THE NE W STAR WHICH FADED INTO STAR-MIST. \ \ 7 



pened there would be just such an accession of splendour as 

 we recognize in the case of the new stars. And as the small 

 local accession of brilliancy lasted only a few minutes, we can 

 well believe that an increase of surface brilliancy affecting a 

 much larger portion of the photosphere, or even the entire 

 photosphere, might last but for a few days or weeks. 



All that can be said in the way of negative evidence, so 

 far as our own sun is concerned, is that we have no reason 

 for believing that our sun has, at any time within many 

 thousands of years, been excited to emit even for a few hours 

 a much greater amount of light and heat than usual ; so that 

 it has afforded no direct evidence in favour of the belief that 

 other suns may be roused to many times their normal splen- 

 dour, and yet very quickly resume that usual lustre. But we 

 know that our sun, whether because of his situation in space, 

 or of his position in time (that is, the stage of solar develop- 

 ment to which he has at present attained), belongs to the 

 class of stars which shine with steady lustre. He does not 

 vary like Betelgeux, for example, which is not only a sun like 

 him as to general character, but notably a larger and more 

 massive orb. Still less is he like Mira, the Wonderful Star ; 

 or like that more wonderful variable star, Eta Argus, which 

 at one time shines with a lustre nearly equalling that of the 

 bright Sirius, and anon fades away almost into utter invisi- 

 bility. He is a variable sun, for we cannot suppose that the 

 waxing and waning of the sun-spot period leaves his lustre, 

 as a whole, altogether unaffected. But his variation is so 

 slight that, with all ordinary methods of photometric measure- 

 ment by observers stationed on worlds which circle around 

 other suns, it must be absolutely undiscernible. We do not, 

 however, reject Betelgeux, or Mira, or even Eta Argus, 

 from among stars because they vary in lustre. We recognize 

 the fact that, as in glory, so in condition and in changes of 

 condition, one star differeth from another. 



Doubtless there are excellent reasons for rejecting the 

 theory that a massive body like a planet, or a nebulous mass 

 like those which are found among the star-depths (the least 



