48 THE BORDERLAND OF SCIENCE. 



minute, but more closely packed (so to speak) than 

 the meteor systems near our own earth. We began to 

 suspect that this unexpected wealth of cosmical matter 

 in the sun's neighbourhood might supply the explana- 

 tion of those interlacing streaks and sprays and hanks 

 of whitish light to which reference has already been 

 made. 



When we were about half-way between the paths of 

 Venus and Mercury, we for the first time noticed a 

 diminution in the distinctness of those auroral radia- 

 tions which had first made their appearance when we 

 were but some six millions of miles from the earth. 

 It seemed as though the glowing streamers were slowly 

 fading from view, in the same way that streamers of 

 an auroral display wane in splendour even as we watch 

 them. In a short time we could no longer distinguish 

 the radiations, the solar atmosphere resuming the 

 appearance it had presented when we first observed it. 

 Unfortunately we were unable to estimate the length 

 of time during which the radiated appearance had 

 continued visible, for we were now much too far from 

 the earth to estimate with any degree of accuracy the 

 amount by which the moon had advanced on her 

 course. But though X.'s ingenious plan had thus failed 

 to afford an exact estimate, we could still infer from 

 the aspect of the earth and moon, that some three 

 hours of common time had passed since the radial 

 streamers appeared. 



It seems difficult to understand how the phenomenon 

 we had witnessed could be otherwise regarded than as 



