54 EXTINCT BRITISH ANIMALS. 
same materials. If any damage does occur, they im- 
mediately find it out and repair it. I have seen them 
swim along the edge of the embankment, carefully 
examining it to ascertain the part most needful of re- 
pairs, then go to work with a will to rectify it. The 
dam is now seventy-eight yards long of still water. 
“ Besides the dam already mentioned, upon which 
they bestow great care in its construction, owing to 
the house being built in it, they have other seven, 
some larger, some smaller; one of them having an 
embankment 105 feet long, and an average depth 
of three feet. These serve as places of refuge if the 
beavers are disturbed when out roaming about in quest 
of food or felling the trees, also asa waterway for con- 
veying their food by when storing it for winter. 
In the construction of their dwelling the same 
kind of materials are used. As to how they built it : 
you must understand that for a considerable distance 
along one side of the stream, or burn, the ground 
rises in a steep bank, but about twenty yards above 
where they began to build the embankment for the 
dam there was a small level spot which they selected. 
Then at the bottom of the water they burrowed in 
three or four feet, rose up eight or ten inches, 
scooped out a space large enough to hold themselves, 
broke a hole in the surface about six inches in 
diameter, then began to cover it over with sticks, 
grass, and a few stones, always keeping it open in 
the centre by placing a few sticks perpendicularly, 
so as to act as a ventilator, and as the water rose in 
the dam and the family increased, they continued to 
