OUR FORESTRY-PROBLEM. 227 



The value of the forest as a producer gains additional significance 

 in the economy of a nation from the fact that it yields a return on 

 land which for other purposes may be useless. Timber is the crop 

 which we can raise on our wastes and barrens, and which enriches and 

 improves the soil instead of exhausting it. For the forest-tree gen- 

 erates most of its substance from the carbonic acid of the atmosphere 

 through assimilation in the leaves, while from the soil it requires 

 mainly water, most of which and of the exceedingly small amounts of 

 mineral food that enter its composition, are derived from the deeper 

 strata. The greater part of this mineral food is returned by the fall- 

 ing leaves to the surface of the soil, and thus that circulation of matter 

 is set up which makes forest-growing a means of improving poor soils. 



The prospects of private gain might seem to be sufiicient to insure 

 the raising of timber as well as of grain or vegetables to the full ex- 

 tent desirable. But against the advantages of the wood-crop just 

 mentioned must be set certain drawbacks. The agricultural crop is 

 produced in one year, during which it is easy, by constant cultivation, 

 to keep up favorable conditions, and the expenditures yield their profit 

 within a year's time. The forest-crop requires ten, twenty, forty, nay 

 one hundred and more years to grow to useful size, does not admit of 

 much aid on the part of the cultivator, and must have the favorable 

 conditions for its development provided in the methods by which it 

 is originated. It not only requires a greater amount of capital, but a 

 greater amount of foresight, to carry on a systematic forestry with 

 similar objects in vicAv to those of systematic agriculture. 



Here, however, enters the national interest in the business of for- 

 estry, based upon the indirect significance of the forest, namely, its 

 influence on climate, water-flow, and soil. Even in ancient times 

 this significance was vaguely realized, when Critias spoke of the " sick- 

 ness of the country in consequence of deforestation." The earliest 

 written expression which ascribes to the forest a definite influence 

 upon climatic conditions we owe to the Spaniard, Fernando Colon 

 (about the year 1540), when he states that, "on Madeira, and the 

 Azores and Canary Islands, the rains have become rarer since the 

 trees, which spread their shade, were cut down." In later times we 

 find similar observations and allusions to this connection between for- 

 ests and climatic or agricultural conditions in the literature of almost 

 all civilized nations. 



But these occasional notes assumed a practical significance only 

 when, after the extensive clearings which were perpetrated by an un- 

 bridled populace during the French Revolution, the injurious conse- 

 quences upon some of the most fertile districts of France made them- 

 selves felt, when fields and pastures which had sustained a thrifty and 

 prosperous population were turned into sand-wastes or made sterile 

 by torrential action of mountain-streams, carrying away the fertile 



