AGRICULTURE AND RURAL ECONOMY. 535 



than in bare soil. In soils covered with stones, the opposite 

 is true. 



MM. Becqnerel have been for some time engaged in the 

 study of soil temperature. In the report of observations for 

 1877, M. Ed. Becquerel shows that in accordance with pre- 

 vious observations a soil covered with herbage at a depth of 

 two inches averaged through the year a little warmer than 

 corresponding uncovered soil. 



Influence of Exposure on Soil Temperature. 



Wollny found, in a series of experiments near Munich, that 

 the warmest slope was, in spring, a southwesterly; in sum- 

 mer, a southeasterly ; in early fall, southerly ; and in late fall 

 southwesterly. Trials in beds showed, as would be expected, 

 that the southern slope was warmest, the level surface next, 

 the eastern and western slopes next, and the northern slope 

 coldest. 



RELATIONS OF THE SOIL TO WATER. 



Mr. H. P. Armsby, Chemist to the Connecticut Agricultu- 

 ral Experiment Station, has prepared a valuable paper on 

 the Present State of Knowledge Regarding the Relations 

 of the Soil to Water, as a prelude to a series of investiga- 

 tions on this very important subject. In view of the results 

 of experiments on the one hand and the action of physical 

 laws on the other, he considers that " there are three points 

 in regard to the relations of the soil to water which are of 

 agricultural importance : 



"1. Permeability. The rapidity with which the water 

 that falls upon the surface of the soil in the form of rain, 

 etc., soaks downward through it. 



" 2. 'Water-holding Power. The amount of water which is 

 held in the various layers of the soil, where it may serve to 

 nourish vegetation. 



"3. Evaporation. The rapidity with which water evap- 

 orates from the surface under different conditions." 



Roughly summarizing the statements which are given in 

 a good deal of detail, it may be said that the above factors 

 are each affected by the fineness of the particles of the soil, 

 the texture, whether loose or compact, and the porosity of its 

 materials. Some of the more important conclusions follow. 



