THE FLOW OF WATER IN WOOD-STAVE PIPE. 75 



No. 5. 6-inch Jointed (Machine- Banded) Wood-Stave Pipe, Sunnyside 



Project, U. S. Reclamation Service, Washington. — This pipe was built for 

 irrigation purposes about five months before the tests. It is practically straight in 

 both horizontal and vertical planes. Water columns were used for both gauges. 

 Discharge was measured over a 12-inch Cipolletti weir. The capacity of this pipe 

 was about 4^ per cent greater than the discharge computed by the new formula. 



Nos. 6, 7, 8. 6-inch Jointed (Machine-Banded) Wood-Stave Pipe, Sunny- 

 side Project, U. S. Reclamation Service, Washington. — This new pipe had 

 been used for irrigation purposes about four months at the time of tests. Alignment 

 and profile were as described for the 8-inch pipe in abstracts for Nos. 9, 10, 11, and 

 12. Water columns were used at both gauges. Discharge was measiured over a 12- 

 inch Cipolletti weir. Usual velocity was about 3 feet per second. Three reaches on 

 the one pipe were tested. The capacity appeared to be about that computed by 

 the new formula. 



Nos. 9, 10, 11, 12. 8-lnch Jointed (Machine-Banded) Wood-Stave Siphon 

 Pipe, Sunnyside Project, U. S. Reclamation Service, Washington. — This 

 pipe, built for irrigation purposes, had been in use about five months at the time of 

 tests in 1909. Approximately the same reaches were again tested in 1910. Nos. 9 

 and 11 consist of two tangents intersecting at an angle of 16° 40^ made by a gentle bend 

 with short lengths of pipe. They include the dip in the profile. No. 11 is 120 feet 

 longer than No. 9. Reach No. 12 includes No. 11 with an additional 540 feet of 

 straight pipe on the upstream end. Reach No. 10 is the final 2,002 feet of Nos. 9, 11, 

 and 12, is straight in horizontal alignment, but includes the dip. A remarkable con- 

 trast appears in these tests . In 1909 the capacity was about 7 per cent less than that com- 

 puted by the new formula. In 1910 the tests on the same pipe indicated an apparent 

 increase in capacity to about 20 per cent more than the discharge computed by the 

 new formula, when reach 11 was considered ; but reach 12 (which includes No. 11 and is 

 but 15 per cent longer) showed the capacity to have increased to but 5 per cent more than 

 the average. It should be noted that velocities in No. 11 were far greater than those 

 in No. 12. A study of figxire 5 fails to show a general tendency toward increase in 

 capacity with age of pipe. The tests on reach No. 11 plot (see PI. VI) in the zone 

 normally occupied by those on a 10-inch pipe. 



No. 15. 10.12-inch Jointed (Machine-Banded) White Pine Plpe,i Bonlto 

 Pipe Line, El Paso & Southwestern Railway, New Mexico. — This pipe Une, 

 part of which is 10- inch and part 16-inch, is more than 100 miles in length and is used in 

 connection with a railway water-supply project. In 1908, 1909, and 1911, J. L. 

 Campbell made tests on both sections. The larger pipe joins the lower end of the 

 smaller pipe at an open standpipe. In measuring velocities the experimenter 

 used bran and colors, accepting the first appearance of the bran or color in 

 computing the period elapsed between the time of their injection and their 

 later appearance. The fact is well known that the velocities near the center of 

 the pipe are higher than those near the perimeter, and thus higher than the mean 

 velocity. Hence if the first appearance of the color is accepted then a velocity in 

 excess of the mean is indicated. In the opinioc of the writer this fact accounts for 

 the low friction factor found, and for this reason he did not use these tests in the deriva- 

 tion of the new formula. For additional discussion of these tests see page 11. Had 

 the elapsed time been considered as from the moment of color injection to the mean 

 of its first and last appearance at the outlet, a highly satisfactory series of tests would 

 have resixlted. The latter method was employed by the writer and is mentioned by 

 Roy Taylor in connection with tests on the Altmar pipe,^ No. 51. 



No. 16. 12-inch Jointed (Machine-Banded) Wood-Stave Pipe, Sunnyside 

 Project, U. S. Reclamation Service, Washington. — This pipe was built for 



1 Engin. News, 60 (1908), p. 225; Trans. Amer. Soc. Civ. Engin., 70 (1910), p. 178; 74 (1911), p. 455. 



2 Engiii. News, Sept. 23, 1915. 



