THE YOUNG FARMER'S MANUAL. 



293 



drain. In order to do this correctly, a ditcher must have a me 

 chanical eye an eye that can, at a glance, detect a depression or 

 an elevation at any point in the bottom of a ditch. If a ditch is 

 cut where there is but little descent or fall, and the bottom is not 

 as straight as a mathematical line, but is sunk an inch too deep 

 here, and a little farther on two inches deeper than the line of a 

 true grade, water will not run out freely ; but the current will be 

 so slow in these level places that in a few years the calibre of 

 small tile will be completely filled up with sediment. But if 

 there is a little inclination all the way, and the inclination is of a 

 true grade, there will be no chance for sediment to lodge and to 

 collect. "Whether a ditch is to be filled with tile, stone, or wood, 

 the bottom should be of a true grade. Some men may dig ditches 

 all their lives, and they cannot grade the bottom of a ditch just as 

 it should be, in a difficult place. It is more important to have the 

 bottom of a ditch very true, where very small tile is to be laid, 

 than it is where large tile is to be used. 



404. The accompanying Fig., 131, will give the young farmer 



FIG. 131. 



CORRECT MANNER OF GRADING THE BOTTOM OF A DITCH. 



a more correct idea of the proper manner of grading the bot 

 tom of a ditch, a a represents the surface of the ground. The 

 line b &, nearly parallel with the surface, shows the common mode 

 of grading the bottom of a ditch, up a slope. The straight line 

 c c represents the most approved manner of grading the bottom of 

 a ditch. A. ditcher who possesses little or no mechanical skill, 

 will be puzzled some to grade the bottom just as it should be ; 

 but if he cannot make calculations about at what point to com- 



