44 



spectrum are similarly affected, and if the degree 

 of their displacement vanes from pole to equator 

 as calculation shows it should do on a magnetized 

 sphere, we may conclude that the whole sun is a 

 magnet. An extended investigation (rendered 

 difficult by the very minute displacements of the 

 solar lines, far too small to appear to the eye in 

 the photographs) has led us to the conclusion that 

 the sun is a magnet, with its poles lying at or near 

 the poles of rotation. 



rrnr 



FIG. 34. -D Lines of Solar Spectrum, with Iodine Absorption Spectrum 



superposed. 



The sun in this respect resembles the earth, 

 which has long been known to be a magnet. 1 he 

 general magnetic field of the sun, although about 

 80 times as intense as that of the earth, is so weak 

 compared with the magnetic fields in sun-spots 

 that the full power of the 75-foot spectrograph was 

 required to reveal it. As the sun rotates on its 

 axis, it permits the magnetic phenomena of all 

 parts of its surface to be studied. Photographs 

 of the spectra over a wide range of latitude are 

 therefore made daily, in order to provide material 

 for charts which will show the exact position of the 



