Prof. Lielegg on the Spectrum of the Bessemer-flame. 303 



first line of the third field an interval is left of the breadth 

 of a third part of the whole. In the fourth field there are 

 visible at nearly equally distant places four blue lines of equal 

 breadth and brightness : in the violet part, with the exception of 

 the potassium-line Ky3, no lines were observed. At the period 

 of great vividness of the spectrum, the spaces between the lines 

 of the third and fourth field appeared dark, and presented the 

 appearance of absorption-streaks, the origin of which would 

 moreover be explicable in the Bessemer-flame. On the other 

 side of the sodium-line, nearly in the position of the orange-red 

 calcium-line Ca«, were visible two lines lying near together and 

 not sharply bounded, which presented the appearance as if a 

 broad bright streak were divided into two parts by a dark band 

 in the middle. 



At the end of the cooling-period the intensity of light of the 

 groups of lines decreased, and shortly before the end of the 

 "charge" all the lines of the third and fourth fields were no 

 longer to be seen; the spectrum had nearly the same character 

 as at the beginning of the combustion-period. 



As the Bessemer-flame is formed principally by means of car- 

 bonic oxide, the groups of lines here described are also to be re- 

 ferred to this, their regular appearance during the combustion- 

 period indicating the beginning of the real decarbonization ; 

 their increase in intensity up to the commencement of the cool- 

 ing-period, and their remarkable fading off at the end of that 

 period, ought to furnish appropriate ground to work upon for an 

 investigation of the nature of the Bessemer-process. 



These observations were made at the Bessemer-works of the 

 Imperial Siid-Bahn Gesellschaft at Graz, permission to make use 

 of which was most kindly granted to the author of this commu- 

 nication bv the Director, Herr Hall. 



Second Paper*. 



This paper is an extension and completion of the previous one. 

 It contains an accurate description of the spectrum of the Bes- 

 semer-flame, which consists of several groups of lines and isolated 

 lines, the relative position of which was determined by measure- 

 ment with a scale. 



As the Bessemer-spectrum owes its origin to the combustion 

 of carbonic oxide gas, it must be looked upon as also the spec- 

 trum of that gas ; and as a spectrum of the flame of this has been 

 hitherto unknown, it follows that a gap in the series of gaseous 

 spectra is here filled up. 



* Read June 6, 1867. 



