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ments of those who opposed the view that the corona is a 
phenomenon of our atmosphere were first directed.* 
It is clearly necessary, in order to establish the truth of such 
a theory, that the path by which the light-rays reach the por- 
tion of the air which is supposed to be illuminated should be 
clearly indicated. It is not sufficient to speak in a general 
way about the course of light-rays through this or that region, 
without showing that the light-rays can get there. In this 
respect the theory is undoubtedly defective, since in place of 
any evidence showing that the sun’s rays traverse the portions 
of our atmosphere which seem to be illuminated during total 
eclipse, we have very sufficient evidence that such rays cannot 
come within many miles of those portions of the air. 
In any considerable total eclipse the breadth of the moon’s 
shadow when it falls upon the earth is about 150 miles. So 
that taking the case of an eclipse occurring when the sun is in 
the zenith (the most unfavourable case for my argument), it 
follows that the observer is in the centre of a circular region of 
the earth 150 miles in diameter, and wholly in shadow (so far, 
that is, as the sun’s direct rays are concerned). For seventy- 
* I am careful to point out this fact, because Mr. Lockyer considers that 
I have misrepresented his opinions, and those of the supporters of the atmo- 
spheric-glare theory. As a matter of fact, the first intimation that I had 
that such a theory had been propounded was from a paper in the monthly 
notices of the Royal Astronomical Society, by Mr. Baxendell. The next 
was from a paper by Mr. Lockyer himself, which certainly confirmed my 
impression that the direct passage of the solar rays through our atmosphere 
was alone in question. Ilis words were simply, 11 My conviction has been 
growing stronger and stronger that the corona is due to the passage of the 
solar rays through our own atmosphere near the moon’s place.” There is 
no word about any possible action by the moon on the rays in question. 
By u the atmosphere near the moon’s place ” he clearly signifies (or intends 
to signify) the atmosphere which lies towards that part of the heavens 
where the moon is. It will be seen from the text above that others besides 
Baxendell and myself have interpreted the atmospheric-glare theory as I 
do ; and I may venture to assert that, so far as Mr. Lockyer was concerned, 
no word of any lunar influence on the rays — of any “ possible action near the 
moon’s edge ” — was heard of, until a mathematical proof had been put 
forward of the impossibility of any direct solar rays reaching the part of our 
atmosphere supposed to be illuminated. The subject was mooted again 
nnd again without the moon being called in to aid the theory ; and at the 
last meeting of the Royal Astronomical Society a paper, specially drawn up 
by Mr. Seacombe at Mr. Lockyer’s instance, was read, in which the idea of 
any lunar action was implicitly negatived ; while in the discussion which 
followed (in which Mr. Lockyer himself took part), no reference was made 
to the moon’s action. If there has been misrepresentation, therefore, it has 
not been such as I at least am in any way responsible for. 
