42 BULLETIN" 376, U. S. DEPARTMENT OF AGRICULTURE. 
well toward the juncture with the cast-iron pipe, which was considered tight. This 
fact permitted a close determination of the pipe's discharge by the rise of water in 
the settling tank (PI. I, rig.. 3), which is 50 feet in diameter, with vertical sides. Cor- 
rections were made for baffle walls and other displacement. The surface of the water 
in the tank was taken at 1-minute intervals with a plumb bob and steel tape. Mer- 
cury manometers were used at both ends of the reach. During any one run of water 
the mercury columns fluctuated but a few thousandths of a foot. The pipe is buried 
about 2 feet deep and is slightly elliptical. The mean of the areas of 10 pieces of pipe 
remaining from construction was taken as the area of the water section. Nothing is 
known regarding the interior of this pipe, but the observations indicate that the 
capacity is 5 per cent less than the discharge computed by the new formula. 
No. 30, Expt. S-l, 24-inch Jointed Machine-Banded White Pine Pipe, 
Norfolk County Water Co., Va.— Water for domestic use in the territory in 
Norfolk County, Va., is pumped through 9 miles of 24-inch Canadian white pine 
machine-banded pipe from the Cadillac Pumping Plant to the plant in Princess Anne 
County. The pipe was laid during 1912 in lengths of from 3 to 12 feet. It is buried 
from 18 inches to 4 feet in sandy soil. The wood where bored for the manometers was 
sound, but the superintendent of the plant stated that there were several leaks in the 
line. This pipe is in use throughout the year. The reach tested is free from either 
horizontal or vertical curvature. It is 1,077.5 feet long, beginning about 100 feet 
below a gentle curve and extending to a point near the second pumping plant, where 
the pipe discharges over a rectangular weir into a concrete reservoir. The absence of 
moist ground indicated that there were no leaks on the reach tested, but the interior 
of the pipe was partly choked by a spongy growth. The velocity of water in the 
pipe was found by fluorescein tests. The discharge was determined by hook gauge 
readings for head on the weir shown in Plate I, figure 2. No correction is necessary 
for velocity of approach toward the weir, but the conditions of contraction are not 
quite standard. Mechanically the weir is well constructed and the discharge was not 
more than 2 per cent in error, in the estimation of the writer. The mean cross-sec- 
tional area of the interior of the pipe was determined by dividing the discharge as found 
above by the velocity as shown by the color. This area was 2.831 square feet, while 
the nominal area of a 24-inch pipe is 3.142 square feet. Loss of area was for the most 
part caused by the dense blanket of spongy growth adhering to the lower third of the 
circumference. As near as the writer could determine from the outlet end of the 
pipe, the rest of the perimeter of the pipe was smooth. With the above assumptions 
as to the true area of the pipe, the capacity is indicated by the observations to be 7 
per cent greater than the discharge computed by the new formula, but if the presence 
of the growth were not known and the nominal size of the pipe accepted as the true 
size, then the capacity would be considered equal to the discharge computed by the 
new formula. 
No. 31, Expt. S-15, 24-inch Continuous-Stave Redwood Pipe, Ogden, 
Utah. — Water for municipal uses is conveyed through Ogden Canyon to a reservoir 
near the city in a 24-inch redwood pipe, originally laid in 1890. The use to which 
this pipe is subjected, of course, requires it to be wet throughout the year, which is 
a more favorable condition than that usually encountered in irrigation practice, where 
a pipe is used but six to eight months. On the other hand this pipe practically 
reaches the hydraulic grade line at some of the summits. (During tests by the writer 
the water column at gauge No. 2 extended but 1 foot above the top of the pipe.) Thus 
there is not sufficient head for thorough saturation, yet the pipe appears to be in fairly 
good condition. The very rugged topography of this canyon precludes the use of 
long tangents in either horizontal or vertical alignment. The reach chosen for test 
commenced at the pipe bridge over Ogden River near "The Hermitage," where a 
mercury manometer was located as gauge No. 1. Gauge No. 2, a water column (PI. 
II, fig. 1), was placed 2,240.7 feet from gauge No. 1. Douglas fir staves had been used 
