276 WOOD AND FOREST. 



once in a given length of time, a year or longer. The time between 

 two successive cuttings on the same area must be long enough to allow 

 the young trees left standing to ripen. 



In a word, conservative lumbering involves (1) the treatment of 

 the forest as a source of crops, (2) systematic gathering, and (3) 

 young growth so left as to replace the outgo. 



The important place that forests fill in the national economy may 

 be realized partly by the citation of a few facts as to the forest 

 products. The lumber industry is the fourth in value of products 

 among the great manufacturing industries of the United States, be- 

 ing exceeded only by the iron and steel, the textile, and the meat 

 industries. It turns out a finished product worth $567,000,000.00. 

 And yet lumber constitutes only about one-half of the value of the 

 total output of forest products. Its annual value is three-fourths of 

 a billion dollars, ($666,641,367 in 1907,) while the annual value of 

 wood fuel, is $350,000,000. More than two-thirds of the people 

 burn wood for fuel. The next largest single item in the list is shin- 

 gles and laths, $32,000,000. (See Forestry Bulletin No. 74, p. 7.) 



Outside of food products, no material is so universally used and so 

 indispensable in human economy as wood. (Fernow, Econ., p. 21.) 



The importance of forest products may also be learned from a 

 mere list of the varied uses to which they are put. Such a list would 

 include: fuel, wood and charcoal; houses (over half the population 

 of the United States live in wooden houses) ; the wooden parts of 

 masonry and steel buildings; scaffolding; barns, sheds and out- 

 houses; ships, with all their parts, and the masts and trim of steel 

 ships, boats and canoes; oars and paddles; railway ties (annual ex- 

 penditure $50,000,000), railway cars, a million in number; trestles 

 and bridges (more than 2,000 miles in length) ; posts and fencing; 

 cooperage stock (low estimate, $25,000,000 annually) ; packing 

 crates, including coffins; baskets; electric wire poles (annual cost 

 about $10,000,000) ; piles and submerged structures, like canal locks 

 and water-wheels; windmills; mining timbers (yearly cost, $7,500,- 

 000), indispensable in all mining operations (for every 100 tons of 

 coal mined, 2 tons of mining timber are needed) ; street paving; 

 veneers ($5,000,000.00 worth made annually) ; vehicles, including 

 carriages, wagons, automobiles and sleighs; furniture; machines and 

 their parts; patterns for metal molding; tools and tool handles; 



