246 STRANGE DWELLINGS. 



mark, or, at all events, to prevent it from sinking below the 

 requisite level. 



If any modern engineer were asked how to attain such an 

 object, he would probably point to the nearest water-mill, and 

 say that the problem had there been satisfactorily solved, a dam 

 having been built across the stream so as to raise the water to 

 the requisite height, and to allow the superfluous water to flow 

 away. Now, water is as needful for the Beaver as for the miller, 

 and it is a very curious fact, that long before millers ever in- 

 vented dams, or before men ever learned to grind com, the 

 Beaver knew how to make a dam and insure itself a constant 

 supply of water. 



That the Beaver does make a dam is a fact that has long been 

 familiar, but how it sets to work is not so well known. Engrav- 

 ings representing the Beavers and their habitations, are common 

 enough, but they are generally untrustworthy, not having been 

 drawn from the natural object, but from the imagination of the 

 artist. In most cases the dam is represented as if it had been 

 made after the fashion of our time and country, a number of 

 stakes having been driven into the bed of the river, and smaller 

 branches entwined among them. The projecting ends of the 

 stakes are neatly squared off, and altogether the work looks 

 exactly as if it had been executed by human hands. One artist 

 seems to have copied from another, so that the error of one man 

 has been widely perpetuated by a series of successors. 



Now, in reality, the dam is made in a very different manner, 

 and in order to comprehend the mode of its structure, we must 

 watch the Beaver at work. 



When the animal has fixed upon a tree which it believes to be 

 suitable for its purpose, it begins by sitting upright, and with its 

 chisel-like teeth, cutting a bold groove completely round the 

 trunk. It then widens the groove, and always makes it wide in 

 exact proportion to its depth, so that when the tree is nearly cut 

 through, it looks something like the contracted portion of an 

 hour-glass. When this stage has been reached, the Beaver looks 

 anxiously at the tree, and views it on every side, as if desirous 

 of measuring the direction in which it is to fall. Having 



