42 HISTORY OF GEOLOGY AND PALEONTOLOGY. 



geologists must feel like the ancient Roman augurs who could 

 not meet each other without laughing. Nevertheless, he 

 resolved to gather together all the actual observations hitherto 

 recorded in geological science, and to construct a more reason- 

 able history of the earth upon this recognised basis. 



His first geological work, Theorie de la Terre, which was 

 published in 1749, marked little advance upon current 

 literature, but it was an able argument against the principles of 

 the earth's origin held by Whiston, Burner, Woodward, and 

 Leibnitz, and boldly denounced the popular idea of a universal 

 Deluge. His great work, kpoquts de la Nature, appeared 

 twenty-nine years later, in 1778. 



Buffon there enumerates five " facts " of first importance, 

 and five additional " monuments " or comments. The " facts " 

 are physical in character; they postulate the oblate-spheroidal 

 form of the earth; compare the small amount of heat received 

 from the sun with the large supply possessed by the body of 

 the earth; the effect of the earth's internal heat in altering the 

 rocks of the crust; and the presence of fossils everywhere over 

 the earth, even on the tops of the highest mountains. The 

 " monuments " assert that all limestones consist of the remains 

 of marine organisms, and that in Asia, America, and the North 

 of Europe the remains of large terrestrial animals occur at a 

 small depth below the surface, showing that they apparently 

 dwelt in these regions at no very remote age; whereas the 

 deeper-lying remains of marine creatures in the same region 

 belong to extinct species, or are related only to forms now 

 inhabiting far distant seas. 



Starting from these axioms, Buffon portrays in very attractive 

 terms the beginning, the past, and the future of our planet. 

 He derives the material of our earth and the other bodies of 

 the solar system from the impact of a great comet with the sun. 

 The earth's material assumed the form of a spheroid flattened 

 at the Poles, and for 2,936 years continued in a molten state. 

 This was the first epoch in Buffon's scheme, and he determined 

 its length of duration by a series of experiments with balls of 

 melted iron of different sizes. In the same way he determined 

 the duration of the molten state to be 644 years in the case of 

 the moon, 2,127 for Mercury, 1,130 for Mars, 5,140 for Saturn, 

 and 9,433 years for Jupiter. The period required for the earth 

 to cool down to its present temperature was calculated by 

 Buffon to be at least 74,800 years. 



