INLAND DRAINAGE 



115 



CLEANING OUT THE DITCH 



The ditch resulting from the explosion will be rough and some- 

 what uneven in depth; occasionally, a few stumps and other 

 debris will roll back into it. To open it up and even the grade, 

 two to four men, equipped with phosphate drags and hoes should 

 follow the blasters, raking out the debris and removing the 

 humps. This work can be done in a comparatively short time, 

 and greatly improves the ditch. 



Fig. 75. — Blasting ditch in tangled underbrush. 



For electrical firing, the procedure is much the same. A few 

 trial shots should be made for determining the proper depth 

 and spacing of the holes. As an electric cap is used in each hole, 

 it is possible to space them further apart in the row than in the 

 case of propagated firing. The usual distances are 24 to 32 

 inches for small ditches and up to 48 and 52 inches for large 

 ditches and heavier loadings. After the charges are planted, 

 the blasting cap wire from each is connected with the loading 



