78 BULLETIN 852, U. S. DEPARTMENT OF AGRICULTURE. 



The quantity was taken as the mean indicated by two current 

 meter tests, one giving 3.19 and one giving 3.65 second-feet. This 

 agreement is not as close as it should be. For this reason the writer 

 would not give too much weight to the results of the experiments on 

 this pipe in considering the friction loss which appears rather low 

 for this type of pipe. The pressure head was measured by a " testing 

 gage." The one observation on this pipe shows a value of C 5 = 0.314. 



No. 19, Experiment. — Fanning 20-inch cement-lined wrought-iron 

 force main pipe. — In 1880, J. T. Fanning conducted a series of experi- 

 ments and listed the results in his well-known work on hydraulics, 1 

 but he does not give a description of the pipe or of his methods of 

 experimentation. Hering and Trautwine say of this pipe: 2 



No short bends, but two large Y branches, two small blow-off branches, and three 

 stop valves. 



No. 24, Experiment N-3. — 30-inch reinforced concrete jointed 

 pipe, T>! siphon, Umatilla project, United States Reclamation Service, 

 Oregon. — This pipe, laid in the winter of 1909-10, was tested for 

 capacit} r by Mr. Newell in 1911 and by the writer in 1915. (See 

 No. 23.) For general data on the Newell tests see No. 12a. 



The elevations of the surface of the water at the inlet and outlet 

 structures were determined by the use of a hose pipe and water pail, in 

 a manner similar to that later used by the writer when other methods 

 were not feasible. By means of a true siphon over the wing walls the 

 surface of the water in the pail and in the canal are brought to the 

 same level. 



For observation No. 1 a single weir measurement was accepted as 

 indicating the discharge, while for observation No. 2 a single meter 

 measurement indicated a discharge of 16.62 second-feet and a meas- 

 urement at the weir at the inlet indicated a discharge of 17.04 second- 

 feet. As noted in Table 2 the various elements have been computed 

 for both these indicated discharges, rather than averaging them. 

 This method follows Mr. Newell' s original article. 



A comparison of the platted points for this pipe (PI. VI) indicated 

 that it was very smooth when new, but had become somewhat ob- 

 structed when tested by the writer four years after Mr. Newell's tests. 

 The relationship of the leading canal to the intake clearly shows that 

 this is highly probable. The average value of C a for the three observa- 

 tions equals 0.408, which is higher than usual, even for the best of 

 construction. 



No. 25, Experiment N-4. — 30-inch reinforced concrete jointed 

 pipe, R 3 siphon, Umatilla project, United States Reclamation Service, 

 Oregon. — This pipe was tested by Mr. Newell when it was in its 

 fourth season of service. The discharge was taken as the mean of 

 three measurements by current meter, ranging from 12.76 to 12.42 

 second-feet, to which was added 0.032 second-foot which passed a 

 weir. Mr Newell states: "It is not unlikely that there is a con- 

 siderable deposit of sand in the first low depression." This would 

 not appear to the writer to be a serious deposit, as the friction loss 

 indicates a very efficient pipe. The relatively great length of the 

 reach, 3,658 feet, makes this a valuable test, so far as one observation 

 is indicative. The value of C s equals 0.351. 



1 A Practical Treatise on Hydraulic and Water Supply Engineering, by J. T. Fanning, 11th ed., New 

 York, 1893, p. 238. 



s E. fJanguillet and W. R.Kuttcr, translated by Rudolph Hering and John C. Trautwine, jr. A General 

 Formula for the Uniform Flow of Water in Rivers and Other Channels. New York, 1907, 2d ed., p. 154-155. 



