68 



Prof. H. A. Rowland on a 





In Arc. 



In Sun. 



Kind 

 of 



Stand- 

 ard. 



Weight. 



Wave- 



Wave- 



Elements. 











length 



length 















Inten- 



Appear- 



Inten-Appear- 



In 



|ln 



in Arc. 



in Sun. 





sity. 



ance. 



sity. ance. 



Arc. 



Sun. 







Fe 



5 





6 





0" 



1 



9 



5434-725 



5434-742 



Fe* ... 



7 





7 





0" 



1 



9 



5447-116 



5447-130 



Fe?| ... 







8 1 



d 



O 



0' 





1 

 8 





5455-666 

 5455-759 



Fe J ... 



6 





6 I 





o 





1 





5455-826 



Ni 



3 





1 





O' 





7 





5462-732 



Fe 



3 





4 





0" 





9 





5463-174 



Fe 



3 





4 





0" 





10 





5463-493 



Fe 



3 





3 





O" 





10 





5466-608 



Ni 



15 



E 



4 





O" 





10 





5477-128 



Fe 



2 





3 





0' 



... 



5 





5487-968 



Fe 



3 





4 





0" 





8 





5497-731 



Fe 



5 





4 





0" 





8 





5501-685 



Fe 



5 





4 





0" 





8 





5507-000 



Ca 



5 



N 



3 





o 



1 



8 



5513127 



5513-207 



Mgt 



10 





7 





0" 



4 



8 



5528-672 



5528 636 



Fe 







2 





0" 





8 





5535-073 



Fe 



3 





2 





0" 





8 





5543-418 



Fe 



3 





2 





0" 





9 





5544-158 



FeJ ...... 



4 





3 





0' 





8 





5555-113 



Fe 



6 





5 





0" 





8 





5569-848 



Fe 



5 





4 





0" 





7 





5576319 



Ca 



6 





4 





MO" 



2 



9 



5582-204 



5582-195 



Ca 



10 



E 



6 





MO" 



2 



9 



5588-977 



5588-980 



Ca 



5 





4 





MO" 



2 



5 



5590-352 



5590-342 



Ca 



7 



E 



5 





MO 



2 



5 



5594-689 



5594-695 



Fe 



3 





SI 



d 



0' 



1 



2 



5598563 



5598-555 



Ca 



7 





0' 



2 



4 



5598-712 



5598-715 



Ca 



5 





4 





M©" 



2 



4 



5601-502 



5601-501 



Fe ] ... 



2 





l}\ 















Ca U... 



6 





t 



0' 





10 





5603-097 



Fe J ... 



5 





5 1 















Fe 



2 





2 





0' 





10 





5615-526 



Fe 



2 





6 





©' 





10 





5615-879 



Fe|! 



o 





2 





O" 





12 





5624253 



Fe-Va|| . 



5 2 





4 





O" 





14 





5624-768 



Fe 



2 





3 





0" 





5 





5634-167 



Fe 



2 





3 





O" 





10 





5641-661 



Si 



*2 





2 

 4 





O 

 0' 





9 



9 





5645-835 

 5655-707 



Fe 



Yt? 



1 





4 





O" 





9 





5658-096 



Fe 



3 





5 





O" 





9 





5662-745 



Ti 



3 





2 





O 





8 





5675-648 



Fe 



2 





3 





0" 





8 





5679-249 



Na ...... 



3 





4 





O" 



... 



9 





5682-861 



* A difficult double. (J.) 



f This Mg line is shaded to one side when there is much Mg in the arc and 

 is therefore a poor metallic standard. The solar line corresponds to the ex- 

 treme edge of this band-like line. (E.) 



J There is a side line towards the violet. 



§ This triplet is made up of close double and a line close to red stronger 

 than either component of double ; wave-length of components about 5602-995 ; 

 5603*080 and 5603'180 as measured on a photographic plate. (J.) 



j| Lines used by Peirce in his determinations of absolute wave-lengths. 



