NATURE S CALENDAR 



stability of the structure, and hence they 

 often erect their houses upon platforms 

 laid in a clump of swamp trees, like the 

 black alder. Such architects, we are told 

 by a New England observer, " exhibit a 

 good deal of the constructive ability of 

 the beaver, cutting their wood on shore 

 in a similar manner, and often towing it 

 long distances to their building sites, 

 where they wattle it firmly between the 

 alder stems for a foundation." Such well- 

 placed cabins, composed mainly of cat- 

 tails and twigs, may last and be continu- 

 ously occupied for fifteen or twenty years. 



When no fixed supports are taken ad- 

 vantage of, the ground is usually care- 

 fully prepared for a foundation. Choos- 

 ing, for example, the end of a peninsula 

 reaching into a marshy stream, the rats 

 will dig off the soil to the level of the 

 hard bottom of the stream, and begin 

 work upon this denuded surface, which 

 will support a part of the house, while the 

 other half rests upon the bottom of the 

 creek. The materials will be gathered 

 from the immediate neighborhood, thus 

 clearing a considerable space about it. In 

 some cases the foundation material con- 

 sists of reeds and sticks laid regularly in 

 a radiating manner from the centre to the 

 circumference, and weighted wnth mud, 

 making the firmest possible underpinning. 



The study of the architecture of the 

 muskrat derives special interest from the 

 popular belief that the height of their 



241 

 November 8 



November 9 



