7.'.'. ■J .".J.". . ."ill ;; 1 1 r.i I;; 1 is 7Ji> II 7 I'l I'll 1 1 1 ■ 1 ;i7 l.'.t 71s 1 ll'.ls IS 1 1.". 7 11 I.-..-. 7.-J _• III'.' . ii.". 1 II . 11 I", l,".7 717 1 ■Jim Hi 1 II • 1 ."I ■,V-lM.|ili>Mi'^il .|..inn:ii 111. ll."i. I'll I. 14ti •nil. DOMINION .\ST;{0I'IIVS|(AI, oHSIUVATOItV. VKTOIUA When tliosc oh^Tx :iti()ii> were |)l<)tto(l it was at once seen that i)y niakiiiK tlic ()rl)it -liulitly (■(•(■(>ntii<' Ix'ltcr anicfiiicnl cmild 1)0 (»l)taino(l tliaii with u circular orl)it. AlthouKli no (■(■(•••iilricitN i< civcn l.y Siiaplcy's i.rhit.* it is pniliahlc tiial Xijlaiul's <.l)scrvatioiis arc lupt n\ Milliciciit accuracy to dctenninc this, and alicrnativc siihitions for ccc(>iitric and cin-ular orbits nave c of system y Longitude e oj Time of jieriastron T (KviuK to the smalliie-s of the eccentricity it was con-idered useles^ to apply least s(|uares corrections to both "l" an.l w and. in thi- case, as the latter seemed hotter deterniined l.y the nraphicai elements, a correction for T was u>ed. The ditTorontial Odofficients oh- tained by Leimian Filhes were used in computing an oi)hemoris and obsopation ociuations which are jjiven in Table \ . I\H1.I. \ ohsi- u\ \ 1 1 IrcKK lUilA ■► 1 IHMl ■li'.iT ;; 1 IHMI <.i.-.;i 1 1 (HMI - (i.V.l ."i 1 IMHI IVJI. li 1 IHMI - ,V».i - . 1 (MM) _^ ■ "JT'J N. . . IIKKI •J'JIl \i 1 IMHI ^ Vi-l 10 I'lMMI ■ >M\ 11 1 IMM) ^ .'I', Is 1'.' . . MIIKI ^ .'.••IK Hi .. 1(I0() ■ si:; 14 1 IHMI i • tiii.'t where \ ^ oy y = 6 K z = K 5 c hSKUVMIoN 11(^1 VnoNS ol rw DR.VCONIS - 1 0111/ t- ■ ■">"() ■t '.ITS f '.HVi f -WW -f- -.M.-. - »J7 - '.i-r> - 11(1 + r.fj -r Ills f 1 mil + ■7'.l-.'ii - 07:! - ■■2'M> - ■701S - •7;i-i - -784 - HHi.l - (MM - Ml - li'l - II.V.I + -I Mil) + -.'iliO Km ■)i The normal e(|uations from ihc-e oIim'|\ ation~ are 14 (HHix + S'jtiy + ;?:v.M.iz - .'••loiu - (i-7() - n s -MT 1 .V.4 + lli.V-' - '.»:VJ7 = 7 :',_>'. I - 1 ■•2\r2 - .'> l">:{ = n .'.••_>:« + U)S = (I f 417 =11 - :i»:f + 1 -^4 - 4 '"I f 7 ■■-'■J + 1-7S - 1 ■ lis - 4- 7-.; + IHIi - lli.-l - :i-7'J + 1 lili -i- •-'•I'.l - 7'.i:'. '('niiliiliuii.'ii- liiiiii I'riii.iton oli-i rvMiciiv. Nii :;. p. !HI. rni; si'i:( rii<>s(in'i< oiuuis ui kcmi'sinc \ \i!i aki.i.: 147 'I'licir soliitiiiii ni\('~ \ - + lti:.-, 7, = -t -sTtiC) u = - r.M>s 6-> - ! II 111 km. 5K -- fl -'Skill. «( - + (IKlti 4T = - (Mil :ili(l llic lilial r'iciiirni- ( <'ccciitrii-ily K .-I'liii ;iMi|)lilU(li' 7 vcliicity sy-ti'iri 'I' tillir dl' pcli.l-ll-iill u; Idiiiritinii' III' ;i|)>i' Ml -in i -ciiii ;i\i- iii;i,i"r rNi, sin 1 IS'tlCiftCi n."):iri ■ (IIS i'..')-7s ■ 1 i:! -11 Ml • (I'.il (lOI'.l ■ niit '.HI ti- 4u:{',i:>| •_'.,'):{.").UI)(i km. ■ ilvjti This fiiiii'tiiiii (if the iiiasx'-. all lliat can lie (Ictcrmincil wlun llit' >ci-(iii(l ~|)C(trum canniit he mmmi. (1(ic> not ^ixi' us intornialiim in icfiani to the dimriisicins (i|- masses ul the system. Fiom tiie photometric orbit we ohtain the liiameteis of the inilisidilal stars ill lerin- of the relative orhil, hut the latter cannot he known wilhout the ratio of the masses. .\s a tirsi ai)i>roximation Shapley assumed the ma»es e(|iial and later used an enipiri<'al formula* for determinintt the masse- of the components. This f.irmula hased on the relative \\n\\\ of the two lioilie-. lia> it> constants determined from spectroscopic binaries in which iioth spectra show and tlie ratio of the ma-ses are known. I'-in^ this formula mi, = 0-4+ I •'-'I.,, tiie ratio comes as brinhler star O-TH fainter star (1-27 total mass. If we use I{ S \ulpe.nila' as an analogy where the system is probai)ie \\u<.\ th.e ratio of the ma-ses assumed above is certainly not too frreat. With 1{ S \ ulpecuhr where t!ie linht ys1em, the ratio of the mas>cs i- IM'll while with T W I )r;iconi-:, where iIh liuhl of the brijiliter -tar i- (ISS.-, ,,f the vy-leii'. it would certainly -eem likely the ratio of ma.~ses would be pealer. .Nevertheless, th,- ratio ni\cn by the lormuia ha- lieen u.-ed, and 1 think may be sifely con-idercd as tjiviii}; minimum dimen-ion< to the orl'il. but of course \hw dimeii>ion- deiieiid upon thi- assumption and cannot lie roii-idered aloolule. a- in the tuo piev iou- orliits. I -ins; Shapley's two solutions, uniform and darkened, ihi' iiicrmation- are 7") 'I'-V and 7!l 1^ , while the >emidiameter> of. iirinhler and faiutiT are bin.'ind ■'A7\ t'or the uniform and ■ ISO and ■V.l\ for the darkeiieil. "C.iiilriliilii.in- llniii llii- I'riiHi 1.111 nli-i.rA:il.iry N" :;. |i 1-' i. ,^^ nil, 1«)MIM(.N VSlKOl'inM. \1. "IIM,1{\ VloilV, \|( TDltIA 'I'lic liiiiifii-ioii- "f till' -y-iiiii .lcM>|l> lllilllili I -lai f;linlil I Mlliil III DiirkriH.I ■J, .11 I ,11011 J.."l7.'i,IMMI T.iH'iT.imii (i,'.«l:l,lMlil '.) IlSI .IHHl '.(.."fclH.IHHI l:i li-J i:< 71 ;i • Til :i Til 1 >l ■J IT .-.111 :; :;n 1 .-iS :i Jl 1 Jl Mill 1 I'l 1 10 IHI'll 01.' 1 .\ si'dpli of till' \('liii-ity I'ui'M' «i'h ( ilMl.l SHIN 111! .;. V w Diii ti- tli|. iiliM ,-\;ili.ili~ M- rivi-l.- i- -liiiWH ill I'iM:- ■^■ U „,.v I,.. of M.li.ivM ,n MuiinKiii.. .I.' ilnniMi>i ot .1,1. two ^yMi.ni> olilaiiu.! luMv .i,l, ,1... >ov..„ ,.ivvi.n.lv M.-iu,.,l, :l.ii an. known .o iii,.. Tt,.. orhi. oi 1 NNDra-onis is no, in..li..l..l in ,ln. su,.nnn,-y. :. iwin. ,„ a.,..,ii i -U.; --1 s.-.-nnn . -■ dnn. . .ions an. not ati.olut... Tli. lollownig laM. «iv,.^ .1... imnnpal ,l„iM.ns,.,ns ,.>...« tli. a.i-ki.uiHl ,.lio,on„.|ni. orl.i. in oa<.|i <:•>: ul,,.,-.. .li...'.. aro two ur nioiv .olution^. •mi. >1M.( llinscol'li iilllUTS HI I < l,ll-IM; \ \l!i\ol.l > TAUli: VI Ml.-..l.ril. 1)IM1.NS|..\> KCLII'MN.. WRIMUI- lU III, !<<"> lt."lM \1:.>-- l>. li-iti. (■.■nil 3 \iirit!ai'' . r llcriiili-' V I'liiM""' II l.vi-M.' ItX llrr.illi-' W Vr-.w MMJ.in- Z IIct.mIi.' I ()|iliinilii. 1! S \ iil|«Tiil,ii' \ :*c. ,1 :.. ^ »:. 'i ■_* PI 1. 1 1 I .'l I n 7^ I ■> II 7 1 77 .; J 10 7 111) II 1 1 II in.'i II 11 II iijj 17 7 1 1 ■• l'< 1 I'l 1 II (lU II II,"..". IJ 7 1 1^ 1 1 .' II (Kll»' II IHHIt .".'.1 •' n ^'' S',1 1 1 .;.'i II ;i 7 .. II i.'i 1 •'• II I'l 1 .'. II :; I •! II III 1.". 1 1 71 II Is 11 tr, IJ s :. HI 1 U'l II i\.; II iiiiir. ■JJ 1 T,,.. .Iiov. ,al.l.- is >..lf .-xplana.iiry if ,. i~ M:....! H.iU .Ih' Ini...- .1, ---•-•- ,.,,,„. „,• „,., ,„„•. ,.a.li.. :..i.l th.. MK.M., ...a .l..-M,i,.^ ill ...nn- ■.! .i>- ■'-" ami il m ,■ (,„hiu,.l,i and I{ S Vuli.....ul;.' ami of tli. a>M,..,..il .l.in..i.M,.,is „f 1 \\ D.a.onw i.i .„'.'„.. -n... i,„'..->...ions .If ,1... v..,.,i,.al ami l„.,u„ii,al .Uu-A ,„.- n,.n-,.n .. . ' of :i,a.^ of ,1,0 .v^.i..... Till. ..n..> of li^un. ,.. .h. lot. .r. ,1,.. ^ys„.|„s a. L ,.lip.. ami thoso ,o ,1... n.l... . MUaH.r n.volu.ion ...y. uli,.,, a. maxinu.ni '7 io„. No at,..,np. hn> ......u mail.. ,o ivpn...... .h- Ma,> a~ ..llipHcal in loni, in ..,. iinurc. Tli.MV i> 01U' olIuT point in connection will, tli.'H. oil.il-, iM f ciiinciilcncf oi- otlicrwisc ,\li:ol, 5 , i,„.., , „, r l,,.,,.nli~ that the plia.- of moan piimar.v chp^c con„.s .lip ht > latci , ah lu Xu^l ... ,han Ihc time .hon n^.^f in the spectn.cpic o.-h.t, while i, i. evi.len X 'Li. should coincide. No explanation i. oiTeivd fm- this .li.cn.pancy and it uilt he of i,„.,,..t to co,npai-e the roults for ihe thn.- varial.le^ discuss..,! here. „. V Ophiuchi m. attea.p. wa^ made ,„ applv a correction for «, the pa., m the ,i,.,„,,r orl.i . owin« to ,l,e hi.h prohahle error ami to the fact ihat n.-arlv all the oi.e, a- ;;;:;; were near their maxiim elocitv. where ihey would have h.tle wei.h, ni the det(.rmiiiatioii of this correction. I,. H S Vul,.ecuhe the velocity -urvo -how- tlia. -he >pec,roM-.p,c P u.>e ,. . on- .idenhlv later than the photometric and, if thetinie wh.... u =-..0 i- computed, it ,- found : +!i 12S ......It! -lavs. In T W Draconi- .^-U... therefore the tune wnen ,-.«,- i. Ihe th,,; T fouml in the orbit, or +.MM.. . ..■..!(. day<. tn both ,he>e . as.., ,he;efore. the >pectroM.opic ..ha^e is later than the pho.o,n..tri.- by a -out .5 hours in 1! S Vulp..cuhe ami 'l minut..> in T W Dracni-. in ,1,.. opposite dilution to that found by Schl<>sins..r. 1 V.^lni|ihv-ir:il ,Joiirii,il :is. i> Hi'' , .. ■' 40, p. :«w 49, p. IS'.t. l.-,(l MM. iMi\iiMii\ \>ii!i>i'insi( \i, (iioi i;\ \ ii)i;> , \ i< riii!i \ It i- IkiiiI ti) ini;ij;ilii' ;i!i\ |)li> -leal i';iii-c which wmild aci'iniiil lur a ilillciciicc in phaM' ill i>rir dirciliim in ■iniiii' iii-laiicc> ami in thr (i|)|Mi>iii' (liifctinii in oihcr-, and llimiiih tlic dilT( Tcncc^ :ili|)('al' lo l)<' Cdn^idiTal)!) Inn meat In I"' I'Xplailird i>,\' iiicii^ nl' iiliMi\a- linn in cilhi'i- tli<' >p('clr'n-cn|iii' nr tlir phnimin'iiii' niliii-. ihcrr x'cin- in he no nihil' alliTiialivc uiilil innrr data ari' a\ailal>li'. Dninininn Astinjihv.-ii'al ( »lp-('r\ ainiy. \ iilniia. H.< ■. Aunu-t (■•. I'.M'i iiii; >i'i ( init.M ni'it KiiiiiTsoi i:ti,ii'-iN(; \ \ui\iii.i l.'il V J \ \ U npfuuchi Sun /' rW Droinnis I'iit. I. (Iriiiiliicul lii-pri-M hl:iMnii Hi' Sy-li-ni-^