The Motion and Distribution of the Sun-spots 



9 



have given a result of not less than 29 periods, with a length varying between 164 

 and 3,6 years. Have these periods an actual existence, or are they to be consi- 

 dered as dependent only on the method employed? Even if the spot-frequency is 

 represented by a series of the form 



v^sin + ^^) 



it does not follow that the periods of the different terms are of real import. 

 The old theory of Epicycles represented also the motions of the planets with 

 considerable accuracy. Professor Turner \ in a discussion of the results of Ki- 

 MURA, remarks that the periods computed by Kimura are as 1:2:3:4:..., and 

 that all these periods may be considered as subperiods of a longer period of 156 

 years. This circumstance, however, may be considered as a control of the numeri- 

 cal computations of Kimura. But from tliis it does not follow that these periods 

 have an actual existence. This remains to be proved, and is a problem which will not 

 be dealt with here. 



The Motions of the Sun-spots. From the motions of the spots over the 

 disk of the sun, the rotation-period and the position of the sun's equator may be 

 computed. In the following we suppose 



i = the angle between the sun's equator and the ecliptic. 

 L = the longitude of the ascending node of the equator. 

 As above mentioned. Scheiner had for these quantities got the values 

 i = 70.5, 

 L = 69".6. 



Amongst other determinations, I mention only the following here: 



Ijaugier : 



i = 7°9' 1 





L = 7508' ) ^ 



Böhm: 







L = 76046'.9 



Carrington : ^ 



/ = 7"! 5' 1 





L = 7304O' I 



Dyson and Maunder: 



i = ino'.G 





L = 73''5Ü'.6 



' H. Turner: On the Harmonic Analysis of Wolf's Sunspot Numbers, with special Reference 

 to Mr. Kimura's Paper. Monthly Notices. May 1913. 



^ R. 0. Carrington: Observations of the spots on the sun from Nov. 9, 1853 to March 

 24, 1861. 



^ F. W. Dyson and E. W. Maunder: Tlie position of the sun's axis as determined from 

 pliotographs of the sun, 1874 — 1911, measured at the Royal Observatory, Greenwich. Monthly 

 Notices LXXIl. 



Lunds Universitets Årsskrift. N. P. Atel. 2. Bd 10. 2 



