THE FLOW OP 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 abounds in gentle cm-ves, 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 measm-e 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 siuface 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 fi'om the pumps, while guuge 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 coiTect. The discharge was measiu-ed 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 (PL 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 cm'ves are so gentle that for all practical purposes they are 



