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the remote parts of America, we learn how far 

 instinct can be aided by imitation. We from 

 thence perceive to what a degree animals, with- 

 out language or reason, can concur for their 

 mutual advantage, and attain by numbers those 

 advantages which each, in a state of solitude, 

 seems unfitted to possess. 



The beavers begin to assemble about the 

 months of June and July, to form a society that 

 is to continue for the greatest part of the year. 

 They arrive in numbers from every side, and 

 generally form a company of above two hundred. 

 The place of meeting is commonly the place 

 where they fix their abode, and this is always 

 by the side of some lake or river. If it be a 

 lake, in which the waters are always upon a level, 

 they dispense with building a dam ; but if it be 

 a running stream, which is subject to floods 

 and falls ; they then set about building a dam, 

 or pier that crosses the river, so that it forms a 

 dead water in that part which lies above and be- 

 low. This dam, or pier, is often four score, 

 or a hundred feet Jong, and ten or twelve feet 

 thick at the base. If we compare the greatness 

 of the work with the powers of the architects, 

 it will appear enormous ; but the solidity with 



