116 NATURAL AND CIVIL 



chosen, it h always such a stream, as will form 

 a pond, thai shaii be every way coavciiient for 

 their purpose. And such is their foresight and 

 comprehension of these circumstances, that tliey 

 never form an erroneous judgment, or fix upon 

 a situation th*at will not answer their designs 

 and convt nience. Tiieir next business, is to 

 construct a dam. This is always chosen in the 

 most convenient part of the stream ; and the 

 form of it, is either direct, circular, or with an- 

 gles, as the situation and circumstances of the 

 Vv-ater and land, require : And . so ^veli chosen 

 is both the place, and the form of these dams, 

 that no engineer could give them a better situa- 

 tion and form, either for convenience, strength, 

 or duration. The materials of which the dams 

 are constructed, are wood, and earth. If there 

 be a tree on the side of the ri^■er, which would 

 naturally fall across the stream, several of the 

 beavers set themselves with great diligence, to 

 cut it down with their teeth. Trees to the big- 

 ness of twenty inches diameter, are thus thrown 

 across a stream, 'i'hcy next, gnaw ofFthe bran- 

 ches from the trunk, that the tree may assume 

 a level position. Others, at the same time, are 

 cutting down smaller trees, and saplings, from 

 one to ten inches diameter. These are cut in- 

 to equal and convenient lengths. Some of tlie 

 beavers di~ag these pieces of wood to the side of 

 the river, and others swim with them to the 

 place, where the dam is to be built. As many 

 as can find room, ai'e engaged in sinking one 

 end of these stakes ; and as many more in rais- 

 ing, fixing, and securing the other end. While 

 many of the beavers arc thus labouring upon 



