168 



THE OLIVER PLOW BOOK 



from the drivers. The other point is the "center of 

 draft" (also called the center of weight or the center of 

 resistance) of the plow. A straight line between these 

 points is the "line of draft." The line between these 

 two points is theoretically always straight. 



Being obliged to turn the front tractor wheels toward the plowed ground 

 indicates that the draft of the plow is pulling the front of the tractor in 

 the opposite direction. This is hard on both the plow and the tractor. 



The center of draft of the plow is an imaginary point 

 in the plow base or bottom from which a single force 

 pulling straight ahead and parallel to the furrow wall 

 will cause the plow to work correctly with the minimum 

 effort. This point is usually placed from 12 to 15 

 inches back from the share point, 2 inches up from the 

 furrow sole and 3 inches from the furrow wall. One 

 must remember that this point is not fixed but con- 



