Nor must the Beaver be forgotten, the most industrial animal of the Rodentia, which has wholly disappeared from Europe, and is yearly growing scarcer in America.
The Beaver (Castor fiber) is specially recognizable by his broad horizontally-flattened tail, which is of a nearly oval form, but slightly convex on its upper surface, and covered with scales. His hind feet are webbed, and together with the tail, which acts as a rudder, propel him through the water with ease and swiftness. His length, exclusive of his tail, which measures one foot, is about three feet; colour, a deep chestnut; hair, very fine, glossy, and smooth. The incisor teeth are large, and so hard, that the North American Indians used them in fabricating their horn-tipped spears and cutting bone, until iron tools were introduced from Europe.
The sagacity with which he constructs his habitation has long been a theme of eulogy, and has furnished moralists with many an apt image and pregnant illustration. Water is the necessity of his life. It is indispensably necessary that the stream near which the animal lives should never run dry; and to prevent so dire a misfortune, he is gifted with an instinct which teaches him to keep the water at or about the same mark, by building a dam across the channel.
In order to comprehend the art with which this dam is constructed, we must watch the beaver at his patient toil.[137]
When the animal has fixed upon a tree which he believes suitable for his purpose, he sits upright, and with his chisel-like teeth cuts a bold groove completely round the trunk. He then widens the groove in exact proportion to its depth, so that when the tree is nearly cut through, it somewhat resembles the “contracted portion of an hour-glass.” When this stage has been reached, he looks anxiously at the tree, and views it on every side, as if to measure the direction in which it should fall. Having settled this question, he goes to the opposite side, and with two or three powerful bites cuts away the wood, so that the overbalanced tree comes to the ground.
The beaver next proceeds to cut it up into lengths of about a yard or so, employing a similar method of severing the wood. The next part of the task is to make these rounded and pointed logs into a dam. For this purpose the logs are laid horizontally, and covered with stones and earth until they can resist the force of the water. Vast numbers are thus laid; and as fast as the water rises, fresh materials are added, being obtained mostly from the trunks and branches of trees which have been stripped of their bark by the beavers.
In those places where the stream runs slowly the dam is carried straight across the river; but where the current is strong, a convex shape is given to it, so as to resist the force of the rushing water. The dam is frequently of great size, measuring two or three hundred yards in length, and ten or twelve feet in thickness. In many localities the streams have been diverted by these erections into entirely different channels.
It is in this manner that the beavers keep the water to the required level; we must next see how they make use of it. They build their houses close to the water, and communicating with it by means of subterranean passages, one entrance of which passes into the house, or “lodge,” as it is technically named, and the other into the water, so far below the surface that it cannot be closed by ice. It is, therefore, always possible for the beaver to gain access to the provision stores, and to return to its house, without being perceived from the land.
“The lodges,” says Mr. Wood, “are nearly circular in form, and much resemble the well-known snow-houses of the Esquimaux, being domed, and about half as high as they are wide—the average height being three feet, and the diameter six or seven feet. These are the interior dominions, the exterior measurement being much greater, on account of the great thickness of the walls, which are continually strengthened with mud and branches, so that during the severe frosts they are nearly as hard as solid stone. Each lodge will accommodate several inhabitants, whose beds are arranged round the walls.”
There is no animal, however, whose sagacity can foil human ingenuity. The trappers, who hunt the beaver for the sake of his fur, and the peculiar odoriferous secretion called castor, are more than a match for all his artifices. Not even in winter-time is he safe from their pursuit. Striking the ice smartly, they judge from the sound whether they are near an aperture; and as soon as they are satisfied, cut away the ice and stop up the opening, so that the beavers, if alarmed, may not escape into the water. They then proceed to the shore, and by repeated soundings trace the course of the beavers’ subterranean passage, which is sometimes eight or ten yards long, and by closely watching the different apertures invariably catch the inhabitants. While thus engaged, they must be careful not to spill any blood, as in case of such a mishap the rest of the beavers take alarm, retreat to the water, and cannot be captured. The trappers entertain a superstitious notion, which leads them to remove a kneecap from each beaver and throw it into the fire.