14 G THE AMERICAN BEAVER. 



two inches of the floor of the chamber. In every 

 lodge opened I have found the floor but a few inches, 

 usually from two to six, above the level of the water. 

 The nearer the two to the same level, the easier the 

 introduction of their cuttings, which must be dragged 

 in with their teeth at no small exertion of strength. 

 From the uniform relation found to subsist between the 

 level of the floor and of the pond, it is evident that the 

 beavers regulate the discharge of the surplus water 

 through their dams with a view to the maintenance, 

 as near as possible, of a uniform level of the pond. 

 Any great variation, in this respect, would either 

 flood their habitations or expose their entrances; and 

 therefore the maintenance of their dams becomes a 

 matter of constant supervision and perpetual labor. 

 We discover also a reason why their principal repairs, 

 both of their dams and lodges, are deferred to the last 

 moment before going into winter quarters; since their 

 comfort and security are involved particularly in the 

 stability of their dams, which for months together, 

 during the winter, are beyond their control. In 

 choosing the sites of their lodges, so as to be assured 

 of water in their entrances and at their places ot 

 exit, too deep to be frozen to the bottom; in the ad- 

 justment of the floors of their chambers to the level 

 of the ponds; and in their appreciation of the causes 

 of a change of level in these ponds, as well as of the 

 remedy, decisive evidence seems to be furnished of 

 their possession of a free intelligence, as well as of 

 constructive skill. 



One other circumstance remains to be mentioned 

 with reference to this lodge. It was opened and 

 measured, as before stated, in 1860. The following 



