4. 



NEW ELEMENTS OF NEPTUNE. 



[From the Monthly Notices of the Royal Astronomical Society (May, 1847), Vol. vn.] 



THE following elements of Neptune have been obtained by taking into 

 account Professor Challis's Observations made since the reappearance. * 

 The elements are now sufficiently correct to enable me to approximate to 

 the perturbations of Neptune by the action of Uranus, in order to compare 

 more accurately the ancient observations of 1795 with those .... made re- 

 cently. I have used the old observations, supposing the elements not to 

 have changed. I hope immediately to set about a new solution of the 

 perturbations of Uranus, starting with a very approximate value of the 

 mean distance. * * * I do not think with Professor Pierce, that the near 

 commensurability of the mean motions will interfere seriously with the results 

 obtained by the treatment of perturbations ; but it will be interesting to 

 see how nearly the real elements can be obtained by means of the pertur- 

 bations. 



Elements of the Orbit of Neptune. 



Mean Longitude, Jan. 1, 1847, G. M. T 328 13 54'5j 



Longitude of Perihelion (on the Orbit) 11 13 41 "5 1 M. Eq. 1847'0 



Ascending Node 130 5 39'OJ 



Inclination to Ecliptic 1 47 1'5 



Mean Daily Motion 21-3774 



Semi-axis Major 30'2026 



Eccentricity of Orbit 0'0083835 



A. 8 



