ON THE MEASUREMENTS OF WAVE-LENGTHS. 
93 
The Spectrum of Air (continued). 
Scale- 
numbers. 
Description of lines. 
Electrodes employed. 
Remarks. 
Copper. 
Aluminium. 
Mean. 
Wave- 
Wave- 
Wave- 
lengths. 
lengths. 
lengths. 
66-35 
Faint, fine. 
3753-7 
3753-7 
3753-7 
66-85 
Strong, fine. 
3749-0 
3748-9 
3749-0 
67-57 
Very faint, fine .... 
3739-3 
3740-1 
3739-7 
68-78 
Strong, fine. 
3726-6 
3726-6 
3726-6 
70-01 
Fairly strong, fine . . . 
3712-2 
3712-2 
70-89 
Very faint. 
J’ *_ . 
3702-0 
An approximation. 
71-89 
Faint, fine, sharp. 
3639-0 
3639-0 
79-21 
’ Faint, fine. 
3613-6 
3613-6 
79-63 
Weak, fine. 
36100 
3610-0 
81-08 
'Weak, fine. 
3595-0 
3594-9 
3595-0 
81-62 
J 
Weak, fine. 
3589-6 
3589-7 
3589-6 
82-29 
Weak, fine. 
3583-1 
3584-3 
3583-7 
82-90 
Weak, fine. 
3575-9 
3576-4 
3576-2 
84-38 
Weak, nebulous .... 
3560-4 
3560-9 
3560’6 
85-10 
Very faint. 
3550-3 
3550-3 
85-93 
Weak, nebulous .... 
3545-6 
3544-8 
3545-2 
89-21 
J 
’ Very faint, fine .... 
35/4-/ 
90-76 
* 
Very faint, fine .... 
3499-7 
91-61 
Weak, fine. 
■ 
3490-7 
93-05 
Faint, fine. 
3478-2 
3478-1 
3478-1 
93-83 
Weak, fine. 
3471-2 
3471-2 
95-51 
'Very faint, fine .... 
3456-2 
96-40 
Very faint, fine .... 
3448-0 
97-63 
Strong, fine. 
3436-8 
3437-1 
3436-9 
This line is much altered 
100-96 
Fairly strong, fine 
3407-8 
3408-2 
3408-0 
in the palladium spec- 
103-08 
Fairly strong, fine 
3389-7 
3390-0 
3389-9 
trum by two strong 
104-51 
'Weak, fine. 
3376-6 
3377-2 
3376-9 
neighbouring lines. It 
105-00 
\ 
Faint, fine, sharp.... 
3373-6 
3373-6 
appears strong in the 
105-28 
Faint, fine, sharp. 
3370-2 
3370-4 
3370-3 
centre, thinning away 
105-65 
' Fairly strong, fine, sharp . 
1 3366-1 
3366-4 I 
3366-7 
towards each end. 
105-77 
Fairly strong, fine, sharp . 
1 
3365-7 
107-28 
Fairly strong, fine . . . 
3353'7 
3353-7 
108-63 
Very faint, nebulous. 
3342-7 
109-88 
' Strong, fine. 
3331-8 
3331-2 
3331-5 
In the antimony spectrum 
110-23 
Strong, fine. 
3329-1 
3329-4 
3329-3 
only the central por- 
110-79 
Faint, fine. 
3324-1 
3325-3 
3.324-7 
tion of this double line 
111-49 
Weak, fine. 
3320-1 
3319-9 
3320-0 
is visible, the two ends 
112-97 
f Very faint, fine .... 
3313-3 
3313-3 
gradually thinning 
113-07 
< 
Very faint, fine .... 
3307-1 
3307-1 
away. A metallic line 
113-75 
\ 
Very faint, fine .... 
3301-1 
3301-1 
fails near it. 
115T3 
Faint, nebulous, broad . 
3289-9 
3289-9 
Possibly a triplet. 
117-26 
Faint, nebulous .... 
3274-6 
3274-2 
118-33 
J 
Weak, fine . 
3265-2 
3265-2 
119-05 
Weak, fine. 
3259-9 
3259-9 
124-57 
Very faint. 
3219-7 
3219-7 
This and the following 
132-97 
Very faint, fine .... 
3157-4 
3157-4 
lines are from the 
135 61 
J 
Fairly strong, fine 
3139-0 
3139-6 
3139-3 
indium and thallium 
136-51 
1 
Fairly strong, fine . 
3134-2 
3134-2 
plates, 11-18. 
138-36 
Very faint. 
3122-4 
3122-4 
148-14 
Very faint, fine ... 
3058-4 
3058-4 
150-00 
Faint, fine. 
3046-3 
3046-3 
150-73 
Very faint, fine .... 
3042-5 
3042-5 
