APPENDIX. 
The following pages are devoted to abstracts of the descriptions of 
experiments made by agencies other than the Irrigation Division, 
Bureau of Public Roads. The first part covers tests made on pipes 
under pressure while the last portion covers tests made on pipes and 
conduits but partially filled. The number before each description 
refers to the corresponding numbers in column 1, Tables 3, 4, and 11. 
PRESSURE PIPES. 
No. 12, Experiment N-l. — 16-inch jointed concrete pipe, Z a , siphon, 
Umatilla project, United States Reclamation Service, Oregon. — In 
1911 and 1912 Herbert D. Newell, manager of the Umatilla project, 
conducted a series of experiments on several of the concrete inverted 
siphons under his charge. For the sake of brevity the descriptive 
matter pertaining to all the tests will be abstracted from his extended 
article, 1 and placed under this number. Matter pertaining to indi- 
vidual pipes will be placed under the proper reference number. He 
states : 
During 1911 and 1912 a number of experiments were made to determine the coeffi- 
cient of friction. The quantity of water was generally determined by meter meas- 
urements. Difference of water surface elevation between the inlet and outlet ends 
were determined from bench marks carefully established on the inlet and outlet struc- 
tures. 
Regarding the 16-inch pipes he adds: 
No information exists as to whether or not the 16-inch pipes are somewhat ob- 
structed near the bottoms of depressions. It will be noted that the 16-inch pipe show 
discharges relatively much smaller than the 30 and 46 inch pipe. The 16-inch are 
made by the dry process and have joints every 2 feet. At every joint there is una- 
voidably a slight irregularity in the cross section. The mixture used in making the 
30 and 46 inch pipe is distinctly a wet mixture. All sizes are grouted on the inside, 
but the grouting on the large size is more smooth, as a man can work inside the pipe 
and it is possible to do a better job. 
The nominal size of the pipe appears to have been accepted as the 
true size. In the experiment on this particular siphon the quantity 
of water for the first observation was taken as the mean of two meter 
measurements, one indicating a discharge of 3.78 second-feet and the 
other 3.70 second-feet. For the second observation the mean of three 
measurements, ranging from 4.78 to 4.97 second-feet was accepted. 
From the amount of the friction loss the writer would judge that 
some debris had accumulated between the time this pipe was laid 
and the date of the experiments. The retardation factors are not 
consistent. 
No. 13, Experiment N-2. — 16-inch jointed concrete pipe, Z c siphon, 
Umatilla project, United States Reclamation Service, Oregon. — In 
addition to the information given under reference number 12a for the 
series of tests conducted by Newell, the following pertains to this pipe 
alone: 
1 Studies of Coefficient of Friction in Reinforced-Concrete Pipe, Umatilla project, Oregon. By H. D. 
Newell, Eng. News, vol. 69, May 1, 1913, p. 904. 
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