HOW THE GREAT DAM WAS BUILT
Shaggycoat, of course, had had no experience in dam-building, but he had
often watched repairs upon the dam in the colony where he and his
grandfather lived, before that terrible winter and the destruction of
their snug city. He was too young at the time to be allowed to help in
such important work as strengthening the dam, which needed old and wise
heads, but there was no rule against his watching and seeing how it was
done.
He had planned to model his dam in the alder meadow after the one at the
old colony.
He had traveled many weary miles by lakes and rivers, to find a spot
where such a dam could be built. A broad meadow surrounded by
foothills, with a narrow neck at the lower end where the dam was to be,
and large trees near to use in its construction. There were many places
where the ordinary dams, made of short sections of logs, piled up like a
cob house, could be built. The brush and stone dam could also be made
almost anywhere, but the kind Shaggycoat wanted, which was easier to
make than any other could be built only in certain places, so he had
chosen the spot with great care.
His observation of repairs on the old dam would stand him in good stead,
but even had he not seen this work, it is probable that his beaver's
building instinct would have supplied the needed knowledge. His kind had
been dam builders for ages.
It was the beaver dams of the eighteenth century that gave us most of
our pleasant meadows, where hay and crops now grow so plentifully.
Originally these lowlands were covered with timber, but the beaver dams
overflowed the valleys, and made them fertile. This also killed off the
timber, which finally rotted and fell into the water, and the meadow was
cleared as effectually as though the settlers had done it with their
axes. Traces of these dams may still be found.
Just to illustrate how ingrained the building instinct is in the beaver:
a young beaver was held in captivity in the third story of an apartment
house in London. There were no sticks, no mud, nor anything to suggest
building. He had no parents to teach him this industry, yet he soon set
to work and built brushes, shoes, hassocks, and anything else movable
that he could get hold of into a wall across one corner of the room.
This was his dam.
One October evening, when the harvest moon was at its full and its
mellow radiance shimmered on tree-top and water, and the world was like
a beautiful dream, half in light, half in shadow, Shaggycoat and
Brighteyes took their places at the foot of one of the great pines at
the lower end of the meadow and the work of dam-building began. But just
how they set to work you could never guess, unless you are familiar with
the habits of these most interesting animals.
They stood upon their hind legs, balancing themselves nicely upon their
broad flat tails, and began nipping a ring about the tree. It was not a
very deep cut, and looked for all the world like the girdle that the
nurseryman makes upon his apple trees, only it was a little more ragged.
When the tree had been circled, they began again about three inches
above the first girdle, and cut another. When they touched noses again
at the farther side of the tree, they began pulling out the chips
between the two girdles. When this operation had been completed for the
entire circumference of the tree, they had made the first cut which was
about three inches broad, and perhaps a half an inch deep, for they had
the bark to help them, and this was the easiest cut on the tree.
Do you imagine that they stopped for a frolic when the first cut had
been made, as many boys or girls would have done? Not a bit of it, for
they knew better than man could have told them how soon cold weather
would make work upon the dam impossible, and there was the lodge to
build after the dam had been made.
You would have laughed if you had seen these two comparatively small
animals at the foot of that giant pine, nipping away at it like
persistent little wood-choppers. The old tree was tall and majestic. It
had withstood the winds of a century, and its heart was still stout. The
chips that they took were so small, and the task before them so great,
but, if you had happened by the following day and seen the furrow, some
two or three inches in depth, you would have marveled, and not been so
sure of the old pine's ability to withstand these ambitious rodents.
Night after night they worked, and once or twice they had to widen the
cut, which had become so narrow that they could not get their heads in
to work, but, even as water wears away stone by constant action, they
wore away the stout heart of the old pine.
At last, one morning, just as the moon was setting and the pale stars
were fading, a shudder ran through the tall pine and it quivered as they
cut through the last fibres of its strong heart. A moment it tottered
like an old man upon his staff, then swayed, as though uncertain which
way to go, and fell with a rush of wind and a roar that resounded from
foothill to foothill until the meadow echoed with the downfall of the
old sentinel.
It had fallen squarely across the stream, just as they had hoped. This
was probably not through any prowess of the beavers as woodsmen, but
nearly all timber that grows upon the bank of a stream leans toward the
water, owing to the fact that trees grow more freely upon that side.
The sun was now rising, so they left their work, well pleased that the
tree was down, but by dusk they were at it again.
The trunk of the pine, and particularly its thick foliage, had dammed
the water somewhat, so it was already beginning to set back, but most of
it trickled through and went upon its way rejoicing at its escape. Some
large limbs upon the tree still held it several feet from the ground, so
they set to work on the under side of the tree, cutting off the limbs
and lowering the trunk to just the height they wished. Some of this
work had to be done under water, but that is no hardship for a beaver,
for he can stay under several minutes. When breathing had become
difficult they would come up, bringing the severed limbs in their teeth.
These would be jammed into the mud just in front of the tree trunk, like
the pickets upon a fence. If you had tried to pull out one of these
limbs after they had once planted it, you would have found it a
difficult task.
In two nights they lowered the pine to the desired height, and made it
look like a dam.
The following night, they began upon the other pine on the opposite
bank, and girdled it as they had done the first. The tree looked lonely
now with its mate gone. Perhaps it felt so and did not care that the
sharp teeth were nipping away at its bark, or maybe it still longed to
battle with the elements, and this spasmodic pain in its sap filled it
with forebodings.
As relentlessly as they had gnawed away at the first tree, they worked
at the second until it, too, fell with a rush of air, the snap of
breaking branches and a thunderous thud that shook the valley. They were
not as fortunate this time as they had been before and though the pine
fell across the stream, it fell further up than its mate, leaving a gap
between them.
You could never guess how they remedied this mishap. They certainly
could not move the tree, but that was really what they did, for they
gnawed off the limbs that supported it on the down-stream side, and it
rolled over of its own weight, so that in this way the gap was filled.
The structure now looked quite like the outline of a dam.
Then work upon it was suspended for a time and they went up-stream about
twenty rods and dug three holes in a knoll that would soon be an
island, for the reason that the water was now setting back quite
rapidly. These holes were started near the bank of the stream running
back under ground for several feet, and then turning upward and coming
out at the surface. Three such holes were dug, each leading to a
different place near the bank of the stream, but all coming out at the
same spot at the top of the knoll.
They soon resumed work upon the dam and small trees and brush might have
been seen floating down the stream, guided by industrious beavers, who
gave the material a shove here and a push there to keep it in the
current. Now that the dam was beginning to flow the meadows, they would
make the stream do their carrying just as it did cargoes for man.
The brush and saplings were stuck vertically in front of the pine
barricade, and the holes between were plastered up with mud and sods,
until the structure was fairly tight. The mud they carried in their fore
paws hugged up under the chin, or on the broad tail which made a fine
trowel with which to smooth it off.
Little by little the holes on the dam were filled, until finally it was
quite smooth and symmetrical. It could be built larger and stronger the
next year, but for this year they only needed a small pond that should
make a primitive Venice for them, and shield their lodge from a land
attack. By the time the first hard freeze came, the dam had been
completed for that year, and the freeze strengthened it just as they had
intended.
A beautiful little lake about a quarter of a mile in length, and half as
wide, now shimmered and sparkled in the valley and the beavers were glad
that they had been so prospered.