io 94 
Journal of Agricultural Research 
Vol. V, No. 23 
is the percentage of increase in discharge, V is the average velocity of 
approach, and a, b , and n are constants for each size of each type of 
notch. 
TabeE XIII .—Velocities of approach {in feet per second) and percentages of increase 
in discharges through rectangular notches caused by different end and bottom contrac¬ 
tions 
HEAD. 0.6 FOOT 
Bottom 
contrac¬ 
tion. 
End 
con¬ 
trac¬ 
tions. 
i-foot notch. 
1 54 -foot notch. 
2-foot notch. 
3-foot notch. 
4-foot notch. 
Veloc¬ 
ity of 
ap¬ 
proach. 
In¬ 
crease 
of dis¬ 
charge. 
Veloc¬ 
ity of 
ap¬ 
proach. 
In¬ 
crease 
of dis¬ 
charge. 
Veloc¬ 
ity of 
ap "u 
proach. 
In¬ 
crease 
of dis¬ 
charge. 
Veloc¬ 
ity of 
ap¬ 
proach. 
In¬ 
crease 
of dis¬ 
charge. 
Veloc¬ 
ity of 
ap¬ 
proach. 
In¬ 
crease 
of dis¬ 
charge. 
Feet. 
Feet. 
Per ct. 
Per ct. 
Per ct. 
Per ct. 
Per ct. 
0.17 
* 115 
. 26 
2. 
.188 
.66 
.288 
2.05 
. 119 
. 17 
2.0 
.141 
•30 
0.191 
0 .53 
0.239 
0.74 
0.308 
1.07 
0.365 
i -33 
\Yz .. 
1-5 
•i 7 S 
.40 
•234 
•73 
.286 
1.01 
•363 
1.44 
.416 
1.74 
1.0 
• 234 
. 76 
• 304 
1.24 
.361 
1.62 
•435 
2.12 
.489 
2.49 
•552 
3*41 
* J 
f 2. < 
. IC 4 
. 19 
• 36 
X. 
{ *-5 
.229 
•50 
•311 
1.09 
•377 
i *55 
•478 
2.25 
•552 
2. 79 
1 1,0 
.308 
1.01 
.400 
1.77 
• 476 
2-39 
•577 
3.22 
.650 
3-83 
l -5 
.469 
2.84 
•573 
3-74 
.646 
4-38 
•735 
5 -i 5 
•794 
5-64 
• 25 
| 2.0 
.268 
.50 
.368 
1.30 
.460 
2.05 
. 624 
3-34 
.711 
4 -OS 
y * . 
\ *-5 
•337 
.94 
■453 
1.94 
•555 
2. 84 
• 70 S 
4.17 
.818 
S’ *5 
S 1.0 
•450 
1.84 
• 588 
3- 22 
•704 
4-35 
• 862 
5-92 
•975 
7.01 
l -5 
•69S 
4-63 
.852 
6-43 
• 970 
7-79 
x. 112 
9.40 
1. 208 
10. 50 
HEAD. 1 FOOT 
f 2. < 
0.132 
0.74 
j 2.0 
•*57 
.81 
0.213 
0.82 
0.269 
O. 84 
0. 342 
0. 83 
0.402 
O. 87 
3 ... 
1-5 
. 196 
.99 
. 260 
1.08 
• 3*7 
I. 14 
•399 
1. 22 
.460 
I. 29 
1.0 
. 260 
1.40 
•337 
1.63 
•398 
I. 8l 
•484 
2. 06 
•543 
2. 22 
l -5 
.40 
2.94 
•477 
3* 22 
•540 
3-44 
.616 
3*72 
.661 
3-88 
f a. e 
, T<0 
•74 
I 2.0 
.178 
.82 
.242 
.88 
.302 
•94 
• 39 i 
1.04 
.460 
I. II 
2 % . 
1 1,5 
. 224 
1.05 
.297 
1.21 
• 362 
*•34 
.461 
*•57 
.528 
I.69 
1 1.0 
.299 
1.58 
•385 
1.89 
•457 
2.14 
•553 
2.50 
.623 
2.76 
l -5 
.462 
3*42 
•549 
3-73 
• 625 
3-99 
.704 
4-25 
• 760 
4.48 
f 2.5 
• *75 
• 73 
2.0 
. 209 
.84 
.284 
•97 
•352 
1.11 
•458 
1.30 
•539 
1.42 
2 . 
i.S 
. 261 
i -13 
.348 
1.42 
.424 
1.67 
•538 
2.01 
. 620 
2. 28 
1.0 
•353 
1.83 
•450 
2. 28 
•535 
2.63 
.648 
3-*4 
•733 
3-52 
l -5 
.538 
4.01 
. 646 
4.46 
. 728 
4.80 
.829 
5-17 
•895 
5-47 
f 2* K 
. 208 
• 74 
[ 2.0 
.252 
•94 
• 34 * 
1.18 
•424 
1.41 
•539 
1. 71 
.638 
1.98 
IK.... 
\ *- 5 
• 3*4 
*- 3 i 
.418 
*•74 
.512 
2.12 
.648 
2.65 
•750 
3*07 
1 1,0 
.424 
2. 24 
•544 
2.87 
.646 
3-40 
.790 
4.14 
.889 
4.68 
l -5 
.648 
4. 80 
.784 
5 - 53 
.885 
6.09 
*•013 
6. 77 
1.091 
7.20 
f 0. C 
. 260 
.82 
2.0 
• 3 i 4 
r. 12 
.427 
*•57 
•532 
2.00 
.694 
2.69 
.810 
3 -IS 
I. 
1 
• 38 s 
*•59 
.528 
2-37 
•645 
2*99 
.820 
3-91 
•952 
4.60 
1.0 
•525 
2.83 
.688 
3-86 
.825 
4 - 73 
•999 
5 - 8 ? 
*•*35 
6.77 
l -5 
.822 
6.00 
•994 
7.29 
1.129 
8.29 
I.298 
9*55 
*•405 
10.27 
f 2 . K 
, a co 
X. II 
a 
.417 
*•45 
•575 
2.40 
. 720 
3-27 
•943 
4. 62 
1.120 
5-65 
5 *. 
\ 1.5 
• 530 
2.20 
.710 
3-53 
.875 
4 - 73 
1.119 
6. 50 
1.308 
7-88 
1* 0 
.716 
3.83 
•930 
5 - 6 $ 
1.118 
7-2 3 
*.380 
9.40 
*•576 
11. 2 
l -5 
I. 120 
8.25 
*•37 
11.0 
,58 
* 3-3 
1.83 
16.01 
2.01 
18.0 
