390 Chronicles of Science. [July, 



this important work, to learn something new about the corona 

 during the two minutes of total obscuration. 



The discovery that the star Eta Argus, around which the most 

 amazing nebula in the whole heavens spreads itself in fantastic con- 

 volutions, is shining with the light of burning hydrogen, is, perhaps, 

 when rightly understood, the most instructive fact which has been 

 revealed by astronomical observation for many past years. We 

 know that this star is now nearly at its minimum of brightness, 

 and astronomers confidently expect that in the course of the next 

 half century it will rise from its low estate as a sixth-magnitude 

 star until it again outblazes even Canopus in splendour. That 

 this star, like the new star which lately shone out in Corona, is 

 surrounded by hydrogen-flames, seems clearly established by the ob- 

 servations of Mr. Le Sueur at Melbourne. He has not been able, 

 indeed, to test the character of the bright lines across the star's faint 

 continuous spectrum, by actually bringing them into juxtaposition 

 with the lines of hydrogen. But he has been able to measure their 

 position with considerable accuracy. He finds, by spectroscopic ob- 

 servation, that the space around the star is really free from nebulous 

 light, and is not merely dark by contrast ; and he deduces the conclu- 

 sion that the star has been fed, so to speak, by the matter of the 

 nebula, since the nebulous light which appears at some distance from 

 the star exhibits one of the hydrogen bright lines. This view may 

 well be demurred to, since it would render the restoration of the star's 

 light a simple impossibility. And besides, when Sir John Herschel 

 observed the star in 1837, the nebula was bright all round the star; 

 whereas, since the star was then shining very brightly, the nebula 

 should have shown signs of having been consumed near Eta Argus, 

 were Mr. Le Sueur's theory correct. It seems far more probable 

 that the amazing variability of this nebula is due to the motion of 

 its parts, and is associated with the equally amazing variability of 

 Eta Argus in such sort that, when a rich region of nebulous matter 

 is brought to the star's neighbourhood the star becomes bright, 

 while when, as now, the star is surrounded by a region bare of 

 nebula, its light sinks low. 



One fact, at any rate, seems placed beyond all question by Mr. 

 Le Sueur's researches. We can scarcely doubt any longer that the 

 nebula and the star are intimately associated, or that the strange 

 variation of one is but the counterpart and measure of the variation 

 of the other. 



Mr. Browning's invention of the automatic spectroscope is full of 

 promise for the advancement of our knowledge of the constitution of 

 the celestial bodies. This is not the place to enter into a considera- 

 tion of the advantages it presents over all other forms of the spectro- 

 scope ; but our Chronicle would have been incomplete without a few 

 words of comment on this most ingenious addition to our means of 



