BEAVER. 



34? 



cause and effect, and instinct, which proceeds from a 

 cause which we are unable to comprehend, but which 

 certainly has nothing to do with experience, without 

 which there can be no reason or forethought plan, 

 produces the same end by very nearly, if not exactly, 

 the same means. 



And when we come to the mechanical operation, 

 we can see that this must be the case. Neither 

 instinct nor reason can alter the properties of that 

 matter on which it acts, whether it be the substance 

 of which its own members are made, or any foreign 

 substance. If the billet or the log is heavier than 

 the strength can move at all, or over the requisite 

 distance, and the purpose either of instinct or of 

 reason is to remove it entire, neither beaver nor man 

 can bring the strength up to the weight, or the weight 

 down to the strength, as both of these fall within the 

 province only of that power, which made the animal 

 structure and the piece of timber. But in the water, 

 the weight of ordinary timber of all which grows 

 where beavers inhabit, is wholly destroyed as a pres- 

 sure on the animal, and there is only the resistance 

 of the water's friction to be overcome. 



It is this use of the water which sends the beaver 

 into that element, just as it is the production of his 

 food there which sends him to inhabit the banks ; or 

 to speak more correctly, the bank ; the beaver and 

 all the circumstances of nature in the locality harmo- 

 nise with each other. Destroy the harmony, and 

 the animal being the most sensitive of the whole, is 

 the first to disappear, though when the combination 

 is broken up, all the others depart, in the ratio of their 

 changeableness ; and the place assumes, to all appear- 

 ance, a new character. Thus, in those places of 

 Berkshire where the skeletons of beavers are found 

 in the marl under the peat, the probability is that 

 there once had been standing pools with thickets of 

 deciduous trees on their margins, and banks in which 

 the beavers could dig their burrows or construct their 

 huts, according as they were less or more numerous. 

 To this stage had followed another of green mosses, 

 first in the stagnant pool, become shallow by deposits, 

 but increasing at the top and dying at the roots, as 

 mosses are known to do under such circumstances, 

 until what was once a hollow changed to a level sur- 

 face or even to a height, and till that height consumed 

 the surrounding thickets and groves, and then, exposed 

 to the frost in winter and the drought in summer, 

 become black and sterile, save here and there a few 

 stunted heaths, and other small plants of the desert. 

 There may have been and in many places there are 

 evidences of changes subsequent to these, in which 

 the powers of life have been brought again into 

 action, in a manner altogether different. Deposits of 

 gravel intermixed with fine particles and finished off 

 with vegetable mould, now lie over many such ante- 

 rior formations as those alluded to, and by the aid of 

 culture are among the most fertile spots in the island. 

 Thus we see that the beaver, as belonging to what 

 we may consider an early stage in the progressive 

 natural history of countries, has a long and a highly 

 interesting story to tell ; and one which, duly studied 

 and applied, might be of vast service to us in that 

 artificial cultivation and fertility, upon which we so 

 primarily depend for our food, our clothing, and very 

 many of the other comforts of life. 



Beavers have wholly disappeared from those parts 

 of North America which are settled and cultivated ; 

 and upon the frontier, where wild nature and man's 



cultivation may be said to divide the management 

 between them, they are few, straggling, and solitary, 

 and invariably spend the winter in burrows. The 

 burrow of a solitary beaver is seldom, if ever, accom- 

 panied by a dam for the regulation of the waters ; 

 and where there are villages or colonies, the dam is 

 used only in those situations where, during the sojourn 

 of the animals in their winter's abode, the water is 

 liable to great differences of level. This depends 

 both upon the nature of the water, and the character 

 of the seasons. It is less in pools and lakes than in 

 rivers ; and less where the winter is open, and the 

 spring gradual, than where the snow lies long and the 

 thaw is rapid and violent. The latter circumstances 

 prevail in a much higher degree in those parts of 

 America which are still well stocked with beavers, 

 than in any part of Europe, or perhaps of Asia. 

 The autumnal rains are not so heavy there, and do 

 not swell the water so much as they do in milder and 

 more variable climates. The humidity falls much in 

 snow ; and the floods occur when that snow melts 

 upon the return of warm weather. Thus, unless to 

 secure a depth which shall not be frozen to the bot- 

 tom, or one which otherwise shall conduce to floatage 

 and swimming in the winter, beavers have no great 

 occasion for dams, on the larger and more slowly- 

 flowing rivers in that part of the world. The smaller 

 creeks, however, are in some situations apt to be 

 very low, and indeed almost dry in the autumn, the 

 time when the beavers require water the most, because 

 that is the time at which they float along their pro- 

 visions and other materials. 



These latter situations give occasion for many bea- 

 vers' dams ; and though the accounts of the manner 

 of constructing these and their neatness when con- 

 structed, have been as much exaggerated as any part 

 in the economy of the animals, yet they are curious 

 structures. The instinct according to which they are 

 made, both as regards the original necessity for them, 

 and their form, is of course as inscrutable by human 

 philosophy as any other instinct. But still the struc- 

 tures themselves are formed upon what we may call 

 sound mechanical principles. The beavers do not, 

 as authors say, fell a large tree so that it may fall 

 across the river and form a head beam for the dam ; 

 and as little do they drive perpendicular stakes, or 

 stakes slightly inclined, so as to bear against the 

 beam. They do not fell great trees at all, neither do 

 they set any timbers on end, or arrange them in what 

 we would consider a symmetrical manner. They do 

 indeed make use of billets of wood much thicker 

 than they can cut at one bite the maximum of 

 which is only about that of an ordinary walking stick. 

 When they cut these larger pieces, they cut them 

 round the circumference, as wood-men do in the 

 operation which in America is termed " girdling," 

 and after once round, they cut round again and 

 again, until a division is effected. 



The construction, and also the necessary repair of 

 their dams, usually takes place during the night ; so 

 that the precise manner of their working is guessed 

 at rather than known ; but the billets of wood are 

 laid across each other, and kept down by means of 

 stones ; and the interstices are filled with mud and 

 clay, until the whole dam is rendered water-tight. In 

 the performing of all these labours, they have no instru- 

 ments that will come into use except the fore-paws 

 and the teeth ; but these, from the description which 

 has been given, are well adapted for the purposes. 



