old
patriarch had lost one tooth, the three that remained had not
deteriorated with age. The outer edge of them was formed of the hardest
enamel; the inner side was of soft ivory. They were like the finest
steel chisels, the enamel never wearing away and the softer ivory
replacing itself year by year as it was consumed. Sitting on his
hindlegs, with his forepaws resting against the tree and with his heavy
tail giving him a firm balance, Broken Tooth began gnawing a narrow ring
entirely around the tree. He worked tirelessly for several hours, and
when at last he stopped to rest another workman took up the task.
Meanwhile a dozen beavers were hard at work cutting timber. Long before
Broken Tooth's tree was ready to fall across the stream, a smaller
poplar crashed into the water. The cutting on the big birch was in the
shape of an hour-glass. In twenty hours it fell straight across the
creek. While the beaver prefers to do most of his work at night he is a
day-laborer as well, and Broken Tooth gave his tribe but little rest
during the days that followed. With almost human intelligence the little
engineers kept at their task. Smaller trees were felled, and these were
cut into four or five foot lengths. One by one these lengths were rolled
to the stream, the beavers pushing them with their heads and forepaws,
and by means of brush and small limbs they were fastened securely
against the birch. When the framework was completed the wonderful cement
construction was begun. In this the beavers were the masters of men.
Dynamite was the only force that could hereafter break up what they were
building now. Under their cup-like chins the beavers brought from the
banks a mixture of mud and fine twigs, carrying from half a pound to a
pound at a load and began filling up the framework with it. Their task
seemed tremendous, and yet Broken Tooth's engineers could carry a ton of
this mud and twig mixture during a day and night. In three days the
water was beginning to back, until it rose about the butts of a dozen or
more trees and was flooding a small area of brush. This made work
easier. From now on materials could be cut in the water and easily
floated. While a part of the beaver colony was taking advantage of the
water, others were felling trees end to end with the birch, laying the
working frame of a dam a hundred feet in width.

They had nearly accomplished this work when one morning Kazan and Gray
Wolf returned to the swamp.