05 THE AMERICAN BEAVER. 



intermixed with loose stones, large and small. The 

 crest line of the dam is, of course, horizontal, although 

 sinuous, while its base line conforms to the irregulari- 

 ties of the original surface. At the point where it 

 crossed the thread of the stream it would necessarily 

 be the hiohest. Here the difference in level between 

 the water in the pond and the water below the dam 

 was ascertained to be five feet; the crest of the dam 

 rising but two inches above the level of the pond, and 

 the water below it being twelve inches deep. The 

 vertical height of the structure at the great curve, 

 therefore, was six feet and two inches. This dijffer- 

 ence of level decreases as either end is approached, 

 until it diminishes to one foot. At the ends, conse- 

 quently, the precise condition of the structure, at its 

 lowest stages, could be seen; not as at first con- 

 structed, but as it would appear after it had settled 

 down and had been repaired and strengthened from 

 time to time. Here it was built with small sticks, 

 from half an inch to an inch in diameter, and from 

 one to two and three feet in length. On the lower 

 side, which we shall call the face of the dam, the 

 sticks are arranged promiscuously, but usually with 

 their lower ends against the ground, and their upper 

 ends elevated and pointing up stream, against the 

 water slope of the dam, thus forming an inclined 

 bank of interlaced stick-work. Earth and mud, inter- 

 mixed with sticks and brush, form the water face or 

 upper slope of the dam, giving to it the nature and 

 appearance of a solid embankment. Thus the lower 

 face of the dam presents a mass of interlaced sticks 

 closely banked together, but still open and loose, and 

 free from earth, while the upper or water face is a 



