TREES AND FORESTRY 45 



her own resources prohibited the exportation of unmanufactured wood 

 (May 1. HMO . 



Durable N oods, and Market for Posts 



If conditions combine a market for posts and a woodland of durable 

 woods such as cedar, white oak. ( >-age orange, catalpa, black locust, chest- 

 nut or mulberry, cypress or redwood see p. 47 for treated wood- serviceable 

 for posts the production of posts may be the aim, with reforesting by the 

 sprout method see p. 63) to gain rapid growth and frequent crop-. It i- 

 the heartwood only that makes a durable post, so tree- must be allowed to 

 attain a diameter that will give a preponderance of heartwood. and naturally 

 the best tree- for the purpose are those in which the formation of heartwood 

 follow- rapidly on the growth of sapwood see Fig. 6, p. 13). Reports 

 from Ohio recommend honey locust for posts; if grown close in a good soil, 

 it i- said to produce straight, smooth post- more durable than even cedar or 

 white oak. 



Durable Woods, and Market for Ties, Poles "/• Piling 

 The cutting of durable woods may be deferred until the tree- attain a size 

 suitable for railway tie- tree- 12 to It) indie- in diameter; also the upper 

 logs of larger tree-'. About sixty per rent of all tie- in use at present are 

 white oak. hut the white oak supply i- now practically exhausted. In the 

 Lake State- hemlock and tamarack are being used. Chestnut sprouts reach 

 ,-ize for railway ties in thirty-five year-. Every mile of railroad requires 

 2500 tie.- and if these ties must be replaced every seven year.-, as previ- 

 ously, the demand means cutting clear one-half million acres of forest 

 annually. It is reported that the Pennsylvania Railroad uses 620,000,000 

 ties in it- system. This corporation has begun planting tree- for produc- 

 tion of its own ties: 3,482,186 trees have been set out; 200.000 seedlings 

 were imported in 1908. More than 1.000.000 trees were planted along the 

 railroad's right of way in 1000. The species are black locust, red oak and 

 catalpa. also various conifer- such as Scotch pine, white pine and Norway 

 spruce. See wood preservation, p. 47. 



If durable wood- are allowed to grow until they cut log- 25 to 80 feet long 

 tipper diameter 5 inches or more), they find sale a- telegraph or telephone 

 pole- with a market value of from two to ten dollar- per pole. 



Chestnut poles may be grown in 42 year- from -prout- and will give 12 

 year-' service. Red cedar, which combines more valuable qualities for poles 

 than any other wood, must pass out of use with the present supph since the 

 posts are cut from tree- 00 year- old and last only about 15 year-. Arbor- 

 vita- also is one of the most desirable timber- for poles but. like cedar, can 

 be depended on only till exhaustion of the present supply since the tree i- 



