Chase.] £o£ [April 4, 



precisely with the theoretical ratio (9J between the two planets, while the 

 former is presumably more accurate 



The uncertainty in regard to ull the planetary masses, except that of 

 Jupiter, is Still SO great, that it is impossible to tell how closely they are 

 represented by the equations for the combined central activities (0, 7, 8). 

 The latest investigations of Leverrier and Newcomb, however, show a 

 closeness of approximation which is remarkable, in view of the wide dis- 

 crepancy in some of the values. Leverrier's mass-denominators, based on 

 the old parallax (8. "57), are: Neptune, 14400; Uranus, 24000 ; Jupiter, 

 1050; Saturn, 3.512; Earth, 354936. The accordance with the combined 

 equation (8) is within f of one percent, if we deduce Earth from the other 

 masses ; within fa of one per cent, if we deduce Saturn. 



If we look to the partial equations, (G, 7), we find that Saturn's mass, as 

 deduced from Neptune, Uranus and Jupiter, (6), is about § of one per 

 cent, greater than Leverrier's assumption, and about the same amount less 

 than Bessel's, which was adopted by Newcomb. The mean of the two re- 

 sults shows an exact accordance, as follows : 



Deduced. Assumed. 



Leverrier 3488.3 3512.0 



Newcomb 3525.0 3501.6 



Mean 3506.6 3506.8 



The results of the second partial equatior, (7 2 ), may confidently await 

 the verdict of the observations upon the last transit of Venus. No other 

 estimate can now claim a greater degree of probability. It may be, as 

 Leverrier suggests, that a small portion of the mass may belong to a group 

 of minute asteroids, near Earth's orbit, but there is no present likelihood 

 that any material inaccuracy will ever be found in the equation which con- 

 nects the two principal intra-asteroidal centres with the two principal extra- 

 asteroidal centres. 



E. Wiedemann's experiments upon the illumination of gases by elec- 

 tricity,* have convinced him that the electric discharge may excite a con- 

 siderable increase of the vis viva of oscillation in sethereal envelopes, with- 

 out increasing the vis viva of the enclosed molecules. Peirce's meteoric 

 hypothesis opens an immense field for new physical speculation and inves- 

 tigation. If the aether is material, where shall we draw the boundary 

 between sethereal and meteoric influences? If cosmical masses have been 

 formed by paraboloidal aggregation, may not radiation also be paroboloidal ? 

 The solar forces of association and dissociation seem to be almost exactly 

 balanced, and the law of equal action and reaction may, perhaps, free the 

 science of thermodynamics from the opprobrium of its apparent tendencies 

 to universal aggregation, stagnation and death. 



* Wied. Ann., vi, p. 331. 



