36 OBJECTS, ADVANTAGES, AND 



with stories which may be of doubtful credit. But the facts now stated 

 respecting- the Ant and Bee, may be relied on as authentic. They are 

 the result of very late observations, and experiments made with great 

 accuracy by several most worthy and intelligent men, and the greater 

 part of them have the confirmation arising from more than one ob- 

 server having assisted in the inquiries. The habits of Beavers are 

 equally well authenticated, and, being more easily observed, are vouched 

 by a greater number of witnesses. These animals, as if to enable 

 them to live and move either on land or water, have two web feet like 

 those of ducks or water dogs, and two like those of land animals. 

 When they wish to construct a dwelling-place, or rather city, for it 

 serves the whole body, they choose a level place with a stream running 

 through it; they dam up the stream so as to make a pond, and perform 

 the operation as skilfully as we could ourselves. They drive into the 

 ground stakes of five or six feet long in rows, wattling each row with 

 twigs, and puddling or filling the interstices with clay which they 

 ram close in, so as to make the whole solid and water-tight. This 

 dam is likewise shaped on the truest principles ;* for the upper side 

 next the water slopes, and the side below is perpendicular ; the base 

 of the dam is 10 or 12 feet thick : the top or narrow part two or 

 three, and it is sometimes as long as 100 feet. The pond being thus 

 formed and secured, they make their houses round the edge of it ; 

 they are cells, with vaulted roofs, and upon piles ; they are made of 

 stones, earth, and sticks ; the walls are two feet thick, and plastered as 

 neatly as if the trowel had been used. Sometimes they have two or 

 three stories for retreating to in case of floods, and they always have 

 two doors, one towards the water, and one towards the land. They 

 keep their winter provisions in stores, and bring them out to use ; they 

 make their beds of moss ; they live on the bark of trees, gums, and 

 crawfish. Each house holds from twenty to thirty, and there may be 

 iVom ten to twenty-five houses in all. Some of their communities are 

 therefore larger than others, but there are seldom fewer than two or 

 three hundred inhabitants. In working they all bear their shares: 

 some gnaw the trees and branches with their teeth to form stakes and 

 beams ; others roll the pieces to the water ; others diving make hoJes 

 with their teeth to place the piles in ; others collect and carry stones 

 and clay ; others beat and mix the mortar ; and others carry it on 

 their broad tails, and with these beat it and plaster it. Some super- 

 intend the rest, and make signals by sharp strokes with the tail, which 

 are carefully attended to ; the beavers hastening to the place where 



* If the base is 12, and the top 3 ieet thick, and the height 6 feet, the face must 

 be the side of a right-angled triangle, whose height is 8 feet. This would be the 

 exact proportion which there ought to be, upon mathematical principles, to give the 

 greatest resistance possible to the water in its tendency to turn the dam round, provided 

 the materials of which it is made were lighter than water in the proportion of 44 to 100. 

 But the materials are probably more than twice as heavy as water, and the form of so 

 flat a dike is taken, in all likelihood, in order to guard against a more imminent danger, 

 that of the dam being carried away by being shoved forwards. We cannot calculate 

 what the proportions are which give the greatest possible resistance to this tendency, 

 without knowing the tenacity of the materials, as well as their specific gravity. It may 

 very probably be found that the construction is such as to secure the most completely 

 against the two pressures at the same time. 



