DRAINAGE 



71 



than in straight tile lines, it is much easier to lay the tile in a 

 straight ditch than in a curved or crooked one. The system 

 should be so planned that all lands needing drainage should 

 be brought under the influence of the drains; or, in other 

 words, the system should insure thorough drainage. 



Staking Out the Drains. After the general plan has been 

 decided upon, the next step is the staking out of the drains. 

 To do this, stations are located at distances of 50 feet apart 

 on the line of the proposed drain. Two stakes are required 

 at each station. One, the hub or grade stake, is driven into 

 the ground, nearly flush 

 with the surface, about 

 one foot to the left of 

 where the center of the 

 ditch is to be located, as 

 one faces the outlet. 

 Levels are taken from the 

 top of these grade stakes 

 and the cut or depth of 



v 



or hubs, and 



ktf-^Grade Stake. 

 or Hub. 



ditch is figured down from Fig. 49. Grade stakes, 



guide stakes. 



them. These grade stakes 



may be of any convenient material. Inch boards split into 

 widths of about 2 inches are very satisfactory. The length 

 should be sufficient to insure that the stake will be solid 

 in the ground. Besides the grade stake, guide stakes of 

 lath or other light material are required. These are located 

 near the grade stakes to aid in finding them, and are 

 marked with numbers to identify the stations. 



All stakes should be left in place until the work is finished 

 and accepted. They should not be placed long before the 

 work is actually to begin, since they are quite likely to be 

 moved out of place. 



