236 NATURAL HISTORY IN ANECDOTE.

ing early in the summer, but their edifices are not commenced
until about the middle or latter part of August, and are not
completed until the beginning of the cold season. The strength
of their teeth, and their perseverance in this work, may be
fairly estimated by the size of the trees they cut down. Dr.
Best informs us, that he has seen a mulberry tree, eight
inches in diameter, which had been gnawed down by the
beaver. The figure of the dam varies according to circum-
stances. Should the current be very gentle, the dam is carried
nearly straight across; but when the stream is swiftly flowing,
it is uniformly made with a considerable curve, having the
convex part opposed to the current. Along with the trunks
and branches of trees they intermingle mud and stones, to
give greater security; and when dams have been long undis-
turbed and frequently repaired, they acquire great solidity,
and their power of resisting the pressure of water and
ice is greatly increased by the trees occasionally taking
root, and eventually growing up into something of a regular
hedge.

“The dwellings of the beaver are formed of the same
materials as their dams, and are very rude, though strong, and
adapted in size to the number of their inhabitants. These
are seldom more than four old and six or eight young ones.
Double that number have been occasionally found in one of
the lodges, though this is by no means a very common
circumstance, When building their houses, they place most
of the wood crosswise, and nearly horizontally, observing no
other order than that of leaving a cavity in the middle.
Branches which project inward are cut off with their teeth,
and thrown among the rest. The houses are by no means
built of sticks first and then plastered, but all the materials,
sticks, mud, and stones, if the latter can be procured, are
mixed up together, and this composition is employed from
the foundation to the summit. The mud is obtained from the
adjacent banks or bottom of the stream or pond near the