SOIL IMPROVEMENT. 6i 



be no necessity for providing aids to drainage of 

 cellars. Sometimes the surplus water so readily 

 passes down to a great depth that it is difficult to get 

 water from wells. There are vast areas of farm lands 

 in the United States where, in a few hours after a heavy 

 rain- fall, the soil is in good condition for cultivation. 

 There is no need that man should undertake to do 

 that which nature has done well for him. 



Reasons for Drainage. — By far the larger part 

 of the land in the United States east of the Missouri 

 river either has needed or still needs more or less arti- 

 ficial drainage. Without this much now valuable 

 land would have been comparatively worthless. 

 Probably no one thing has done more to increase the 

 value of the farm lands of several of the central west- 

 ern states than has the extensive work recently done 

 in them in the way of land drainage. 



Obviously swampy land, or that with ponds, or that 

 on which water stands for a considerable time after 

 heavy rains, is not naturally well- drained and should 

 have work done to it in this direction. Much land 

 which does not show the signs of need of better drain- 

 age may be greatly improved by either surface or un- 

 derground drainage. 



A wet soil is a cold soil. If the surface water can 

 not flow off or down into the deep sub-soil, it can be 

 removed by evaporation only. Evaporation is a cooling 

 process. Much heat is consumed in causing the 

 evaporation of stagnant water in wet soils. Water is, 

 relatively, a poor conductor of heat. Warming a 

 vessel of water by applying heat at the top is a slow 

 process. The heat from the sun's rays has much less 

 effect in warming a wet soil than it has on a dry soil. 



