1074 
Journal of Agricultural Research 
Vol. V. No. 23 
ence in discharge was found to be Z>—.609# 25 . By adding the term 
.609 H 2 ' 5 to the general formula for discharges through rectangular 
notches (page 1064), the general formula for discharges through Cipolletti 
notches was found to be 
Q - 3 - 24 7LH'-« - H 1 »+o.6o 9 fP* 
This formula gives discharge values for 1-, 2-, 3-, and 4-foot 
notches that agree within 0.5 per cent of the values indicated on the curves 
plotted from the experimental data, except for the lower heads on the 
1-foot notch, where the maximum discrepancy, owing to the small dis¬ 
charge, is approximately per cent. The discrepancies are positive in 
some cases and negative in others. (See Table VII for discharge values 
indicated by the curves plotted from the experimental data and discharge 
values computed by the formulas.) 
Table VI gives the discharge values for Cipolletti notches of different 
lengths computed by the new formula. 
Table VI .—Discharges (in cubic feet per second) through Cipolletti weir notches 1 
Head. 
i-foot crest. 
iK-foot crest. 
2-foot crest. 
3-foot crest. 
4-foot crest. 
Feet. 
O. 20 
Inches. 
2 H 
O.30 
0.45 
0. 60 
0.90 
1. 20 
. 21 
2^ 
• 3 2 
. 48 
.64 
•97 
1. 29 
. 22 
2$4 
•35 
•52 
. 69 
1. 04 
1.38 
•23 
•37 
•55 
•74 
1. iz 
I- 47 
• 24 
2 y% 
•39 
•59 
•79 
1 . 18 
i- 57 
•25 
3 , 
.42 
.63 
.84 
1-25 
1.67 
.26 
zX 
•45 
.67 
. 89 
I- 33 
1.77 
.27 
zX 
•47 
• 7 i 
.94 
1.40 
1.87 
.28 
zn 
•50 
•75 
•99 
1.48 
1.97 
.29 
zX 
•53 
•79 
1. 04 
1. 56 
2.08 
*30 
zX 
.56 
.83 
1. to 
1.64 
2.19 
*31 
zX 
•59 
.87 
i -15 
i- 73 
2.30 
•32 
. 61 
.91 
1.21 
1.81 
2.41 
•33 
zU 
4ik 
.64 
•95 
1.27 
1. 89 
2. 52 
•34 
.67 
1.00 
1.32 
1.98 
2.64 
•35 
4 * 
.70 
1.04 
1.38 
2. 07 
2- 75 
•36 
4 A 
•73 
1. 09 
1.44 
2.16 
2.87 
•37 
4 tV 
•77 
i-13 
1. 50 
2.25 
2.99 
.38 
4 * 
.80 
1.18 
i- 57 
2. 34 
3.11 
•39 
4 tt 
.83 
1.23 
1.63 
2.43 
3 - 24 
.40 
•87 
1. 28 
1. 69 
2. 53 
3 - 3 6 
.41 
4 i$ 
5A 
.90 
1. 32 
1. 76 
2. 62 
3-49 
.42 
•93 
i -37 
1. 82 
2. 72 
3 - 6l 
•43 
5A 
•97 
1. 42 
1. 89 
2.81 
3 - 74 
• 44 
sX 1 
1.00 
1. 47 
i- 95 
2. 91 
3 - 87 
1 Computed by the formula j 2 “ 3**47 LH ua — 
