GASEOUS SPECTRA UNDER HIGH DISPERSION". 



423 



Orange band, 94 in the Citron, 97 in the Green, 107 in the Blue, and 71 in the 

 Violet. Their distribution in each band appearing thus — 



>wed by linelets 27 



14 



11 



7 



5 



6? 



25 



12 



9 



7 



31? 



41 



11 



7 

 7 



17 

 21 

 14 

 12 « 



5 

 55 



. 20 

 Subsequent and ebief band contains lines and 



linelets of various kinds, certainly . 51 ; 



and probably many more ; each being- 

 fainter and fainter in every successive 

 repetition beyond. 



This is also probably the case with the linelets of the more refrangible ends 

 of each of the earlier bands, for they are all vanishing series to that side. 

 Hence to record more, or fewer of them, tells nothing new in the theory, but 

 speaks only to the brightness of the optical images ; and as I usually stopped, 

 not when a definite end was arrived at, but when the linelets had become so 

 faint and diffuse that it did not seem worth while to go on any longer, — other 

 persons may succeed with better apparatus in chronicling more lines and 

 linelets than I have done ; — such gatherings however being always fainter than 

 those now tabulated. 



But even with them, the strain on the eye to measure their places micro- 

 metrically was often so great, that I was not unfrequently afraid I might be 

 deceiving myself, and undoubtedly must have made many mistakes, particularly 

 in setting the pointer between the close linelets, instead of upon one or other 

 of them. Yet after completing the measurement of any band, there was found 

 on the whole such a decided order, or law of increasing distance from linelet to 



VOL. XXXII. PART III. 3 Z 



Orange band- 



—1st lea 



der 



consists of lines 



2 } 





2nd 





J? 



2 





3rd 





>> 



2, 





4th 





„ 



2, 





5 th 





" 



2, 





6th 





" 



1?, 



Citron band- 



-1st 





i> 



2, 





2nd 





)> 



2, 





3rd 





» 



2, 





4th 





» 



2, 





5th 





» 



2 



Green band- 



-1st leader, 



"Green giant" 



2, 





2nd 



lines consists of 



2 





3rd 







2, 





4th 









1?, 





5th 







» 



2?, 





6th 







•> 



1?, 



Blue band- 



-1st 

 2nd 

 3rd 

 4th 

 5 th 







> 



3 



2, 

 2, 

 2, 



2?, 

 2?, 



Violet band— 



-Prelimi 



nar 



7 bai 



id has linelets 



