EXPERIMENT STATION BULLETINS. 501 



In like manner a second cut will be made and as many more as may 

 be necessary (nsin.ar the ditchino: spade) to bring the ditch to within 

 a few inches of the bottom. It is tisually best to throw all of the dirt 

 to one side of the ditch. 



(e) Before beginning the last cut, the line should be tightly stretched 

 over the tops of the bars and just over the straight edge of the ditch 

 and the rod brought into use to guard against getting the ditch too 

 deep, at any point. If in stretching the line the ends are tied to the 

 end grade-bars, braces should be placed against the stakes; otherwise 

 the bars and their stakes will be drawn out of place. A good way is to 

 drive a stake into the ground beyond the end bar, wrap the line once 

 around the grade bar and then tie to the stake just driven. 



(f) After any cut, if for any reason a considerable amount of loose 

 dirt lies in the ditch it should be removed by the use of the long-handle 

 shovel before the next cut is begun, or, if the last cut has been made, 

 before starting to use the tile-scoop. 



(g) When the ditch has been dug to within two inches of the bottom 

 as above described, the line above the bars is carefully moved out over 

 the center of the ditch and tightened. Then with the tile scoop, a trough 

 or hollow is dug along the center of the ditch and finished so that at 

 all points it shall measure just 5.5 ft. below the line. This requires care- 

 ful work and frequent use of rod bearing the 5.5 ft. mark previously 

 mentioned. 



If at any point too much earth is removed and the ditch made too 

 deep thereby, a sufficient amount must be returned and carefully moulded 

 into place with the scoop to bring the bottom up to grade. The less the 

 fall the greater is the care that must be exercised in finishing the bot- 

 tom. This part of the work is not difficult. It does require care. It 

 is sometimes done from the surface. Usually, however, the workman 

 stands in the ditch. 



LAYING THE TILE. 



The laying of the tile should begin at the outlet and proceed toward 

 the upper end. 



It is usually best to lay the sections of tile as rapidly as the bottom 

 of the ditch is made ready with the tile-scoop to receive them. 



Some workmen lay the tile by hand and some use the tile hook. Some 

 workmen stand upon the surface to finish the bottom of the ditch and 

 to lay the tile. 



It will be found that the ends of the tile are frequently not square, — 

 are not at right angi3S to the sides of the tile. It will be found that 

 the tile is sometimes warped, or bowed, thus throwing the ends out of 

 square. There are likely to be little inequalities in the bottom of the 

 ditch. Because of these three facts, it will be found that if a lot of tile 

 be laid, promiscuously, end to end in the hollow at the bottom of the 

 ditch, many of the joints will be so open that sand will very readily drop 

 through into the tile drain, so that if the tile were left in this position 

 and the ditch filled, the drain would be clogged in a very short time. 

 There should be no open joints. 



