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.