BEAVER LODGES AND BURROWS. 143 



accommodations of the chamber. It had no support 

 under it of any kind whatever. After removing the 

 materials which had fallen in from the roof upon the 

 floor, we found the latter hard, smooth, and clean, 

 with fresh-cut grass around the outer border for their 

 nests; thus showing that it was an occupied lodge. 

 In standing upon the floor of the chamber, the heel of 

 a boot did not indent the surface, although it was but 

 two inches above the level of the pond. This last 

 fact was shown by the level at which the water stood 

 in the entrances, two in number, which came through 

 the floor in the outer edge of the chamber, as shown 

 in the figure. 



Measurements. 



Longitudinal diameter of clianiber 7 ft. 8 in. 



Transverse 7 " 



Vertical height 1 ft. to 1 ft. 4 in. 



Size of entrances through floor 15 in. square. 



Length of each entrance respectively 10 and 7 feet. 



The roof was about three feet, and the side walls 

 from four and a half to five and a half feet thick, which 

 rendered it, as a structure, both strong and durable. 

 Among the characteristics of the beaver is that of 

 cleanliness in his lodges and burrows. Nothing ap- 

 peared in this chamber to detract from his reputation 

 in this respect. There was no opening for light or 

 ventilation; but yet, from the porous nature of the 

 materials, as put together, sufficient air would pene- 

 trate the lodge from without to satisfy the require- 

 ments of its occupants, whose low respiration enables 

 them to endure the confined atmosphere of the lodge 

 and the burrow. In the winter season, their breath, 

 rising through the top of the lodge, dissolves the snow 

 and forms a chimney opening over it, which not only 



