26 BULLETIN" 852, U. S. DEPARTMENT OF AGRICULTURE. 
2. Water entered the riser from an 8-inch pipe directly opposite 
the pipe line tested. In the reach, 1,310.9 feet long between gauges 
there are 3 smaller riser pipes. Gauge No. 2 is attached to a 
piezometer identical in construction with No. 1, held in a position 3 
feet above the outlet of the pipe. 
The water for this system is clear, being pumped from wells in the 
"Palomares Cienaga." 1 So far as the writer was able to determine 
from the inlets and outlets of pipes in this system, there was no 
deposit of either vegetable or mineral nature. 
The nominal diameter of the pipe was used in computing the area 
and quantity. As the velocity was found by the direct method, any 
difference between the true and the nominal area does not affect the 
velocity. If methods of construction used in the eighties were the 
same as to-day, it is possible the pipe is undersized, as that appears 
true of most present-day pipes. 
As it was not practicable materially to vary the discharge in the 
pipe the three observations were taken at about the same velocity, 
although extended over two days. The velocity for any one run 
was taken as the mean of three batches of fluorescein, injected with a 
" color gun" into the intake of the pipe line at the foot of the riser 
pipe at gauge 1, and observed in the low riser pipe at gauge 2. Water 
was immediately withdrawn from the pool so that there was no 
uncertainty due to color lagging at the outlet. 
The capacity of this pipe is slightly greater than that of most 
pipes built in the eighties, but it appears to be absolutely clean, 
though with rough joints. The value of C s is about 0.292. * 
No. 2, Experiment S-21. — 10-inch jointed cement pipe, Irrigation 
Co. of Pomona, Calif. — This pipe line, between boxes 364 and 366, 
was laid in 1888. The gauges and piezometer connections were 
identical with those used and described under No. 1. Piezometer 
No. 1 Was placed 6 feet down the pipe line from the riser pipe forming 
delivery box No. 364 while piezometer No. 2 was thrust 1.7 feet into 
the pipe against the current, from box No. 366. A reach of line 
1,107 feet long, straight in alignment and profile, was thus tested. 
Three batches of fluorescein were timed for each observation, the 
mean time being accepted in computing velocity of the water. The 
nominal diameter was accepted in computing areas and quantity of 
water (see No. 1, p. 25). So far as is known, this line had never 
been disturbed since it was laid. There is probably little or no sedi- 
ment in the line, as the water is clear. The capacity of this line is 
slightly more than usual in this vicinity, the value of C s being about 
0.272. 
No. 3, Experiment S-28. — 10-inch jointed cement pipe, San 
Antonio Water Co., Ontario, Calif. — This experiment was conducted 
on a straight reach of pipe laid in 1905 diagonally through an orange 
grove. In the 10 years since then it has not been necessary to dig 
up the pipe for root troubles. The nominal diameter was accepted 
in computing area and quantity of water (see No. 1, p. 25). Both 
gauges consisted of piezometer tubes of type A leading to water 
columns in glass. The orifices for gauge 1 were located 12.8 feet 
down the pipe from its intake in a masonry division box, while those 
for gauge 2 were 936.2 feet farther downstream, and 2 feet above the 
i The Use of Underground Water for Irrigation at Pomona, Calif., by C E. Tait, O. E. S. Bui. 236, U. S. 
D.A.,p.35. 
