e labor required to fit and smooth and
polish them, that a pair of them costs several thousand dollars before
they are completed and ready to fulfill their function.

The superiority of metallic boats, whether of copper or iron, made in
the manner above described, over those of any other construction, is
growing every year more and more apparent. They are more light and more
easily managed, they require far less repair from year to year, and are
very much longer lived. When iron is used for this purpose, a
preparation is employed that is called _galvanized_ iron. This
manufacture consists of plates of iron of the requisite thickness,
coated on each side, first with tin, and then with zinc; the tin being
used simply as a solder, to unite the other metals. The plate presents,
therefore, to the water, only a surface of _zinc_, which resists all
action, so that the boats thus made are subject to no species of decay.
They can be injured or destroyed only by violence, and even violence
acts at a very great disadvantage in attacking them. The stroke of a
shot, or a concussion of any kind that would split or shiver a wooden
boat so as to damage it past repair, would only indent, or at most
perforate, an iron one. And a perforation even, when made, is very
easily repaired, even by the navigators themselves, under circumstances
however unfavorable. With a smooth and heavy stone placed upon the
outside for an anvil, and another used on the inside as a hammer, the
protrusion is easily beaten down, the opening is closed, the continuity
of surface is restored, and the damaged boat becomes, excepting,
perhaps, in the imagination of the navigator, as good once more as ever.

Metallic boats of this character were employed by the party under Lieut.
Lynch, in making, some years ago, their celebrated voyage down the river
Jordan to the Dead Sea. The navigation of this stream was difficult and
perilous in the highest degree. The boats were subject to the severest
possible tests and trials. They were impelled against rocks, they were
dragged over shoals, they were swept down cataracts and cascades. There
was one _wooden_ boat in the little squadron; but this was soon so
strained and battered that it could no longer be kept afloat, and it was
abandoned. The metallic boats, however, lived through the whole, and
finally floated in peace on the heavy waters of the Dead Sea, in nearly
as good a condition as when they first came from Mr. Francis's