THE ORIGIN OF THE WORLD 



/CENTURY marks are of course only arbitrary 

 v^f divisions of time. But they enter so constantly 

 into human calculations, that it is difficult not to re- 

 gard them as actual mile-stones of progress. So it 

 seems altogether fitting that a brand new explanation 

 of the origin of the solar system should have been 

 one of the earliest contributions to theory and knowl- 

 edge at the beginning of the twentiet century. 



It is a doubly auspicious augury that the idea 

 should have come out of America as the first great 

 contribution to the theory of world-making that has 

 originated in the western hemisphere. 



The new theory found its origin, or at least its 

 chief tangible support, in the observations of a famous 

 American astronomer, Professor Keeler, then direc- 

 tor of the Lick Observatory. This keen-eyed ob- 

 server devoted the last two years of his life (1898- 

 1900) to the special investigation of that curious 

 member of the celestial family, the nebula. Working 

 with the famous three-foot telescope known as the 

 Crossley reflector, Keeler found that the universe is 

 thickly tenanted with nebulae. He estimated that at 

 least 120,000 of these bodies lay within the range of 

 his vision as aided by the three-foot mirror. Several 

 times that number are probably visible in the five- 



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