PLATE LXXVIII. 



OR 81 



TRANSACTIONS R.S.E. 



VOL. XXXII. 



The Green CO 



Band's Beginning , on the Scale-for Size emp loyed by MM. Angstrom and Thalen, in 

 a 

 THEIR MESURES M ICRO METRIQUEs" / &? f ', BUT TRANSLATED HERE FROM THE 



Positive, to the Negative, manner , as regards Light and Shade. 



The Same GREEN CO Band's Be&in 



NIN&, RESOLVED IN EdINBUR&H BY C 

 EXPLICATED AS TWO SERIES I N ARITH METI C AL PROGR E 



Theoretical Arithm. Progression, 



Split-line Spectrum produced upwards. 



OBSERVATIONAL, 



i//z. Every Line, 



in Negative Representation 



EXACTLY AS MEASURED, 



Full Size of the Instrumental Record. 



<ain-line Spectrum produced downwards. 



pUw,6. 



to 



II 



/I 



Theoretical Arithm. Pro&ression a&ain,| 

 Be&innjn& on 5^ Line of First Series. 



Spectrum-Place in Wav e-Numbe r per Br.InchJ 

 Approximately only: 



Co ul> .. . /Split-Line Spectrum, with 



v °MPARiS0N of V 



£ES, oiiii4l.l. \Main-Line Spectrum Set 10 units' bac 



I ! : 



-L. 



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\ '■ i 

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J 



$u.nt>M , = 



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