CULTIVATION. 197 



means of doing this, as it is tlie best means of lessen- 

 ing the evaporation, and of preventing the puddling 

 of the claj in the soil. 



The foregoing are some of the more important 

 reasons why under-draining is always beneficial. 

 Thorough experiments have amply proved the truth 

 of the theory. 



" Land which requires draining is that which, at 

 some time during the year, (either from an accumu- 

 lation of the rains which fall upon it, from the later- 

 al flow or soakage from adjoining land, from springs 

 which open within it, or from a combination of two 

 or all of these sources,) becomes filled w^ith water 

 that does not readily find a natural outlet, but 

 remains until removed by evaporation. Every con- 

 siderable addition to its water wells up, and soaks 

 its very surface ; and that which is added after it is 

 already brim-full, must flow off over the surface, or lie 

 in puddles upon it. Evaporation is a slow process, 

 and it becomes more and more slow as the level of 

 the water recedes from the surface, and is sheltered 

 by the overlying earth from the action of snn and 

 wind. Therefore, at least during the periods of 

 spring and fall preparation of the land, during the 

 early growth of plants, and often even in mid- 

 summer, the water-table, — the top of the w^ater of 

 saturation, — is within a few inches of the surface, 

 preventing the natural descent of roots, and, by 

 reason of the small space to receive fresh rains, caus- 

 ing an interruption of work for some days after each 

 storm. 



