448 Intelligence and Miscellaneous Articles. 



C b b being the capacity of B, and C* the coefficient of induction of B 

 upon A. We have to demonstrate that Cj=C£. Let us superpose 

 these two states of equilibrium, characterized by the charges M 6 and 

 M$ upon the conductors A and B : — 



M.-CCV.+CUY,;! (1) 



M 4 = C 4 °V 1+ C»V 2 . J 

 The actual electrical energy W of the system is, by equations 

 (1) of the form 



W=iSMY=r(Y 1 ) 2 +^V i y 2 + 6-(Y 2 ) 2 (2) 



Let us now subject the system to an infinitesimal deformation 

 by producing, for example, a very slight relative displacement of 

 the conductors. The charges will not change ; the potentials alone 

 will vary ; and the corresponding variation of the energy will be 



gW=iM gV 1 +iM 4 SV 3 . 

 Therefore JM ffl and |Mj are respectively the partial differential 

 coefficients of the function "W with respect to the potentials Y 2 and 

 V 2 . Differentiating, therefore, (2) with respect to Y v one finds 

 for the development of M a 



2rY 1 + tY 2 ; 

 in the same way, differentiating with respect to V 2 , one finds for 

 the development of ~NL b 



tY 1 +2sY 2 . 

 Finally, comparing these results with the equations (1), it is seen 

 that C 5 =C" 



a o' 



which was to be demonstrated. — Oomjptes Rendus de VAcademie des 

 Sciences, Nov. 7, 1881, t. xciii. pp. 719, 720. 



ANOTHER CONFIRMATION OF PREDICTION. 

 BY PLINY EARLE CHASE, LL.D. 

 On the 4th of October, 1878, I presented a communication to 

 the American Philosophical Society*, in which I showed that the 

 position of Watson's first intra-Mercurial planet, as computed by 

 Gaillot and Mouchez, represented the third intra-Mercurial term 

 of my harmonic series. At the last meeting of the British Asso- 

 ciation, Prof. Balfour Stewart read a paper, in which he gave indi- 

 cations of sun-spot disturbances by a planet revolving in 24*011 

 days, and consequently having a semiaxis major of 163. This con- 

 firmation, both of my own predictiont and of the calculations of the 

 Prench astronomers, is the more interesting, because the first con- 

 firmation of my series was contained in a communication which 

 was made to the Royal Society by Messrs. De La Bue, Stewart, and 

 Loewy, forty-one days after I had announced the series to the Phi- 

 losophical Society and published it in the ' New York Tribune ' %. 

 The accordances are as follows : — 



Prediction. Confirmation. 



t, I .„** 



i , • , • i • , 0fi ,, f De La Bue, btewart, i « 



1st interior harmonic term '26 1 <( , T ' ' y '26 



I and Loewy J 



r, -, -, n % J Graillot and Mouchez *164 



* rd » " ' ibo t Stewart -163 



■ Proceedings, xviii, pp. 34-36, t Ibid. xiii. p. 238. X Ibid. p. 470. 



