72 AGRICULTURAL ENGINEERING 



QUESTIONS 



1 . What is the discharge end of a tile line called? The upper end? 



2. What is a lateral drain? A submain? A main? 



3. How should tile drains be laid on slopes, and why should they 

 be so laid? 



4. How deep should tile drains be placed? 



5. What are some of the factors to be considered in determining 

 the distance between drains? 



6. Explain the following systems of tile drains: The natural 

 system, the grouping system, the gridiron system, the single line system. 



7. Why should short laterals be avoided? 



8. Why is a straight tile line desired? 



9. What two kinds of stakes are required in staking out a drainage 

 system? 



10. Describe the location and purpose of each. 



