COMMERCIAL USES OF DOUGLAS FIR 



73 



conditions of service. Wood block pave- 

 ments have reduced the noise of traffic 

 so that property values and rents of 

 buildings abutting streets so paved have 

 increased materially. 



Fully fifty per cent of the cross arms 

 used by telephone and telegraph com- 

 panies are of Douglas fir. In 1909 one 

 and three-quarter million cross arms 

 were manufactured from Douglas fir. 

 These were sold for an average f. o. b. 

 price of 38 cents each, which was slightly 

 above the price paid for other competing 

 species. Lightness and strength are the 

 principal requisites in cross arms. 



Douglas fir is now used extensively 

 for boxes and heavier crating purposes, 

 especially where greater strength is re- 

 quired in a box than the softer woods 

 most used possess. Douglas fir veneers 

 are now used in fruit and vegetable 

 basket manufacture. 



Lath are manufactured from this wood 



THE LARGEST WOOD PIPE IN THE WORLD 



Phis pipe is 13 feet 6 inches in diameter. Built of Douglas fir staves. Wood stave 

 pipe has a low initial cost, exceedingly low maintenance cost, a low factor of 

 friction, and will withstand very heavy pressures. As its merits become more 

 widely known its use will no doubt be largely extended. 



Copyright photograph by Darius Kinsey. 



FELLING A DOUGLAS FIR TREE 



Showing the "undercut" preliminary to felling a Douglas fir 

 giant 17 feet in diameter. This tree contains sufficient 

 lumber to build four modern cottages complete. Trees of 

 this species have been found of even larger diameters. 



to the extent of over one-half billion pieces per 

 year, and their value for this purpose runs close 

 to the million-dollar mark. 



A field which is fast developing is in the use 

 of wood stave pipe, stave tanks, and stave silos. 

 The requirements of a wood stave for these pur- 

 poses are strength, close grain (water-tight), 

 durability, and absence of defects. Douglas fir 

 is a favorite wood for this purpose, as attested 

 by the large amount of lumber cut annually into 

 staves for such construction. 



Continuous stave pipes, bound together by 

 iron bands, are well adapted for purposes where 

 the internal pressure is quite high, such as found 

 when water is transported under a high head. 

 This style of pipe is extensively used in con- 

 ducting water for irrigation purposes, hydro- 

 electric projects, and for city water supplies. 

 The Pueblo Rocky Ford Company, in Colorado, 

 carries water four miles from a dam to the 

 head of their irrigation canal by a continuous 

 Douglas fir stave pipe eighty-four inches in diam- 

 eter. Seattle brings its water supply a distance 

 of forty miles from the Cedar River through 

 two lines of Douglas fir stave pipe. The largest 



