Mar. 13,1916 
A New Irrigation Weir 
1129 
Table I .—Effect of size and shape of weir box on discharge 1 
SPECIAL TESTS 
No. 
Length 
of weir 
crest. 
Width 
of weir 
box at 
crest. 
Width 
of weir 
box at 
20 feet. 
Equation of di 
charge curve. 
1 
Feet . 
1 
iML 
is 4 L 
0=4.641 lh;™. 
2 
1 
2 L 
2 L 
0=3.768 LH 1 * 622 . 
3 
1 
3 L 
3 L 
Q=3.44l 
4 
1 
4 L 
4 L 
Q-3.343 
5 
1 
SL 
sL 
Q=3.3i6 Lg“. 
6 
1 
6 L 
6 L 
Q=3.m LHM". 
7 
1 
3 L 
3 L 
0-3-7= 
8 
1 
2 L 
3 L 
0=3.69 EH 1 ’ 506 .. 
9 
1 
2 L 
3 E 
0=3-71 LHi-622., 
10 
1 
2 L 
2KE 
0=3.73 lh;-™.. 
11 
1 
2 L 
2KE 
0=3-73 LH'-“».. 
12 
i.S 
2 L 
3 E 
Q=3.64 EH 1 - 523 .. 
13 
2 
L 
iKE 
0=4-375 EHJ**». 
14 
2 
2 L 
2 L 
0=3.749 EH 
15 
2 
2 J 4 L 
2^ E 
0=3*552 LH ‘» . 
16 
2 
3 L 
3 L 
0=3-439 EHJ*^ 
17 
2 
3 L 
3 E 
0=3-749 EH 1 ' 646 , 
18 
3 
3 L 
3 E 
0=3.63 EHi*B«. 
19 
3 
2 L 
3 ^E 
0=3.640 LH 1 " 660 
20 
3 
2 L 
3 E 
0=3.604 EHi*6«° 
31 
4 
x % L 
iKE 
0=5.327 EHJ*“® 
32 
4 
i^L 
iME 
0=4.105 lh;-“ 
33 
4 
iML 
i^E 
0=4.053 LH 1 m 
24 
4 
iKE 
iKE 
0=3.839 LHf^ 
25 
4 
2 L 
2 E 
0=3-599 LHJ**w 
36 
4 
2 L 
2 L 
0=3-590 LH 1 ' 580 
37 
4 
2 L 
2 E 
0=3-714 Eff-H® 
28 
4 
3 L 
2 E 
0=3.642 LH 1 * 642 
29 
4 
2KL 
2KE 
0=3-403 EH 1 ’ 500 
Fig. 
No. . 
Length 
of floor. 
Remarks. 
, 
Feet. 
Sides parallel, no wings. 
1 
32.67 
1 
32.67 
Do. 
1 
32-67 
Do. 
1 
32.67 
Do. 
1 
32.67 
Do. 
1 
32.67 
Do. 
2 
32.67 
Sides extended at same angle to dis¬ 
tance of 32.5 feet from crest. 
3 
32.67 
Sides extended to sides of concrete 
box at angle of 45° to axis. 
4 
32.67 
Sides extended to sides of concrete 
box at angle of 90® to axis. 
4 
3 
32.67 
32.67 
Do. 
Sides extended to sides of concrete 
box at angle of 45 0 to axis. 
2 
Sides extended at same angle to dis¬ 
tance of 32.5 feet from crest. 
1 
32.67 
Sides parallel, no wings. 
1 
32.67 
Do. 
1 
32.67 
Do. 
1 : 
5 
32.67 
32.67 
Do. 
Sides parallel, with 45® wings con¬ 
necting parallel sides 12 feet long, 3 L 
apart. 
Sides extended at same angle to dis¬ 
2 
32.67 
tance of 32.5 feet from crest. 
6 
32.67 
Sides extended 12 feet parallel to axis 
and 2 % L apart. 
2 
32.67 
Sides extended about 5 feet at same 
angle to sides of concrete box. 
7 
20.00 
Sides parallel, no wings. 
7 
2 
20.00 
32-67 
Do. 
Sides parallel, extended to distance 
of 32.5 feet from crest. 
7 
20.00 
Sides parallel, no wings. 
7 
2 
20.00 
32.67 
Do. 
Sides parallel, extended to distance 
of 32.5 feet from crest. 
8 
32.67 
Sides parallel, with 45® wings ex¬ 
tending to sides of concrete box. 
9 
32.67 
Sides parallel, with 90® wings ex¬ 
tending to sides of concrete box. 
10 
32.67 
Full width of concrete box. 
STANDARD TESTS 
30 
I 
3 L 
2^E 
Q-3.ru LH 1 ' 69 . 
2 
32.67 
Sides extended at same angle to dis¬ 
tance of 32.5 feet from crest. 
31 
1.5 
2 L 
2KE 
0=3.720 LH 1 * 54 . 
2 
32.67 
Do. 
32 
2 
2 E 
2 x A E 
0=3.690 EH 1 * 54 . 
2 
32.67 
Do. 
33 
34 
3 
4 
3 E 
2 E 
2^E 
aME 
0=3-630 EH 1 * 66 . 
0=3 S 70 EH 1 ’ 58 . 
2 
2 
32.67 
32.67 
Do. 
Sides extended at same angle to sides 
of concrete box. 
SPECIAL NOTCH TESTS 
Degrees. 
Feet. 
Feet . 
35 
90 
10 
10 
Q= 2 . 54 i H*«. 
11 
33.67 
36 
90 
3 
7 
0=2.667 H 2 ' 621 .. 
12 
32.67 
37 
90 
3 
0=2.679 H 2 ' 517 . 
13 
32.67 
No sides, channel full width of con¬ 
crete box. 
Sides extended about 10 feet at same 
angle to sides of concrete box. 
Sides 5 feet apart at 10 feet, then ex¬ 
tended 12 feet parallel to axis. 
1 Level wood floor placed about 4.5 feet above floor of concrete weir box; angle iron weir crest. 
