THE 

 LONDON, EDINBURGH,, and DUBLIN 



PHILOSOPHICAL MAGAZINE 



AND 



JOURNAL OF SCIENCE. 



[FOURTH SERIES.] 







FEBRUARY 1873. 



X. On the Spectrum of the Bessemer-flame- ByW. Marshall 

 Watts, D.Sc, Physical Science Master in the Giggleswick 

 Grammar School*. 



[With Two Plates.] 



IN the Philosophical Magazine for December 1867 I pub- 

 lished the results of observations on the spectrum of the 

 Bessemer-flame, made with a one-prism spectroscope on the Lon- 

 don and North-Western Company's Works at Crewe. These 

 experiments showed that the Bessemer-spectrum contained, 

 besides the lines of potassium, sodium, and lithium, certain lines 

 due to iron ; but most of the lines were not found to be coinci- 

 dent with the known lines of carbon or of any other element. 

 Nevertheless I held strongly the opinion that the spectrum was 

 mainly due to carbon, for the following reasons : — 



(a) Carbon is known to give more than one spectrum (Phil. 

 Mag. Oct. 1869, Chem. News, Oct. 1870); and though the 

 Bessemer-spectrum does not coincide with any recognized spec- 

 trum of carbon, it is yet observed in the flame of burning coke, 

 and in other cases where carbon would seem to be the essential 

 element present. 



(b) The spectrum disappears almost precisely at the right 

 moment for stopping the blast, which is supposed to be when 

 the carbon in the pig iron has been burnt out and the iron is in 

 the condition of molten wrought iron. 



I have now to give the results of further observations on the 

 spectrum of the Bessemer-flame, which show that the lines are 



* Communicated by the Author. 

 Phil. Mag. S. 4. Vol. 45. No. 298. Feb. 1873. G 





