268 Trowbridge and Hutchins — Oxygen in the Sun. 



4583-15 



Very strong. 



4587-45 



Sharp. 



4588-05 



u 



4588-92 



Very faint. 



4589-40 



" 



459000 



(i 



4590-95 



| Strong-, may 

 1 agree. 



4592-00 





4592-95 



Strong. 



4596-20 



u 



4601-37 



Very strong. 



4607-20 



u 



4609.45 



| Sharp, may 

 i agree. 





4612-75 



Faint. 



4614-05 



Strong, agrees. 



4621-42- 



Strong. 



4630-73 



Very strong. 



4634-00 



Sharp. 



4638-90 



Strong. 



4640-75 



Rather faint. 



4641-90 



Fairly strong. 



4643-45 



Strong. 



4645-40 



Faint. 



4649-25 



Strong. 



4651-02 



Fairly strong. 



4654-10 



Faint. 



4654-85 



" 



4655-90 



Faint band. 



4658-05 



Very faint. 



4659-60 



" 



4665-70 



Faint. 



4667-55 



" 



4671-65 



a 



4872-30 



If 



4673-30 



Very faint. 



4674-95 



( Faint, may 

 \ agree. 





4676-40 • 



Faint, may 



4822 



12 



Faint. 



agree. 



4825 



12 



Faint, may agree 



4681-10 



Very faint. 



4842 



00 



Faint but sharp. 



4682-40 



1! 



4863 



92 



u u 



4687-15 



I. 



4877 



70 



Faint. 



4688-80 



." 



4878 



80 



Very faint. 



4691-40 



11 



4879 



90 



a 



4694-15 



Strong. 



4891 



27 



u 



4695-15 



Faint. 



4894 



90 



a 



4696-70 



Very faint. 



4898 



70 



a 



4699-40 



Broad and faint. 



4906 



77 



a 



4700-40 



Faint. 



4907 



67 



a 



4701-65 



u 



4913 



69 



Sharp. 



4703-02 



Agrees. 



4915 



12 



Sharp, but faint 



4705-42 



Fairly strong. 



4916 



86 



Sharp. 



4710-20 



" 



4936 



86 



Band. 



4712-87 



Very faint. 



4940 



85 



Sharp. 



4719-92 



" 



4945 



01 



" 



4731-27 



" 



4945 



81 



" 



473395 



" 



4950 



21 



u 



4740-20 



it 



4951 



41 



Nebulous band. 



4744-20 



ii 



4953 



85 



Sharp, agrees. 



4753-82 



Sharp. 



4955 



16 





4760-07 



" 



4960 



16 





4763-82 



u 



4969 



85 





4771-82 



" 



4972 



85 





4775-07 



" 



4979 



90 





4782-62 



Very strong. 



4983 



06 



i Sharp, may 

 j agree. 



4788-27 



Very faint. 



4791-32 



Sharp, agrees. 



4993 



95 



Faint. 



4798-97 



Very faint. 



4997 



60 



" 



4800-82 



u 



4999 



31 



Agrees. 



4802-37 



Very strong. 



5001 



55 



Faint. 



4808-94 



Very faint. 



5011 



06 



Sharp, agrees. 



4810-02 



Faint. 



5012 



'50 



Faint 



4811-92 



" 



5018 



55 



May Hgree. 



4813-52 



" 



5022 



95 



j Faint, may 

 f agree. 



4816-60 



Very strong. 



4820-90 



Faint. 



5033 



85 



Very faint. 



In regard to the accuracy that may be expected of the above 

 positions, we feel sure that few of them are wrong by more 

 than a tenth of a wave-length, and those are of the class "Very 

 faint," or "Broad and nebulous." The better defined lines we 

 believe to be correct to within less than the above amount. 

 The method of comparison we have used admits of much greater 

 accuracy than this, but the ill-defined character of the air lines 

 puts a limit to their accurate placing. Compared with Thalen's 

 positions, they should be credited with ten times the accuracy 

 at least. Some of Thalen's bands are resolved into two or more 

 in our instrument. 



Prof. John 0. Draper projected his spectra upon a scale of 

 wave-lengths by means of a stereopticon, — a method which does 

 not inspire confidence in his results, when we consider the dis- 

 tortion produced by projecting lenses. . 



The scientific world seems largely to have accepted the wave- 

 lengths of Angstrom and Thalen as final. One eminent au- 



