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 IMAGE EVALUATION 
 TEST TARGET (MT-3) 
 
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 1 1.1 
 
 s la nzo 
 
 
 &5iri!si^ 
 

 4§o 
 
 CIHM/ICMH 
 
 Series. 
 
 CIHM/ICMH 
 Collection de 
 mi 
 
 Canadian Inatituta for Hiatorical Micrcraproductiona / Inatitut Canadian da mibroreproductiona liiatoriquas 
 
Technical and Bibliooraphic Notaa/Notaa taohniquaa at bibliographlquaa 
 
 to 
 
 The Inatituta haa attamptad to obtain tha baat 
 original copy avaiiabia for filming. Faaturaa of thia 
 copy which may ba bibliographioaHy uniqua. 
 which may aKar any of tha imagaa in tha 
 raproduction, or which may aignificantly changa 
 tha uaiiai mathod of filming, ara chackad balow. 
 
 □ Colourad covara/ 
 Couvartura da coulaur 
 
 rn Covara damagad/ 
 
 n 
 
 Couvartura andommugte 
 
 Covara raatorad and/or laminatad/ 
 Couvartura raataurAa at/ou paiiiculAa 
 
 □ Covar titia miaaing/ 
 La 
 
 titra da couvartura manqua 
 
 lourad mapa/ 
 Cartaa gtegraphiquaa wi coulaur 
 
 Colourad inic (i.a. othar than blua 
 
 Encra da coulaur (i.a. autra qua blaua ou noira) 
 
 I I Colourad mapa/ 
 
 I I Colourad inic (i.a. othar than blua or black)/ 
 
 r~n Colourad piataa and/or iliuatrationa/ 
 
 
 D 
 
 D 
 
 D 
 
 Pianchaa at/ou iliuatrationa an coulaur 
 
 Bound with othar matarial/ 
 Rali4 avac d'autraa documanta 
 
 Tight binding may cauaa aliadowa or diatortion 
 along intarior margin/ 
 
 Laraiiura aarrte paut cauaar da I'ombra ou da la 
 diatortion la long da la marga intiriaura 
 
 BIttnk iaavaa addad during raatoration may 
 appaar within tha taxt. Whanavar poaalbla. thaaa 
 hava baan omittad from filming/ 
 II aa paut qua cartainaa ivagaa Manchoa oloutiaa 
 lora d'una raatauration apparaiaaani dana la taxta, 
 maia, loraqua cala Atait poaalbla, caa pagaa n'ont 
 paa 4ti f iimtea. 
 
 Additional commanta:/ 
 Commantairaa aupplAmantairaa: 
 
 L'Inatitut a microfilm* la maillaur axamplaira 
 qu1l lui a At* poaalbla da aa proourar. Laa dAtaila 
 da cat axamplaira qui aont paut-Atra unlquaa du 
 point da vua bibiiographiqua. qui pauvant modiflar 
 una imaga raprodulta, ou qui pauvant axigar una 
 modiflcatiof^ dana la mithoda normala da f ilmaga 
 aont indiquia ci-daaaoua. 
 
 D 
 D 
 D 
 
 a 
 
 D 
 
 D 
 D 
 D 
 D 
 
 Colourad pagaa/ 
 Pagaa da coulaur 
 
 Pagaa damagad/ 
 Pagaa andommagAaa 
 
 Pagaa raatorad and/c r laminatad/ 
 Pagaa raat&uriaa ot/ou pailiculAaa 
 
 Pagaa diacoiourad, atainad or foxad/ 
 Pagaa dAcoiorAaa. tachatiaa ou piquiaa 
 
 Pagaa datachad/ 
 Pagaa dAtachAaa 
 
 Showthrough/ 
 Tranaparanca 
 
 Quality of print variaa/ 
 Qualit* inigal* ^ I'impraaaion 
 
 Includaa aupplamantary matarial/ 
 Comprand du material auppMmantaira 
 
 Only adition avaiiabia/ 
 Saula MKIon diaponibia 
 
 Pagaa wholly or partially obacurad by arrata 
 alipa. tiaauaa. ate., hava baan rafiimad to 
 anaura tha baat p;.«aibla imaga/ 
 Laa pagaa totalamant ou partlaHamant 
 obacurclaa par un fauillat d'arrata. una palura, 
 ate. ont AtA film4aa A nouvaau da fa^on i 
 obtanir la maWaura Imaga poaaiMa. 
 
 Th 
 po 
 of 
 fHv 
 
 OffI 
 bai 
 th« 
 aio 
 
 oti 
 fin 
 aio 
 
 or I 
 
 ahi 
 
 Tin 
 
 wh 
 
 Ma 
 
 difl 
 
 Thia itam la filmad at tha raduotton ratio chackad balow/ 
 
 Co documant aat film* au taux da iMuctton in<Mqii* d-daaaoua. 
 
 10X MX WX 
 
 2SX 
 
 asx 
 
 12X 
 
 1«X 
 
 a«x 
 
Hm 00^ fllfii«d bmm Hm bmn raproduoMl thanks 
 to th« oMMfOshy of: 
 
 Unlvtnityof Altoffta 
 Eflmotitoii 
 
 L'Mompiairo f llmA fut roproduit grioo i lo 
 g4nArotit* do: 
 
 Unhrtrsity of Albarta 
 * Edmoiiton 
 
 Tho Imogoo appoorlng horo ore tho boot quolltv 
 poMiblo eofwMoring ttio eondltflofi ond loflitoWty 
 of tho original eopy and In kooplng with tho - 
 fHmlng oontraot ipoolfioationd 
 
 Orlglnol sopioo in printod popor oovora a«o fHmod 
 boginning with tho fiont oovof ond onding on 
 tho loot pago with a printod or Hhiotratad improo- 
 •lon. or tho boeii eovor whon o pp r oprtoto. AN 
 othor original oopioo oro fHmod boginning on tho 
 first pogo with o printod or Hhioiratod Improo* 
 skNi, snd snding on tho lost pogo w4th o printod 
 or muotratad impraaslun. 
 
 Tho loot roeordod fromo on oooh nderofieho 
 shod oomain tho symboC "-^ i m oo n ing "COH- 
 TINUfO"). or tho symbol V inisjonlng "END"). 
 
 Los Imogos suivsntss ont Sc4 rsproduitss avsc It 
 plus grand soln. compto tonu do la condition st 
 do lo nottot* do I'oxompioiro film*, st sn 
 oonfermitd avoe los conditions du contrst ds 
 flimogo. 
 
 I.OS oxompioiros originoux dont lo couvorturs sn 
 poplor oot Imprlmdo sont fllmds sn commonpant 
 por lo promior plot «t on tormlnont soit psr Is 
 dsmlAro pogo qui comporto uno smprsints 
 d'improssion ou d'iilustrstlon. soit par lo sscond 
 plot, solon lo COS. Tous Iss sutrss sxsmplsirss 
 originoux sont fiimds sn common^snt por Is 
 prsmMro pogo qui comporto uno omprointo 
 dimproosion ou d'iiiuotrotion ot on isrminont psr 
 lo domlAro pogo qui comporto uno toilo 
 omprointo. 
 
 Un doo symboios sulvonts spporottra sur la 
 damiAro imaga «la chaqua microficho. ssion Is 
 cos: lo symbolo -^ signifio "A SUIVRE", lo 
 symbols ▼ signifio "FIN". 
 
 Mopo. plotos. ehorto. ots.. moy bo fHmod ot 
 difforont roduetion rotios. Thooo too larga to bo 
 ontlroly inohidod in ono oxpoouro oro fNmod 
 boginning bi tlio uppor loft bond eomor, kift to 
 right ond top to bottom* oo mony fromoo oo 
 roquirod. Tho foNoMdng diogromo Wustroto tho 
 
 Los cartas, planchos, tabiooux, stc. psuvont Atrs 
 filmte A dss taux do reduction diffirsnts. 
 Lorsquo lo documont ost trop grond pour Atfo 
 roproduit on un ssui ciichA. il sst films A psrtir 
 do I'ongio supdrisur goucho, do goucho i droito. 
 ot do hout on boo. on pronom lo nombro 
 d'Imogoo ndcooooiro. Los diogrommos sulvsnts 
 iUustrsnt Is mdthodo. 
 
 1 2 3 
 
 1 
 
 2 
 
 3 
 
 4 
 
 5 
 
 6 
 
r 
 
 L 1 
 
 I 
 
nepH,Mfr„n, the Mohthi.t Noticrs of thb Rotat 
 
 Vol. LIV. Ao. s. 
 
 ASTnOVOMIOAl SoCIKTV, 
 
 REMARKS ClOX MR. STOKE'S PROPOSED COR 
 BECTIONS TO THB MEASURE OF TIME SINCE 
 1864. 
 
 BT 
 
mnmmmmm 
 
 286 
 
 Prof. Newcomb, Remarl-t on Mr. Stone's lit. 5, 
 
 I 
 
 Ber/iarl's upon Mr. Stone's Proposed Ocrrredhns to the Measure of 
 Time since 1864. By Professor Simon Newconib. 
 
 In the December number of the Munthhj Notices Mr. Stone 
 presents a very able and elaborate statement of certain correc- 
 tions which he claims shoald be applied to the adopted measnre 
 of time from and after the beginning of 1864, together with the 
 resulting corrections to the tabular places of the Moon derived 
 from Hansen's tables. The great importance of the question 
 raised by Mr. Stone seems to make it only respectful to him 
 that I should once more state the difficulty in the way of 
 accepting his conclusions. 
 
 The following numbers are extracted from Mr. Stone's paper 
 on page 4 of the Monthly Notices for November, which give the 
 results of certain Kadcliffe observations of the Moon, made 
 in 1892 : — 
 
 Bate, 1892 January 6. 
 
 m s 
 Correction to be subtracted from M.T. for change uf Sidereal 
 
 Time at Mean Noon since 1864 4i'Sl 
 
 Observed Right Ascentiion of the Moon 49 19-57 
 
 R.A. from Hansen's Tables for uncorrected Mean Times ... 20'93 
 
 Hansen minus observed uncorrected +1*36 
 
 Correction due to the change of unit in M.T —v^6 
 
 Hansen minus observed corrected —010 
 
 In this and other papers it is claimed by Mr. Stone that the 
 above correction of 4i''5r to the sidereal t:me of mean noon 
 since 1864 has resulted from a progressive change, starting from 
 the epoch 18640 and increasing uniformly at the rate of about 
 i'-48 annually. From this it follows that the tabalar Right 
 Ascensions of the Moon at transit over the meridian at Oxford, 
 as computed from Hansen's Tables, should on the above date 
 
 .■ \ 
 
 fMir(--:'-i'i'S.^''Li-i'^''>-^^ ir . 
 
March 1894. proposed Corrections to the Measure of Time. 287 
 
 •5» 
 
 >-93 
 
 •36 
 
 •46 
 
 10 
 
 reoeive a oorreotion of i* 36 in oonseqnenoe of the alleged 
 change in the sidereal time at mean noon. 
 
 The claim that this correction starts from zero aboat 1864*0, 
 and increases uniformly at the rate of about 1**48 annually, is 
 based by Mr. Stone on the fact that that was the date when 
 Le Verrier's tables were introduced into the Nautical Almanni',, 
 and when, in consequence, according to Mr. Stone's theory, the 
 new measure of time began. 
 
 Now, to show my difficulty, let us suppose that the old 
 tables of the Sun had been continued up to the end of the year 
 1891, and that in the year 1892 Le Verrier's Tables had for the 
 first time been introduced. To make my meaning perfectly 
 clear I shall call the case of actual introduction in 1864, case 
 A; and the supposed case of introduction in the year 1892, 
 case B. On Mr. Stone's theory, the time t should in case 
 B be counted from 1892*0, and the correction therefore for 1892 
 January 6 would have been substantially zero. 
 
 But it is evident that the tabular numbers for the whole 
 year 1892, and therefore for January 6, would have been exactly 
 the same in case B as they are in case A ; that is to soy, if tho 
 solar ephemeris from Le Verrier's Tables had been computed foi 
 the first time for the year 1892, all the quantities taken from the 
 tables and printed in the Nautical Almanac would have been the 
 same as they actually are. To claim that they would have been 
 different would imply that the results of making a computation 
 from Le Verrier's Tables are not merely a function of the 
 numbers contained in the tables, but of the time when they 
 began to be used for the ephemeris of the Nautical Almanac. 
 Were this doctrine true it might also be possible thai the 
 quantities taken out from a table of logarithms were different 
 from year to year. As this cannot be the case it conclusively 
 follows that all the numbers used in computing the tabular 
 place of the Moon at transit over the meridian of Oxford on 
 1892 January 6 would be ertactly the same in case B that they 
 are in case A. Consequently the result would have been the 
 same as Mr. Stone gives it for the nncoi-rected time ; that is to 
 say, we should have had — 
 
 Observed Bight Ascension of the Moon ... 
 R.A. from Hansen Tables for uncorrected M.T. 
 Hansen minus observed uncorrected 
 Correction due to the change of unit in M.T. 
 Hansen minus observed corrected 
 
 49 I9S7 
 
 20-93 
 
 + 136 
 
 000 
 
 + 1*36 
 
 out 
 
 ght 
 
 ,rd, 
 
 ^ate 
 
 Thus Mr. Stone's theory and his method of npulying it giva 
 a correction zero for 18940 in case B, when in fact the numbers 
 to be corrected are the same- as they are in case A. From this 
 conclusion I see no escape From Mr. Stone's theory the use of 
 the new unit of time would, in ca«e B, have commenced in 1894. 
 
a88 
 
 Prof, Newcomhy Uemarha ef<'.. 
 
 uv. 5. 
 
 Here / must be reokonod from 18940, and tlie correction munt 
 b» zero. Tims liis thcorjr gives two iucunHiHteiit correct ions to 
 the Hanie numbers. 
 
 SiiolUtirouile ± Co. Prinleri, X-ir-xIrrrl Si/imie, Lviidon. 
 
 
mmm