236 NATURAL HISTORY IN ANECDOTE. 



ing early in the summer, but their edifices are not commenced 

 until about the middle or latter part of August, and are not 

 completed until the beginning of the cold season. The strength 

 of their teeth, and their perseverance in this work, may be 

 fairly estimated by the size of the trees they cut down. Dr. 

 Best informs us, that he has seen a mulberry tree, eight 

 inches in diameter, which had been gnawed down by the 

 beaver. The figure of the dam varies according to circum- 

 stances. Should the current be very gentle, the dam is carried 

 nearly straight across ; but when the stream is swiftly flowing, 

 it is uniformly made with a considerable curve, having the 

 convex part opposed to the current. Along with the trunks 

 and branches of trees they intermingle mud and stones, to 

 give greater security ; and when dams have been long undis- 

 turbed and frequently repaired, they acquire great solidity, 

 and their power of resisting the pressure of water and 

 ice is greatly increased by the trees occasionally taking 

 root, and eventually growing up into something of a regular 

 hedge. 



"The dwellings of the beaver are formed of the same 

 materials as their dams, and are very rude, though strong, and 

 adapted in size to the number of their inhabitants. These 

 are seldom more than four old and six or eight young ones. 

 Double that number have been occasionally found in one of 

 the lodges, though this is by no means a very common 

 circumstance. When building their houses, they place most 

 of the wood crosswise, and nearly horizontally, observing no 

 other order than that of leaving a cavity in the middle. 

 Branches which project inward are cut off with their teeth, 

 and thrown among the rest. The houses are by no means 

 built of sticks first and then plastered, but all the materials, 

 sticks, mud, and stones, if the latter can be procured, are 

 mixed up together, and this composition is employed from 

 the foundation to the summit. The mud is obtained from the 

 adjacent banks or bottom of the stream or pond near the 



