AMERICAN INSTITUTE. 



291 



The cutting of tile drains requires precise work, and should be performed 

 wilh tools made expressly for it, consisting of a narrow spade, long in the 

 blade, which turns the sides of the drain and throws out the loose soil 

 readily. Connected with this instrument there are two other tools that 

 will be found indispensable, a narrow hoe to remove small stones, and nar- 

 row scoop to remove wet earth. I usually finish the beds of the drain with 

 a trov/el, before laying the pipe. 



The cost of land drainage per acre, with tiles 1^- inches, at $7 per 1,000, 

 may be approximated as follows : 

 Tenacious gravelly clay soils, drains 15 ft. apart, 2 ft. 6 in. deep,, . 



Friable clay, 18 ft. apart, 2 ft. 9 in. deep, . . 



Clayey loam, 22 ft. apart, 3 ft. deep, 



Light gravelly loam, 33 ft. apart, 3 ft. 6 in. deep,. . 



Sandy loam, 39 ft. apart, 4 ft. deep, 



Sandy soil, 45 ft. apart, 4 ft. deep, 



Coarse gravel, 60 ft. apart, 4 ft. 6 in. deep,. . 



Loose gravel, 66 ft. apart, 4 ft. 6 in. deep,. . 



Minor. Main. Minor. Main. 



I 



29 

 25 

 20 

 15 

 14 

 13 

 11 



Ma 



The smaller the quantity of water to be discharged, the greater care 

 you must take, not only in the concentration of the flow, but exactitude of 

 the construction of your pipes, as it is of far more importance than smooth- 

 ness of surface. A perfectly smooth glass pipe, with a wavy surface, will 

 discharge far less water at the same inclination, than clay pipes of perfect 

 construction. 



I have observed a great error made by farmers in common practice, 

 which is to form the junctions of their drains at right angles, with pieces 

 projecting, which impedes the flow nearly as follows : Equal quantities of 

 water running in a straight line at the rate of eighty seconds, with a turn 

 at right angles, the discharge will be eff"ected in 130 seconds, while with a 

 moderate curve, in 100 seconds. 



In calculating the expense of forming ditches or drains, one of the prin- 

 cipal items is the quantity of dirt that has to be thrown out, which of 

 course depends on the size of the ditch. The cost of labor increases with 

 the weight of earth to be removed ; therefore it is well to know the num- 

 ber of cubic yards of cutting in a ditch of any given dimensions. Thia 



