100 • THE AMERICAN BEAVER. 



it issues from the lake. It performs the important 

 office of protecting the great dam below from the 

 effects of a sudden rise of the waters of the lake. In 

 consitruction, it is in all respects like the Grass Lake 

 dam. It is ninety-three feet long, and two and a half 

 feet high at the centre, from which it diminishes 

 gradually to the ends. I first saw it in 1860, and 

 last in 1866, when it was still in good condition. A 

 dam at this point is apparently of no conceivable use 

 to improve the lake for beaver occupation. It has 

 one feature, also, in which it differs from other dams 

 except those upon lake outlets: and that consists in 

 its elevation, at all points, of about two feet above the 

 level of the lake at ordinary stages of the water. In 

 all other dams except those upon lake outlets, and in 

 most of the latter, the water stands quite near their 

 crests, while in the one under consideration it stood 

 about two feet below it. This fact suggests, at least, 

 tne inference, although it may have but little of prob- 

 ability to sustain it, that it was constructed with 

 special reference to sudden rises of the lake in times 

 of freshet, and that it was designed to hold this sur- 

 plus water until it could be gradually discharged 

 through the dam into the great pond below. It 

 would, at least, subserve this purpose very efficiently, 

 and thus protect the dam below it from the effects of 

 freshets. To ascribe the origin of this dam to such 

 motives of intelligence is to invest this animal with 

 a higher degree of sagacity than we have probable 

 reason to concede to him; and yet it is proper to 

 mention the relation in which these dams stand to 

 each other, whether that relation is regarded as acci- 

 dental or intentional. 



