294 REPORT OF NATIONAL MUSEUM, 1904. 



already conveniently accounted for by assuming- that it was derived 

 from the primeval ocean at the time it shrank away and left the dry 

 land. Sufficient water to cover, when forced to the surface, the high- 

 est mountains, could, he calculated, be contained in a cavity the cubical 

 content of which was only one two hundred and sixty -fifth part of the 

 globe. 



Assuming that the antediluvian mountains were the same as to-day, 

 but somewhat higher (say, 5i miles), and accepting the fact that they 

 were covered by the water, Silliman proceeded to show that, with a 

 time limit of forty days, the water rose at the rate of a foot in two 

 minutes — i. e., 30 feet an hour, or 1S1 feet in the time of a common 

 flood or ebb tide, 362 feet in the time of the ordinary ebb and flow of 

 the tide, or 726 feet in twenty-four hours. 



The inequalities in the surface of the land would, however, increase 

 even this rate, and a very graphic picture is drawn of k 'the incon- 

 ceivably violent torrents and cataracts everywhere descending the 

 hills and mountains and meeting a tide rising at the rate of more than 

 TOO feet in twenty-four hours.'' 



It is to such a catastrophe that he believed to be due the extinction 

 of whole races of vertebrate animals, like the Siberian mammoth and 

 others. That such would be amply sufficient no one will be likely to 

 doubt. 



