RESULTS OF COMPARATIVE OBSERVATIONS: BAVARIA. 245 



Difference in evaporalion of moisture from saturated soil, in cubic inches, from a squarcfoot of 



surface. 



Differences between es'aporatiou in open fields and in woods, and the effect upon evapora- 

 tion from the removal of litter. 



The above diagram represents the dififerences stated in the fore.cfoiug 

 table. The lower pair of lines is from the middle column, and shows 

 the excess of evaporation from naked soil in the woods over the same 

 soil in woods where the leaves and other litter are allowed to remain. 



The middle pair of lines (simply marked 1869 and 1870) refers to the 

 first column of the table, and shows the differences between uncovered 

 soil in the fields and uncovered soil in the woods. 



The upper pair of lines (also marked 1869 and 1870) refers to the third 

 column of the table, and shows the differences between the evaporation 

 from uncovered fields and litter-covered woods. 



The influence of the forests upon evaporation is, therefore, as great as 

 that on a free water surface, and in the warmer months — May, June, and 

 July — they assist more in retaiuing the moisture than in the other 

 months. The loss of moisture of the soil in the summer season of 1869 

 (during the period of. vegetation), in the average mean, was, in the for- 



