THE FLOW OF WATER IN CONCRETE PIPE. 41 
In other words, as is to be expected from the conditions, the weir 
discharges more water for a given head than a standard Francis weir 
would have done. As mentioned above, the velocities used in the 
computations in tables 3 and 4 were all based on the color method. 
The mean diameter of this pipe, found by measuring two diameters 
on each of nine pieces remaining from construction is 3.50 feet, 
agreeing with the nominal diameter. All things considered, the 
writer regards this series as among the best, due to the very favorable 
conditions for experimentation. The value of C s is about 0.375 and 
may be taken as for a very smooth pipe with an excess of curvature. 
No. 31, Experiment S-48. — 42-inch jointed reinforced concrete 
gipe, siphon No. 5, Victoria Aqueduct, Vancouver Island, British 
olumbia, Canada. — This series of tests was conducted on the last 
of the siphons on this pipe line, siphon No. 5, located between man- 
holes 67 and 68. The same general discussion applies to this series 
as to No. 30. This siphon is much shorter, and in consequence the 
series should not be as reliable as No. 30. As shown in Plate V, 
figure 3, the siphon pitches down a steep grade, thence extends 
horizontally over a concrete trestle, thence climbs a steep hillside 
to the outlet manhole (in the foreground). 
The values of C s being around 0.390 would indicate a higher 
capacity than the observations on pipe No. 30, but those should be 
accepted over the tests on siphon No. 5. 
No. 32, Experiment S-35. — 46-inch jointed reinforced concrete 
pipe, E-i siphon, Umatilla project, United States Keclamation Service, 
Oregon. — Water for irrigation is conveyed across a wide valley, from 
one open channel to another, by means of an inverted siphon pipe 
9,830.8 feet long and subject to a maximum pressure head of 110 feet. 
It was constructed in the winter of 1909-10. The joint units are 8 
feet in length, reinforced with a spiral of five-sixteenth-inch steel 
wire wound round longitudinal rods (PI. VIII, fig. 2). The concrete 
was mixed in a ratio of 1 part cement to 1.44 parts sand and 2 parts 
gravel. The units were cast in steel forms and afterward painted 
on the inside with a grout made by pouring one-half bucket of cement 
into two-thirds of a bucket of water. This made a full bucket of a 
mixture of about the consistency of cream. 1 . 
As shown in Plate VIII, fig. 2, the pipe is straight in alignment, 
while the profile is evident, with the exception of the deep sag across 
the lower lands, where the pressure head reaches 110 feet. Within the 
reach of pipe tested there are eight 6-inch valves, two 6-inch blow-offs, 
and four manholes, each 12 by 14 inches. 
This line was tested by Mr. Newell in 1911 and again in 1912 (see 
No. 33a, p. 79). During the season of 1915 the writer conducted 
experiments on the same reach of pipe, between a valve 72 feet from ■ 
the inlet and the outlet chamber, a distance of 9,774 feet. 
For gauge No. 1 a mercury column was used, while for gauge No. 2 a 
piezometer tube of type B, extending into the jet at the outlet, led to 
a stilling box wherein the water-surface elevation was determined 
with a hook gauge. Two diameters were measured on each of 8 pipe 
units remaining from the original construction. The mean area of 
these units was 11.52 square feet, while the exact area of a 46-inch 
1 The details of manufacturing experience and costs covering a period of about three years are given in 
"Reinforced-Concrete Pressure Pipe on the Umatilla Project, Oreg., XJ. S. Reclamation Service," by 
H. D. Newell, Eng. News, vol. 65, Feb. 16, 1911, p. 208. 
