LAND DRAINAGE 



43 



Junctions of tile. — The junction of two linos of tile should 

 be in the form of a Y witji the lateral jiointing down the slope 

 and with the center of the two lines of tile on the same level, 

 especially for the smaller sizes of mains. 



Filters and silt wells. — Surface intakes, filter basins and silt 

 wells are details that are sometimes very important. At best, 

 surface intakes are dangerous and in all cases much care is 

 required in the use of screens and settling basins so as to admit 

 only water free from much sediment or rubbish. 



A rock filter to admit surface water should have fme gravel, 

 small stones or straw around the tile to hold back the flow of 

 water and collect 

 the sediment. 



Silt wells, Avhich 

 are wells in the line 

 of the drain and 

 several feet deep- 

 er, in which sedi- 

 ment is collected, 

 require a large 

 exercise of judg- 

 ment in their loca- 

 tion and construc- 

 tion. 



Drainage tools 

 and machinery. — 

 The tools for con- 

 structing the ordi- 

 nary farm drain especially for tile may be divided into three 

 groups : 



(1) Where the Avork is done by hand they include various 

 types of narrow, long-pointed spades, round-pointed, long- 

 handled shovel, grading scoop, pick and perhaps a tile hook for 

 placing tile in a narrow deej^ ditch. No more earth is moved 

 than necessary and consequently the trench is not more than 

 twelve to fifteen inches wide. 



(2) The second group of tools embrace: Horsepower exca- 

 vating plows that range from a blacksmith-made tool for loosen- 

 ing the earth to big-wheeled plows drawn by six or more horses, 

 which both loosen the earth and more or less completely elevate 

 it out of the ditch. 



(3) The third group of tools includes the engine power exca- 

 vator ; some of these excavators cut the trench to full depth and 



Fig. is. — Ditching plow used for loosening the earth in 

 the bottom of the ditch. A number of patterns of 

 plows of this type are on the market. The handles 

 and the hitch are usually ad justal>]i', in order to suit 

 the depth of the trench. The plow is drawn by two 

 or more horses, attached to a long evener so that 

 tlioy travel on either side of the trench. — ~Neio York 

 State College of- Agriculture. 



