“The situation chosen is various where the Beavers are numerous. They tenant lakes, rivers and creeks, especially the two latter for the sake of the current, of which they avail themselves in the transportation of materials. They also choose such parts as have a depth of water beyond the freezing power to congeal at the bottom. In small rivers or creeks in which the water is liable to be drained off when the back supplies are dried up by the frost, they are led by instinct to make a dam quite across the river, at a convenient distance from their houses, thus artificially procuring a deep body of water in which to build. “The dam varies in shape; where the current is gentle it is carried out straight, but where rapid it is bowed, presenting a convexity to the current. The materials used are drift wood, green willows, birch and poplar, if they can be secured, and also mud and stones. These are intermixed without order, the only aim being to carry out the work with a regular sweep, and to make the whole of equal strength. “Old dams by frequent repairing become a solid bank, capable of resisting a great force of water and ice; and as the willows, poplars and birches take root and shoot up, they form by degrees a sort of thick hedgerow, often of considerable height. Of the same materials the houses themselves are built, and in size proportionate to the number of their respective inhabitants, which seldom exceeds four old and six or eight young ones. The houses, however, are ruder in structure than the dam, the only aim being to have a dry place to lie upon, and perhaps feed in. “When the houses are large it often happens that they are divided by partitions into two or three, or even more compartments, which have in general no communication except by water; such may be called double or treble houses rather than houses divided. Each compartment is inhabited by its own possessors, who know their own door, and have no connection with their neighbors, more than a friendly intercourse and joining with them in the necessary labor of building. “So far are the Beavers from driving stakes, as some have said, into the ground when building, that they lay most of the wood crosswise, and nearly horizontal, without any order than that of leaving a cavity in the middle, and when any unnecessary branches project they cut them off with their chisel-like teeth and throw them in among the rest to prevent the mud from falling in; with this is mixed mud and stones, and the whole compacted together. The bank affords them the mud, or the bottom of the creek, and they carry it, as well as the stones, under their throat, by the aid of their fore-paws; the wood they drag along with their teeth.