SIR NORMAN LOCKYER AND OTHERS 
Proto-calcium (K) 
7800 miles. 
Hydrogen . . . . 
Helium, 4471’65 . 
5800 ,, 
„ 4026-34 . . 
5000 ., 
Strontium, 4077-89 
.... 4800 .. 
„ 4215-70 . 
.... 3800 
Th(' Spoctrum of the CoroncL 
Coronal rings are shown on photographs a, 6, and 7. 
The green ring at 5303'7 is the brightest, but that at 3987’0 is also very distinct 
and more continuous than the green ring. The rings generally appear to be less 
bright than in 1898, and many of the fainter rings recorded in 1898"^ have not been 
detected on the 1900 series of photographs. The following table shows the wave¬ 
lengths of the rings Avhich have been noted, with general remarks indicating 
the distribution of intensity in them. 
Table of Coronal Radiations. 
’Wave-leiwth. 
O 
Averarre Intensity. 
Max. = 10. 
Remarks. 
3800 
2 
Brightest from AY. to N.AAk 
3987-0 
5 
A nearly continnons ring a little brighter in west than elsewhere. 
4231-3 
•> 
o 
Brightest in west and south-west, very similar to chief ring 5303. 
4359-5 
o 
Brightest from S. to N.E. 
4568-5 
3 
Yery similar to 3987-0 in distribution of intensity. 
5303 - 7 
10 
Brightest between west and south-west. 
The above correspond with the principal rings recorded in 1898. Others are 
suspected, but they are too indistinct for satisfactory measurement; one of them, 
not previously recorded, is near \ 5537. 
The dissimilarity of form of the rings indicates that they have probably not all 
the same chemical origin, as I have previously pointed out,t three different sub¬ 
stances probably being in question. 
Besides the bright rings, the spectrum of the corona shows a considerable amount 
of continuous spectrum. This is brightest in the parts corresponding to the inner 
corona generally, as indicated by its being broken up into bands by the elevations 
and depressions of the moon’s limb, but it also has places of maximum brightness 
agreeing in position with the brighter parts of the green coronal ring. In the eclipse 
of 1898 the feature last mentioned was'also noted, and the opinion was expressed 
* ‘ Roy. Soc. Proc.,’ vol. 66, p. 191. 
t ‘Roy. Soc. Proc.,’ vol. 66, p. 191. 
