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136 



HARDWICKE'S SCIENCE-GOSSIP. 



•(fmuvre. The weir is about forty feet in length, and 

 has a beautiful S curve from the top of the boundary 

 parapet wall at the east end to the opposite bank. The 

 curve near the south-east end has its convex side facing 

 up the stream, and it is at this point that the current 

 is strongest during floods. The parapet boundary 

 wall here has an iron railing along its top to prevent 

 the animals from escaping. The weir is nine feet in 

 height from the bed of the burn, and twenty feet broad 

 ^\. the bottom ; and its surface is so level that I could 

 not point to one spot where more water was running 

 over than at another. The framework is made up of 

 branches and twigs and small logs, all mixed up in 

 an apparently confused manner, but so effectually that 

 no water escaped except over the top. The modus 

 operajtdi was not at first apparent, but as we walked 

 along the top of the weir, in crossing to the other 

 side, the keeper pointed out that although we were 

 treading on a lot of loosely piled sticks, yet, im- 

 mediately below our feet, the interstices were com- 

 pletely closed up with mud and sods of grassy turf, 

 tlie whole forming a very compact mass. There are 

 two principal buttresses to this weir. One tree had 

 been made to fall up stream and hit the weir about 

 its centre, or near the centre, of the concave side of 

 the upward curve, and the other had fallen from the 

 western bank in an oblique but upward direction, and 

 i'ts top rested very near the first. The purpose was 

 evident at a glance, and the supports could not have 

 been better and more accurately placed by human 

 hands. 



In order to study the habits of the beavers, the 

 keeper had watched them very often, in summer 

 particularly, which is their working season, when the 

 wind was favourable for concealment in some suitable 

 spot — generally amongst the branches of a neigh- 

 bouring fir-tree. The utmost caution was necessary, 

 as they are so shy that they will not show themselves 

 on any account, so long as they are aware that there 

 is anybody near them. The working hours he found 

 were from 7 p.m. till 7 a.m. In the evening they 

 start from the house and burrows at the lower dam in 

 a line, like a gang of labourers, swimming up the 

 dams and climbing over the weirs, and every now 

 and then two or three drop out of the line and 

 remain at certain spots where work is to be done, till 

 the whole gang is pretty equally distributed along the 

 course of the burn. The keeper thinks they have a 

 store of clayey mud collected at some part of the dam, 

 and when they want a supply they swim to the place, 

 take a piece in their fore-legs, and, holding it to the 

 breast, swim back to the weir at which they are 

 working. There they push it in between the sticks, 

 and along with the mud, or before it, they stuff in 

 pieces of grass sods. On the edge of the large weir 

 I saw grassy sods that had been newly put in, and 

 masses of mud that had been shoved in after them. 

 The mud retained the shape so familiar to us in the 

 thick mud of our country roads that has been pushed 



aside by the surface-man's " clawt," the curved 

 wrinkles being quite distinct. There was nothing, 

 however, to lead one to suppose that the tail had 

 been used in the operation. A considerable number 

 of stones of various sizes were placed at intervals 

 amongst the sticks, to add, no doubt, to the solidity 

 of the structure. The largest I noticed was about 

 eight inches in diameter. For some time the beavers 

 had been adding to the height of the weir at the rate 

 of one foot per annum, and it had now got to the 

 level of the copestone of the wall, which runs along 

 the south side of the plantation, and if raised higher, 

 the water would run over the top of the wall. As it 

 is, little jets of water were coming through at one 

 or two places where the lime had given way. 



About half-way up the dam, and close to the 

 west bank and out of the way of the current in floods, is 

 the beavers' house. It is a rough-looking heap of mud 

 and sticks, but principally mud, whereas in the weir 

 the sticks are more prominent, probably in con- 

 sequence of the mud having been washed away by the 

 running water. The building, which is somewhat 

 dome-shaped, rises about four feet above the surface of 

 the water, which at this part is five feet deep. There 

 are two entrances, one on the lower and the other on 

 the upper side, but as they are some distance under 

 the surface — in fact near the bottom — they could not 

 be seen. On the top are a lot of loosely piled sticks, 

 placed over the air-hole to keep the ventilation open. 

 The interior communicates by a built passage with a 

 burrow in the bank. There are also several burrows 

 in the bank on the opposite side of the dam. 

 The entrances to these are beneath the surface of the 

 water, and they run up the bank for from six to ten 

 feet. The position of the chamber of each burrow is 

 marked by a few loose sticks on the surface of the 

 ground, like a half-built crow's nest, which cover the 

 air-hole as in the house. The keeper could not tell 

 the use of these burrows. The house, he knew, was 

 used principally for rearing the young, and he 

 suggested that the burrows might be used by the 

 males in the nursing season as places to which they 

 retired to be out of the way. He also suggested that 

 they might be used as places of refuge when the 

 beavers were disturbed in their house. I' so, they 

 are little better than traps, for the animals could be 

 dug out with spade and mattock in a few minutes. 



Immediately above the house, but still in the large 

 dam, is the store of food for the winter. It consists of 

 a pile of sticks with the bark on, each from two to 

 four feet long, and about three or four inches thick. 

 They are mostly, pieces of the branches of the trees that 

 have been cut down, and are built apparently from 

 the bottom of the water, which here is about four feet 

 deep. A small tree lies across the pile in one direction, 

 whilst another from lower down has been made to 

 fall upwards, and a third obliquely downwards. 

 These trees hold the bundle down and prevent the 

 sticks from floating and being carried away by spates 



