1072 
Journal of Agricultural Research 
Vol. V, No. 23 
Table V .—Discharges (in cubic feet per second) for rectangular notches as shown by 
curves plotted from experimental data , and discharges computed by curve and straight-line 
formulas 
Head. 
i.ooss-foot notch. 
x.5026-foot notch. 
2.0057-foot notch. 
2.997-foot notch. 
4.0056-foot notch. 
Experimental 
data. 
Curve formula. 
I, 
if 
P 
to 
Experimental 
data. 
Curve formula. 
Straight - line 
formula. 
1 . 
•p 
& 
Curve formula. 
Straight - line 
formula. 
Experimental 
data. 
Curve formula. 
Straight - line 
formula. 
Experimental 
data. 
Curve formula. 
Straight - line 
formula. 
Feet. 
o. 2. 
0.293 
o. 293 
0. 294 
0.443 
0.440 
0.442 
0.593 
0. 590 
0. 593 
0.890 
0. 886 
0.889 
1.194 
1.189 
x. 190 
.3. 
• 53 i 
•530 
• 532 
. 800 
• 797 
. 801 
I- 079 
1.071 
1.074 
1.617 
1.610 
1.613 
2.163 
2.161 
2.162 
.4. 
.806 
.808 
.811 
x. 220 
x. 217 
x. 220 
1.640 
1.6351 
1-637 
2.461 
2.462 
2.461 
3-302 
3-304 
3* 302 
• 5 . 
1. IIS 
x. 120 
1.123 
1.680 
1.688 
1.692 
2. 267 
2.268I 
2. 271 
3 - 4 H 
3.418 
3.416 
4 - 594 
4 - 589 
4 - 585 
.6. 
I- 459 
1.462 
1.467 
2.195 
2. 205 
2.210 
2. 969 
2.964 
2.966 
4 - 474 
4.470 
4*465 
6. 013 
6.004 
5-997 
• 7 . 
i- 834 
1.830 
1. 838 
2. 755 
2. 761 
2. 770 
3. 718 
3* 7 i 6 
3 - 719 
5 - 595 
5- 605 
5. 600 
7 - 532 
7 - 533 
7-524 
.8 . 
2 - 233 
2.223 
2.235 
3-354 
3-357 
3-368 
4-519 
4 - 519 
4 - 5 2 3 
6. 795 
6.821 
6.814 
9-157 
9.171 
9.156 
• 9 . 
2. 660 
2.639 
2. 655 
3.988 
3 - 987 
4.002 
5*367 
5-369 
5-375 
8.090 
8 . no 
8.101 
10. 910 
io. 906 
10. 892 
1. 0. 
3 -103 
3-076 
3 - 097 
4. 664 
4.650 
4.670 
6. 238 
6. 265 
6. 273 
9-432 
9.467 
9-457 
12. 706 
12. 734 
12. 720 
5 * 37 ° 
5 * 346 
5. *6q 
7. 100 
7 . 2 o«r 
7. 214 
10. 866 
10.893 
10.878 
14. 642 
14- 656 
14. 635 
6.133 
6. 068 
6- 099 
8.174 
8.181 
8.195 
9. 215 
12.356 
12.374 
12.361 
13.001 
16.666 
16. 653 
16. 635 
6.903 
6. 819 
6.857 
9 -196 
13- 876 
13*918 
** O. 
In locating the straight lines on the logarithmic plot, it was found that 
the points for the 1.005 5-foot notch could be covered quite closely by 
three straight lines approximately equal in length. The same was 
approximately true of the points for the 1.5026-foot notch. Only two 
4 
\.J 
y/o 
S 3 . 
■S 
c 
V* 
§ 
^ $ 
Exponent values of individual equations. 
Fig. 9 .—Curve showing relation of n to length of rectangular notches. 
straight lines each, however, were required for the 2.0057-foot and 2.997- 
foot notches, although a third could be assumed near the upper part of 
the curves in each case. For the 4.0056-foot notch there was only one 
point of change, and it was well above the middle of the curve. These 
facts indicate that had large enough heads been run on the longer notches 
to give the same ratio of length of crest to head as was obtained with the 
