224 THE BOUNDARY-LINE BETWEEN GEOLOGY AND HISTORY. 



lloDian Listoriaus, we find uotbiug but a few obscure traditious. It is 

 kuown, however, especially through the cxaiuiuation of aucieut graves, 

 that these regions were inhabited by people who made their weapons 

 and tools of bronze, a mixture of copper and tin. The remnants left 

 by these people indicate peculiar taste for ornaments and great skill in 

 the working of these metals. This great epoch of civilization is called 

 the ac/e of bronze. 



Other discoveries show that before the age of bronze there lived a 

 I)eople who were ignorant of the manner of working the metals. They 

 made their weapons and utensils only of stone, sharp splinters of bones, 

 and of wood. This more ancient epoch has been called the age of stone. 

 To it belongs a great number of the graves found in Denmark ami 

 Sweden. Our knowledge of the mode of life of some of these ancient 

 peoples has been increased in an unexpected manner by the discoveries 

 of the Swiss archaeologists. The very low w^ater-mark to which the 

 Swiss lakes fell in 1854 laid bare extensive palafittes or pile-construc- 

 tions in the lakes of Geneva, Constance, and many others. In some of 

 these, remnants of the age of bronze, and in others of the age of stone, 

 were found between the piles in the muddy bottom of the lakes. On 

 these piles were erected formerly the habitations of the natives in such 

 a manner as to protect them against the attacks of their enemies and of 

 wild beasts. It is known that such palafittes are still in use in is'ew 

 Guinea ; and Herodotus gives a detailed description of similar construc- 

 tions in Lake Prasias, where Megabazus, the general of Darius, found 

 them. 



Apparently the age of stone can be divided into an earlier one, in 

 which men only knew how to cleave stones in order to give them the 

 required shape, and a more recent one, in which they understood the 

 art of grinding and polishing stone articles. The traces of the oldest 

 time are the most interesting, because we can inquire how far they corre- 

 spond with the facts which natural science reveals to us. Here, then, 

 geology and pahieoutology have their brightest pages, while history 

 shows us the first traces of human existence. For this reason our con- 

 sideration of the question is geological rather than archaeological. Our 

 method will be as follow^s : First, we shall consider the i)henomena ap- 

 parent in the inorganic creation of that epoch, and then describe the 

 plants and animals which existed in these regions immediately before 

 the appearance of man. We shall also show under what circumstances 

 traces of the oldest age of stone have been in various places discovered. 



There are in these places large masses of loose rocks, which evidently 

 came into their i^reseut position at a time after the surrounding country 

 >had assumed its present condition. The most remarkable of these are 

 \those brought to their i^resent places by the glaciers. Ice is not abso- 

 lutely solid, but possesses a certain degree of viscosity, which causes 

 masses of it collected on the high mountains to flow slowly down into 

 the valleys in the form of great streams of ice. These would soon fill 



