96 LIGHT SCIENCE FOR LEISURE HOURS. 



terrestrial atmospheric origin is quite out of the. 

 question.' 



And here, in passing, I may venture to note as 

 somewhat surprising in the presence of such an 

 opinion, announced publicly before the highest astro- 

 nomical tribunal of this kingdom the statement made 

 by the President of the last meeting of the British 

 Association, that the observations during the eclipse 

 of 1870 proved the terrestrial atmospheric origin of at 

 least the principal portion of the coronal light. It is 

 amusing to read this now, when the last shred of the 

 terrestrial theory has vanished. Even if we rejected 

 the positive evidence obtained during that eclipse, and 

 even if we regarded Herschel's opinion as of no weight 

 whatever, it would still be impossible to point to a 

 single fact discovered in December 1871 which tended 

 to confirm the atmospheric theory. Facts were noticed 

 then, as facts had been noticed before, which at a 

 first view seem to suggest a terrestrial origin of the 

 coronal phenomena; but undoubtedly none of those 

 facts were novel. Every circumstance that was new 

 to astronomers was in favour of the extra-terrestrial 

 origin, which, as we have seen, Sir John Herschel 



tions relating to a theory that the radiations of the corona are produced 

 by the passage of the solar rays past the moon's edge, through dis- 

 persed meteoric matter between the earth and the moon. I submitted, 

 amongst other matters, this question to the great astronomer Whether 

 the light due to the illumination of this dispersed matter would not be 

 altogether inferior in amount to the light received from the illumi- 

 nation of similar matter lying beyond the moon, up to and beyond the 

 sun's place ? His reply was, as I had fully expected, that undoubtedly 

 this consideration (which he had not before noticed) rendered the lunar 

 theory of the corona altogether untenable. 



