1871.] The Eclipse of Last December. 239 



been known for more than a century and a half, and only 

 that forgetfulness of past labours and their results which 

 has so constantly characterised eclipse observation, could 

 have caused any stress to be laid on the recognition of so 

 well-worn a fact. 



For a similar reason, I should be disposed to lay little 

 stress on the evidence obtained respecting the coronal radia- 

 tions, conceiving as I do that all that could be learned 

 respecting their general characteristics had been long since 

 ascertained. But as to many, unaware of the immense 

 mass of evidence already available, this feature of the 

 corona has seemed worthy of special study, it will be well 

 to consider what fresh evidence has been obtained during 

 the recent eclipse. Fortunately, I am able to do this without 

 altogether repeating an oft-told tale, — partly because photo- 

 graphy has supplied a new kind of evidence on the point, 

 and partly because a new fact has been brought out in con- 

 nection with it. 



Considering the unfavourable circumstances under which 

 the recent eclipse was viewed, and that the eclipse itself was 

 much less important than many during which the corona 

 has been studied, it may be regarded as fortunate that the 

 corona presented one feature which could scarcely escape 

 the notice of any moderately attentive observer. Opposite 

 the south-eastern quadrant of the moon's limb, there was a 

 well-marked gap — V-shaped — whose apex reached close up 

 towards the moon. So close, indeed, that, as depicted in 

 figure 9, the distance of the apex from the sun was actually 

 less than that of the highest parts of the inner corona. 

 Under this gap the inner corona sinks lowest, while on each side 

 it rises quickly up to about its mean level. Still referring to 

 Lieutenant Brown's picture, let it be noticed that the 

 V-shaped gap is the most striking feature of the corona. It 

 is the sort of feature which might well be expected to afford 

 a crucial test of the vexed question whether the radiations 

 really belong to some solar appendage or are merely pheno- 

 mena of our own atmosphere. If it shall appear that this 

 V-shaped gap was seen at other stations, and more particu- 

 larly at stations far removed from Lieutenant Brown's, then 

 all further question on this point becomes impossible.* It 



* Note, however, in passing, that if the depression of the brighter part of 

 the corona beneath the great gap be admitted, on the strength of Lieutenant 

 Brown's drawing, then the matter is disposed of at once ; for the connection 

 between the matter in which the gap exists and the inner corona is at once 

 established. It need hardly be said that the shape of the inner corona could 

 not possibly be refle&ed — as it were — in the illumination of our own atmo- 

 sphere. 



