50 ROMANCE OF THE BEAVER 
I found myself at a loss for a way of crossing a 
stream until the fortunate discovery of a beaver 
dam has enabled me to avoid a wetting. 
Having now seen something of the dams, so that 
without going into a lot of tiresome and unneces- 
sary detail such as exact measurements of numerous 
structures (which must vary continually), the reader 
has at least a general idea of what they are like 
,/without, I hope, being too much bored. We have 
seen that the dams range in length from a few 
inches to two thousand feet or more, and in height 
up to fourteen feet, containing from a pound or two 
of building material up to several hundred tons, all 
- earried laboriously by the industrious builders in 
- their tiny hands or with their powerful teeth. Also 
that the idea of this stupendous work is to enable 
the animals to keep water at a constant level for the 
protection of their lodge and to furnish them with 
a convenient means of transporting their supply of 
wood. This brings us naturally to their wood-cut- 
ting operations, about which many wonderful tales 
have been told. Before going into the methods, it 
might be well to give the reason for woodcutting 
,even at the risk of slight repetition. Beavers’ 
- natural food consists of a purely vegetable diet, the 
‘chief item being the bark of trees, not the outside 
shell, but the cambium layer which contains the 
very life of the tree. To a limited extent they also 
use the wood itself,, but the nutriment obtained 
from it is so insignificant that it is only occasionally 
