3n 



grove to the place by the dam where the work 

 was going on. This ditch was about twenty-five 

 inches wide and fifteen deep. The waters filled 

 it and thereby afforded an easy means of float- 

 ing or transporting the poles from the grove to 

 the place where they were being used. This 

 ditch was carried forward along the upper line 

 of the dam, and several feet in advance of the 

 spot where the outbuilding work was advanc- 

 ing. Upon the earth thrown up from this were 

 laid the upper or high ends of the poles. When 

 the dam was finally completed, it was approxi- 

 mately eight feet wide on the base and stood four 

 feet high. As soon as it was completed, the 

 beaver stuffed the water-front with mud and 

 grass roots, which were obtained by digging from 

 the construction ditch immediately in front of 

 the dam. In other words, they enlarged their 

 pole-floating ditch above the dam into a deeper 

 and wider channel, and used this excavated ma- 

 terial for strengthening and waterproofing the 

 dam. 



The longest beaver dam that I have ever seen 

 or measured was on the Jefferson River near 

 78 



