244 EESULTS OF COMPARATIVE OBSERVATIONS: BAVARIA. 



evaporation of moisture in the soil. A comparison of results shows 

 that upon the whole, a stratum of soil half a foot deep, saturated with 

 water, will furnish more aqueous vapor to the air than a free water sur- 

 face of the same area. At some stations, and in some months, it was 

 more, and in some less, which is jirobably due to difiereuces in the 

 motion of the air over the surface. 



The importance of the latter is seen from the circumstance that with 

 decreased motion of the air in the forests, the evaporation of water in 

 the soil is always greater than from a free water surface. In the gen- 

 eral mean the evaporation from the soil in difiereut months was greater 

 or less, as shown by the following table : 



Greater or less evaporation from a square foot of water than from the savie area of satiiraftd 

 soil, in cubic inches. 



Anril, ISeO-.- 

 April, 1870... 

 May, 1869.... 

 May, 1870.... 

 June, 1869 ... 

 June, 1870 ... 

 July, 1869 ... 

 July, 1870... 



In open 

 floMs. 



4- 63. 50 

 + 38. 85 

 + 106.78 

 + 13.14 

 + 18.38 

 + 27. 66 



- 31.99 



- 65.75 



In wool's 

 without 

 litter. 



+ 40.92 

 +84. 40 

 +35.11 

 -15.91 

 + 0.18 

 4- 5.00 

 -15.66 

 - 2.25 



Angniat, 1868 ... 

 August, 18('i9 ... 

 August, 1870 .. . 

 September, 1868 

 September, 1869 

 September, 1870 

 October, 1868 ... 

 October, 1869 . . . 



witbout 

 litter. 



+13. 32 

 + 2.72 



- 4.95 

 -33.21 



- 1.75 



- 2.80 

 +34. 88 

 -12.45 



SvcPves. 



es/tpL-eMcfy. Jicnyej.JitJy. t:>'vu^. ^ep, C^aC. 



Comparative evaporation from water and from saturated soil In open fields and in woodlands. 



Influence of forests on the evaporation of loaterfrom soil free of litter. 



To determine the influence of forests on the evaporation of water in 

 the soil, independently of the litter, a comparison was made between 

 the amount evaporated from a stratum of uncovered soil half a foot 

 deep in the fields and a like stratum in the forests. The average mean 

 shows that the evaporation in the forests was less than in the fields, as 

 follows: 



