MOUNT WILSON SOLAR OBSERVATORY. 197 



(13) The secondary phenomenon sometimes shows vortex motion 

 of the high-level calcium vapor, visible evidences of vortex move- 

 ments, and stream-line structure of the Ha flocculi, depending upon 

 the strength of the magnetic field and the rotational energy of the 

 underlying vortex. 



(14) The structure of the hydrogen flocculi does not represent 

 true stream-lines, but lines of force due to the low-level vortex which 

 produces the magnetic field. 



(15) The dominant charge of the electrons in this low-level vortex 

 is negative. 



(16) The observed decrease in the strength of the field along the 

 axis of the spot can be accounted for by assuming the thickness of 

 the electric vortex to be about equal to its diameter. 



(17) The forms of prominences surrounding a sun-spot at the sun's 

 limb closely resemble lines of force projected in a meridian plane. 



(18) The absence of stream-line structure in the Ho flocculi follows 

 from the quiescent state of the calcium vapor producing these 

 flocculi. 



(19) The flux of gases into and below the lower portion of the 

 reversing layer would cause a piling up of material, raised to a high 

 temperature by the rapid transformation of the chemical energy 

 into heat, and resulting in the observed increased emission of the 

 calcium vapor. 



(20) AVhen the displacements of lines in the red and violet of 

 equal solar intensities are compared, the lines in the violet show the 

 smaller displacements and therefore originate at higher levels, a 

 consequence of the scattering of light. 



(21) The displacements of the Fraunhofer lines in the penumbrse 

 of sun-spots give means of sounding the solar atmosphere and of 

 assigning relative levels to the sources of the lines. Aside from the 

 inherent probability of the interpretation, it is confirmed by eclipse 

 results, is in harmony with a wide range of solar observations, and 

 opens the way to further solar research. 



(22) With the aid of the relation between displacement and in- 

 tensity found for the iron lines, the relative levels of 26 other elements 

 of the reversing layer and chromosphere have been determined. 



(23) The H3 and K3 lines of calcium, followed by Ha of hydrogen, 

 represent the highest level. In general, the heavy elements occur 

 only in the lower portions of the solar atmosphere. 



(24) The enhanced lines appear to originate at higher levels than 

 the unenhanced lines. 



(25) The iron lines of different pressure groups are associated 

 with different levels. 



(26) The quantity of absorbing vapors in the solar atmosphere 

 seems sufficient to produce in general complete absorption. 



