[34 THE AMERICAN FARMER 



it will not grow less by use. The improvement of the farm by drainage should be a part of 

 the regular work of each season ; when thus carried out, it is not the burden that many make 

 it, in order that the work of years may be put into one. In case of so-called partial drainage, 

 the depth of four feet is even more strongly recommended, as such is usually made with 

 large-sized tiles, and it should be, with the view of making in the future the drain s main, or of 

 a system, at least, of getting the greatest benefit from them.&quot; 



Scarcely any person whose experience and judgment are of value in successful agricul 

 ture, would think of laying tiles at a less depth than three feet, while, comparatively speaking, 

 those soils of clay or loam having a clay subsoil will receive so much additional benefit from 

 a greater depth than this, that we might almost say, no man can afford to place his tiles at a 

 less depth than four feet. As draining is generally an expensive operation, it should be done 

 with care, and with a view to permanency. If this is done, the work will remain as long as 

 the tiles will last, which, if they are of the proper kind, will be a very long time. Waring, 

 as well as many others of our best writers on the system of drainage, states that tiles are 

 much cheaper than stone drains, and by far more durable, being less liable to fill up with 

 sand, mud, or other obstructions. In constructing the drain, it is important that the bottom 

 of the trench be cut out just wide enough to admit the pipe, and no more, as tiles fitted in 

 that way are less liable to become displaced than if it were cut too large and again filled up 

 with loose earth. Various kinds of draining-tools have been invented for this purpose, such 

 as trench-plows, long, tapering spades for digging out the middle and bottom of the trenches, 

 recurved scoops for removing the earth, and pipe-layers, by means of which a workman can 

 hook up a pipe and collar and put them in place in the trench while standing on the margin 

 of the drain. When the bottom of the trench is clay or hard gravel, with a desirable grade, 

 there is no trouble in placing the tile; but when the bottom is sandy, peaty, or soft, it will be 

 found advantageous to put strips of rough boards at the bottom to place the tiles on, and 

 prevent them from settling beyond the common depth and becoming displaced. 



Size and Kind of Tile for Drainage, etc. In the selection of tiles for the 

 mains as well as the tributaries, it is important that they be of sufficient size to take the water 

 as fast as the soil can furnish it in heavy rains. The mains had better be too large than too 

 small, as economy here will prove poor economy in the end. It is often surprising to see how 

 soon, in a shower, the water will percolate through the soil, be collected by the laterals, and 

 reach the mains, and how perfectly the system of drainage works, when everything is con 

 structed properly. Considerable expense may be saved by having the upper portion of tho 

 mains smaller, and the size increased as the surface from which it receives the water is 

 increased. It is estimated that a three-inch main will answer a good purpose until it hag 

 received the water from the laterals of two acres, then add a four inch to receive the water 

 until four acres are drained, a five inch up to six acres, and so on. 



The rule to find how many acres a given main will drain, by squaring its diameter, thus, 

 a 3-inch main will drain 9 acres ; a 4-inch. 16 acres, a 5-inch 25 acres, etc., may do very 

 well for some purposes, like a limited range of sizes of tiles, and variations in grade ; but to 

 make allowance for variable and heavy rain storms, this would give too many acres for the 

 size of main. Mr. Chamber kin, of Ohio, gives, we think, a better and safer rule to follow, in 

 what we subjoin : 



For sizes from 3 to 6 inches, and grades less than three feet to the 100, square the diam 

 eter and divide by 4. Thus 



A 3-inch main will drain 2 acres. A 5-inch main will drain 6 acres. 



4 do. do. 4 do. 6 do. do. 9 do. 



For heavier grades it may do to divide by 3. Thus 



A 3-inch main will drain 3 acres. A 5-inch main will drain 8 acres. 



4 do. do. 5 do. 6 do. do. 12 do. 



