THE TRACTOR PLOW HITCH 173 



distances between the plow and the tractor necessitate 

 different adjustments to plow the same depth. In 

 other words, the farther the tractor is removed from the 

 plow, the lower it is necessary to hitch in the vertical 

 clevis if the operator desires to plow at the same depth 

 as when the tractor is hitched to the plow at point B. 



When the hitch on the tractor is exceedingly high it 

 may become necessary to lengthen the hitch between the 

 plow and the tractor to make the plow run at the depth 

 the operator desires. This is another way of saying, 

 keep the draft line straight. 



The reader will permit a diversion at this point long 

 enough to say that there is no truth in the theory that a 

 short hitch makes possible lighter draft than a long 

 hitch. The reason for this is very plain when we once 

 understand that the minimum amount of draft required 

 to pull a plow must be through a straight line from the 

 center of draft or center of weight to the center of power. 

 As long as the tractor and plow are in this relation the 

 only difference is the weight of the additional length ot 

 the draft bar. 



It is further apparent from Fig. 5, that if the hitch 

 line is BKC and the force on the plow bottom is sufficient 

 to draw line BKC into BGC, more power will be re- 

 quired to pull the plow because the front wheel will have 

 to sustain the brunt of the downward pressure. This 

 naturally will cause the plow to run on its point, mak- 

 ing an uneven furrow bottom and interfering very 

 materially with the pulverizing of the ground by the 

 mouldboard. This is apt to throw the ground over 

 into clods, breaking them rather than pulverizing. 



