TILE DRAINAGE. 115 



3. Expense may be saved by diminishing the size of the mains 

 toward their upper ends. For example, three-inch will dp till it, 

 has received water' from two acres of laterals, then four-inch up 

 to four acres, then five-inch/ up to six acres, and so on. 



Since the above was written we have had twelve hours of 

 moderate rain which has melted four inches of snow; total water, 

 over an inch. The soil was saturated before ; surface not frozen. 



1 have been to examine the main drains on my own and two 

 neighboring farms. They are as follow 



Two two-inch tile drains draining- about 1 acre each. 

 Two three-inch tile drains draining about \%. acres each. 

 Seven four-inch t ile drains draining 1 about 4 acres each. 

 Five four-inch tile drains draining- about 5% acres each. 

 One six-inch tile drain draining- about 12 acres. 



All are worked up to full capacity. The first three sets in the 

 above table come under the first rule given above. They have a 

 small surplus of water that they can not carry. The last two sets 

 come under the second rule. They have quite a large surplus. 

 In the case of a few, surface wash comes on from undrained land 

 lying above. Due allowance is made for this. 



W. I. CHAMBERLAIN. 



I think our American drainage authorities recommend 

 sizes far too small. The latest of these authorities, C. G. 

 Elliott, a civil and drainage engineer whose work has been 

 chiefly among the level soils and large rainfalls of Illinois, 

 says : " For drains not less than three feet deep, and with 

 grades of not less than 3 inches to the ICO feet, for such 

 drains not more than 500 feet long, a two-inch tile will drain 



2 acres. Lines more than 500 feet long should not be laid of 

 two-inch tiles." 



Putting his rules in tabular form we have : 



A 2-inch tile will drain 2 acres. 

 A 3-inch tile will drain 5 acres. 

 A 4-inch tile will drain 12 acres. 

 A 5-inch tile will drain 20 acres. 

 A 6-inch tile will drain 40 acres. 

 A 7-inch tile will druin Ml acres. 



Waring says : u In view of all the information that can be 

 gathered on the subject, the following directions are given 

 as perfectly reliable for drains four feet or more in depth, 

 laid on a well-regulated fall of even 3 inches in 100 feet : 



