( 212 ) 



follow one way or tlio other in reference to the observations of 

 Pulkowa. 



For the initial epoch and the length of the period itself we obtain 

 in the two cases: 



Ila 2408565 431.17 days. 



m 2408570 430.6t) „ 



Although after all the first solution seems preferable, I have given 

 below the deviations of the observations from both, besides those from 

 Chandler's two formulae of 1894 and of 1898. In order to show in 

 what relation the results of the observations before 1858 stand to 

 those of later years I also include the former. 



The consideration of the deviations for the observations 1858 — ■ 

 1896 shows that the agreement for Chandler's formulae, notwith- 

 standing their greater intricacy, is not better than that for mine. 

 If, in order to compare in this respect E.B. Ila with Ch.94 and 

 Ch.98, we omit, as is only just, the two Polaris-series of Pulkowa, 

 we shall find that the sum of the squares of the residuals multiplied 

 by the weights is even smallest for E.B. Ila. The distribution of 

 weights, however is of very great influence on these results. 



With regard to this period (1858 — 1896) therefore I should like 

 to give as the results of my investigation : 



1". For the present there is no sufficient reason to assume in the 

 14-monthly motion since 1860 a non-uniform velocity. 



2°. The length of the period in these years has not deviated 

 much from 431 days. 



These results clash entirely with those of Chandler's last paper 

 and little change has been brought about in the conclusions, at 

 which I arrived in my previous communication agreeing in the 

 main with the anterior results of H. G. v. D. S. Bakhuyzen. 



The epochs according to both solutions Ila and lib coinciding about 

 1893 and no reason existing not to adopt for the length of the 

 period the round number of 431.0 days, lying between both solu- 

 tions, I assume for the present as final result: 



Elements II of Hie \i-montlihj motion since 1860. 

 Epoch of maximum for Greenwich . . . 2412446 



Length of the period 431''.0 



Amplitude 0."156 1) 



') Mean viilue deduced from tlie previous suminai-y. 



