009, _C_ should have been 131. It
was actually 138, making _n_ = 0.00866. The 16-in. line was working on a
grade of 0.0030625, and, with _n_ = 0.009, _C_ should have been 145. It
was actually 141, making _n_ = 0.0092.
Referring to the estimated hydraulic grade between Coyote and Corona
(Plate V), the coefficients, 0.01 and 0.012, were used for wood and
iron, respectively, on which basis, the maximum pressure at Coyote was
expected to be 304 lb. and, at Luna, 310 lb. per sq. in. The actual
maximum at Coyote, with pumps at full normal speed, was 270 lb., and, at
Luna, 278 lb., indicating that the values of the coefficients taken were
too high. This checks with the tests between Bonito and Nogal.
Of course, the iron pipe will increase in roughness, and, in time the
pumping pressure will approach the calculated amount. The interior of
the iron pipe now has a smooth coat of asphalt.
_Pipe Breakage_.--The breakage or damage to the wood pipe in shipment
occurred on the ends, the tenons being most exposed to injury from
shifting in the cars. The damage due to the shipment and handling of the
Elmira pipe was 1% and one-half as much for the Bay City pipe. Less than
6 pieces out of 100,000 laid have had to be removed from the trench.
The iron pipe came from Chattanooga, and was badly handled in transit.
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