BEAVER DAMS. 



97 



Length of Dam measured on the Crest Line. 



From station No. 1 to Station No. 2 (See Plate VIII.) 39 feet. 



" 2 " " 3 4-1 " 



" 3 " " 4 62 " lOin. 



" 4 " " 5 52 " 



" 5 '• " G 80 " 



" 6 " " 7 83 " 



Total Length 260 feet 10 in. 



Other Measurements. 



Height of structure from ground, 

 or base line 



Depth of water in small pond be- 

 low dam 



Differenoe of level of water above 

 and below dam 



Height of water above base line.. 



Approximate width of base, trans- 

 verse sections 



Length of slope of poles, lower 

 face of dam 



Length of slope of water face of 

 dam 



Depth of water in pond at the end 

 of slope 



6 ft. 2^^ 

 1 ft. 



5 ft. 



6 ft. 



18 ft. 

 13 ft. 



7 ft. 6^^ 

 4 ft. 



No. 41^. 



5 ft. 3^/ 

 1 ft. 



4 ft. 



5 ft. 



15 ft. 

 11 ft. 9^^ 



8 ft. 



8 ft. 6^^ 



No. 3. 



3 ft. 6'^ 



3 ft. 2^^ 

 12 ft. 

 9 ft. 

 7 ft. 

 3 ft. 



No. 2. 



2 ft. V^ 



2 ft. 

 6 ft. 

 6 ft. 

 4 ft. 

 2 ft. 



The following figure represents a transverse section 

 of the dam at the head of the great curve, Station No. 

 4, and distinguishes the part which is a solid embank- 

 ment from that which consists of sticks and poles free 

 from earth. 



Fig. 8. 



Fole k 6tick wnrK BASE 18 Fr. 



Transverse section. 



Y 



A computation made from the preceding, and some 

 additional measurements, shows that this dam con- 



7 



