It is a very curious circumstance that the beavers do all their work in the night, and thus no person can watch them at their operations except at a great disadvantage. In the day time they keep very quiet. Their motive, probably, in thus arranging their time, as far as action prompted by such animal instincts may be said to have a motive, is doubtless to avoid attracting the attention of their enemies.

   The beavers were once very numerous throughout the whole northern portion of the territory now occupied by the United States. In all the settled parts of the country, however, they have nearly or entirely disappeared; and so valuable are their skins, and so closely do the hunters and trappers