466 
DK. W. M. HICKS: A CEITICAL STUDY OF SPECTKAL SERIES. 
consist of two doublet series each'with separation of order 167 and a third singlet 
series. The two sets of doublet series appear to converge to the same limits, in the 
same way as the satellites of a D series. The first lines given by him are of the order 
m = 3, but amongst the B.M.M. as also the Meissner lines those for m = 2 are also 
seen. Further, there appear close strong companions to the second lines of doublets in 
the first series, and in this they recall the behaviour of the F lines in the alkaline 
earths'^ and so suggest that they are really lines of the F type, but belonging to a 
different f sequence from that discussed above. If so the limit must behave as a 
displaced value from the 31852. The sets are, in Rowland units:— 
in. 
t 
(4) 11767-48 
107-63 
t t 
r 
('2) 11875-11 
3- 
'■ 
(5) 17176-58 
46 39 
, t 
(5) 17222-97 
t 
(6) 19677-64 
23-92 
1 
t 
(4) 19701-56 
^ -04 
(5) 21033-94 
5< 
1408 
1 
_ -'02 
(4) 21048-02 
" •04 
(2) 21850-62 
6 c 
10-17 
1 —■25 
(1) 21860-79 
r ’06 
(3) 22380-18 
9-91 
.-•01 
(0) 22386-29| 
8 
•07 
(0) 22742-78 
1) 
•20 
[23168-167] 
165-44 
(8) 
11932-92 
16717 
(0) 
4-65 
168-29 
(4) 
1—‘ 
CO 
R 
o 
(8) 
17342-68 
16716 
(1) 
3-74 
168-21 
( 5 ) 
17391-18 
166-58 
(6) 
19844-22 
167-86 
( 5 ) 
19869-42 
166-87 
( 5 ) 
21200-81 
167-59 
(3) 
21215-61 
167 08 
( 3 ) 
22017-70 
169 63 
(4) 
22030-42 
167-18 
(2) 
22547-36 
167-31 
(0) 
22910-09 
23168 (L.D.) 
* [III., p. 383, sej.] 
t Lines used in calculating formula-. 
1 This line was not included by Ro.ssi. 
