206 
SIR NORMAN LOCKYER AND OTHERS ON THE 
The coronal rings not only differ from the chromospheric ones in regard to the 
heights to which they extend above the photosphere, but also in appearance. 
The outlines of these rings are distinctly not connected with the configuration 
of the chromosphere and prominences. In photographs taken near the beginning and 
end of totality, the green ring is brightest on the same side of the moon, although 
the chromcisphere and prominences are first visible on one side and then on the other. 
None of the rings give any indications of increased brightness at the places occupied 
by prominences. The green ring, which is the brightest of the rings seen, can he 
traced completely round the limb, and while in some parts it is very feeble, in others 
it is bright enough to show the brightest projections of the inner corona as photo¬ 
graphed with short exposures with the coronagraph. The other principal rings at 
3987 and 4233 can also be traced completely round the limb, but they are fainter on 
the average and of much more uniform intensity than the green ring. 
The Wave-length of the Chief Lme in the Green. 
The reasons which led to a re-examination of the wave-length of the chief coronal 
radiation in the green, and the result of the nerv measurement, have already been 
stated in a preliminary note communicated to the Society.'”' The main point of this 
communicatiOJi was that two of the chief coronal lines, one in the blue about X 4231, 
and the other in the green, had been supposed coincident with two bright chromo¬ 
spheric lines which my investigations had shown to correspond to enhanced lines of 
iron. The absence of other prominent enhanced iron lines from the corona spectrum, 
and the improbability of there being a sufficiently high temperature in the corona to 
produce enhanced lines, suggested a more complete investigation of the supposed 
coincidences of the coronal and chromospheric lines. The non-coincidence of the 
coronal line 4231 with the chromospheric line 4233 which was indicated by the 
measurement of the photographs of 18931 was fully confirmed, and it was also found 
that the green line was by no means coincident with the chromospheric line 1474 K. 
Its wave-length was, in fact, estimated as 5303'7, or about 13 tenth-metres more 
refrangible than 1474 K (5316'79). This result has since been confirmed by 
CAMPBELpj; and Evershed.§ 
The Coronal Radiations. 
In anotlier preliminary communication to the Eoyal Society,|| I gave the results of 
a more general investigation of the coronal spectrum. The main points may be briefly 
summarised as follows :— 
* ‘Roy. Soc. Proc.,’ vol. 64, p. 168. t ‘ Phil. Trans.,’ A, vol. 187 (1896), p. 593. 
\ ‘Astro-Physical Journal,’ 1899, vol. 10, p. 186. 
§ “ The Indian Eclip-se, 1898,” publication of the Brit. Astrononi. Assoc., 1899, p. 79, 
|1 ‘Roy. kSoc. proc.,' vol, 66, p. 189, 
