( 104 ) 



Tij and the motions — . The results are collected in the following 



ilt 



tattle. The values of to, for 11)00.0, given in the last two columns, 

 have been derived from those for the individual epochs for each 



system separately l>v means (it the motions — corresponding to the 

 1 • ' dt ' 



assumed masses. The perijoves are counted from the assumed vernal 



equinox of Jupiter, whose longitude in 1900.0 is 135°. 45. 



The values of these elements, on which Souillart's theory is 



based, are: 



The results from the two systems are practically identical. The 

 corrections to SouiLLART's values for the satellites II, 111 and IV, are 

 considerable, ami on the whole much larger than the deviations of 

 the three epochs inter se. These corrections are thus undoubtedly 

 real. The most remarkable of them is certainly the large own 

 excentricity of II. The value of this element, assumed by Delambre 

 and Damoiseau is zero. The value used by Souillart in his theory 

 is a pure arithmetical result, and has no weight whatever as a 

 determination of the element. Damoiseau, however, has suspected the 

 existence of an excentricity of practically the same amount as is 

 found here. This is shown by the following quotation from his un- 

 published memoir, written in explanation of the construction of his 

 tattles, which I quote after Souillart 1 ). Damoiseau says there: 

 "Nous avons des motifs de soupconner dans l'orbite du second 

 satellite line equation du centre propre de 32° en temps synodique 

 (ce qui correspondrait a une excentrieke propre de 0.00032738), 

 mais notre incertitude sur la position du périjove, dont Ie mouvement 

 est encore a calculer par la theorie, nous a fait remettre cette re- 

 cherche a mi autre temps." This excentricity, expressed in arc is 

 0°.0188, and it is therefore practically the same as the value found 

 by me. The reason adduced by Damoiseau for not using it in his 

 tables sounds somewhat strange: as a matter of fact the motion of 

 the perijove had been determined long ago by Laplace. 



With regard to Satellite I it is clear (hat the apparent equations 



') Mémoires des Savants drungers, tome XXX, page 28. 



