190 



Sir Norman Lockyer and Mr. F. E. Baxandall. 



not accepted as furnishing any proof of the existence of that element 

 as an impurity in the vanadium. This comparison shows that, in 

 addition to those belonging to silver, the only lines which with any 

 degree of probability can be attributed to other metals, are traces of 

 the very strongest lines only of iron, manganese, chromium, cobalt, 

 calcium, strontium, aluminium, and lead. Such lines (a list of which 

 is given later in the paper) have been left out of the following table. 



Although Rowland gives his wave-lengths to one-thousandth of a 

 tenth-metre, for convenience of comparison with the other records his 

 values are quoted, throughout the present paper, to the nearest 

 hundredth of a tenth-metre. A brief reference must be made to 

 Rowland's scale of intensities. In his paper he states that the scale 

 he has adopted is from 1 to 15. There are, however, several intensities 

 given which are beyond these limits; but they are probably due to 

 typographical errors. Such cases are indicated in the column for 

 remarks. It would seem rather difficult to reconcile his adoption of 

 such a scale with the opinion expiessed in the introduction to his 

 " Preliminary Table of Solar Spectrum Wave-lengths "to the effect that 

 "the ordinary scale from 1 to 10 or from 1 to 6 is far too limited for 

 the spectral lines, especially for the metallic spectra; 1 to 1000 is 

 hardly great enough for the enormous difference in intensity. The 

 small range, 1 to 10, ordinarily used gives an entirely wrong idea to 

 the worker in this subject, and many books with spectroscopic theories 

 might have been saved by using a scale from 1 to 1000." 



Vanadium Arc Lines. 



Comparison of Kensington Records with Hasselberg's and Rowland's. 



Kensington. 



Hasselberg. 



Rowland. 







Int. 





Int. 





Int. 



Remarks. 









A. 



Max. 



A. 



Max. 



A. 



Max. 







= 10. 





= 4-5. 





= 15. 





3887 '69 



<i 













88 '20 



2 



3888 '23 



1 









88 -47 



3 



88-50 



2 









89-36 



1-2 













89 -91 



<1 













90-30 



7 



90-33 



3 



3890 -30 



4 





91 '25 



5 



91 -27 



2 









91 -88 



1 













92 -53 



2-3 







92-47 



4 





92 95 



6-7 



93 -03 



3 









93-88 



<1 













94 -16 



4-5 



94-19 



2 









95 -86 



2-3 













b6 29 



4 



96-29 



2 



96-26 



2 





