ON WAVE-LENGTH TABLES OF THE SPECTRA OF THE ELEMENTS. 403 

 Indium (Arc Spectrum) — continued. 



Wave- 

 length 

 (Kowland) 



2470-65 

 2468-09 

 2460-14 

 2430-8 

 2429-76 

 §2399-33 

 2389-64 

 t2379-74 

 2357-7 

 2340-30 

 2306-8 

 2278-3 



**2260-6 

 2241-6 

 2230-9 



**2218-3 

 2211-2 

 2200-0 

 2197-5 

 2187-5 

 2180-0 



Limit of 

 Error 



0-15 

 0-05 

 0-05 

 0-50 

 0-20 

 0-15 

 0-05 

 0-20 

 0-50 

 0-15 

 0-50 

 0-30 

 0-30 

 0-30 

 0-30 

 0-30 

 0-30 

 0-30 

 0-30 

 0-30 

 0-30 



Previoiis Measurements 

 (Angstrom) 



2470-2 H. & A. 



2468-4 

 2460-8 

 2429-0 

 2428-6 



2388-0 



2357-0 



2306-9 



Oscillation 



Frequency 



in Vacuo 



40462-4 

 40504-4 

 40635-3 

 41125-7 

 41143-3 

 41665-1 

 41834-0 

 42008-1 

 42400-7 

 427160 

 43336-3 

 43878-4 

 44221-9 

 44596-8 

 44811-6 

 45065-2 

 45209-9 

 45440-1 

 45491-8 

 45699 7 

 45857-0 



The oscillation frequencies (in air) of the pairs marked * can be calculated from 

 "^ - '^ " -' where a = 44515-4 for the^Vs^ line and 46728-6 for 



the formula lQi^=a — hn-'^—cn-*: 



the second line of the pair, 6 = 13930-8, <? = 131103-2, and for the pairs marked f 

 «-445350 for the fast line, and 467482 for the second line of the pair, J= 12676-6, 

 c' = 64358-4. The figure preceding the sign * or f shows the value of n. 



Thallium. 



Kayser and Eunge (' Ueber die Spectren der Elemente,' Pt. VI. Berlin, 1892). 



II See Indium. 



D D 2 



