THE FLOW OF WATER IN DRAIN TILE. 
43 
60 
I 
40 
.9 
.8 
.5 
Depth ofF/oiy§ 
.6 .7 .8 
.9 1.0 
^L 
CONCRETE TILE 
-^A ?f 
Eguat/on of l/ne K^SUef^J 
Fig, 3.— Relation of coefllcient K to depth of flow in formulae 46-51. 
.5 
Depth orr/owf 
.6 .7 .8 .9 1.0 
^^^Ss^ 
f 
y 
\^ 
CON 
ICRETI 
: Til 
> 
.E 
c ^ 
^ 
V 
I 
2 
Equation of Line oc ^.SSSll-^j 
Fig. 4.— Relation of exponent of D to depth of flow in formulae 46-51. 
The exponent of s in all cases is very nearly 0.5, while the constant 
K also varies but little. Following the same method as before (see 
text-figs. 3 and 4) to obtain the formula for any depth of flow, 
Z=51.2( 
and 
(.7\0.0 
a = 0.558l('-^y'* 
Thus, the equation for any depth of flow in concrete tile is 
0.5581 
(J\0-01653p -l/<^\ 0*4601 
(52) 
(53) 
(54) 
