174 



LAND DRAINAGE 



rod upon grade stake 2 and carefully holding it in a per- 

 pendicular position, brings the tube against the side of 

 the rod, and raises or lowers the tube until the top of 

 the water column comes to rest even with, or at the zero 

 mark. 



(6) At the same time the other party, whom we will 

 call the long-rod man, places the long rod upon grade 



FIG. 73. Hose-level in use. 



stake 1, holds it carefully in a perpendicular position, and 

 brings the tube of his end of the level against the scale side 

 of the rod and, if necessary, raises or lowers the tube to 

 permit the short-rod man to bring the column at his end 

 to the zero. (See and study Fig. 70.) The short-rod 

 end should be held so that the bottom of the curve 

 (meniscus) of end of the water column stands even with 

 the zero line. 



225. How to read height of column. When the short- 

 rod man indicates that the water column at his end is at 

 zero, the long-rod man should read the height of the water 

 column, as indicated by the bottom of the curve (menis- 

 cus). This reading is used to determine the height of 

 stake 2. 



