248 
PROF. A. FOWLER ON SERIES LINES IN SPARK SPECTRA. 
1 p l = 85,462-9, 
1 p 2 = 85,550-2. 
2 d = 49,790, 2.s = 51,328, 
3 d = 27,958, 3s = 28,464. 
The calculated terms of the “ F.P.” doublets may thus be considered identical with 
the corresponding terms of the Wide doublets, within the possible limits of error. In 
that case the corresponding subordinate series would run parallel to each other in the 
two systems at distance apart of 
SiOo-^oo = 85,508-6-40,618-4 = 44,890'2 = P 1 (2)-P 1 (l) 
and 
s 2 oo- s ,oo = 85,600-1-40,648-9 = 44,95P2 = P 3 (2)-P 3 (l). 
A further important indication of a close connection between the two systems 
results from a consideration of the .P series of Wide doublets, of which only the 
pair XX 2802, 2795 falls within the region of observation. In view of the relations of 
the other series to which reference has been made, the limit of the P series is probably 
given exactly as 85,508"6 + 35,761"l, or 85,600T + 35,669"6 = 121,2697 as shown in 
Table VI. With this limit, the formulae for the two components of the series, derived 
from the observed pair are, 
P 2 (m) 
121,269-7 
4x 109,679 3 
(m + P263889) 2 
Pi M 
121,2697- 
4 x 109,679-3 
(m+1'265100) 2 ’ 
From these equations we find for the P series the results shown in Table IX. 
Table IX.—Principal Series of Wide Doublets (Preliminary Calculation). 
Limit = 121,269-7. 
m. 
X 
(LA.). 
n. 
mlX. 
wPj. 
8n. 
Remarks. 
1 
2802-698 
35,669-6 
85,600-1 
91-5 
Observed lines (Table X r I.). 
2795-523 
35,761-1 
85,508-6 
9 
1248-64 
80,087 • 1 
41,182-6 
30-5 
1 
1 
1248-16 
80,117-6 
41,152-1 
! 
Calculated. 
3 
1029-45 
97,138-8 
24,130-9 
13-7 
J 
1029-31 
97,152-5 
24,117-2 
