148 SCIENCE LST SHORT CHAPTERS. 



To understand this clearly, we must consider the fact that 

 what appears to us as the outline of a flat disk is really that 

 part of the sun which we see by looking horizontally athwart 

 his rotundity, just as we look at the ocean surface of our own 

 earth when we stand upon the shore and see its horizon out- 

 line. When the moon obscures all but the last film of this 

 solar edge, we see only the surface of the supposed gaseous 

 orb, just that portion of the blazing gases which are not greatly 

 compressed by those above them, and which accordingly 

 should, if they consist of the vapors or the gases above named, 

 display a bright-striped spectrum, provided the intervening 

 non-luminous vapors of the same metals are not sufficiently 

 abundant to obscure them at this particular moment, when 

 only the absolute horizon-line is seen, and the body of the 

 moon cuts off all the intervening solar surface, and the lower 

 or denser portion of the intervening super-solar vapors, though, 

 of course, these are not so entirely cut off as the continuous 

 background. 



The reversion of the dark lines therefore reveals to us the 

 stupendous fact that the surface of the mighty sun, which is as 

 big as a million and a quarter of our worlds, consists of a flam- 

 ing ocean of hydrogen and of the metals above named in a 

 gaseous condition, similar to that of the hydrogen itself. 



This fact, coupled with the other revelations of the spectro- 

 scope, which, without the help of an eclipse, reveals the surface 

 outline of the sun, the ** sierra'' and the " prominences" tell us 

 that this flaming ocean is in a state of perpetual tempest, heav- 

 ing up its billows, and flame-Alps hundreds and thousands of 

 miles in height, and belching forth above all these still taller 

 pillars of fire that even reach an elevation of more than a 

 hundred thousand miles, and then burst out into mighty clouds 

 of flame and vapor, bigger than five hundred worlds. 



What does the last eclipse teach us in reference to the 

 corona ? Firstly and clearly, that Lockyei 's explanation 

 which attributed it to an illumination of the upper legions of 

 the earth's atmosphere must be now forever abandoned. 

 This theory has died hard, but, in spite of Mr. Lockycr's 

 proclamation of "victory all along Hie line," it is now past 

 galvanizing. There can be no further hesitation in pronouncing 

 that the corona actually belongs to the sun itself, that it is a 

 marvellous solar appendage extending from the sun in all 

 directions, but by no means regularly. 



The immensity of this appendage will be best understood by 



