120 



down the columns of soil, which by the way, throughout 

 the entire semi-arid belt are almost invariably found in 

 a perpendicular position. 



In section 3, we have again reproduced our soil mulch 

 by cultivation to stop the evaporation or loss of our water 

 from the surface, and we find the moisture below has per- 

 colated on down until the water is all distributed, each 

 little particle taking on its film of water to a given thick- 

 ness which it seems to steadily hold onto while the bal- 

 ance of the free water finds its way on down until it is all 

 distributed in like manner. 



The next rain will result the same as is shown in section 

 2, only we have six, eight or twelve inches more moist 

 soil for it to pass through before reaching the dry soil. 



An illustration will make this more clear. In setting 

 out our cabbage or tomato plants in the spring of the 

 year when the surface is dry and fine we usually water 

 them. In our first application of water to this dry surface 

 we notice the water does not seem to percolate, but for a 

 little time remains dormant on the surface. After a little 

 it finds its way down through the dry particles by force 

 of gravity, leaving each particle it passes covered with a 

 thin film of water. Then we apply a second application 

 of water while the surface is still moist and we notice the 

 water immediately disappears. The reason of non-perco- 

 lation of the first application is because of the resistance 

 of the dry particles to moisture, or repulsion for water. 

 The quick movement of the second application of water 

 into the ground is the result of the attraction of water for 

 water, together with gravit^ 



The following will illustrate this natural law: take a 

 piece of glass, or a smooth earthen plate and oil it slightly, 

 then put drops of water, a half dozen or more, on the gla?> 



