Precision-measurements in the X-Ray Spectra. 643 

 Table II. 



_. ± Distance a, — a„, 



Plate - in mm. 



J.47 0-385 



J.48 0400 



0-367 



J. 43(2ord.) 0-77 



J. 41 0-376 



W.3 0391 



, 0-372 



W.4 0-373 



0-403 



W.5 0398 



0-412 



W.6 0-402 



0412 



Mean 391 



AX 4-68 X.U. (lord.) 



AX 4-65 X.U. (2ord.) 



Mean AX 4"67 X.U. 



From this wave-length difference between <x x and « 2 

 we obtain as value for the wave-length 



K« 2 = 213*52 X.U. 



For the weaker components /3 X and j3 2 of the K-groap 

 the following measurements were taken : — 



Table III. 



Reflexion-angle for 



Plate. „ * N 



ft. lS 2 . 



W.3 1° 44' 27" — 



W. 2 1 44 48 1° 41' 45" 



W.6 1 44 39 1 41 52 



Mean 1° 44' 38" 1° 41' 49" 



x in X.U 18436 179-40 



As results from the measurements of the K-group of 

 tungsten, we may then note : 



K« 2 = 213-52 X.U. 

 K«j = 208*85 „ 

 KA= 184-36 „ 

 K& = 17 ( >40 „ 



