UNDERDRAINING AND DEEP TILLAGE. 135 



Fi^. 3. 



Explanation of the Figures 1, 2 and 3. 



a. a. a. — Surface and subsoil. 



b. b. b. — Solid soil or shavings. 



c. c. c. — Covering stones. 



d. d. d. — Conduits. 



The stone conduit should be covered in with small stones to the 

 depth of a foot or more. The top layer of small stones should be at 

 least twenty inches or two feet below the surface of the soil. The 

 earth first thrown in upon the small stones should be very firmly 

 trodden down before the drains are filled, to prevent any washing in 

 of soil so as to obstruct the conduit. Sometimes the same result is 

 effected by shavings, but the pressure by the trodden soil above will 

 save the trouble and expense of the substitute. Stone drains cost 

 more for excavation than tile drains, because they require to be 

 wider ; but otherwise, when well laid, may be considered good and 

 economical. They will last indefinitely, and, if carefully laid, will 

 not easily become obstructed. 



The best mode of draining is by tile. These are merely different 

 forms of conduits made of brick clay burnt hard. They are now 

 made in this State, and with increased demand, manufacturers will 

 multiply in number and the price diminish. Two inch tile now cost 

 in Portland about ,|14 or $15 per 1000. They can be afforded 

 when there is a sufficient demand, for $10. This is a size suitable 

 for minor drains, while main drains should be of a size commensur- 

 ate with the amount of water to be conveyed in them. 



