26 STATEMENT AND EXPOSITION OP 



(U)— J ^ r-; or 



^ m -\- in 



( U J'' — ; — ; whence 



7n 4- m 



7n(Uy + m'(Uy ^ wi',a'^+ «i,a*; and 

 I I (U)'- a4 ^ m' I a'^- (U)' l ; and 



«'+ (U) X (tt'-(U) 

 (U) + a X (U) - a 



which, as a', (U), and a are all determined, will give us m in terms of m'. 



Substituting, then, the values of «', (U), and a, as found in the column of Laio 

 in Table (B), in (14), we have 



m = (1.38866) ?n', 



i. e., the mass of Si = (1.38865) of the mass of Uranus ; or, substituting the value 

 of the latter, as found in Table (A), in (3), we shall have 



Mass of ^i = 15^ = 0.00006312- of the mass of the sun. 



Tlie most probable Answer to the Question — What has lecome of the Missing Mass ? 



(42) The most ready reply to this question would seem to be — that the missing 

 mass had, (29), been formed into a group of asteroids. But then, as this region of 

 the planetary system is one in which large masses abound, it would also seem that 

 the mass of a group of asteroids here, might reasonably be supposed to be very 

 considerable, even if the computation already made, (41), had not indicated this very 

 mass to be almost ly*^ that of Uranus. 



And if these considerations are conceded to have weight, the existence of the 

 seemingly missing mass, in the form of a group of asteroids, becomes at once inad- 

 missible; since, if such a group were there, its existence Avould speedily be evi- 

 denced by the perturbations of both Uranus and Saturn, which such a group Avould 

 produce. 



(43) Rejecting, then, the hypothesis of the existence of a group of asteroids in 

 this region, the next hypothesis which it may be found to be appropriate to con- 

 sider will be, whether, in the accumulation of the great mass which was to consti- 

 tute Saturn, the material which would have formed the interior half-planet ^i was 

 not itself drawn over and invmrd hy the overmastering attraction of the Saturn- 

 forming mass, which thus attached to itself the interior half-planet mass rent away 

 from Uranus. 



In favor of this hypothesis we shall find ten special consistencies, which in their 

 turn will introduce others, having more extended relations. 



