HOW A BEAVER BUILDS HIS HOUSE 65
low plain with a stream running through, out of which a pond can be made.
It must be a very, very long while since beavers first found out that the way to make a pond out of a stream was to build a dam across it so strong that the water could not break through. To begin with, they have to know which way the stream runs, and in this they never make a mistake. Then they gather together stakes about five feet long, and fix them in rows tight into the ground on each side of the stream; and while the older and more experienced beavers are doing this — for the safety of the village depends on the strength of the foundation — the younger and more active ones are fetching and heaping up green branches of trees. These branches are plaited in and out of the rows of stakes, which by this time stretch right across the river, and form a dam often as much as a hundred feet from end to end. When the best workmen among them declare the foundation solid, the rest form a large wall over the whole, of stones, clay, and sand, which gradually tapers up from ten or twelve feet at the bottom, where it has to resist the pressure of the stream, to two or three at the top, so that the beavers can, if necessary, pass each other in comfort. And when the dam is pronounced finished, the overseer or head beaver goes carefully over every part, to see that it is the proper shape and exactly smooth and even, for beavers cannot bear bad work, and would punish any of their tribe who were lazy or careless.
The dam being ready and the pond made, they can now begin to think about their houses, and as all beavers have a great dislike to damp floors and wet beds, they have to raise their dwellings quite six or eight feet above the level of the stream, so that no sudden swelling of the river during the rainy season shall make them cold and uncomfortable. Beavers are always quite clear in their minds as to what they want, and how to get it, and they like to keep things distinct. When they are in the water