NATURAL HISTORY. 279 



filling tlie water, and, when it has passed its bounds, 

 for maintaining its weight, or baffling its attack. At 

 the top of their dike or mole, where it is least thick, 

 they form two or three openings : these they occasion- 

 ally enlarge or contract, as the river occasionally 

 rises or falls ; and when, from inundations or torrents, 

 their works have been damaged, they immediately re- 

 pair them with the utmost care. 



After this display of their labours to accomplish a 

 public work, it would be superfluous to add to it a de- 

 cription of their private constructions, were it not that, 

 in history, -an account should be given of every fact, 

 and that, in this first grand work of the beaver, the 

 intention uniformly was, that the little habitation of 

 each family should be rendered more commodious. 



This habitation is always furnished with two pas- 

 sages ; one for the purpose of a land, and the other 

 for that of a water excursion. In shape it is almost 

 always either oval or round ; sometimes it is from four 

 to five feet in diameter, and sometimes it consists of 

 two, and even three stories, while the walls are always 

 two feet thick. When it happens to consist of but 

 one story, the walls are but a few feet high, and there 

 is a kind of vault over them, that serves as a covering 

 for the edifice. It is constructed with such solidity as 

 to be impenetrable to the heaviest rains, to defy the 

 most impetuous - winds, and is plastered with such 

 neatness, both without and within, that it might na- 

 turally be thought an effort of human skill : these 

 animals, nevertheless, use no instrument for the pre- 

 paration of their mortar, but their feet, or for the ap- 

 plication of it, but their tails : they make the greatest 

 use of such materials as are not easily dissolved by- 

 water : their wooden work consists of such trees as 

 Vol. I. L I 



