IMPROVEMENT OF THE SOIL 41 



order to secure a proper outlet for drainage ditches. 

 If the slope of the land will permit, ditches should 

 always be laid out parallel with each other as the 

 land between them will be so much easier plowed and 

 cultivated. The shape of the ditch will depend on 

 the character of the soil and also on the kind of tool 

 used in making it. In stiff soils a ditch with per- 

 pendicular banks will often stand very well, and 

 this form is most economical when dug by hand. 

 Other soils cave so badly that it is necessary to give 

 the banks a very easy slant. Ditching by hand with 

 spade and shovel is laborious and expensive. Where 

 the nature of the soil will permit, shallow ditches can 

 be quickly and cheaply made with the plow, followed 

 by a V-shaped scraper made from one long and one 

 short plank. The long plank acts as a rudder and 

 holds the scraper straight in the furrow, while the 

 short arm pushes the dirt out on to the bank. By 

 giving two or three plowings and scrapings a fairly 

 deep ditch may be dug. A road-grading machine 

 drawn by six horses will, where the land is free from 

 obstructions, do still cheaper and quicker work. 

 When dee23er canals are required, the bottom must be 

 finished by pulling out the dirt with the steel scrapers 

 used by railroad contractors. 



Open ditches are very useful and often indispensa- 

 ble, especially for the larger central drains, and their 

 first cost is much less than that of a proper system of 

 under drainage, but they are objectionable for many 

 reasons. They take up much room, and it is difficult 

 to keep the waste land along the banks free from nox- 

 ious weeds. They prevent passing freely about the 



