24 



With these values were deterinined the normal places of the four principal 

 stars used for compai'ison in the equatorial instruments, by a discussion of all the 

 equatorial measures in the Astron. Nachr. to No. 591 inclusive, and in the pro- 

 ceedings of the Royal Astronomical Society, and in the United States. The 

 mean places of these stars for January 1st, 1847, thus obtained, are as follows : 



a = 327° 32' 16".71 

 b = 327 51 42 .75 

 c = 328 2 25 .95 

 d = 329 48 55 .93 

 To these add 38 Aquarii = 330 36 38 .55 



a' = 



V = 



c' = 



di = 



— 13° 23' 39". 44 



— 13 25 57 .75 



— 13 35 4 .23 



— 13 15 16 .39 



— 12 18 52 .04 from B. A. C. 



With these places* of the stars used for comparison, all the equatorial mea- 

 sures were reduced to observed places of Neptune ; and then XIII normal 

 places were formed from a combination of 479 observations. These normal 

 places, with the correction of Ephemeris V from Disturbed Elements V, are 

 here appended. The places are Right Ascensions and Declinations of Nep- 

 tune, referred, as before, to the mean equinox of January 1st, 1847, corrected for 

 pai-allax, but not for planetary aberration. The corrections a x and a p are 

 those of the heliocentric longitudo and latitude. 



SECOND GEOCENTRIC NORMAL PLACES OF NEPTUNE. 







Date. 





Obs. R. A. 



Weig-ht. 



Obs. Dec. 



Weig-ht. 



Correction of the heliocentric 

 places. 



No. 



Obs.— Eph. V. 



Obs.-Eph. V. 





Mean noon Green'h. 





A'. 







D'. 







A ^ 



A 



A 13 





' 





^ 



' o 



// /; 





' o 



; 



II 



r N 



II 



II 



I. 



1846. 



Aug. 



9 



329 



26 49.17 



2.0 



— 13 







6.97 



2.0 



— 0.22 



— 0.72 



II. 



" 



Sept. 



28 



328 



13 44.17 



24.7 



— 13 



26 



13.51 



24.5 



+ 0.08 



-f 0.37 



III. 





Oct. 



8 



328 



3 31.66 



62.0 



— 13 



29 



45.57 



66.2 



+ 0.17 



+ 0.28 



IV. 





(( 



18 



327 



55 56.59 



43.4 



— 13 



32 



21.64 



39.3 



— 0.06 



+ 0.09 



V. 





a 



28 



327 



51 17.81 



68.6 



— 13 



33 



.54.50 



65.0 



— 0.20 



+ 0.71 



VI. 





Nov. 



7 



327 



49 50.22 



80.2 



— 13 



34 



21.63 



74.2 



— 0.13 



— 0.42 



VII. 





ii 



17 



327 



51 39.64 



61.5 



— 13 



33 



38.79 



54.8 



-f 0.25 



— 0.27 



VIII. 





ii 



27 



327 



56 47.94 



33.0 



— 13 



31 



45.60 



26.1 



— 0.25 



— 0.05 



IX. 





Dec. 



7 



328 



5 10.16 



36.1 



— 13 



27 



46.67 



36.4 



— 0.49 



— 0.08 



X. 





11 



17 



328 



16 35.10 



34.0 



— 13 



24 



42.99 



32.6 



-f 0.29 



+ 0.25 



XI. 





a 



27 



328 



30 46.26 



13.6 



— 13 



19 



41.49 



15.0 



+ 0.13 



+ 0.33 



XII. 



1847. 



Jan: 



16 



329 



6 0.48 



18.1 



— 13 



7 



15.48 



23.1 



-f 0.34 



— 0.93 



XIII. 



a 



April 



6 



331 



49 47.18 



25. 



— 12 



9 



17.28 



18. 



— 0.10 



+ 0.65 



* The correction of the places of the first two stars, as used in Section 2, are, respectively, 



d a =z 

 db = 



0".08 

 .06 



da' = 

 db' = 



0".27 

 .53 



