CIRCULATION OF THE ATMOSPHERE 459 



lines have different values from iron lines, and therefore the entire 

 subject is open to an extensive investigation. 



The atmosphere of the earth is rilled with what is called atmospheric 

 electricity. This consists of positive and negative charges of electricity 

 distributed in a very complex way, depending upon temperature, vapor 

 contents and barometric pressure. The distribution of electricity 

 changes with the season of the year, and with the hour of the da} r , and 

 differs from latitude to latitude, and from elevation to elevation above 

 the same place. Similarly the sun's atmosphere is filled with electric 

 charges. Every electric charge in motion produces magnetic field. If 

 particles of electricity rotate about an axis, and parallel to a given plane, 

 there will be a magnetic field perpendicular to that plane. These mag- 

 netic fields may occur at any temperature, provided the charge of elec- 

 tricity and the motion in a closed curve is at hand. If a ray of light in 

 a strong magnetic field is looked at along the lines of force of the field, a 

 single ray is split up into two lines slightly displaced and circularly 

 polarized in opposite directions. If the line of light in the magnetic 

 field is looked at perpendicular to the lines of the magnetic force, a 

 single is split up into three or more lines. In the case of three lines the 

 outside lines are displaced and polarized in one direction, while the 

 middle line is not displaced but is polarized at right angles to the two 

 side lines. These effects of the magnetic field upon a ray of light are 

 called the Zeeman ejfect, and if these effects are seen it is strong evi- 

 dence if not proof that the magnetic field has been acting upon the 

 ray of light. The Mount Wilson Observatory has been able to show 

 that the light which comes from the interior of the sun spot or vortex 

 produces both types of the Zeeman effect, the two circularly polarized 

 lines when one looks at the spot near the center of the solar disc; that 

 is down the tube of the vortex ; and the three p*lane polarized lines when 

 one looks at the sun spot near the edge of the sun, that is, nearly at 

 right angles to the sun spot vortex tube. At any rate enough has been 

 shown to make it more than probable that magnetic field exists cer- 

 tainly in the solar spots, and probably throughout the mass of the sun 

 where gyrations and internal vortices doubtless take place. If the 

 sun spot produces a magnetic field strong enough to show the Zeeman 

 effect at a distance of 93,000,000 miles, it is entirely reasonable to sup- 

 pose that magnetic fields occur through the solar mass wherever there 

 is actual circulation. It has already been intimated that the entire 

 body of the sun consists of an enormous number of circulating tubes 

 directed more or less perpendicular to the equator, and as a corollary 

 the entire mass of the sun would be a magnetized sphere. The ends of 

 these polarized circulations at the solar surface should develop an out- 

 side magnetic field to correspond with the interior. In my early re- 

 searches of nearly twenty years ago it was shown that the lines in the 



