i66 



Journal of Agricultural Research 



Vol. XII. No. 4 



Fig. 14. — Projection of the paths shown in Plate 9. 

 the plane j'=0. 



A, upon 



(D) That the maxi- 

 mum difference, z—s, 

 for each path decreased 

 uniformly across the 

 furrow slice. Thus, for 

 Row I, ji(;= 0.85 inch, the 

 maximum z—s=i.o5 

 inches, and when 

 3^=13.6 inches, the 

 width of the furrow- 

 slice, the maximum 

 z—s=0; so when 

 x=7.$ inches, the max- 

 imum z—s for Row V 

 is 0.45 inch. 



(E) That the stretch- 

 ing in each row took 

 place uniformly up to 

 the maximum point 

 and then decreased 

 uniformly until it was 

 zero when z=s = 40. 



(P) That the maxi- 

 mum stretching 

 occurred midway be- 

 tween the point where 

 the soil particle passed 

 upon the plow bottom 

 and the point ^ = 40. 

 Thus, for Path I where 

 the soil particle passed 

 upon the moldboard at 

 the point ^ = 0.6: 



40 —0.6 = 39.4 inches. 

 39.4 -^ 2 = 19.7 inches. 

 19.7 + 0.6 = 20.3 inches, 



4 For Path I the point 

 of maximum stretch- 



2 ing was at ^• = 20.3 

 inches. 



^ The computations 

 below show that for 

 Path V, where the soil 



4iP 



36 



34 



32 



30 



28 



26 



24 



22 



ZO 



16 



10 



