THE FLOW OF WATEE IW WOOD-STAVE PIPE. 41 



although the observations show that the capacity of the pipe is 10 per cent below 

 the discharge computed by the new formula. 



No. 19, Expt. S-10, 14:-inch Jointed Machine-Banded Douglas Fir Pipe, 

 Congdon Orchards, North Takima, Wash. — ^About 1 mile of 14-iiich pipe con- 

 veys water from the Yakima Valley Canal to the Congdon Orchards. A reach 

 1,251.7 feet long was chosen near the lower end. A mercury manometer was used 

 as gauge No. 1 and a water column as gauge No. 2. The velocity was determined 

 with fluorescein. The color was injected at gauge No. 1 and appeared at a 4-inch 

 hydrant about 100 feet below gauge No. 2. The capacity of this pipe is about 4 per 

 cent less than as computed by the new formula. 



No. 26, Expt. S-13, 18-inch Continuous-Stave Redwood Siphon Pipe, 

 Taliima Valley Canal Co., Washington. — Irrigation water is conveyed across two 

 depressions between open reaches of canal by means of a redwood siphon of the con- 

 tinuous-stave type, built in the winter of 1913-14. Thus the pipe had been in use 

 but a few months at the time of the test. It is bxiried about 3 feet in sandy and 

 gravelly soil. Blow-off valves are located at the low points, while a valve allows 

 the escape of air at the one summit on the line. Gauge No. 1, a mercury manometer, 

 was located 279.3 feet from the inlet. Gauge No. 2, a water column, was located 

 1,787.5 feet from gauge No. 1 and 19.7 feet from the outlet. The nominal size of the 

 pipe was accepted. The velocity within the pipe was determined with fluorescein. 

 It was not practicable to vary the velocities through the pipe, but so far as two 

 observations can be accepted the capacity of the pipe is 18 per cent greater than the 

 discharge computed by the new formula. Some excess is to be expected, as newly 

 planed redwood is very smooth and the pipe was so new that material deposits of 

 silt were unlikely. 



No. 27, Expt. S-7, 18-inch Jointed Machine-Banded Douglas Fir Siphon 

 Pipe, Burbank Co., Washington. — Irrigation water from Snake River is carried 

 over a swale between open sections of a small ditch by means of an inverted siphon. 

 This pipe was laid duiing February, 1913. The top of the pipe is about 18 inches 

 below the surface of very gravelly, open soil. However, the pipe surface is protected 

 with a heavy coating of asphalt, so that the wood appears to be perfectly soimd. The 

 maximum head is only about 14 feet. Water columns were used at both ends of the 

 reach tested. Gauge No. 1 was located 67.1 feet from the inlet while gauge No. 2 was 

 located 1,479.1 feet from gauge No. 1 and 7.6 feet from the outlet. The nominal size 

 of the pipe was accepted as correct. For each run the velocity within the pipe was 

 determined through fluorescein tests by taking the mean velocity of five batches of 

 color. The pipe is straight in horizontal alignment and has no summits in the ver- 

 tical plane. For all practical purposes it may be considered straight from the fact that 

 the low pointis but 14 feet below the hydraulic gradient, in a total distance of 1,553.8 

 feet. At no point was there any indication of leakage, but there was no way of deter- 

 mining the interior condition of the pipe. It is used for irrigation about seven months 

 of the year, but is kept full all winter. This probably accounts for the absence of 

 leakage. The water as pumped from Snake River contains some sand, but all of the 

 heavier particles have settled to the bottom of the canal before reaching the siphon, 

 which is some distance from the stream. For this reason there is small likelihood of 

 a deposit at the low point of the siphon, although the two observations taken indicate 

 that the capacity is 6 per cent below the discharge computed by the new formula. 



No. 29, Expt. S-2, 24:-inch Jointed Machine-Banded White Pine Pipe, 

 Butler Water Co., Butler, Pa. — ^Municipal water for Butler, Pa., reaches a pumping 

 plant near the city by gravity flow through a 24-inch pipe line laid in 1907. This 

 pipe is 5 milos long from Boyds Town Reservoir to a settling tank. The max i m um 

 static head is about 67 feet. The last half mile is a cast-iron pipe, while the rest is 

 a white pine machine-banded wood pipe. As there was considerable leakage through- 

 out most of the wood pipe a straight reach of the latter 1,357.7 feet long was chosen 



