Jan. 28, J918 



Study of Plow Bottoms 



157 



coordinates came at O, figure 8. The plane y=0 contains the points O, 

 m, and n; and the plane x=0 contains the points O and m and is per- 

 pendicular to the plane y = 0. The plane 2 = is perpendicular to both 

 the planes y=0 and x=0. The axes are considered to be positive in the 

 directions indicated by the arrowheads (fig. 8). Three transverse lines, 

 ab, cd, and ef (fig. 8), were selected and the following data obtained: 



Fig. 8. 



TABtE I. — Values (in inches) developed for the surface of the plow bottom shown in 



Plate 6, A 



Xi= 2.04 

 J'i= 5-7 



2i = l6.0 

 *4= 8.54 



74= 6.43 



24=23.0 



X2= 7.42 

 J2= 3-78 

 22=19.0 



X5= 9-7 



)'5= 10.88 

 2t = 26.0 



X3= 4-42 



J'3= 8.74 

 23 = 20.0 



0:6=12.58 



>'6= 7-65 

 2fi=28.0 



When the above values are substituted in the equations already 

 developed, 

 From (16) 



-2.28i< : + i3-83 



(33) 



