124 
Journal of Agricultural Research 
* VoL IX, No. 4 
The equation is therefore y=0.6 x. With the origin moved to the 
point 0, o , the equation of the upper limiting parabola becomes 
(y - 0.2)*« 0.6 (x - 0.96) (5) 
and similarly the equation for the lower limiting curve, H a , approxi- 
Coefficient C 
Pig. 10.— Plot of constants for curves shown in figure 9. 
mately 0.4 foot, is found to be 
(y — 0.03)* = 0.6 (x— 0.935) (6) 
The constants for each curve were assumed to take a straight line 
variation, as shown in figure 10, in which the a line is for the constants 
with y, and the b line is for the constants with x . 
By proportion from figure 10 and the substitution H a for y, 
or 
and 
a=o.i4y—0.02 
a=o.i4// a —o.o2 
b = o.o2H a + 0.93 
