38 INDIRECT UTILITY OF FORESTS. 



open country as taken from the ordinary meteorological 

 stations : — 



Excess of Rainfall in Forest 

 Stations over that of Open 

 Country, in per cent, of 

 the latter Rainfall. 



Between Sea level and 328 feet elevation . 1*25 per cent. 



328 and 556 feet „ . 14-2 



1,969 and 2,297 feet „ . 19 



2,297 and 2,625 feet „ . 43 



These figures seem to indicate that, within a certain distance 

 from the sea, forests have very little effect upon the rainfall 

 in the plains, if any at all, but that their influence becomes 

 considerable with increasing elevation in mountainous 

 countries. 



The results of 7 3^ears' observations made at two stations 

 near Nancy show a decided increase of rainfall in the forest. 

 The stations are situated 1,247 feet above the sea, one in the 

 middle of an extensive forest 5 miles to the west of Nancy, the 

 other in an almost woodless country 6 miles to the north- 

 east of Nancy. The results were as follows : — 



Increase of Rainfall in 

 Forest over that in the 

 Open, in per cent, of the 

 latter. 



February to April . _. . .7 per cent. 



May to July 13 „ 



August to October . . . .23 ,, 

 November to January. . . .21 ,, 



Mean of Year . . . .16 ,, 



that is to say, an increase of 16 per cent, at the forest station. 

 Other evidence tending in the same direction is available, 

 but the Bavarian observations, as w'ell as those made during 

 the last few years, do not justify any direct conclusion as to 

 any increase in the absolute rainfall due to the action of 

 forests. The increased quantity of precipitation which has 

 been recorded in some cases mav to a considerable extent be 



