492 AGRICULTURE. 



enable each team, in all future time, to carry a heavier load than 

 is now practicable, or to carry the same load more easily, must 

 add to the permanent money value of the farm. 



What is Underdraining ? It is an axiom of good farming 

 that all land shall be thoroughly underdrained ; underdrained, 

 of course, either naturally or artificially. There is nothing 

 mysterious, either in the operation or in its effects. The ability 

 to plow and plant early in the spring ; the perfect germina- 

 tion of seeds, and rapid and luxuriant growth of healthy plants ; 

 the ability to plow and otherwise cultivate growing crops ; and 

 the opportunity for seasonable harvesting and for fall plowing, 

 all depend more upon the condition of the soil as to moisture 

 than on any other single circumstance. For the purpose of illus- 

 tration, we will suppose an acre of land to be enclosed in a 

 water-tight box, its bottom being four feet below the surface, 

 with no outlet at any point. The whole acre lies open to the 

 rain, and the whole depth is saturated by every heavy storm. 

 This acre of land may have the most thorough cultivation of 

 which it is capable, and may be manured as land was never ma- 

 nured yet, and its produce will inevitably be precarious. In very 

 good seasons it may be fair ; in wet seasons it will be weak and 

 badly matured ; and in dry ones it will be mean and stunted. 

 Now let us knock the bottom out of our box and see the result. 

 Of course we must assume that it is underlaid by a stratum of 

 gravel or other porous material. The water which has filled 

 the spaces between the particles of the soil, lying there until 

 evaporated at the surface, sinks slowly away and leaves the 

 whole mass pervaded by air, the particles themselves holding 

 by absorption enough water to make them sufficiently moist for 

 the highest fertility, but affording very little for the cooling 

 operation of evaporation at the surface. When a heavy rain falls, 

 the soil may be for a short time saturated with water, and this 

 drives out all of the air it has contained. As the water settles 

 away after the rain, fresh air follows and embraces every atom 

 with its active, fertilizing oxygen, and deposits, in the upper 

 layers, carbonic acid and ammonia, and all else that makes air 

 impure and soil rich. Indeed, the water itself has washed the 

 air clean, and then, on filtering through the loose soil, has depos- 

 ited all of its impurities near enough to the surface to be within 



