208 



CARNEGIE INSTITUTION OF WASHINGTON. 



the identification of the hnes is given in connection with the plotted 

 velocities. The ordinates are entirely arbitrary. They are only 

 meant to indicate the increasing velocities of inflow with increasing 

 elevation above the region of velocity inversion and the increasing 

 velocities of outflow as the depth increases below this level. At the 

 right are given some elevations taken from Jewell's table, which is 

 based upon eclipse observations of the levels of bright lines in the 



Pressure Elevation 

 in aim's in km. 



H3K3 



0.0 25000 



-.^y 



^-^— Mgb.bz^' 



Chromosp>iere 



-/~^0,AI 15-^0 iFeds-'io) Ley^l of velocity-inversion ^^' 



I'/ 10 — 7^- Fe ^^v. Reversing layer 



11/ / ^ / ^v. 



I' z-f s-Fe/ ^s, ^y 



\\ 7/ — V^Fe ^^y 



'il ll'. 



->-Fe-'' 



— ^Fe ^--\ 



^— -F^Pb,La 



,"> Fe.Ba, 



— :r^ Nb 



; III I I I 1 



Vertical Section of Reversing Layer and Chromosphere, showing Distribution 

 of Radial Velocities of Sun-spots. 



The lengths of solid lines are proportional to radial displacements of the corresponding Fraunhofer lines. 

 Arrows indicate direction of flow. The rounded head of the cyclonic disturbance is suggested by the broken- 

 line curve enveloping the outward velocities. Broken lines with arrows refer to possible velocities below the 

 levels. Lines of force of the magnetic field are indicated in the usual way. 



flash spectrum. In the diagram are also given results obtained in the 

 course of an extended investigation of pressures in the solar atmos- 

 phere, upon which considerable reliance can be placed when it is a 

 question of the variation of pressure with depth. 



It seems safe to conclude, from the evidence presented, that the 

 outward velocities in the reversing layer at the outer boundaries of 



