TENTH ANNUAL YEAR BOOK— PART X 555 



THE BRAKCIIES. 



In level lands the branches should "be laid parallel so that every part of 

 the field may be drained and no part doubly di-ained by having lines too 

 close together. This plan of laying lines equally distant apart should be 

 followed as nearly as possible in all cases, even in lands of irregular sur- 

 face. Junctions should be made v.ith a curve so that the stream will enter 

 the main as nearly as possible in the direction of the flow in the main. 



DISTANCE APART. 



In tight soils drains should be located nearer together than in loose 

 soils. The general practice in this section is from four to six rods apart. 

 It will sometimes be found necessary to place them nearer in springy 

 sloughs requiring a line on each side and sometimes a third in the mid- 

 dle. 



The amount of fall required is much less than some would suppose. The 

 fall is determined by the depth of the outlet, the depth wanted at any par- 

 ticular place up the line, and the general lay of the land. The Illinois 

 river only has a fall of 27 feet in a distance of 220 miles, less than IJ 

 inches per mile. 



A drain can only take water as deep as it is dug. Tile do not draw 

 water but simply furnish a hole for it to run through. Deep drains give 

 deep porous soil to hold the water from heavy rains. This mellow soil 

 will hold an ordinary rainfall below the surface until it can be taken away 

 by the tile. Small tile laid deep are often better than large tile laid shal- 

 low. The deeper the drain the more soil is available for the roots. Writers 

 cite many instances in w-hich roots of ordinary crops sink to the depth of 

 four to six and in some instances twelve to fourteen feet. This shows that 

 roots will go deep into the soil in search of food. In deep soils the lower 

 parts can only be used by the crops when they are free from standing 

 water. This is certainly a strong argument in favor of deep drainage. 

 Deep soils wath shallow drains only give a portion of their wealth to the 

 crops. Many have hesitated to lay deep drains into stiff clays for two rea- 

 sons. They feared the water would not sink and drain off quickly after 

 rains, and they thought the lower soil was of little value. In both they 

 were mistaken. After the water has drained out the air enters and the 

 subsoil slacks and becomes mellow. Roots work their way downward and 

 decay and together w'ith the influence of the air they change the subsoil 

 and it soon becomes very much like the surface. Emerson truly said that 

 "There are farms underneath our farms that we know not of until we un- 

 der drain." The worst mistake we have made is that we have not laid 

 our drains deep enough. 



