A HISTORY OF SCIENCE 



Lyell, and Darwin in his interpretation of the geological 

 records as he found them written on the rocks. 



It is in this field of geology that Leonardo is entitled 

 to the greatest admiration by modern scientists. He 

 had observed the deposit of fossil shells in various 

 strata of rocks, even on the tops of mountains, and he 

 rejected once for all the theory that they had been 

 deposited there by the Deluge. He rightly interpreted 

 their presence as evidence that they had once been 

 deposited at the bottom of the sea. This process he 

 assumed had taken hundreds and thousands of cen- 

 turies, thus tacitly rejecting the biblical tradition as 

 to the date of the creation. 



Notwithstanding the obvious interest that attaches 

 to the investigations of Leonardo, it must be admitted 

 that his work in science remained almost as infertile as' 

 that of his great precursor, Bacon. The really stimula- 

 tive work of this generation was done by a man of 

 affairs, who knew little of theoretical science except 

 in one line, but who pursued that one practical line 

 until he achieved a wonderful result. This man was 

 Christopher Columbus. It is not necessary here to tell 

 the trite story of his accomplishment. Suffice it that 

 his practical demonstration of the rotundity of the 

 earth is regarded by most modern writers as marking 

 an epoch in history. With the year of his voyage the 

 epoch of the Middle Ages is usually regarded as coming 

 to an end. It must not be supposed that any very 

 sudden change came over the aspect of scholarship 

 of the time, but the preliminaries of great things had 

 been achieved, and when Columbus made his famous 

 voyage in 1492, the man was already alive who was 



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