124 TWO NEW WORLDS 



but no longer, it would still be quite invisible to us. 

 And when we consider that it would, in all proba- 

 bility, take a billion years for two galaxies to 

 approach each other and meet, we can understand 

 that such an event must be a rare occurrence. Rare 

 as it is, Prof. Kapteyn and Mr. Eddington have 

 found some evidence to show that it is taking 

 place in our own system. 



Our galactic system consists, in fact, of two 

 independent systems which are gradually travelling 

 through each other, the faster system travelling 

 directly away from Hercules with a velocity seven- 

 teen times greater than the slower system, which 

 is making for a point near i Ursa3 Majoris. 



Such an observation pleads eloquently for the 

 view developed here viz., that there are external 

 galactic systems at a considerable distance from 

 our own. For, if the systems had not been inde- 

 pendent formerly, they could never have acquired 

 the independent directions and velocities they 

 actually exhibit. 



We may take it, then, that our present visible 

 universe is in process of transformation by the 

 intrusion into it of an independent " galaxy " (as 

 we may for short term a stellar system containing 

 some 100 or 1000 million stars). There is, in fact, 

 a " collision " of two galaxies an event for which 

 the chances at any time are less than 1 in 10 billion. 



The existence of 100,000 million galaxies within 



