The Sun.
London, England, 1863-08-22 00:00:00

IRON SHIPS AND IRON PLATING.

The following extract from the Mechanic's Maga-
zine of Saturday, June 5, 1824, shows how corn
pletely the ideas of what are considered modern
discoveries was anticipated by scientific writers 40
years ago. It would seem as if 40 years represented
the necessary time between the conception and the
execution of an idea :

" Since the discovery by Mr. Perkins of so vast a
destructive power as his steam artillery, it becomes
of more importance than ever that nations should
learn to make their ships as shot and shell proof as
possible. On this subject there is, in Ferusae's
Bulletin des Sciences Technologiques, a memorial by
M. de Montgery, a captain in the French navy,
which is well worth attention, and from which
chiefly we shall extract the materials of the present
notice.

" The author's object is to recommend the uni- I
versal adoption of iron instead of wood in the struc-
ture of ships. A. multiplicity of objects formerly
composed of wood are now formed of iron—bridges,
arches, aqueducts, public highways, and other
objects not so colossal, but very important in their
application to maritime affairs, such as wrought
iron tanks and hollow cylinders for masts and yards,
and chains in lieu of hempen cables and cordage.
But why up to this time have there been so few
vessels constructed entirely of iron ? Will not man-
kind
at some future period wonder how enlightened
nations could have thought of building objects so
stupendous and so expensive with so fragile and
perishable a substance as wood, while they possessed
a material to substitute for it so solid and durable
as iron ? The ordinary term of duration of wooden
ships is 20 years, and during that period they
must be hove down and thoroughly repaired three
or four times. To the duration of an iron ship,
on the contrary, it would be difficult to assign
any period. Vessels of this description have no
need of caulking, or copper bottoming. Little sub-
ject to leaks, there is less fear of their running
ashore ; and still less are they subject to the
casualty of fire. The first cost of them might be
greater (that we doubt), but from their far greater
durability, and standing so little in need of repairs,
the saving in the end would be immense. It de-
serves further to be considered that large timber is
becoming every day more and more scarce, while
from the increased dimensions of new ships more
wood is required in ship building ; of iron, on the
contrary, the stores are inexhaustible. It may be
said that the adoption of iron would serve to uncraft
or disqualify a numerous body of men (the ship-
wrights), and throw them for a time out of employ-
ment. A temporary inconvenience to a few ought
not, however, to be opposed to a great general good,
considering, moreover, how much the country at
large would gain by the increased activity which
this new demand for iron would give to our mines,
commerce, and agriculture.
"M. Mon tgery contends that while we have
vessels of war constructed of wood they should at
least be plated with iron, and it will be seen from
the following passage that he had distinctly antici-
pated such an application of projectile force as that
discovered by Mr. Perkins :

For more than 350 years it has been in agita-
tion to throw shells from mortars horizontally, in-
stead of elevating them according to the general
practice. The adoption of howitzers in the field of
battle, independently of a great number of special
experiments, has at length proved beyond doubt
the importance of this mode of firing, which it has
also been proposed to adopt on board ships and on
marine batteries.'
"Loag before any one had thought of substitut-
ing metal for wood in the construction of large
vessels, plates of iron or brass had been used for
covering ships of war and battering rams. The
cerebrated galley built by Archytas and Archi-
medes for Hien, tyrant of Syracuse, was cased in
this way. Philo, of Byzantium, afterwards pro-
posed using battering machines made entirely of
metal ; but Father Mersenne appears to have been
the first who thought of adopting them for ships.
Montgery says that to lender the sides
of a vessel shot and shell proof they should have a
plating of iron about Gin. thick—that is, a series of
sheets of iron, with blocks of cast iron between.
He conceives that the block would only be neces-
sary in the parts exposed to the tire of the enemy,
and that there would be no occasion for them to-
wards the keel of the vessel."