87 



DOI'GI.AS FlK 



On the Pacific coast this timber species holds for piHiig purposes a position 

 of supremacy similar to that held in the southern and eastern United States by Southern 

 pine. This is due to its superior excellence, as compared to other timbers here available, 

 in practically every one of the qualities which have been named — form, strength, 

 available lengths, quantity obtainable and moderate cost. It has no natural resistance 

 to any of the marine wood borers, so that it must be artificially protected from their 

 attacks; and to injection by preservative chemicals, which is the most common 

 method of [)rotection, it presents very considerable refractoriness. That, in spite of 



- i:a 



Fig. 31. (1) Untreated Douglas fir pile from Oakland Municipal Quay, east of Grove Street sewer, 

 driven 1913, removed October, 1920. Destroyed at mud line b^- Bankia, surface eroded 

 by Limnoria. 

 (2) The same, end view. 



