The Uses of Wood 



and growing wild on the earth. The tropical woods are full of 

 undiscovered possibilities. Our own rich forest flora has but 

 begun to show its value to man. 



THE FOREST AS A UNIT 



In a literal and an emphatic sense the wooden walls of a 

 nation are its forests. The trees on mountain slopes restrain the 

 waterflow in the valleys, preventing flood and drought, and thereby 

 hoarding for cities their supply of water. Trees temper climate, 

 drain swamps, add a stimulating tonic to the air, and take from 

 it the poisonous carbonic-acid gas. The pine forests are sought 

 by invalids for the healing of lung troubles in every country. 

 Our Adirondacks and the Colorado mountains have their proto- 

 types in the pine-clad health resorts of southwestern France and 

 the region around Baden in Germany, whose famous Black 

 Forest has a balsamic breath. 



European nations that have cut down their forests and failed 

 to store them have proved their national weakness and their 

 dependence upon wiser neighbours. The Mediterranean countries 

 are among the foolish buying lumber continually from Norway, 

 Sweden and Germany, and suffering in climate, water supply and 

 in the poverty of the peasant class, the results of having no home 

 forests. 



Tree roots are rock breakers, able to make their way even 

 through granite boulders. The root hairs excrete an acid that 

 eats away limestone and disintegrates rock particles, while the 

 mighty pressure of growth is crowding the sides of cracks apart. 

 In time, with water and frost and other forces co-operating, the 

 forbidding rock ledges have a crumbling layer kept from blowing 

 away by the falling leaves and sheltering undergrowth. The 

 leaf carpet rots, earthworms mingle its substance with this 

 "rock meal," and the name of the mixture is soil broken-down 

 vegetable and mineral substance yielding plant food to the 

 hungry roots of trees. 



Thus a forest makes soil, deepening and enriching it the more 

 the roots take from it. "Virgin soil" is that which has been 

 covered with trees for hundreds of years. Waste land moist 

 enough to grow trees may be reclaimed by this agency in a few 

 years. Even semi-arid regions will grow trees if only the proper 



534 



II 



