24 



of Agriculture 1949 



service with moderate care. A house 

 built of wood can be altered easily. 



How is wood used chemically? 



To make charcoal, wood alcohol, 

 acetone, ethyl alcohol, wood-sugar mo- 

 lasses, fodder yeast, synthetic fibers, 

 photographic films, and other molded 

 articles, modified wood products such 

 as compreg and impreg and staypak, 

 many specialized products of wood 

 pulp and paper, and a host of other 

 chemical products. 



Is it true that most of the paper that 

 we use today is made from wood? 



Yes. Only small quantities of paper 

 are now made from linen or other 

 cloth rags the reverse of 150 years 

 ago, when little, if any, paper was 

 made from wood. 



How much wood is used for fuel? 



It is estimated that 63,000,000 cords 

 of wood are annually used for fuel 

 about one-eighth of all the wood used 

 in the United States. 



What major improvement has been 

 made in recent years in the use of 

 wood for shipbuilding? 



Ship keels and other long, heavy, or 

 curved members can now be laminated 

 from relatively small pieces of wood by 

 the use of waterproof glues. Such lam- 

 inated members often are superior to 

 the solid pieces formerly used. 



How many cross ties are required 

 for a mile of railway track? 



Three thousand cross ties are used 

 in the average mile of railway track. 



How many cross ties are there in 

 railway tracks throughout the United 

 States? 



More than one billion. 



How many cross ties do the railroads 

 install in a year? 



An average of about 50 million. 

 Approximately 80 percent of the cross 

 ties installed in replacements in recent 

 years have been treated that is, sat- 



urated with creosote, zinc chloride, or 

 other preservatives to prevent decay or 

 destruction by insects. The treatment 

 more than doubles the service life of 

 the ties. Bridge timbers, piling, poles, 

 and other woods are also treated in 

 this manner before use. 



Why is black walnut the outstanding 

 wood for gun stocks? 



It is one of our best shock-resistant 

 woods, it keeps its shape, attaches well 

 to metal, and is durable. Black walnut 

 also makes excellent furniture wood 

 it has a beautiful grain, is easy to work 

 into any desired shape, and takes a 

 good finish. 



How many wooden fence posts do 

 American farmers use? 

 About 500 million a year. 



What wooden shipping container is 

 used today in much the same form as 

 in the days of antiquity? 



The common barrel or cask ; cooper- 

 ing is one of the oldest known crafts. 



What is the hardest American wood, 

 in terms of density? 



Black ironwood, of a little-known 

 species found in southern Florida, has 

 a specific gravity of 1.04. It is so heavy 

 it sinks in water. 



What is the softest American wood, 

 in terms of density? 



Corkbark fir, found in parts of Ari- 

 zona and New Mexico, has a specific 

 gravity of 0.28. 



What are the main causes of forest 

 fires? 



There are seven: Those caused by 

 smokers' matches or by burning to- 

 bacco in any form; campfires; debris 

 burning fires which are originally set 

 for clearing land or disposing of rub- 

 bish, stubble, and such and which get 

 beyond control; incendiary, which are 

 deliberately started with the intention 

 of burning over the land or damaging 

 property owned by someone else ; light- 

 ning; lumbering; fires resulting from 



