346 



less than 0,001 A so long as I lie distance exceeds twice the width 

 of a line. On closer approach the lines rapidly grow very asym- 



£1/1-/1 

 k ' 



2A-IB 



ii.uio A 



•SB 



Fig. 7. 



•3B 



metric; at distances smaller than about 1,5 times the widtii, the 

 second term of (20) becomes imaginary and the formula impracticable. 



^ 9. Comparison of the theory witJi the results of observations on 

 Frnunhofer lines. 



In the foregoing we have supposed, for simplicity's sake, that 

 the width of the true absorption lines could be neglected; hut there 

 are, of course, reasons for assigning a finite width to these cores 

 of the Fraunhofer lines. Especially as far as very strong lines of 

 the solar spectrum are concerned (which were not considered in 

 the above), it would have been necessary, therefore, to base the 

 calculations on a still closer approximation to the shape of the 



