CHAPTER IV. 



DRAINING THE SOIL. 



METHOD BY WHICH THE SOIL IS SUPPLIED WITH MOISTURE: EAIN, 

 SPRINGS DESCRIPTION OF DIFFERENT STRATA CAPILLARY ATTRAC- 

 TION. METHODS BY WHICH WATER IS REMOVED : RUNNING OFF ITS 



SURFACE — EVAPORATION PERCOLATING THROUGH ITS SUBSTANCE. 



WHAT LANDS REQUIRE DRAINAGE THE DIRECTION OF THE DRAINS 



THE DISTANCE THE DEPTH THE MATERIAL TO BE USED NUM- 

 BER OF TILE TO THE ACRE — MANNER OP OPERATION. THE EFFECTS 



OF drainage: promoting pulverization PREVENTION OF INJURY 



BY DROUGHT INCREASE OF THE ABSORPTION OP MOISTURE VEN- 

 TILATION PERMITTING THE WARM SPRING SHOAVERS TO ENTER THE 



SOIL FREEZING THE LAND DEEPER DEEPENING THE SOIL DE- 

 STROYING WEEDS CAUSING A MORE HARDY GROAVTH PRODUCTION 



BECOMES MORE CERTAIN. 



A S food enters plants through the -medium of 

 water, the proper regulation of it is of par- 

 amount importance. Rain-water is not only a 

 powerful solvent, but it extracts ammonia from the 

 atmosphere, which increases and elaborates those 

 elements of fertility in the soil on which vegetation 

 depends for health and fruitfulness. There are 

 three methods by which the earth is supplied with 

 moisture. 



1. Bif rain. The average annual quantity which 

 falls throughout the United States is between thirty 

 and forty inches. It is a source of great wealth, and 



