18 



Mr. G. J. Stoney on the Physical 



[Recess, 



1, 2, 3, 4, 5 or 6, which also indicates its strength in the solar spectrum, 

 6 meaning the darkest and 1 the faintest recorded by Kirchhoff. 



28. The study of this Table is particularly instructive. It will be con- 

 venient to begin by studying the iron lines, since they are numerous, 

 extend over a great range of the spectrum, and above all because there 

 appear to be no bright lines in the iron spectrum to which dark lines in 

 the solar spectrum do not correspond. This was invariably the case with 

 those observed by Kirchhoff, who has mapped upwards of 70 of them 



Table {continued). 



Wave-lengths 







Wave-lengths 







in 







m 







eighth-metres, 





Kirchhoff's 



eighth-metres, 

 i. c. metres di- 





Kirchhoff'. 



i. e. metres di- 





arbitrary 





arbitrary 



vided by 10 s . 





scale. 







scale. 



49-30 corresponds to 1998-0 



55 cor 



responds ta 1309-0 



<±y < ±u 



l| 



1 QQP.l 



iy<3o i 



OO i\J 





1^4o-4 



49 - 50 



)> 



1974*3 



55-80 



OO OU 



» 



1240*2 



4y 50 



5> 



1 AGO. K 



iyo2*o 



oo yu 



» 



1232-0 



/l A.TA 





iyoo o 



OO 



fj 



1223 o 



OU 



» 



1 A1 O.A 9 



iyio U r 



OO 1U 





1210.O 



01 





1/oJ : 



OO ZVJ 



" 



1 OAT. A 

 120/ '4 



.Pa 



» 



1673*0 



OO OU 



5> 



1199*3 



f;i .ta 

 01-/U 



J> 



lboo*3 



0/ 



|] 



1144-0 ? 



ki .qa 

 01 OU 



»» 



1 a A A . o 

 1044 o 



Oo 



iy 



1070*0 ? 



1^1 .OA 



oi yu 



JJ 



IboU o 



oo yu 



jj 



1 AAA T 

 1009*7 





it 



loi ro 



oy 





1003 



KO.l A 



oZ 1U 



» 



1004*o 



AO 

 OU 



» 



948*0 ? 



52-20 



!> 



1591-2 



01 





897*2 



52-30 



5J 



1578-3 



ai -in 



Ol 1U 





891-9 



52-40 



>> 



1565-5 



ai -on 



Ol Z\j 





886-6 



52-50 



>i 



1552-8 



AI -QO 



oi ou 



» 



881-3 



52-60 



>> 



1540-2 



AI .J.O 



Ol -±u 





876-1 



52-70 





1527-9 



AI -r^n 

 Ol OU 



J> 



870-9 



52-80 





1516-1 



61-60 





865-7 



52-90 



J" 



1504-8 



61-70 





860*6 



53 



>> 



1494-1 



61-80 





855*5 



53-10 



» 



1483-8 



61-90 



>J 



850-5 



53-20 





1473-7 



62 





845*5 



53-30 



>) 



1464-0 



63 



J> 



800*0? 



53-40 



>> 



1454-4 



64 



55 



758-5 ? 



53-50 





1445-6 



65 



55 



719-1? 



53-60 



j> 



1436-1 



66 



55 



682-3 



53-70 



5) 



1426-6 



67 



55 



648-3 ? 



53-80 





1417-2 



68 



55 



615-9? 



53-90 



55 



1407-7 



69 



55 



584-8 



54 



J) 



1398-3 



70 



55 



555-8? 



54-10 



5J 



1389-0 



71 





528-4? 



54-20 





1379-7 



72 



55 



502-4? 



54-30 





1370-5 



73 



55 



477-7? 



54-40 





1361-2 



74 



55 



453-8? 



54-50 



5! 



1352-1 



75 



» 



430-3? 



54-60 





1343-3 



76 





406-9 



54-70 





1334-7 



77 





383-6? 



The following Table contains the original determinations expressed in metrical mea- 

 sures on the supposition that a Paris inch =27*07 millimetres. The sign 4- is added where 

 the omitted decimals lay between -0016' and '005, and- where they lay between -005 



