THE FLOW OF WATER IN WOOD-STAVE PIPE. 
25 
Table 1. — Velocities by color (fluorescein) compared with velocities by weir and current 
meter. 
Refer- 
ence 
No. 
Pipe 
diam- 
eter. 
Crest length of 
weir. 
Meter method. 
j Velocity 
per second 
by color. 
Velocity 
per second 
by meter. 
V m 
Velocity 
per sec- 
ond by 
weir. 
V w 
v -v m 
V e 
V c -Vw 
Ve 
60 
Inches. 
8 
8 
8 
8 
8 
18 
36 
36 
48 
48 
48 
78 
78 
78 
78 
78 
78 
78 
78 
Feet. 
1.05 Cip.i 
Feet. 
1.251 
1.736 
2.048 
3.043 
3.294 
2.08 
3.48 
3.48 
3.14 
3.75 
4.75 
0.911 
0.963 
1.51 
2.063 
2.16 
2.40 
2.44 
2.79 
Feet. 
Feet. 
1.295 
1.735 
2.09 
2.97 
3.37 
Per cent. 
Per cent. 
-3.8 
61 
do 
2.84 Rect.2 
+0.1 
62 
-2.0 
63 
do 
do 
* 6-tenths V". .'.'_'. 
Int.* 
6-tenths 3 
2+8? 
do 
do... 
Curves 
do 
do 
do 
do 
do 
do 
do 
+2.4 
64 
-2.4 
132 
1.99 
3.48 
3.55 
3.05 
3.71 
4.73 
0.928 
0.974 
1.60 
2.08 
2.10 
2.37 
2.42 
2.51 
+4.3 
0.0 
-2.0 
+2.9 
+1.1 
+0.4 
-1.9 
-1.1 
-6.0 
-1.0 
+2.8 
+1.2 
+0.8 
+3.1 
( 4 ) 
( 6 ) 
192 
lO.OCip.i 
do 
3.47 
3.47 
+0.3 
+0.3 
193 
194 
263 
264 
265 
266 
( 6 ) 
269 
270 
271 
i Cipolletti weir with good conditions of contraction and velocity. See p. 40. 
2 Rectangular weir with end contractions and sharp crest. See p. 40. 
3 Meter held in each vertical at 0.6 depth from surface. 
* From tests on a concrete pipe, made in 1915. 
6 Velocity integrated by moving meter slowly from top to bottom and return. 
6 Excluded from Table* 2 because gauge data'lost for manometer No. 1. 
7 Meter held at 0.2 and 0.8 depths in each vertical; mean accepted for vertical. See p. 44. 
6 Rating curve developed by meter measurements. Velocity taken from curve. See p. 45 
FIELD PROCEDURE. 
After the reach of pipe was selected, the manometers attached, 
and other equipment put in readiness the method for proceeding 
with the field test was in general carried out as described in the 
paragraphs following. Any necessary changes are noted in the text 
in connection with the description of the individual pipes tested. 
The watches used at both ends of the reach were adjusted to agree 
to the second, and again compared at the end of the observation. 
Manometers were read every one or two minutes (depending on the 
amount of pulsation in the water) for a period of 30 minutes. If a 
weir was used to measure the discharge of water a hook gauge above 
the weir was read every two to five minutes, depending on the varia- 
tion of discharge. If a current meter measurement was necessary 
to determine the discharge it was made either during or immediately 
following the series of manometer readings, the manometers being 
watched for appreciable variations of discharge. Where fluorescein 
was used to time the actual velocity of the water it was injected into 
the pipe at approximately known intervals, say, five minutes, through- 
out the time during which the manometers were read. Ordinarily 
the second gauge was near enough to the outlet of the pipe so that 
one observer could both read the manometer and watch for the 
appearance of the color. Sometimes a third observer was necessary. 
