THE FLOW OF WATER IN WOOD-STAVE PIPE. 43 
in replacing some deteriorated redwood staves, and both gauges had been attached 
to the pipe through these because the harder fir appeared to give a tighter repair when 
plugs were inserted in the tap holes after the gauges had been removed. However, 
according to the superintendent of the line, that part of the pipe between the gauges 
was of redwood. The nominal size of the pipe was accepted as correct. The velocity 
was determined by injecting fluorescein at gauge No. 1 and timing its travel to an aux- 
iliary tap on the same circumferential ring with gauge No. 2. Although the pipe was 
24 years old the two observations at commercial velocities indicate its capacity to be 
3 per cent greater than that computed by the new formula. 
No. 37, Expt. S-4, 36-inch Continuous-Stave Douglas Fir Pipe Line, Pasco 
Reclamation Co., Washington. — The rolling ground in the vicinity of Pasco, 
Wash., does not furnish adequate support for an open canal. For this reason, and 
because of the sandy nature of the soil, water for irrigation is conveyed in pipes after 
settling in a reach of open canal where it has a very low velocity. Tests for loss of 
head were made on the 36-inch pipe shown in Plate IV, figure 2. Gauge No. 1 was 
placed about 800 feet from the intake and gauge No. 2 was located 2,516 feet farther 
on. The line aboimds in gentle curves, both horizontal and vertical. Mercury 
manometers were used for both gauges. The nominal diameter of the pipe was ac- 
cepted as correct. As all the water flowing in the canal entered this pipe, it was only 
necessary to measure this flow for discharge. This was done by weighted rod floats 
of such lengths that any one float just cleared the bottom throughout the reach on 
which it was used. This pipe was laid in the winter of 1909 and 1910. For the most 
part it is buried from 1 to 3 feet in light sandy soil. Exterior decay cf the pipe indi- 
cated that it would have been better to place the pipe on the surface of the ground. 
The two observations taken at commercial velocities indicate that the capacity of this 
pipe is 15 per cent less than that computed by the new formula. The writer can not 
account for this. Velocities are so low in the feed canal that all sediment should 
precipitate before reaching the pipe. 
No. 38, Expt. S-5, 36-inch Continuous- Stave Douglas Fir Discharge Pipe, 
Pasco Reclamation Co., Washington.— Water for domestic and irrigation use is 
lifted 107.2 feet vertically from Snake River to the canal-reservoir shown in Plate II, 
figure 2. All of the pumps feed one continuous-stave wood pipe 36 inches in diam- 
eter. This pipe, 893 feet in length, was built in 1909. Though at a rather sharp 
incline, the pipe is practically straight. Gauge No. 1, a mercury manometer, was 
located 335 feet from the pumps, while gauge No. 2, a water column, was located but 
20 feet from the outlet shown in the plate and 538.1 feet from gauge No. 1. The pulsa- 
tion due to the pumps was evident in the mercury columns, but at gauge No. 2 their 
effect was hardly noticeable, even in the water column. The nominal diameter of 
the pipe was accepted as correct. The discharge was measured with weighted rod 
floats in the concrete section of open canal shown in the plate. These were of such 
length that they barely cleared the bottom of the channel. It was not practicable 
to vary the discharges through this pipe. The two observations taken at the com- 
mercial velocities indicate that the capacity of this pipe is about 13 per cent below 
the discharge computed by the new formula. 
No. 39, Expt. S-8, 38.13-inch Continuous-Stave Douglas Fir Siphon Pipe, 
Burbank Co., Washington. — Irrigation water from the Snake River is conveyed 
across a wide swale in section 16, township 8 north, range 31 east, by means of a con- 
tinuous-stave siphon 6,170.4 feet long, built in February, 1913 (PI. II, fig. 3). This 
pipe is 38.13 inches in diameter, as determined by measurements of outer circum- 
ference throughout its length and by measurements of stave thickness. It is sup- 
ported on cradles on the surface of the ground and appears to be in perfect condition. 
During the colder months water is withdrawn and the ends are plugged. Irrigation 
continues about seven months each year. The pipe is straight in horizontal align- 
ment, while the vertical curves are so gentle that for all practical purposes they are 
