CHAPTER II 

 SOIL MOISTURE 



ALL bodies in the universe attract each other. The 

 greatest sun in the heavens and the smallest speck of dust 

 under the microscope are mutually attracted. This 

 universal force of attraction finds different expressions 

 under varying conditions. Thus, the heavenly bodies, 

 immense distances apart, are given definite motions and 

 are held in their places by their mutual attractions. 

 Bodies near the earth and belonging to it, instead of revolv- 

 ing in space, fall to the ground by virtue of this attrac- 

 tion which the earth exercises upon all bodies on or near 

 its surface. In both these cases the attracting bodies are 

 considerable distances apart. 



11. Attraction between near bodies. When the 

 attracting bodies are brought very near each other, within 

 reach of the molecular forces, which, probably are only 

 expressions of the universal force, special attractions 

 are observed. For example, if two plates of glass, evenly 

 and highly polished, are laid upon each other they, adhere 

 so firmly that it is practically impossible to separate 

 them. A square of iron, with a highly polished surface, 

 may be lifted by simply lifting a similar square which 

 has been placed on the lower square with the polished 

 surfaces in contact. Two pieces of lead, with clean sur- 

 faces, will adhere very firmly, as will also india-rubber, 

 wax and similar substances. These attractions act only 

 through extremely small distances. If the polished plates 



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