EXCURSIONS OF AN EVOLUTIONIST 



we have to go back a long way before we en- 

 counter an absolute scarcity of information ; 

 there was a great deal more literature in the 

 Middle Ages than is commonly supposed, and 

 it is possible to describe many long past events 

 with great minuteness and accuracy. Mr. Free- 

 man devotes the greater part of a volume of 

 768 pages to the political and military history 

 of England during the single year 1066. But 

 the history during the spring of 1 8 1 5, if treated 

 with equal thoroughness, would fill a good many 

 volumes as big as this ; and this is owing largely 

 to our increased wealth of materials. When we 

 go back far enough and encounter a positive 

 dearth of material, we can devote but a few 

 pages to the history of a century, as in the case 

 of the earliest Teutonic invasions of Britain ; 

 or, as in the case of the long ages before Caesar's 

 invasion, we can barely say that such and such 

 races of men inhabited the island, and we can 

 give little or no account of what they did. This 

 is one reason why we find it so hard to form and 

 preserve an accurate mental picture of the dura- 

 tion of past time. It requires a deliberate effort 

 of the mind to realize, for example, that the in- 

 terval between the proclamation of Constantine 

 the Great by the Roman legions at York and 

 the invasion of William the Conqueror was 

 exactly equal to the interval between the latter 

 event and the accession of George IV., or the 

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