The beavers begin to assemble in June or July in order to form themselves into a society. They arrive in numbers from all sides, and soon form a company of two or three hundred; the place of meeting is generally that where they intend to fix their abode, and is always by the side of some lake or river. If it be a lake wherein the waters always remain upon a level they dispense with making a dam; but if it be a running stream, subject to floods and falls, they build a bank or pier quite across so as to secure a piece of water always at the same height, and this bank is frequently from 80 to 100 feet long, and ten or twelve thick at the base. If we compare the greatness of the work with the size[R] of the architect, it will appear enormous, but the solidity with which it is constructed is still more astonishing. They commonly choose that part of the river which is most shallow, and if possible, where some large tree is growing by the side of the stream; this they instantly set about cutting down, and although it is sometimes much thicker than a man's body, they very soon accomplish it without any other instrument than their four incisive teeth; and they always contrive to make it fall across the stream; they next cut off the top branches to make it lie level. These operations are performed in common. Several are employed at the foot of the tree in gnawing it down, others sever the branches, while others are, at the same time, engaged in parties along the banks of the river in cutting smaller trees, from the size of a man's leg to that of his thigh; these being cut to a certain length, they drag, by land, to the brink of the river, and then by water to the place allotted for their building; having pointed them at one end, they sink them down at small distances from each other, and then interweave them with pliant branches; the placing of these piles is the most difficult part of their operations, but they accomplish it by one party supporting the thick end with their teeth, while others plunge to the bottom and dig holes with their feet to receive the points that they may stand upright. While some are thus employed, others bring earth and clay, which they prepare for their purpose with their feet and tails; and they transport it in such large quantities, that they block up all the intervals between the piles. These piles are formed by a number of stakes in several rows, exactly of a height; they are placed opposite to each other, and extend across the river: that this embankment may sustain the weight of the water, it is made sloping, so that although it is twelve feet at the base, it is not more than three at the top; from which ingenious contrivance it has not only the requisite thickness and solidity, but also a form of others the most proper for confining the water, maintaining its weight, and baffling its attacks. Near the top of this bank they make two or three openings for the superfluous water to escape, and which they