the Spectrum of Copper. 467 



m=2. The p./ give /i(2) = 12257-10, / 2 (2) = 12246*01 



with satellite separation 11*09. In the d'.f there 

 now appears a representative of d\—f\. They give 

 /i (2) =12264-15 (1-34) and / 2 (2) = 12249-53(1-34). The 



denominator of 12257*19 is 2*991400, that of 12249*45 

 is 2*992313, which differ by 6±S. Also 12257*10 and 

 12264*15 differ by the same within limits. We are here 

 clearly in the presence of successive satellite displacements. 



It may be noted that again the p. /'and ^'./combinations 

 both give f 2 <fi in agreement with the higher orders and in 

 opposition to what is apparently the normal rule. 



The mantissse are of the same order of magnitude as 

 those of higher orders. Generally they increase as the 

 order decreases. It is probable therefore that the lines 

 indicated are not the normal ones, but may be displaced 

 representatives. 



There are in fact several sets of lines in this neighbourhood 

 suggesting p,f combinations. The whole deserves a more 

 exhaustive discussion. 



The d(2)—f(2) would lie far in the ultra-red above 

 Randall's longest wave-lengths. 



wi = l. The p—f would be above Randall's longest. The 

 P1+/1 gives / = 27445* 74- 35 d\. The ^(2) -f\, d l (2)-f 2 

 give / = 27445*36, / 2 = 27470' 52, whilst of the summation 

 lines suggested the first as di+f x gives f 2 (l) =27448*00 

 and the second as d 2 +f 2 gives f 2 (l) = 2747700 and 

 probably do not belong to the same system. If the d(2)—f 

 allocations are correct the numerical values of /deduced are 

 very exact. The satellite separation <r = 25*07 requires a 

 change in mantissse of 913 and 6^8 = 913. Thus we find 

 the 6J 8 of the higher orders exactly reproduced. There are 

 however a large number of lines, especially in the spark, in 

 this neighbourhood which may correspond to series depending 

 on different d{2) and /(I) and they should repay further 

 consideration. As an example, may be taken the set 



d x (2)- A (1) =-(5rw) 14983-35 : 



d x (2) +/i(l) = (2)39718-36 5 



d 2 {2)+f 2 {l) = (1)39751*635 



(\\= 6672-234 I.A. Aretz. 2517*03, 2514*87 E.V.) 



which give /i(l) = 27349*31, 27352*40, /" 2 (1) =27378*98 

 with (j = 26*48. If the last is rf 1 +/ 2 ,/ a = 27385'67. 



