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THE ROYAL SOCIETY OF CANADA 



Carbon. 



The carbon vacuum arc spectrum was obtained by using carbon ' 

 alone as terminals in the vacuum arc lamp. A continuous arc was 

 obtained by using a current of about 10 amperes. In addition to the 

 lines given below a large number of broad and poorly defined bands 

 occur which seem to correspond to those of the carbon monoxide 

 spectrum. Upon measuring some of the more prominent ones, it was 

 found that their wave lengths were different from those of the carbon 

 monoxide spectrum obtained from the discharge tube. This may be 

 due to the fact that the carbon arc is at a very high temperature 

 compared to that of the discharge tube. 



The lines of the spectra of copper, aluminium, zinc and carbon 

 were measured last year by Ainslie, using the same apparatus but 

 without the hydrogen comparison spectrum. The measurements 

 were not very accurate and were repeated this year, using standard 

 gas lines for comparison. 



The carbon line spectrum is very strong in this region and the 

 lines 1548-5, 1550-7 (1560-5, 1561-2, 1562-0) and 1656-9 correspond 

 apparently to 1548-2, 1550-8, 1561-2 and 1656-8, given by Lyman 

 as lines of certain origin. The line at 1561 appeared as a poorly 

 defined triplet and was found in the spectra of all the metals worked 

 with except zinc. 



Line Spectrum of Carbon 



