THE FOREST AS A CONDITION. 63 



policy, especially in Germany, made vigorous prop- 

 aganda for the theory of the protective value of 

 forest cover, and, as is natural for propagandists, 

 made many sweeping and extravagant claims, and 

 an extensive literature, characterized by vigorous 

 declamation of unsubstantiated facts, and by ab- 

 sence of exact data, was the result. 



The condition of Palestine and other Eastern 

 countries, of Greece, Sicily, and Spain, once fertile, 

 now more or less desolate, was cited, and morals 

 were drawn from these experiences ; discrimina- 

 tion as to historic evidences of cause and effect 

 was mostly wanting, so that this historic method 

 of discussing the problem has been largely dis- 

 credited. 



Systematic attempts to establish by experiments 

 and exact methods the truth in the matter, at least 

 as far as climatic influence is concerned, were made 

 only within the last thirty-five or forty years. In 

 France, Becquerel began in 1858 a series of obser- 

 vations on temperatures within and without a forest 

 cover; in 1866, the forestry school at Nancy was 

 engaged in determining moisture conditions at sta- 

 tions in the forest, and later in the open ; and 

 several other investigators, both in France and 

 Germany, carried on such observations about the 

 same time. In 1868, the Bavarian government in- 

 stituted an exhaustive series of observations under 

 Dr. Ebermayer, to determine the climatic condi- 

 tions within a forest area. Switzerland followed 



