OBSERVATIONS BY EBERMAYER. 209 



In open land. In the woodt. 



April, 1869 399 200^ 



April, 1870 373 226 



July, 1869 407 151 



July, 1870 394 151 



October, 1868 158 73 



October, 1869 194 50 



" There evaporated, therefore, from the water contained in the soil 

 of wood-lands, as well as from open water-surfaces, far less than 

 evaporated from the water of the soil of the open grounds — about 40 

 to 50 per cent, in April, 60 per cent, in July, and 70 per cent, in 

 October — and this decrease reaches its maximum in the hottest 

 season. Still more glaring does this difference of exhalation appear 

 when wood-soil, covered with leaves and pine-needles, is compared 

 with wood-soil which is free of litter of this description. 



" Under the first-mentioned conditions the evaporation from one 

 square foot (Parisian measurement) amounted, in Paris cubic inches, 

 to the following : — 



From uncovered From wood-soil 



wood-soil. covered with litter, 



April, 1869 200J 78 



April, 1870 226 102 



July, 1869 151 55 



July, 1870 151 55 



October, 1869 50 25 



" In wood-soil covered by litter, when compared with the bare soil 

 of the fields, the difterence in the amount of evaporation per square 

 foot (Parisian measurement) is shown, in cubic inches, by the 

 following figures : — 



From bare soil of From litter-covered 



the field. forest soil. 



April, 1869 399 78 



AprU, 1870 373 102 



July, 1869 407 55 



July, 1870 394 55 



October, 1869 194 25 



" From these figures, therefore, it is perfectly apparent how impor- 

 tant are the influences of the woods of a country upon the abundance 

 of its springs and the mellowness of its soil ; and in this connection 

 how essential are wood-lands which are covered with the litter of 

 fallen leaves, the uprooting of which effects a direct injury to 

 cultivation. 



Y 



