R E S U L T S I RVAT ASTRONOM CAL OBSE IONS, MADE A T THE OBSERVATORY OF THE I E UN V RSITY, D U R H A M , N 184-6 TO UL 1848 FROMJA UARY, , J Y, , UN DEB THE DI RECTI O N O F L B . H E V . L L F T R . R E D . s TE M P E C H EV A I ER, , A _ PRO F B SO B O E A N D A STRO N O I Y I N THE UN I V ERS I TY O F DURHA M . R EV . N H N B . A . THE ROBERTA CHORT OMPSO , O BS ERV ER I N THE UN I V ERS I TY. D U R H A M PRIN D P HUMBLE. TED BY THE E! EC UTO RS O F E W . IN TRODUCTION . HE servat r of the niversi of Durham was built in 1841 rin T Ob oy U t , ci all y p p y h ubscri tion . The servati ns un er t e eneral su erint n byprivate s p Ob o , d g p e den ce of the r fess r of at ematics and str n m are c n uc e an O server P o o M h A oo y, od tdby b , Th f ll win a es c ntain the results resident at the Observatory . e oo gpg o of O bser ns ma e et ween anuar 1846 and ul 1848 . vatio d b J y, , J y, i n Lon i ude o the O bservator La t tude a d t . I . g f y The latit ude was determined in the year 1843 from a large number of direct d refle te servati ns of a 3 and a rsae in ris and f un to be an c dOb o , U M o , o d h r en taken 6 f s rva r as i e e as m . 18s . es The longitude o the Ob e toy hth tob W t . is value was taine as sumin the l n itu e of ur am athe ral as Th ob dby g og d D h C d , v n in a eneral surve to be 6m . l 6s . and measurin ri n me ricall the i e y, , gt goo t y g g a difference of longitude of the O bservatory and the C thedral . Thatdifference in time and the resul in l n i u e of the serva r 6m . is , t gogtd Ob toy, . k n . th earest w le num er of sec n s 6m . 18s was a e e n ho b od , , t I n r er to c rrect t is a r imate value of the l n i u e the meri ian oh od o h ppox ogtd , d servations of the moon made on the same nights at Durham and at Greenwich av e een c m are and the l n i u e e uce fr m em in the f ll win h b o p d, o td dd d o th oo g g m anner . cl ck err r has een f un means of the n - ulminatin ars and A o o b o d, by Moo C gSt , ’ as sum other stars lying near the Moon s parallel. The ed places of the stars are those deduced from the whole of the Observations made at Greenwichdurin g s has een so serve less han re M s it eac ear. h en an tar e e s Ri hy W b ob d t th , ght y scensi n has in eneral een r u u fr m the reenwic a al A o , g , b boght p o G h C t ogue of 1439 stars . The places of stars contained in the N autical Almanac have been ’ aken as as sum at reen The i scensi ns of the t ed G wich . Rght A o Moon s Limbs at the reenwic Transi s are h se iv en the reen wic O serva i ns in G h t to g by G h b to , e en en l of t - ul n the dp d ty h Moon C minatingSta rs . The motio of Moon in one “ e hour of longitude has been interpolated from the N autical Alman ac ; the longi u e of ur am is n td D h then fou dby a simple proportion . 4 01 9 3 6 iv ( . ) The Durham Observations up to the end of 1845 were made by the late O b s B eanlands se in 1846 m self. erver M r. , , tho by y The re sults are as follows - ' Du m a s non or Lo nol runn o r G nanxw rc n A N D De a nn a. J an . 1 M ar. 29 ’ O bservations of the M oon s 2nd Limb . Th f all the resul s ‘ ivin e ual wei ts to eac c m arison is 6m e mean o t , g g q gh h o p , ' the serva i ns fr m 1842 to 1845 ive 6m . 19 00s . t se of 1846 Ob to o g , ho , 6m . 19 228 . The Transit nstrument ulle has a f cal len t of 4 ft . 2 in . the dia I , byT y, o g h , h las s in The m n meter of t e object g be g 3§ inches . agnifyi gpower of the e e y piece used is about 100. The eclinati n ircle is imms . I t is 2 feet in iameter and is D o C byS d , inde ’ pendentlydivided to 5 of arc . It is readby two microscopes at the extremities of the horizontal axis . ’ The l ck is a v er e cellent one ar furnis e wit . C o y x by H dy, hd h Hardy s escape ment . The uat real is Utzscheider and raun f r Eq o by F ho e . I ts focal length is 8 feet 3 inc es and the a erture of its ect las s 6 in h , p obj g ; ches . ( V The Observatory is indebtedto the munificence of the late Duke of N orth l ss f n 5in . i . f l en an umberland for a sec n ua rea o 7ft . 4 ca l t d odEq to , byRo , o g h, aperture ; but no Observations withthis instrument are contained in the re p sent series . The ransit lock c an be ear and seen fr m the me of the uat real T C h d o Do Eq o , i s and is eref re em l e w is n rumen . , th o , poyd thth I t t I Tra t O bs ati I I . nsi erv ons . The general m ethod of observing is totake the second from the clock face and reserve the c untin till the ransi is c m lete w en it is v erifie p o g T t o p d, h dby l ooking at the clock . revi usl e ruar 18 18 the ransi I ns rument carrie five vertical P o ytoFb y, , T t t d wires at the f cus of the e e - iece calle w en the I llumina e o p , d A, B, C, D, E, h td y nd of the elesc e is as and the s ar se e rve a ve the le . new T op E t, t ob d bo Po A ’ ’ s s em of wires was en su s i u ed and two a i i nal wires were in yt th bttt , ddto B , D , s rted etween the mi dle wire and the two ad acent ir s e b d j w e . F or the c rrec i n of im erfec Transi s the in ervals of the wires fr m the o to p t t , t o m ean of all were e ermine in anuar 1845 fr m wen c m le e ransi s dt d J y, , o t ty o p t T t 1 n l is serve e ween N ov . 1 1843 a d une 3 844 of ar 1 . The values Po , ob dbt , , J , en f un were em l e for O serva i ns m a e u ecem er 29 1846 th o d poyd b to d p toD b , , when a new set cam e into use determined from twelve complete Transits of laris serve e w en m 8 1846 nd 18 e e e er 2 a e ruar 12 4 . The Po , ob dbt Spt b , , Fb y , 7 two sets are as follows N or rno n THE I TERVAL EACHWIRE MEAN . For an Equatoreal star 1845. 1847 . A 37 ‘ 499 375 14 B 18 696 j: 187 28 C O ° Ol4 00 18 D 18 798 E 37 ‘ 435 37 ‘ 425 For the new s stem of wires the in ervals fr m the mean r y , t o we e determined in ril 1848 m eans of ten c m le e ransi s of laris n Ap , , by o p t T t Po , exte ding from Fe ruar 23 ril 14 and f un to b y , to Ap , o d be For an Equatoreal star 18 715 93 74 0 024 G 93 64 U 18 720 M ( vi- l ese alues were em l e for servati ns from Februar 1848 .