48 



THE TRANSATLANTIC LONGITUDE. 



The correction for inequality of pivots, as deduced from the Calais observations, 

 is +0'.022; the pivot at the perforated end of the axis being the smaller. The 

 mean of the results from five previous campaigns having been found to be +0'.027, 

 and no individual determination differing from this amount by so much as 0'.002, 

 the value +0^025 has been employed in the reductions. 



The observations here given were made by Mr. Boutelle on December 12, 13, 

 14, 15, and by Mr. Chandler December 11, 16, and 18. The correction for per- 

 sonal equation will be applied when deducing the resultant longitudes, and is not 

 needed here, since no group contains observations by both gentlemen. It will be 

 seen that the transit of only a single star could be obtained before or after exchanges 

 on the 16 th, one of these being moreover a circumpolar, and that the obstacles in 

 the way of good determinations of time were quite serious on other nights, when 

 exchanges were made with Newfoundland. On those dates when the Calais sky 

 was clearest, the weather at Newfoundland seems to have been unfavorable. It is 

 to be regretted that opportunities did not continue for exchange of signals on at 

 least two more dates, as desired by Mr. Boutelle, and the accordance of longitudes 

 resulting from observations obtained under such unfavorable circumstances is in 

 the highest decree honorable to the sjentlemen concerned. 



1866, December 11— C, Obs. | 



star. 



Lamp. 



Threads. 



31 



60 



R 



Bb^+k 



a Pegasi ■ . . . . 



E. 



D.-F.[C3DJost] 



23" 0""56'.69 



— 0M8 



+ 0" 0=.61 



— 0M8 



Cephei IJ. C. . . 



" 



El— E5 [F, lost] 



15 0.19 



—0.19 



+ 1 0.47 



—0.50 



" " . . 



w. 



E.-F, 



17 12.56 



—0,23 



—1 11.53 



—0 59 



e Piscium . . , 



" 



B-P. 



24 2.57 



—0.25 



0.00 



—0,21 



y Cephei U.C. . . 



" 



B.-C, 



34 59.88 



—0.25 



+ 1 47.89 



—1 01 



" "... 



E. 



B— C5 



38 33.75 



—0.21 



—1 47.89 



—0.86 



Groombr. 4163ir,C. 



" 



E.— 



50 21.95 



—0.20 



+ 53.32 



—0.67 





W. 



E-F, 



23 52 47.72 



—0.24 



—1 27.00 



—0.80 



T = 



e=_2°'49'.00 p=_0'.080 c 



= — 0^090. 



Star. 



i 



f 



Cc 



"0 



Aa 



At 



a Pegasi .... 



23" O^ST" 12 



SS-" 8^02 



— 0».09 



+ 0'.53 



— 0M5 



— 2"49M2 



Cephei U.C. . . 



16 0.30 



13 11.77 



. 



—0.98 



+ 0.28 



48.87 



e Piscium . . . 



24 2.36 



21 13.13 



+ 0.09 



+ 0.64 



—0.18 



49.01 



y Cephei U.C. . . 



36 4.5.88 



33 57.53 



.... 



—2.32 



+ 67 



49.04 



Groombr. 41 63 L.C. 



23 51 14.76 



48 26.11 



.... 



—1.70 



+ 0.49 



—2 49.15 





5 M — 3.831 a = + 0=.f)20 







— 3.831 A9 + 9.906 a = — 2.704 







a =■- — 0=.289, AO = — 0^037, A(! = + 2" 49".037 





