A HISTORY OF SCIENCE 



might have been required for their elevation from the 

 place in which they have been formed." 2 



From all this, therefore, Hutton reached the con- 

 clusion that the elevation of the bodies of land above 

 the water on the earth's surface had been effected by 

 the same force which had acted in consolidating the 

 strata and giving them stability. This force he 

 conceived to be exerted by the expansion of heated 

 matter. 



"We have," he said, "been now supposing that the 

 beginning of our present earth had been laid in the bot- 

 tom of the ocean, at the completion of the former land, 

 but this was only for the sake of distinctness. The 

 just view is this, that when the former land of the globe 

 had been complete, so as to begin to waste and be 

 impaired by the encroachment of the sea, the present 

 land began to appear above the surface of the ocean. 

 In this manner we suppose a due proportion to be al- 

 ways preserved of land and water upon the surface of 

 the globe, for the purpose of a habitable world such as 

 this which we possess. We thus also allow time and 

 opportunity for the translation of animals and plants 

 to occupy the earth. 



11 But if the earth on which we live began to appear 

 in the ocean at the time when the last began to be re- 

 solved, it could not be from the materials of the con- 

 tinent immediately preceding this which we examine 

 that the present earth has been constructed; for the 

 bottom of the ocean must have been filled with ma- 

 terials before land could be made to appear above its 

 surface. 



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