CHAPTER III. 

 LAND DRAINAGE PRACTICE. 



Land Drainage is the removal of surplus water from 

 the soil. 



Various descriptive terms are used in connection with 

 the word drainage according to the purpose for which 

 this removal is effected. When done for the better 

 growth and protection of useful plants it is called 

 Agricultural Drainage, When done for the better 

 construction and maintenance of public highways it is 

 called Road Drainage, When done for the benefit of 

 health, either in city or country, it is called Sanitary 

 Drainage. 



It will be the object of these pages to discuss these 

 questions and describe the methods which engineers, 

 or those expecting to act as such, are called upon 

 to deal with in the planning and execution of work 

 pertaining to land drainage. 



The definition of drainage indicates that it is a very 

 simple operation, yet its practical attainment is accom- 

 panied with no little uncertainty unless correct prin- 

 ciples and methods are followed out. Investigations 

 along this line are somewhat difficult, for the reason 

 that the action of drains is hidden from the eye, and is 

 known only by the effect which is produced. Nature 

 has in many localities provided thorough drainage of 



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