THE SUWS CORONA AND HIS SPOTS. 19 



for the corona in 1867 should have closely resembled the 

 corona of 1878, if this theory were sound. 



It would be idle, I think, to seek for farther evidence 

 either in favour of the theory we originally proposed to 

 discuss, or against it : for the evidence of the eclipse of 

 1867 disposes finally of the theory in that form. I may 

 note in passing that the eclipse of 1868 gave evidence 

 almost equally unfavourable to the theory, while the evi- 

 dence given by the eclipse of 1869 was neutral. It will be 

 desirable, however, to consider, before concluding our 

 inquiry, the evidence obtained in 1871 and last July, in 

 order that we may see what, after all, that evidence may be 

 regarded as fairly proving with regard to coronal variations. 



First, however, as I have considered two eclipses which 

 occurred when the sun spots were decreasing in number 

 namely, those of 1842 and 1851, midway (roughly speaking) 

 between the crest and hollow of the sun-spot wave on its 

 descending slope, it may be well to consider an eclipse 

 which was similarly situated with respect to the ascending 

 slope of a sun-spot wave. I take, then, the eclipse of 1858, 

 as seen in Brazil by Liais. The picture drawn by this ob 

 server is one of the most remarkable views of the corona ever 

 obtained. It is given at p. 339 of my book on the Sun. 

 Formerly it was the custom to deride this drawing, but 

 since the eclipse of 1871, when the corona was photographed, 

 it has been admitted that Liais's drawing may be 'accepted 

 as thoroughly trustworthy. It shows a wonderfully complex 

 corona, like that of 1871, extending some 700,000 mile? 

 from the sun, and corresponding in all respects with such a 

 corona as our theory (if established) would have associated 

 with the stage of maximum solar disturbance. As in this 

 respect ihe eclipse of 1858, when sun-spots were increasing, 

 resembled those of 1842 and 1851, when sun-spots were 

 diminishing in number, we find no trace of any law of asso- 

 ciation depending on the rate of increase or diminution of 

 solar disturbance. 



If we limited our attention to the eclipses of 1871 and 

 c 2 



