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SCIENCE 



[N. S. Vol. XLVI. No. 1199 



heart. Alike they seek to deduce from 

 known facts the underlying principles of 

 nature. If the modern hypothesis appears 

 to lie much nearer to the truth, it is be- 

 cause the facts upon which it is based are 

 more numerous and more completely veri- 

 fied. Nor should we forget that it has had 

 the advantage of a long series of tentative 

 explanations, which it now replaces. All 

 our advances have been made over the re- 

 mains of discarded theories. 



It is here proposed to trace in outline 

 the history of the theories which from time 

 to time have been suggested to account for 

 the way in which the earth was formed. 

 It will be seen that we have here three 

 stages in human intellectual development. 

 In the first the world was conceived to be 

 due to the literal handicraft of a beast, a 

 demigod or a divinity. In the second it 

 was realized that a nobler origin must be 

 sought, but methods of scientific criticism 

 had not been perfected sufficiently to put 

 the theories to the test. In the third, every 

 one had to be submitted to the most rigid 

 dynamical analysis. 



In order that these primitive theories 

 may have an unprejudiced hearing it is 

 well for us to try and put ourselves in the 

 place of their authors. Let us view the 

 world as seen through the eyes of the an- 

 cients. 



At the time of the dawn of consciousness, 

 man found himself on what appeared to be 

 a flat and circular earth. As he extended 

 his wanderings this way and that, although 

 great ranges of mountains occasionally 

 stood in his way, they could eventually be 

 crossed, but sooner or later he seemed al- 

 ways to come to the shores of the impas- 

 sable sea. So he concluded that the disc- 

 shaped land was completely surrounded 

 by the ocean, which flowed like a mighty 

 river around the earth. Above him was a 



great dome, forming a lid to it all. This 

 was evidently of solid material, glass or 

 some metal, possibly brass. Some claimed 

 that it must be transparent, others, that it 

 was perforated by windows, for at night 

 the light of the celestial regions shone 

 through, and he called these bright objects 

 stars. The Egyptians had a slightly dif- 

 ferent explanation, for, according to them, 

 the stars were lamps hanging down from 

 the ceiling of the world on the end of 

 chains. Over this dome he saw passing, 

 with wonderful regularity, various bright 

 objects, notably the sun, and he soon ob- 

 served, in addition to its regularity, that it 

 had a very rapid motion, for it came up 

 from beyond the River Oceanus, probably 

 through a great door, in the morning, and 

 in about twelve hours had crossed the dome 

 of the heavens and was at the door of the 

 evening, ready for its return journey 

 through the upper world down to the gate 

 of the morning once more. This rapid 

 journey, in the days before steam or gaso- 

 line, could be explained only by the use of 

 swift animals, and what animals are so 

 swift as horses. 



Above the dome of the heavens there 

 seemed to be another ocean, for ever and 

 again the roof leaked and showers of rain 

 fell upon the earth. It was evident also 

 that there must be beings there who con- 

 trolled the activities of nature, and prob- 

 ably they could occasionally climb down 

 by way of the sides of high mountains, 

 whose tops, inaccessible to man, undoubt- 

 edly touched the sky, and indeed, prob- 

 ably helped to support it. 



Now all the mysterious and terrifying 

 forces of nature were to be explained in a 

 perfectly naturalistic way, by the inter- 

 vention of these beings from the upper 

 world. "Was the oak under which our fore- 

 father had taken refuge in a storm, shat- 

 tered by the lightning, it was because one 

 of the gods had hurled a flaming dart. 



