42 BULLETIlSr 376, V. S. DEPAKTMENT OF AGEICULTUEE. 



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, fig. 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, iler- 

 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-1, 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 Pimiping 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 neai' 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 



