Date. Obs. Right Ascen. Observed Dec. Obs. — Eph. d a. Obs. Eph. d 8. 



o I II o I It It II 



1795, May 8th 212 59 35.00 —11 20 39.10 —1.34 +0.79 



10th 212 ,56 36.30 —11 19 38.80 +1.73 +0,31 



Mean result, + 0.20 - + 0.55 



The Ephemeris for 1846 and 1847 is also computed from these second elliptic 

 elements, and is referred to the date of mean midnight, Greenwich, and to the 

 mean equinox and obliquity of January 1st, 1847. It has, however, a column for 

 reduction to the apparent place which, when applied, gives the ordinary form of 

 Astronomical Ephemerides, as affected with aberration. 



I have added the Ephemeris for the opposition and autumn quadrature of 

 1848. This is a reprint in a modified form of that which was distributed in June, 



1848, by the Smithsonian Institution. The change consists in the addition of 

 the aberration time to the absolute date of the Ephemeris, so as to make it cor- 

 respond in this respect to the usual form of publication of Ephemerides. A 

 small term, amounting at most to three and a half seconds of space, which was 

 retained in last year's Ephemeris by inadvertency, is here omitted. The pre- 

 sent form corresponds to that of the Ephemeris of 1846 and 1847, after applying 

 to it the reductions from the mean to the apparent places. 



I have also computed, and have now the honor to present to the Smithsonian 

 Institution, the Ephemeris for 1849, in the form of that of 1848, as remodeled 

 above. 



In the preface to my Ephemeris of 1848, it was remarked that "• the theory of 

 Neptune can hardly be expected to make farther progress till another opposition 

 is observed." 



I have now the pleasure to add, that the discussion of ninety-three meridian 

 observations of the opposition and quadrature of 1848, and their comparison 

 with the Ephemeris, lead me to extend the same remark to the opposition of 



1849. The Ephemeris of 1848 gives places of Neptune quite as precise as the 

 best normal places which I have been able to derive from the ninety-three 

 European observations of that year. In other words, the averages of the series 

 from the best observatories differ among themselves, more than either does from 

 the actual places given by the Ephemeris. 



The discussion of more than a thousand recent observations has afforded the 

 following comparison with the theory of Neptune, since its actual discovery. 



