AGRICULTURAL ENGINEERING. 



163 



Table of Size of Tile Pipe of Main Drain. 



(MCCONNELL.) 



Fall. 



foot in 



Acres Drained. 



3-inch 

 Tile. 



20 



30 

 40 



50 

 60 

 70 

 80 

 90 

 100 



150 



200 



250, 



300 



400. 



500 



600 



800 



1000 



1500 



2000 



18.6 



15 -I 

 12.9 

 II. 9 

 10.9 

 10. o 

 9-3 

 8.1 



7-3 

 6.7 



5-7 

 5-1 

 4.6 

 4.1 

 3-7 

 3-3 

 2.9 

 2.6 

 2.1 

 1.9 



12-inch 

 Tile. 



426.0 

 346.0 

 298.4 

 269.0 

 246.0 

 228.1 

 213.0 

 200.5 

 190.5 

 154-4 

 132-5 

 117. o 

 107.0 



90.7 

 81.6 

 74.0 

 65.0 

 56.0 

 47.0 

 40.8 



Rule for Obtaining- Size of Main Pipes. — Multiply the 

 square root of the number of small drains (of fair average 

 length) by the diameter of small pipes; the quotient gives the 

 diameter of main. 



If the distance apart of drains in feet be denoted by F, that 

 in links by L, and the length of drains in chains per acre by C, 

 then 



__ 660 _ 1000 



