556 



BIOLOGY AND HUMAN LIFE 



carefully burned, instead of being left under the trees as a 

 constant fire risk. At the Forest Products Laboratory in Madi- 

 son, Wisconsin, one of the eight forest experiment stations, in- 

 vestigations are constantly being made to find the best methods 

 of utilizing wood and other forest products for various purposes. 

 402. Advantages of public control. The extent of the national 

 forests may be seen in the map below. In these forests are 



Fig. 228. United States national forests, 156,000,000 acres (1924) 



The economy of national control of forests, as well as the protection of public 

 interests thereby, has been strikingly demonstrated 



conserved and protected the water supplies for more than a 

 thousand cities and towns, for over twelve hundred irrigation 

 projects, and for over three hundred water-power plants ; nearly 

 ten million head of sheep, horses, and cattle graze every year, 

 and nearly half a million people find recreation. The forest 

 service sells timber to private users and gives away firewood to 

 settlers in agricultural lands included within the forest areas. 

 403. Forest dangers. Four serious dangers menace the forest : 

 I. The person who cuts recklessly and destroys for imme- 

 diate profit what ought to last practically forever. This enemy 



