DRAINAGE. 31 



Note results. How long did it take the water to run out? Was there 

 any water left in the pipe? 



8. Perform the same experiment as in (7) giving the gas pipe 

 an amount of fall at one end at the rate of 3 inches per 100 feet ; 5 

 inches per 100 feet, 10 inches per hundred feet ; and in each case find 

 the time required for the water to run out. 



Farm Lands: 



Let pupils use sand to show topography of immediate lo- 

 cality ; draw map of a well-drained farm and illustrate eleva- 

 tions, depressions with relief worked out in sand ; show water 

 courses ; arrangement of fields. Show location of buildings, or- 

 chards, wells, woodlands, pasture lands, crops and other impor- 

 tant features of farm management. 



Questions. 



1. What effect does a tile drain have on percolation? 



2. What effect does tile drainage have on erosion? 



3. How does drainage increase the feeding area of plants? 



4. How does drainage affect the growth of plants in dry weather? 



5. Can a soil be too well drained or aerated? 



6. If the water level is three inches below the mouth of the tile 

 at the outlet, how much rainfall will be required before the water will 

 run through the tile? 



7. Make a list of tools required for constructing tile drains. 



8. What is a catch basin, how constructed? Give use. 



9. In what type of soils are tile drains apt to become filled up? 

 Why ? 



10. Describe the difference between the two systems of draining 

 rolling and level land. 



11. Will a tile drain in a basin "draw" or drain a larger area than 

 a drain in a level field? 



12. Describe some of the soils that have natural drainage. 



13. What are some of the disadvantages of a leachy self drained 

 soil? 



14. Is land that requires tiling and ditches usually the most valu- 

 able land? Why? 



15. What effect has drainage had upon the flood areas of the 

 country? 



16. What is the difference 'between irrigation and drainage? 



17. Describe a system of irrigation. 



18. Explain how freezing caused heaving in wet soils. 



19. What is a dead furrow? What are its uses and inconveniences? 



20. How does a tile drain reduce the effects of erosion? 



