114 LAND DRAINAGE 



in labor. The angle of discharge should be governed by 

 the suggestions above. 



155. The location of the upper end of mains and 

 laterals. It is not necessary to carry the end of either 

 main or lateral to the very edge of the area to be drained. 

 The water in the soil will move toward the end as readily 

 as it will toward any other point in the drain. The line 

 of equal influence of the drain at this point is the arc of 

 a circle whose center is the end of the drain. 



156. Measurements. Due care should be exercised 

 in laying out each simple drain, main and lateral. The 

 distance between stakes should be carefully measured, 

 and the distance of each stake from the lower end of the 

 drain carefully recorded. This information will be needed 

 (1) in determining the grades, and (2) in estimating the 

 size and the amount of tile needed. 



157. Estimate of tile and order for it. If a preliminary 

 survey and estimate of the size and amount of tile needed 

 has not already been made, this should be done now, and 

 the tile ordered. Paragraph 116 should be studied to 

 assist in making these estimates. 



Many of the manufacturers of glazed tile manufacture 

 also angles for connecting laterals to mains and sub- 

 mains. When glazed tile is used, it is well to purchase 

 these angles for connections, and the number and sizes 

 needed should be included in the order. 



158. Hauling and distributing tile. While not ab- 

 solutely necessary, it is desirable that the tile be hauled 

 upon the ground and distributed near the lines in which 

 it is to be used, before the leveling begins. The driving 

 of teams and the handling of the tile is likely to result 

 in disturbing the grade stakes, and these should not be 

 disturbed from the time the leveling is completed till 



