ound Durable Metal Coating an
excellent preservative. Bands coated with this preparation were buried
in a salt marsh, and, after a year, the metal was found intact and the
coating fresh and elastic. This coating, however, does not adhere very
firmly to a smooth metal surface, so that, with careless handling,
patches may become rubbed or torn off.

There is no advantage in coating the surface of the pipe. To prevent
decay, such pipe should carry water under pressure or be laid in a
saturated soil, so that the wood of which it is made will always be
saturated, and coating the wood may interfere with this. Under these
conditions the life of such pipe is not known, but it is evidently very
great. Large quantities of wood pipe have been removed from trenches in
Boston, New York City. Philadelphia, Baltimore, and elsewhere, usually
in perfectly sound condition. It was commonly made of logs of spruce,
yellow pine, or oak, from 12 to 18 ft. long, 12 to 24 in. in diameter,
and with a bore from 3 to 6 in. in diameter. Some 6-in. pipe taken up in
Philadelphia had an external diameter of 30 in. The ends were usually
bound with wrought-iron collars, and adjacent lengths were connected by
an iron thimble driven into the end of each piece.

A few years ago the writer took up more than 2000 ft. of wood pipe of
this kind, which had been laid in saturated soil about a century
earlier. It was of Southern pine logs, about 16 in. in diameter, 14-1/2
ft. long, and had a 5-in. bore. Joints were made with tapering cast-iron
ferrules 9 in. long, and connections to smaller service pipes were made
with similar but smaller ferrules of cast brass. The wood was apparently
as sound as when it was first laid.

The use of flat iron for wrapping or banding pipe is believed to be
wrong in principle. Round iron furnishes the requisite strength with the
least exposure to corrosion, and ensures a more perfect contact with the
wood.

In a 42-in. stave pipe laid by the writer for the Water Department of
Atlantic City, N.J., the lumber used was Washington fir, cypress having
been found difficult to procure in sufficient quantity, and redwood
being more costly and no better. In this, his experience coincided with
that of the author. Cedar was considered, but could not be obtained in
sufficient lengths or quantity, and long-leaf pine which would have
passed the somewhat rigid specifications would have been difficult to
secure. It is believed, however, that t