84 ROMANCE OF THE BEAVER 
them a space of about six feet, which they so 
ingeniously fill in with stones, clay, and branches 
that one would expect nothing better from the 
most skilful architect. The length of the structure 
is greater or less, according to the size of the stream 
which they wish to restrain. Dams of this kind 
a fifth of a mile long are sometimes found.” This 
is a strange mixture of truth and error which is 
difficult to account for. The double barrier and 
rampart filled in with stones and clay and branches 
is very far from the actual construction. As a 
matter of fact, the building of an ordinary dam 
consists originally of a number of sticks and brush 
being laid (no stakes are driven) in the water with 
the butts up-stream. When slightly weighted 
with sod, stones, and water-soaked billets of wood 
they become anchored, each projecting twig acting 
as a brace against the bottom. Little by little 
more material of the same description is added 
until from shore to shore there is an unbroken 
line which at first only slightly retards the flow 
of the stream. Then sod and muck, with roots 
and grass, are laid against the upper side or face. 
By the force of water all this material is worked 
in among the network of sticks, the beavers assisting . 
the water by pushing clots of fibrous muck, usually 
gathered from the bottom of the pond, into the 
openings until gradually the face of the dams 
assumes a smooth appearance levelled to an angle 
of about forty-five degrees. If the work is properly 
