TILLAGE 671 



one. The plow swings on a swivel in such a way that 

 it may be locked on either the right or the left side. It 

 removes the necessity of plowing in beds, and, by per- 

 mitting all the work to be done from one side, enables 

 the plowman to lay the furrow slices in one direction. 

 On the hillside this direction is down the slope, because 

 of the greater ease in turning the soil in that direction. 

 This plow also removes the difficulty of pulling up and 

 down the hill. There is another type of moldboard plow, 

 designed to eliminate " dead furrows " and " back fur- 

 rows." Dead furrows are developed by the last furrow 

 slices of two lands being turned in opposite directions, 

 thereby leaving a gulley between, which is often unpro- 

 ductive in character; the back furrow consists of two 

 furrow slices thrown together, usually forming a ridge 

 more productive than the average of the land. This 

 plow is of the sulky type, the plow being carried on wheels 

 and regulated by means of levers and the traction power. 

 Two plows are carried, one having a right-hand turn to 

 the moldboard, and the other a left-hand turn. By 

 using one plow in one direction and the other in the oppo- 

 site direction, it is possible to begin on one side of the field 

 and throw the furrow slice in one direction until the 

 entire area is covered, thereby leaving the soil in a uni- 

 form condition. Such plows, being heavier than the 

 single, walking plow, are not adapted to very uneven 

 ground. ^ 



577. Covering rubbish. -^- The secondary function of 

 (tthe plow is to cover weeds^- manure, and rubbish that 

 may be on the surf acec This also the turning plow 

 does very effectively.~~ J The cutting and turning of the 

 sod, rubbish, and weeds is facilitated by -several attach- 

 ments, such as colters, jointers, and drag chains. There 



