of the Bessemer -flame. 



85 



I. Measurement of the Wave-lengths of the Lines in the ordinary 

 Bessemer-spectrum, in the Spiegel-spectrum, and in the spectrum 

 of Manganese Oxide (Plate IV.). 







Manga- 





Bessemer. 



Spiegel. 



nese 

 oxide. 



Remarks. 



6560 ? 



6560 





1 Two red lines, not always seen, estimated 

 f position only. 



6460 ? 



6460 





^6234 



6234 



6234 



Fine line. 





6218 







Fine 1 ue ; occurs only in Bessemer. 





6204 



6204 



6204 



Most refrangible edge of band, shading 

 away (like all the bands in ihe Bessemer- 

 spectrum) towards the red. Appears in 



"1 







the Spiegel as a bright line, and in the 

 n anganese-oxide spectrum as the least- 

 refracted edge of a verv narrow band. 

 See figure (PI. IV.). 



j 6185 





6185 



Fine line. 



I 6178 



6178 



6178 



Edge of band. The remark to 6204 applies 

 also to this. 



6161 



6161 





Fine line, faint. 



. i 6109 

 p 1 6097 



6109 





{_ Conspicuous pair of red lines, absent in 



6097 





j manganese-oxide spectrum. 







f 60801 ? 

 1 6060 J" 



Four faint lines, too strong in drawing; 







position estimated only. 



6040 



6040 



Faint line. 



6012 



6006 



6012 

 6006 





> Pair of faint lines. 



y 5972 



5972 





Strong line, absent in the manganese-oxide 

 spectrum. 





5946 





Four equidistant lines, not very bright, of 

 which the most refrangible read 5946. 





5932 



5932 



Line. In manganese-oxide spectrum only, 



5917 

 5909 







and sometimes in Spiegel. 





5909 



In Bessemer-spectrum as a faint line; in 









the manganese-oxide spectrum as the 









edge of a band. 



T5895 

 1 5889 



5895 



5889 





> Sodium lines. 



5872 



5872 





V Two faint lines, absent in the manganese- 

 J oxide spectrum. 



5865 



5865 







'5847 



5847 



5847 



Maximum of light. 





5819 



5819 





Brightest edge of band, fading away to- 



S< 









wards the red. 





5807 



5807 





Fine line. 





5790 



5790 





Strong fine line, forming the brightest edge 









of the whole group. 





( 5705 







Fine line. 





j'5688 

 [5683 



5688 



5688 



Splendid double line, conspicuous among 





5683 



5683 



the fine lines which make up the whole 











of this group, nearly coincident with 



e< 









Natfj 5687 





5644 



5644 



5644 



Brightest edge of band, shading off into red. 





5607 



5607 



5607 



Brightest edge of band. 





L 5580 



5580 



5580 



Edge of band, hazy in the manganese-oxide 









spectrum, but sharply defined in the 









Bessemer and Spiegel. 



