1. 



KESULTS OF CALCULATIONS OF THE ELEMENTS OF AN EXTERIOR 

 PLANET, WHICH WILL ACCOUNT FOR THE OBSERVED IRREGU- 

 LARITIES IN THE MOTION OF URANUS. 



[From the Monthly Notices of the Royal Astronomical Society, Vol. vn. (1846). Papers 

 delivered to the Astronomer Royal Oct. 21, 1845 and Sept. 2, 1846.] 



I. 



ACCORDING to my calculations, the observed irregularities in the motion of 

 Uranus may be accounted for by supposing the existence of an exterior 

 planet, the mass and orbit of which are as follows : 



Mean Distance (assumed nearly in accordance 



with Bode's law) 38'4 



Mean Sidereal Motion in 365 '25 days l30'-. f ) 



Mean Longitude, 1st October, 1845 323 34' 



Longitude of Perihelion 315 55' 



Eccentricity O'lGlO 



Mass (that of the Sun being unity) 0'0001656. 



For the modern observations I have used the method of normal places, 

 taking the mean of the tabular errors, as given by observations near three 

 consecutive oppositions, to correspond with the mean of the times ; and 

 the Greenwich observations have been used down to 1830 : since which, 

 A. 1 



