. .L 



DRAINAGE AND PIPE-FITTING 365 



slope of the ground, place the grade parallel to the slope. If 

 the ground is practically level, a grade line can be established 

 by means of an ordinary carpenter's level. Drive in a series 

 of stakes from 4' to 5' long at intervals of 25'; for long drains, 

 stakes are placed every 50'. By using long stakes, a guide 

 line to dig by can be placed as the grade is established. If it 

 is desired to have a fall of 1/4 " to the foot, take a straight V x 

 2" scantling 4' long; tack a 

 V block under one end, 

 and fasten to lower side of 



level with block on lower 



" 

 side. Tie a cord to stake = I 



at the outlet at a point 



FIG. 352. Sewer tile made tight. 

 about 3' above the surface 



of the ground, stretch the cord to the second stake, and test it 

 for grade by placing the level in position so the block will be 

 down grade (Fig. 350). When the bubble of the instrument 

 indicates that it is level, it shows that there is a rise of V to 

 every 4' along the cord*. 



340. Digging Ditch to Grade. Use a gage rod of defi- 

 nite length, and dig ditch so its bottom will be parallel to the 

 cord. If it is desired to have the drain 4' deep at the outlet, 

 the gage rod should be 7' long since the cord was placed 3' 

 above the surface of the ground at the outlet. If the soil is 

 heavy and sticky, an open spade can be used to advantage; 

 use a round-nose spade or a tile scoop for cleaning the bottom 

 of ditch to receive the tile. 



341. Laying the Tile. Lay the tile as the ditch is com- 

 pleted, beginning at the outlet. The ordinary farm tile can 

 be laid either by hand or by means of the tile hook. The tile 



