FORESTRY IN GERMANY. I 27 



The foregoing table shows to what degree the air in the forest is filled 

 with moisture caused by the evaporation of the water that is held in the 

 forest. Not all the water falls upon the ground, but a large amount remains 

 on the leaves and evaporates. According to the investigations of Ebermayer 

 from 100 per cent, of rain falling on the open land there reaches the ground 

 in the forest — 



Per cent. 



In spring 68 



In summer 72 



In autumn 73 



In winter 75 



According to the observations of Mathieu, a celebrated French scientist, 

 from November to April 13 per cent., and from May to October 18.8 per 

 cent., or an average of 16 per cent, for the year, of the rainfall is prevented 

 by the trees from reaching the ground. That which falls to the ground is 

 also better protected from evaporation because of the lower temperature and 

 less movement of the atmosphere in the forest than on the open field. 



Ebermayer states the evaporation from saturated ground as follows : 



100 volumes on the open land. 



38 volumes on naked land of the forest. 



15 volumes on land of forest covered with litter. 



In the forest more water sinks into the ground than in the field, since 

 there are so many more obstacles to prevent its flowing off, and since it is 

 cooler here the snow does not melt so rapidly. From one to four feet deep 

 deep under the ground the investigations, according to Ebermayer, give fol- 

 lowing result : 



100 on forest land covered with litter. 



85.8 on naked forest land. 



56.5 on open land. 



That forests of greater extent induce rain is a fact not much disputed by 

 authorities on the subject. 



The air within the forest becoming warm by the absorption of heat, both 

 from the ground and the air next above it, leaves over the forest a current 

 considerably colder than the neighboring air, and rain clouds passing over 

 are, in most cases, condensed by coming into contact with this colder atmos- 

 phere. Authorities on the subject of forest culture, both in Prussia and 

 Bavaria, are unanimous in the opinion that rainfall is more abundant and 

 regular in districts well wooded than in bare lands. 



The meteorological institute in Berlin intends to constitute a large num- 

 ber of stations in the German Empire for the purpose of making observations 

 as to the nature of thunder storms. 



Some of these observatories will be located on the highest points in the 

 Thuringian forest. 



RECLAMATION OF SAND DUNES OR WASTE PLACES BY TREE PLANTING. 



The waste places in Saxe-Meiningen mostly consist of limestone forma- 

 tions, barren tracts of sandstone land and much less common, and when 



