CHARTING THE UNIVERSE 



less photographic plates. An Englishman, Mr. H. C. 

 Plummer made the same discovery through independ- 

 ent observations almost simultaneously. 



These vast star streams are moving in nearly 

 opposite directions in the plane of the Milky Way. 

 But they do not include the stars of the Milky Way 

 itself. The myriad clusters that make up that galaxy 

 lie far out beyond the star streams. So distant are 

 they that they show neither proper motion nor paral- 

 lax nor actual motion. For the most part they are 

 too faint to be tested accurately with the spectro- 

 scope. The actual forms of the streams or clusters 

 into which they appear to be grouped are as yet only 

 matters for conjecture. The distances at which these 

 swarming myriads are aggregated staggers even the 

 astronomical imagination. It is probably not less 

 than three thousand light-years. 



If all the stars of the Milky Way had been blotted 

 out of existence at about the time when Moses was 

 leading the Children of Israel out of Egypt, these 

 stars would still seem to shine for us just as they do. 

 And as to certain of the nebulae, the question has 

 recently been revived as to whether they may not 

 in reality constitute isolated universes at distances 

 still more unthinkable each one a galaxy of stars 

 comparable to our own. But data are lacking for 

 adequate judgment as to this conjecture. 



THE SCHEME OF THE UNIVERSE 



If, by way of summary, we attempt to interpret 

 the observed phenomena of star clustering and star 

 .movement just outlined, it would appear that the 

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