BEAVER DAMS. 113 



of the trapper's art. That night the beaver, whose 

 skull is number one in the table of measurements in 

 the Appendix, was caught, and this, together with the 

 tail and feet, were sent to me the following day, by 

 the successful trapper, who proved to be my friend, 

 Captain Bridges, the trackmaster of the railroad. 



On Carp River there is a series of thirteen dams, 

 one above the other, commencing with dam No. 50 on 

 the map, which are much alike in size and external 

 appearance, and may therefore be referred to in one 

 group. They are constructed with interlaced stick- 

 work and poles on their lower faces, and banked in 

 with earth on their water slopes above, and discharge 

 the surplus water, at ordinary stages, by percolation. 

 While they are more or less sinuous in their crest 

 lines across the channel, the principal curve, at the 

 highest part of each structure, is usually down stream. 

 These dams are all situated within a distance of six 

 miles, measured along the winding channel of the 

 stream, the borders of which are fringed, here and 

 there, with beaver meadows, and these in turn are 

 bordered with a forest of tamarack and spruce. I 

 have passed over them in a fishing boat three succes- 

 sive seasons; the first time in 1860, and when they 

 were in a good state of preservation, with their ponds 

 full, and still occupied by beavers. They have since 

 then been deserted, and the greater part of them have 

 been carried away; thus showing the necessity for 

 constant watchfulness and repairs which their preser- 

 vation entails upon their builders. These dams were 

 from forty to one hundred feet in length, and from 

 three to five feet in vertical height at the thread of 

 the stream. As each d;im, in nearly every instance, 



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