144 RODENT WATER TRESPASSERS. 



ciple as that of an ordinary water-mill. This fact has 

 long been known, but the manner in which the dam is 

 constructed has been much misunderstood, and some 

 of the stories respecting the Beaver's powers of build- 

 ing are nearly as fabulous as those of the sailing 

 powers of the nautilus shell. 



For example, we used to be told that the Beaver 

 made the dam by cutting long stakes, sharpening one 

 end, driving them into the bed of the river, and then 

 intertwining smaller boughs between the uprights. 

 The work was finished by filling all the interstices 

 with stones and mud, which were brought on their 

 tails, just as a mason carries mortar on a board. The 

 tail was also said to subserve the purpose of a trowel, 

 and to be chiefly used in smoothing and patting down 

 the mud. 



As a boy, I was always puzzled to understand 

 how a Beaver should be able to drive stakes into the 

 bed of the river, not seeing where the necessary power 

 could be obtained. I had often constructed dams 

 across streamlets, but could not have driven stakes 

 without the use of a heavy mallet, an implement which 

 a Beaver was not likely to possess. Similarly, being a 

 swimmer, I could not understand how the Beaver could 

 carry mud or stones on its tail, conjecturing, from 

 practical experience, that the weight of the cargo 

 would sink the tail in the water, so that everything 

 upon it would slide off. 



On land, the conveyance was supposed to be 

 managed in a different manner. An old Beaver, whose 

 teeth were too much worn to be serviceable in cutting 

 down trees, was utilized as a timber cart. He had to 



