( 47 ) 



The error of the hypothesis of Chandler is thus ah'eady rather 

 considerable in 1895. 



Let us now consider the amplitude. Uniting according to the 

 weights my results obtained by the a- and by the y and adding to 

 them some values, formerly found, we obtain 



Amplitude 



Leiden 1864 — 68 Fundaiu. stars. 0".156 



» 1864-74 Polaris .158 



Pulkowa 1882—92 .139 



Fiual result of H. G. B. 1860—92 .168 



Result 1890-96 .148 



We have to remark here, that the result of Pulkowa is probably 

 too small on account of the unequal distribution of the observations 

 of the individual stars, for which Wilterdisk applied a correction 

 in dealing with the Leiden observations. 



So a change in the amplitude since 1860 is no more probable 

 now than it appeared before to H. G. v. D. S. Bakhuyzen. On 

 the; other hand we may not, as he already remarked, combine the 

 observations before 1860 with the later ones, certainly not so far as 

 the amplitude and perhaps not so far as the phase is concerned. 

 This might be reconciled with the conception of the 431 day-period 

 as a time of oscillation proper to the earth, when we assume M that 

 from time to time sudden causes may change the mutual position 

 of the axis of rotation and the axis of inertia. 



Finally I should like to lay down as most probable elements of 

 the motion of 431 days since 1860 



Time of transit through the posit, axis of x 2408565 



Period 431.1 days 



Amplitude 0". 155 



consequently 



X ^z -\- U".155 cos 2 n 



= — 0".155 sin 2 n 



<— 2408565 

 ^431.1 



<— 2408565 

 431.1 



') See also Gylden Astr. Nachr. Vol. 132. N". 3157. 



