332 PROFESSOR W. R HARTLEY ON SPECTRUM PHOTOGRAPHY 
3612-6 or 3601’ 2 , yet it is not so persistent. From appearing as a 
disappears rather suddenly. 
The line with wave-length 2815'3 is the strongest in this spectrum. 
The Indium Spectrum. 
Scale numbers. 
Wavedengths. 
1 per cent. 
O'l per cent. 
0-01 per cent. 
Hundredths of an inch. 
15'88 
4510-2 
4510-2 
39-91 
4101-3 
4101-3 
119-31 
3257-8 
119-68 
3255-5 
3255-5 
3255-5 
151-35 
3038-7 
3038-7 
3038-7 
168-00 
2940-8 
2940-8 
177-34 
2889-7 
2889-7* 
214-56 
2709-3 
2709-3 
251-76 
2559-5 
332-2 
2307 
2307 
The Thallium Spectrum. 
Scale numbers. 
Wave-lengths. 
l - 0 per cent. 
01 percent. 
0'01 per cent. 
Hundredths of an inch. 
64-55 
3775-6 
3775-6 
3775*6 
88-7 
3518-6 
3518-6 
143-0 
3091-0 
3091-0 
172-21 
2917-7 
201-87 
2767-1 
2767-1 
2767-1 
259-86 
2530-0 
2530-0 
335-27 
2299-3 
2299-3 
,g line it 
* This is barely visible. 
