lb. strength, with an elastic limit half as great. The winding was
spaced to limit the tension to 15,000 lb. per sq. in. If severe
water-hammer is present, the ordinary working stress should be
materially less than the latter, otherwise the spiral bands will stretch
enough to permit the water to spurt out between the staves. This was
determined to be true on 4,500 ft. of 12-in. pipe connecting the
Carrizozo Reservoir with a water column at the roundhouse there. In
pumping tests at the mills, attempts were made, at various times, to
burst the pipe, but they never succeeded. Before the elastic limit was
exceeded, the water was running out between the staves as fast as the
pump forced it in. On the following day, pipe thus tested would carry
the pressure for which it was designed without leaking. Except for
defects in the band, pipe of this kind will not burst in the service
for which it is properly designed. This is true, without exception, of
the 100,000 pieces of pipe in this service.

There has been some trouble with a number of the riveted splices on the
banding. Such a splice occurs for every spool of banding used. In every
case where one of these splices has pulled apart, the break was the
result of defective riveting, permitting the rivets to pull out. In no
case has a rivet been found sheared off, and even one good rivet appears
to be sufficient to prevent rupture. The explanation is found in the
high frictional resistance between the band and the pipe, which
distributes the weakness of a bad splice over several adjacent turns of
the band around the pipe. The band loosens a few turns only on either
side of a parted splice, generally not more than three. In no case has
any pipe been removed from the trench, repairs being made without
interruption to the flow of water.

It is desirable to substitute welding for the riveting of these splices.
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