"That must be a work of very great labour, Uncle Thomas."

"The labour is very considerable, Boys; but the power which, for want of
a better name, we call Instinct, comes wonderfully to their aid. For
instance, it has been observed that they seek all the branches which
they want on the banks of the river, higher up than their construction,
so that having once got them conveyed to the water, they are easily
floated to it."

"Very good, Uncle Thomas."

"When the beavers have finished the dam, they then proceed to construct
a house for themselves. First they dig a foundation of greater or less
capacity, in proportion to the number of their society. They then form
the walls of earth and stones, mixed with billets of wood crossing each
other, and thus tying the fabric together just in the same way as you
sometimes see masons do in building human dwellings. Their huts are
generally of a circular form, something like the figure of a haycock,
and they have usually several entrances--one or more opening into the
river or lake, below the surface of the water, and one communicating
with any bushes and brushwood which may be at hand, so as to afford the
means of escape in case of attack either on the land or water side."

"They must be pretty safe then, Uncle Thomas, since they can so readily
escape."

"They are pretty secure so long as they have only unreasoning animals to
contend with, Frank; but when man, armed with the power, before which
mere Instinct must at all times bow, attacks them, they are very easily
overcome. Shall I tell you how the hunters capture them?"