JI 



( 470 ) 



sufficient precision, we find from these formulae the most probable 

 values of x and y/ as follows; 



4.t' = _ rr + (M. - M,) + 2 (.¥3 - M,) - (.¥, - M,) 

 4l/= rr -f- {M, - M,) — 2 {M, - J/ J - (.¥, - M,) 

 If we combine only similar phases, we get 

 2,^=-Jt^{M, -i¥,)j 



The two solutions are identical, if 



In A. N. n°. 3456 Dr. Pannekoek summarises the intervals, counted 

 from the principal minimum, for different observers between 1842 

 to 1895. 



Dividing this period in two, he finds on an average: {11=12^.91) 

 maxj — mini m'm^ — miuj max^ — min^ 

 1842-1870 3^112 6^.40 9'^.54 



1870—1895 3^132 6-^.48 9^.73. 



From these values we find, for the first period : 



according to form. {[): according to form. {II): 



I e 6>m w = — 0.0052; e :=r 0.009 I sm to = + 0.0067 ; 6 = 0.008 

 j g COS «>= + 0.0076; to = 326° I e cos tu = — 0.0043 ; to r=r 123°. 



Similarl}^ for the second period : 

 I 6sm to = + 0.0040; e = 0.013 I e sin at — -0.0030; e = 0.006 



j g cos to = — 0.0125; to =r 162° < e cos to = — 0.0055 ; oj = 209° 



The only conclusion to be derived from these results is that e 

 was very minute in both periods, and hardly exceeding 0.01. 



9. A single glance at the numbers communicated by Dr. Pannekoek 

 shows that a trial to derive something more definite from the results 

 of the separate observers would be quite hopeless. In particular we 

 may allege the considerable difference between the results obtained 

 by LiNDEMANN and Pannekoek, in their reduction of the observations 

 of Plassmann. It thus seems to be out of place, from these observations 

 alone, to draw the conclusion that the excentricity has increased. 



Dr. L. Terkan has proposed the following method of deriving 

 the inclination of the orbit. ^) 



i) A. N. nr 4067. 



