516 BAUER: ANALYSIS OF THE SUN's MAGNETIC FIELD 



important, from a cosmical standpoint, to test the new period as soon 

 as additional series of observations are available. It may also play 

 an important part in the discovery of the cause of the sun-spot cycle, 

 however, the period obtained must be regarded at present as but a 

 preliminary one. 



4. It is found that the solar magnetic field is as complex as that of 

 the earth and that the distorting or disturbing systems which are super- 

 posed upon a primary, simple magnetic field follow laws very similar 

 to those disclosed in the study of the terrestrial magnetic field. Thus, 

 for example, the plane containing the magnetic axis of the sun is dis- 

 placed in passing from the northern to the southern hemisphere in 

 precisely the same direction, eastward (in the direction of rotation), as 

 was found to be the case with the earth's magnetic axis. Accordingly, 

 to give the requisite precision to the term ''magnetic axis," the region 

 from which it is determined must be carefully stated, as well as the 

 method employed for fixing its position. 



The close analogies that thus appear to exist between the 

 magnetic field of the sun and of the earth, coupled with the fact 

 disclosed by Hale that the magnetic polarity of the sun corre- 

 sponds to that of the earth, may possibly indicate, since the direc- 

 tion of rotation of the two bodies is the same, that the origin of 

 both magnetic fields will have to be referred finally to similar 

 causes. In any case, the fact that the sun's field turns out to be 

 as complex and as irregular as that of the earth and that these 

 apparent irregularities follow similar laws for both bodies, would 

 seem to strengthen the conclusion already reached in the investi- 

 gation^ of the terrestrial magnetic field, that it may not be neces- 

 sary to refer the cause of the non-coincidence of the magnetic 

 axis with the axis of rotation chiefly to heterogeneity of structure 

 of the bodies under discussion. 



' A consistent theory of the origin of the earth's magnetic field. This Journal. 

 3: 1. 1913, and On the origin of the earth's magnetic field (Phys. Rev. N.S., 

 1: 256. 1913. 



