1871J The Eclipse. of Last December. 231 



no better worthy of study, than the radial beams of light 

 which extend from between clouds over large arcs on the 

 heavens, the enthusiasm of eclipse observers might well have 

 been diminished. It was, indeed, on this account that, more 

 than a year ago, I earnestly and persistently dwelt upon the 

 objections, simple and obvious though they are, against the 

 atmospheric theory, pure and simple, or modified so as to 

 include lunar action. The new theory, fortunately adopted 

 early enough to prevent the mischief I had feared — was not 

 only far more accordant with observed facts, but even if 

 erroneous could in no way interfere with the work of ob- 

 servers. 



It was now urged that the bright light seen close around 

 the moon during total solar eclipse may be the real cause of 

 the atmospheric glare which the theory requires in explana- 

 tion of the fainter light seen farther from the moon.* This, 

 in facl:, corresponds with what I had myself pointed out in 

 oppugning the atmospheric glare theory (" Monthly Notices 

 of the Royal Astronomical Society" for March, 1870, p. 141), 

 when I wrote that " the only light which can reach this part 

 of the atmosphere " (the part towards the moon's place) " is 

 that from the chromosphere and the coloured prominences, 

 or from the earth and surrounding illuminated air." It is 



* As it has been denied that the atmospheric theory had been in any way 

 modified, I may as well remark at this point that my only means for deter- 

 mining what the original theory was, had been the words used in its enunciation. 

 They asserted that " the corona is nothing else than an effect due to the 

 passage of sunlight through our own atmosphere," and they were understood 

 by Baxendell, Curtis, Harkness, myself, and others, to mean that the air seen 

 towards the moon's place is lit up by diredt sunlight. Nor was exception taken 

 for several months to the fact that our objections were founded on this suppo- 

 sition. Last J une, however, it was said that the theory had been misrepresented, 

 and in this way, that no notice had been taken of " a possible lunar adtion" 

 really included in the theory. Here, it should seem, was the opportunity for 

 introducing as a part of the theory the possible chromospheric adtion now 

 believed in ; yet nothing was said of it. In writing on the late eclipse, 

 however, Mr. Lockyer says of his own views, after the eclipse of 1869 : — " I 

 thought the explanation still possible which regarded the corona as of terres- 

 trial origin ; that is, which assumed it to be an appearance due to the presence 

 of light" (no longer sunlight, it will be noticed), "in our own atmosphere. 

 The problem was one of such difficulty that there seemed a possibility that, by 

 some unexplained cause, some of the solar light might be diffused and beat out 

 of its course, and then, mixing up with the light of the chromosphere, give us 

 a sort of continuous spedtrum ; in other words, that as the eye perceives 

 a bright irregular region or glare round the uneclipsed sun, an effect due to our 

 atmosphere, so also the eye might perceive a bright irregular region or glare 

 round the uneclipsed chromosphere during eclipses, due also to our atmosphere." 

 These are, indeed, other words, for they have another meaning. In fadt, if 

 the atmospheric glare theory had originally been propounded in the vague form 

 here assigned, it would have escaped attack. The "possibility" that "a sort 

 of" effedt might result from " some unexplained cause" would be difficult to 

 disprove. 



