The Colorado Statute Inci-i 
7 
Inches equal to one second foot is given in the last column. It will be 
seen that, in general, the discharge for any certain size of orifice in¬ 
creases as the width of the box is increased, except for a slight reduction 
when the orifice is nearly the same size as the box. The number of 
statute inches to one second foot therefore decreases with a decrease in 
the size of the box, and it will also be noticed that the number of statute 
inches to one second foot increases as the size of the orifice is increased, 
which means that the discharge of each square inch of orifice decreases 
as the size of the orifice is increased. This is the opposite to the results 
obtained with thin-edged orifices having free flow, as given in tables 2 
and 3. Box-tubes with orifices from 12 to 9 6 square inches gave dis¬ 
charges with the number of statute inches to one second foot varying 
from 33.7 to 38.4, and a greater number would no doubt be obtained for 
still larger orifices. 
Thin-Edged Orifices With Free Flow.—A large majority of the 
present day Miner’s Inch devices have a thin-edged orifice placed in the 
vertical side of a box, so the water passes into the a‘ir as it flows through 
the orifice. Experiments were made with this type of orifice in sizes 
ranging from 1 inch square to 6 inches deep by 16 inches wide. The 
depth of water above the top of the orifice was five inches in every case. 
The brass orifice taples were placed in the end of a concrete box having 
a cross-section of 10 feet by 6 feet deep. The experimental results are 
given in tables 2 and 3. 
TABLE 2. 
RESULTS OF EXPERIMENTS WITH COLORADO STATUTE INCH DEVICES. 
(Thin edged orifices.) 
No. Of 
Experi¬ 
ment 
| Orifice 
1 
j Nominal 
|area in Sq. 
| Inches 
Discharge 
in Cubic Feet 
Per Sec. 
D 
Depth in 
Inches 
B 
Breadth in 
| Inches 
Observed 
by experi 
ment 
| Corrected 
- |forNoininal 
area 
Curve 
Values 
1395 
1.005 
1.004 
1 
.024 
.024 
.024 
1396 
1.005 
1.004 
1 
.024 
.024 
.024 
1393 
1.000 
2.003 
2 
.047 
.047 
.047 
1394 
1.000 
2.003 
2 
.047 
.047 
.047 
1387 
1.005 
3.011 
3 
.072 
.071 
.071 
1388 
1.005 
3.011 
3 
.072 
.071 
.071 
1385 
1.000 
4.003 
4 
.095 
.095 
.095 
1386 
1.000 
4.003 
4 
.095 
.095 
095 
1379 
1.005 
5.000 
5 
.119 
.118 
.118 
1380 
1.005 
5.000 
5 
.119 
.118 
118 
1391 
2.003 
1.000 
2 
.049 
.049 
.049 
. 1392 
2.003 
1.000 
2 
.049 
.049 
.049 
1377 
2.006 
2.001 
4 
.096 
.096 
.097 
1378 
2.006 
2.001 
4 
.097 
.097 
.097 
1373 
2.001 
2.998 
6 
.145 
.145 
.145 
1374 
2.001 
2.998 
6 
.145 
.145 
.145 
1369 
2.005 
4.004 
8 
.194 
.193 
.193 
1370 
2.005 
4.004 
8 
.194 
.193 
.193 
1365 
2.009 
5.007 
10 
.243 
.242 
.242 
1366 
2.009 
5.007 
10 
.243 
.242 
.242 
