372 NATURE-STUDY 



place a mass of cotton batting on the board and repeat the 

 experiment. Note how much more slowly the water runs off, 

 but how much longer it continues to trickle out. By placing 

 some leaf mould on the inclined board the experiment may 

 be repeated and the retarding effect of the same noted. 



One other fact should be mentioned in this connection. 

 Forests on the hills are a perennial supply of fertility for the 

 lowlands. The waters that seap through the leaf mould 

 take up soluble matter and convey it to the fields below. 



In primitive times man was very dependent upon forests 

 for fuel, shelter, fruits, nuts, roots, and game. And man to- 

 day makes much more use of forests than did his primitive fore- 

 fathers. Forests are used to-day as windbreaks and shelter for 

 man and beast, as game preserves, as pleasure parks, and 

 as summer and health resorts. The wood is used for fuel 

 for our homes, factories, and kilns. The fuel value of our 

 forests is enormous. Even coal, derived from plants, may 

 be considered under this head. 



The railroads require millions of ties and telegraph poles. 

 Vast amounts of timber are used for telephone poles and for 

 fence posts. Large timbers are used for bridge and founda- 

 tion pilings and for supporting pillars in mines. Small, 

 slender saplings are used by the million for hoops, bean and 

 hop poles. 



A number of industries are dependent upon forests. The 

 charcoal industry, once very important, is one. Oak and 

 hemlock bark are used for tanning leather. In southern 

 states the pitch and turpentine industry flourishes in the 

 pitch pine regions. In the northern states the maple sugar 

 industry is carried on in forests of hard maple. Different 

 kinds of nut trees afford profitable industries in various parts 



