(Engineering 



around it. A fire and excessive cutting by beav- 

 ers had left but few aspens near the water. These 

 could furnish food for no more than two autumn 

 harvests, and perhaps for only one. Other colon- 

 ies had met similar conditions. How would the 

 Moraine Colony handle theirs? 



The Moraine colonists mastered the situation 

 in their place with the most audacious piece of 

 work I have ever known beavers to plan and ac- 

 complish. About one hundred and thirty feet 

 south of the old pond was a grove of aspens. Be- 

 tween these and the pond was a small bouldery 

 flat that had a scattering of dead and standing 

 spruces and young lodge-pole pines. A number 

 of fallen spruces lay broken among the partly ex- 

 posed boulders of the flat. One day I was aston- 

 ished to find that a dam was being built across 

 this flat, and still more astonished to discover 

 that this dam was being made of heavy sections 

 of fire-killed trees. Under necessity only will 

 beavers gnaw dead wood, and then only to a 

 limited extent. Such had been my observations 

 for years; but here they were cutting dead, fire- 

 hardened logs in a wholesale manner. Why were 

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