The trouble is not present with the round band, the wrapped splice of
the latter giving practically 100% efficiency.
The flat band was chosen for this work because it is the more
effectively buried in and protected by the asphalt, and will not crush
the soft wood staves under high pressure. The longevity of either the
flat or the round steel band is dependent primarily on effective
protection against contact with corrosive elements. Wrought iron should
be used for this kind of service, and, for the same reason, for many
other purposes. Engineers and consumers should join in some
comprehensive and effective plan to bring back the old-time production
of high-grade wrought iron.
_Wood Staves_.--The staves of this pipe are of Michigan and Canadian
white pine. This pine cannot now be had of clear stuff or in long
lengths in large quantities; otherwise, it is unexcelled. Douglas fir
and yellow pine, coarser and harder woods, have the advantages of clear
lumber and long length. Cypress is not as plentiful, and redwood is
costly. The mill tests did not determine definitely the minimum degree
of seasoning necessary, and press of time compelled the acceptance of
some rather green lumber. Service tests do not show that there is any
abnormal leakage from pipe made of such lumber, and it could not now be
distinguished in the trench by such tests.
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