PROF. A. FOWLER ON SERIES LINES IN SPARK SPECTRA. 
235 
Calcium — 
Wide doublets . 
Narrow doublets 
Strontium — 
Wide doublets . 
Narrow doublets 
f D (m) 
l S (m) 
F (m) = 
7 0,289-2 
70,512-2 
70,289-2 
70,512-2 
81,948-6 
4 x 109,675 
m + 0'396204 — 
0106980V’ 
m / 
4 x 109,675 
m + 0‘222264 — 
4 x 109,675 
0143832V 
m 
- 
82,0091 J (m-0-013703) 2 ' 
D (m) = 
l S (m) = 
64,323-3 
65,123-3 
64,323-3 
65,123-3 
4 x 109,675 
m + 0-611476 
0-283578 V 
m 1 
4 x 109,675 
m + 0'344681 - 
0'233220 1 
m ) 
T7i / \ 73,968"3 
F +> = 74,218-0 
4 x 109,675 
(m-0-028718) 2 ' 
The numeration of the members is shown in Tables III. and IV. 
Details as to wave-lengths and wave-numbers of the lines involved, as quoted by 
Lorenser, are shown in Tables III. and IV., which also indicate the differences 
between the wave-lengths observed and those calculated from the two sets of 
equations. 
An inspection of the tables will show that the observations are more closely 
represented in every case, and especially in the case of the negative terms, by the 
Hicks formula involving 4N than by the formula which has been employed by 
Lorenser. The superiority of the former is further shown in the greater accuracy 
with which it proves the identity of the limits of the F series with the variable parts 
of the expressions for the first line of the D series and its satellite. Lorenser has 
assumed this identity in determining the limits of the F series, thus— 
Ca: 70,117 + 11,703-0 = 81,820-0 
70,117 + 11,763-8 = 81,880-8 
Sr: 64,154+ 9,679'5 = 73,833-5 
64,154+ 9,959-2 = 74,113-2 
If, however, the formulae for the F series be calculated entirely from the F lines 
themselves we get the equations 
2 H 2 
