90 



Oakland, Calif., as well as by this Committee. Further doubt of the asserted results 

 with Cottonwood is occasioned b>- the report of the Alaska Packers Association to this 

 Committee that they have secured only a 3->-ear life from this timber in Alaska and 

 are contemplating creosoting it in the future. 



The species of Cottonwood common to the Pacific coast and doubtless that used 



l>?*»^S*WJfc^^ggC 



Fig. 33. Redwood pile from Fort Mason, attaclved by Linmoria. 



A* 



^i? 



Uf' 





Fig. 34. Section of cottonwood pile exposed less than six months in San Francisco Bay. 



in the experiments of the railroads mentioned is known as "Black Cottonwood" 

 (Populiis trichocarpa). The total stand of this black cottonwood on the coast is rela- 

 tively limited. Its form Is much less desirable than that of the Douglas fir, and its 

 inferiority as a timber for structural purposes is shown by the following comparison 

 with Douglas fir: 



