88 BULLETIN 852, TJ. S. DEPARTMENT OF AGRICULTURE. 
The discharge was measured with a current meter. Depths were 
determined from a horizontal straightedge. On account of rough 
topography, floor elevations as furnished by the company were 
accepted in computing the slope of the water surface. The value of 
n was found to be 0.0127. (See p. 1 1 for Mr. Lippincott's conclusions.) 
No. 59, Experiment JBL-2. — Tunnel No. 23 of the same system as 
above. — Of this experiment Mr. Lippincott writes: 1 
This test was made at tunnel No. 23 of the same system. Conditions were similar 
in all respects, except for slight curves just below north portal and above south portal. 
The length of tunnel is 318 feet and grade of floor 0.00095 foot per foot; n here was 0.0115. 
(See p. 11 for Mr. Lippincott's conclusions.) 
No. 60, Experiments JBL-5 and 6. — Main supply conduit for Los 
Angeles, Calif. — These tests are described as follows: 
These were on the main supply conduit for Los Angeles, near the old ostrich farm, 
several miles north of Los Angeles. It is covered and has been in use four years. The 
length of section was 700 feet, being between two manholes. A curve occurred on this 
section. The wetted perimeter was very smooth, apparently of a 1 to 3 cement 
mortar. There was no sand, moss, or vegetable growth of any kind. Experiment 5 
was at the upper and 6 at the lower manhole. The grade of the floor was the 
same as that of the water surface. The surface was a cement plaster on concrete. 
The value of n here was 0.0112 and 0.0109. (See p. 11.) 
No. 61, Experiment AFB-1. — Loch Katrine Aqueduct, Glasgow, 
Scotland. — The concrete-lined portion of the new aqueduct from 
Loch Katrine to Glasgow was tested in 1895 by A. F. Bruce. 2 Of 
the construction he writes : 
Open frames of 6-inch by 2-inch battens were first placed in position and three- 
fourth-inch tongued and grooved boards, smeared with soft soap, nailed to the frames 
horizontally as the concrete was filled in. Every possible precaution was taken by 
working with spades to obtain a good face, and except where some defects showed 
themselves, no redressing was afterwards necessary. 
About 53 per cent of the aqueduct was lined. The section units 
were from 12 to 15 feet long, generally 12 feet. The reach tested 
was straight. The quantity of water was measured over a weir. 
The depths of water in the aqueduct were read on gauge rods in the 
chambers. Water at the lower end was checked by the fact that 
one siphon gate below the reach under test was closed. 
The lined section is 9 feet 1 inch wide on the bottom, with the 
invert dished 6 inches. The sides batter until at the spring line the 
width is 10 feet. The rise of the arch is 3 feet. Depth over all is 
9 feet. 
Most of the observations indicate a correct value of n for this new 
channel of about 0.0124. 
No. 62, Experiment P-l. — Aqueduct of the Serrino, Naples,Italy. — 
In 1896 Perrone wrote 3 of a test made on the aqueduct of the Ser- 
rino, at Naples, Italy. This channel, of pure cement, polished, had 
vertical sides and elliptical bottom. The discharge was measured 
with a current meter. The value of n, being but 0.0107, indicates 
the workmanship and lack of slime to be all that the short descrip- 
tion implies. 
1 Observations to determine the value of C and n as used in the Kutter formula by J. B. Lippincott, 
Engin. News, June 6, 1907, vol. 57, p. 612. 
2 Observation on the Flow of Water in the New Aqueduct from Loch Katrine; Glasgow Corporation 
Waterworks, A. F. Bruce, Paper No. 2921, Pro. Inst. Civil Engineers, Vol. CXXIII, 1895-96, part 1, p. 
410. 
3 Zoppi, Sul Volturno, Carte Hydrographique d'ltalia; The Flow of Water, by Louis Schnieer, New York 
1909, pp. 46, 80, 93. 
