69 



This is secured in a great measure by laying off the rows according 

 to the contour of the surface, so that each row will have a very slight 

 incline of not more than from 1 to 7 inohes in 100 feet, and in which 

 the flow of water would be so slow that there would be little or no 

 erosion. Theoretically, this is a fine idea, to let each row carry off 

 its own proportion of the excess of rainfall so gently that there shall 

 be no erosion, thus acting as a miniature drain. Practically, how- 

 ever, it is often impossible to keep these rows from breaking through, 

 and when the bed is once broken and the water overflows into the 

 next row the accumulation of water is sufficient to break down bed 

 after bed until the rows from all the field are discharging into this 

 narrow channel. 



To overcome this difficulty sidehill ditches may be used in which 

 larger and more substantial ditches are provided, following very 

 nearly the oontour of the field, so that there shall be a fall of from 1 

 to 6 inches in 100 feet. The distance apart of the ditches will depend 

 upon the slope of the field ; with a very steep slope they should be 

 close together, often not over 6 to 10 feet apart ; with a gentle elope 

 they should be at intervals of 15 or 20 feet, or even further apart, de- 

 pending upon the texture of the soil and the contour of the surface. 



These sidehill ditches are very easily constructed, being made 

 almost entirely with the plough. A bank ii formed by running a num- 

 ber of furrows, throwing the dirt toward the middle. The last far- 

 row on the upper side is cleaned out with a spade to form the bottom 

 of the ditch. If the plough is well handled it takes very little work 

 with the spade to make a very substantial ditch. It is well to get the 

 bank forming the lower side of the ditch sodded with grass to help 

 hold it and to lessen the danger of its giving way during a heavy 

 rainfall. When the slope is thus protected with a number of ditches 

 at the proper distance apart, the rows can be given a rather steeper 

 fall so that they shall ran out into the drains at frequent intervals 

 and not have to carry the water so far. These ditches have to be con- 

 structed with care and have to be strengthened where they cross any 

 depression or sudden ourve by building up an embankment with 

 sticks and brush thrown across to support the embankment. Unless 

 these ditches are thoroughly constructed they are worse than useless, 

 for if they break they concentrate a volume of water upon one point 

 in the field which would otherwise have been distributed over the sur- 

 froe, and this often forms a torrent which does great damage. 



It is essential that these ditches and rows be run according to the 

 contour of the surface of the land, and that there shall be no low 

 places where the water would accumulate and gather force. They 

 should always be run with a level, of whioh there are several forms on 

 the market suitable for this work. 



A more efficient, but at the same time muoh more expensive, method 

 of preventing the washing of lands where there is a considerable slope 

 is to terrace the fields so that there shall be level steps upon which 

 the water can rest for a while and be absorbed. In terracing, the 

 lines are run with a spirit level following the contour of the surface so 

 as to give a perfectly level line. A furrow is run along this line, and 

 a similar furrow is run along a lower contour, the distance apart de- 

 pending upon the nature of the land and the slope of the surface, as in 



