176 



Table 154. 

 WAVE-LENGTHS OF FRAUNHOFER LINES. 



For convenience of reference the values of the wave-lengths corresponding to the Fraunhofer 

 lines usually designated by the letters in the column headed " index letters," are here tabulated 

 separately. The values are in ten millionths of a millimetre, on the supposition that the D hne 

 value is 5896.155. The table is for the most part taken from Rowland's table of standard wave- 

 lengths. 



Index Letter. 



Line due to — 



a 



B 

 CorH, 



a 



Di 

 D2 

 Do 



E2 

 bi 

 b. 



Wave-length in 

 centimetres X lo'. 



For H^ 



d 

 G' or H 



(O 

 (O 



O 

 H 

 O 



Na 



Na 



He 



f Fe 



(Cz 



Fe 



Mg 



Mg 



r Fe 



Jfc 



'Fe 



'Mg 



H 



Fe 



H 



Fe 



7621.28* 



7594.06* 



7164.725 



6870.182! 



6563.045 



6278.303 1 



5896.15s 

 5890.186 



5875-985 

 5270.558 

 5270.438 

 5269.723 



5183.791 

 5172.856 

 5169.220 

 5169.069 

 5167.678 



5167.497 

 4861.527 

 4383-721 

 4340.634 

 4325-939 



Index Letter. 



g 

 h or Hj 

 H 

 K 

 L 

 M 

 N 

 O 

 P 



Q 



R 



Line due to — 



:l 



rFe 

 ^Ca 

 Ca 

 H 

 Ca 

 Ca 

 Fe 

 Fe 

 Fe 

 Fe 

 Fe 

 Fe 

 Ca 

 Ca 

 Fe 

 Fe 

 Fe 

 Fe 

 Fe 

 Fe 

 Fe 



Wave-length in 

 centimetres X lo^. 



4308.081 

 4307.907 

 4226.904 

 4102.000 

 3968.625 



3933.825 

 3820.586 

 3727778 

 3581.349 

 3441.155 

 3361.327 

 3286.898 

 3181.387 



3179-453 

 3100.787 

 3100.430 

 3100.046 



3047.725 

 3020.76 



2994-53 

 2947.99 



J 



• The two lines here given for A are stated by Rowland to be : the first, a line " beginning at the head of A, out- 

 side edge ; " the second, a " single line beginning at the tail of A." 



t The principal line in the head of B. 



t Chief line in the a group. 



See Table 152, Rowland's Solar Wave-lengths (foot of page) for correction to reduce these values to Fabry-Buisson 

 system of wave-lengths. 



Smithsonian Tables. 



I 



i 



