20 



Mr. G. J . Stoney on the Physical 



[Recess 



that given between iron electrodes from a battery of 50 cells, which give3 

 a far greater number * of iron lines, and with this apparatus he has been 

 able to observe the enormous number of 460 coincidences. 



Table {continued). 







rt 



>? 



, 6 being the 

 breadth of 

 very broad, 

 Kirchhoff. 







is in eighth- 



en rays h 



positions 

 s arbitral 





O 



g « 



P CD 



•MM 



S»t3 bD O 

 § £ s 



Remarks. 



fl 



o 





Ja CD 





o „x> a 





esignati 



r ave-len 

 metres. 



itervals 

 tenth-ir 



)rrespoi 

 on Kirc 

 scale. 



arkness 

 darkest 

 ray, Gr 

 accordi 





P 





W 

 1—1 



O 



P 







53-69+ 



25+ 



1428-2 



56 



Fe. 





•71+ 



2 



1425-4 



56 



Fe. 





•74+ 



3 



14230 



5 6 



Fe. 





•76- 



1+ 



1421-5 



6c 



Fe. 





54-08+ 



33- 



1390-9 



5d 



Fe. 





•10- 



1 + 



1389-4 



6c 



Fe. 





•28+ 

 •34- 



19- 



1372-6 



56 



Fe. 





5+ 



1367-0 



6cZ 



Fe. 





•49 4- 



16- 



1352-7 



5 6 



Fe. 





•51 



1 + 



9 



1351-1 



56 



Fe. 





54-60- 



1343-5 



6c 



Fe. 





55-77- 



117 



1242-6 



6c 



Fe. 





•91 



14+ 



1231-3 



5cZ 



Fe. 





•99 



8 



1224-7 



5d 



Ca. 





56-03- 



4- 



1221-6 



5tf 



Ca. 





•07 



4+ 



12178 



5d 



Fe; Ca. 





•20 



13 



1207.3 





Fe. 





58-94+ 



274+ 



1006-8 



6 6 



ISfa "[ Interval between D 2 and D, 





59-00+ 



6 



1002-8 



6 6 



Na J = 6-03Xth-metres. 



61-05- 



204+ 



894-9 



2c 



Ca. 





•24- 



19 



884-9 



46 



Ca. Co. 





•39- 



15 



877-0 



4c 



Fe. 





•43+ 



5- 



874-3 



4 6 



Ba. 





•63+ 

 •71 



20 



863-9 



5 6 



Ca. 





8- 



860-2 



3d 



Ca. 





•92- 



21- 



849-7 



3c 



Fe. 



a 



62-59 



67+ 



309 







A strong line caused by the earth's 

 H ; winged. [atmosphere. 



C 



65-68 



694-1 



6c 



B 



68-75 



307 



592-7 



6c 



Winged on one side. 



A 



76-12 



737 



404-1 



6 



Winged. 



6 



In this list two of Angstrom's rays have been omitted — those to which he assigns the 

 wave-lengths 1903*4 and 1936-4 VHIth-inches, which correspond to 51-53 — , and 

 52-42 Vlllth-metres ; since there are no conspicuous lines in the solar spectrum cor- 

 responding to them, and since, in the case of the latter at least, there is plainly some 

 misprint. If we might conjecture that they ought to have been entered as 1900-4 and 

 1932-4 eighth-inches, they would correspond to 51-44+ and 52*31 eighth-metres, and 

 belong to two strong iron rays. 



* This appears at variance with the usual law that spectral lines increase in bright- 

 ness with the temperature, inasmuch as the temperature of a Ruhmkorff's spark is 

 probably very much higher than that from the battery of many cells. We are still too 



