SCIENCE AT THE BEGINNING OF THE CENTURY 



answers, they are suns, each and every one of all the 

 millions suns, many of them, larger than the one that 

 is the centre of our tiny system. Not only so, but they 

 are moving suns. Instead of being fixed in space, as has 

 been thought, they are whirling in gigantic orbits about 

 some common centre. Is our sun that centre? Far from 

 it. Our sun is only a star, like all the rest, circling on 

 with its attendant satellites our giant sun a star, no 

 different from myriad other stars, not even so large as 

 some ; a mere insignificant spark of matter in an infinite 

 shower of sparks. 



Nor is this all. Looking beyond the few thousand 

 stars that are visible to the naked eye, Herschel sees 

 series after series of more distant stars, marshalled in 

 galaxies of millions ; but at last he reaches a distance 

 beyond which the galaxies no longer increase. And yet 

 so he thinks he has not reached the limits of his vi- 

 sion. What then ? He has come to the bounds of the 

 sidereal system ; seen to the confines of the universe. 

 He believes that he can outline this system, this universe, 

 and prove that it has the shape of an irregular globe, 

 oblately flattened to almost disklike proportions, and di- 

 vided at one edge a bifurcation that is revealed even to 

 the naked eye in the forking of the Milky Way. 



This, then, is our universe as Herschel conceives it a 

 vast galaxy of suns, held to one centre, revolving, poised 

 in space. But even here those marvellous telescopes do 

 not pause. Far, far out beyond the confines of our uni- 

 verse, so far that the awful span of our own system 

 might serve as a unit of measure, are revealed other sys- 

 tems, other universes, like our own, each composed, as 

 he thinks, of myriads of suns, clustered like our galaxy 

 into an isolated system mere islands of matter in an 



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