The Liverpool Standard and General Commercial Advertiser.
Liverpool, Merseyside, England, 1842-06-07 00:00:00

to some useful end."
He afterwards adds on this point—
" If we view the subject with respect to very large vessels
--ships of the line or first-class steamers, in which inter-
mediate decks are not only not objectionable, but requisite
for the guns and stores, and in which entire or partial bulk-
heads may be multiplied without causing much inconveni-
ence—we have in iron the means of dividing the shell into
small sections, affording the strongest supports directly op-
posed to the strains that tend to disturb the form of the
plates, and in the direction in which they can least resist
such strains. The sides between these decks and bulkheads
would be strengthened by the ordinary mode of framing.
In addition to this, the lower part of the vessel might be
again intersected by longitudinal divisions; arid these decks,
bulkheads, and subdivisions would not only be securely fas-
tened to the shell, but to each other,—the whole thus becom-
ing a mass of almost irresistible strength, meeting the strains
in whatever direction they might arise. while, at the same
time, the weight would be far below that of a timber vessel
of only moderate scantling, and the room for stowage would

be much greater."
In comparing the fastenings of iron ships with those of
wooden vessels he says—
" A most elaborate system of bracing by iron straps,
knees, and bolts with nuts, in addition to the ordinary knees,
diagonal internal planking, stringers, &c. is now pursued.
Tree-nails used to secure the planking are giving way to
bolts, either of copper, iron, or composition, and great addi-
tional strength is thus imparted. But the grand objection
still remains. The bolts do not accord with the materials
they fasten together, and the wood is so soft that when a se-
vere strain arises, a general yielding takes place, by the bolt
heads sinking into it, and the wood itself giving way to the
pressure it receives from the neighbouring parts. In proof
of this it is only necessary to examine the copper sheathing
of a large vessel after a trying voyage, when the waving sur-
face too often betrays the detects within. This effect of
straining is most perceptible in steam-vessels, particularly
under the paddle beams, and sometimes abaft them. The
creaking of a timber-built ship, too, so distressing to lands-
men, and adding so much to the terrors of a storm at sea, is
the result of the unceasing motion which takes place in the
seams, acting on the internal timber work, and particularly
on the cabin partitions and bulkheads.
" A wooden vessel is made up of a great number of parts
of various forms and sizes, placed in different directions,
which, like the stones in an arch, are dependent on each
other for support. If one becomes loose, the whole struc-
ture is more or less endangered. This is evident from the
fact that much of the stiffness of a wooden vessel depends on
the caulking of the outer plank."
Our author quotes in corroboration of his opinions the
following passage from a paper by Mr. Creuze, superinten-
dent of her Majesty's dock-yard at Plymouth, and author of
several highly approved works on naval architecture :
" Two questions naturally arise ; first, what are the ad-
vantages or disadvantages of the substitution of iron for
timber, in the construction of ships ?—and, secondly, to what
limit may this substitution be advantageously carried?
Amongst the advantages are the employment of a less costly
material, of which the supply is inexhaustible, and for which
supply we are totally independent of other nations ; also, the
greater durability of the material, not only from its relative
durability with that of timber, but from its requiring no such
metallic sheathing to protect it from the ravages of worms-
the greater durability of the structure, as a whole, in
Auence of the greater permanency in the perfect combi-
nation of its several parts, arising from the fastenings being
of the same texture as the portions of materials brought into
connexion. The metallic fastenings to a timber-built vessel
act, it must be remembered, not only chemically, but also
mechanically, to accelerate her destruction so soon as the
close connexion of the several parts is at all diminished."
Instances are then adduced in which iron vessels have
suffered severe beating on rocks, shores, and sandbanks in
gales. without sustaining any material injury, while wooden
vessels, under similar circumstances, would inevitably have
been entirely lost. The greater room for stowage in iron
ships is also discussed, and on this point he remarks :
" The shell of a timber-built vessel is so much thicker
than that of an iron vessel, that, with the same outside
dimensions, the latter is frequently 18 inches wider and 12
inches deeper in the hold than the former. Taking the most
favourable part of a vessel—namely, in the centre of the
length—in a vessel of 200 tons, the proportion in favour of
the iron vessel will be as 5 to 6 ; but in the ends, which are
drawn finely off, the disparity is much increased, making the
proportion of the whole contents about as sto 4. Supposing,
therefore, that a vessel built of timber could stow 200 tons,
she would, if made of iron, have room for 250 tons. The
total capacities of the largest vessels will probably not ap-
proximate nearer than as 3 to 6; making the iron ship of
600 tons not to exceed in outward dimensions the timber one
--= The advantage of this is very great, and enables

an iron vessel to trade, and remunerate the owners, in cases
in which a wooden vessel would not return a profit ; for, if
we suppose that the freight of a 500-ton ship would just pay
the expenses required to navigate her, an iron vessel would
leave the freight on the extra 100 tons as clear profit.
" With steamers, the comparison is much more in favour
of iron than with wooden vessels. As the average cargo of
a steamer is only, perhaps, about one-third of the load, in
engine, cargo, and coals together, an increase of one-fourth
in her stowage adds 75 per cent. to her capacity for carrying
cargo. In other words, to carry a given cargo, the iron
steamer may be much less than a wooden one."
The greater safety of iron ships from casualties, as well as
from the dreadful calamity of fire, is ably set forth ; and with
respect to speed it is remarked:—
" The late register laws, which caused more injury to our
mercantile marine than those at present in operation are ever
likely to repair, and which originated and fostered evils that
it may require ages to correct, are no longer obstacles to im-
provement, and their abrogation affords us some hopes that
we shall not for ever be left behind other nations in the speed
of our vessels. I believe I may safely assert that when iron
becomes generally used for the purpose of ship-building, a
much finer form may be adopted, without incurring the dis-
advantages that arise under the same circumstances, in even
the most approved construction of wooden vessels. The ma-
terial being much lighter to attain the same strength, and
occupying less space, the model of the vessel may be made
finer, and better adapted for high speed, without a cor-
responding loss in the amount of stowage and carrying qua-
lities ; and iron vessels, as they have more buoyancy, are
not so liable as timber-built vessels to pitch when in a heavy
sea."

Under the head " durability" our author ably confutes the
supposed rapid corrosion of iron vessels, as proved by several
vessels that had performed long voyages, and thus notices
the decay of timber-built ships :
" The dry rot in wooden ships (which finds no parallel
evil in those of iron) is frequently as remarkable in the ear-
liness of its commencement, as it is invariably rapid in its
progress ; and no appliance hitherto resorted to has, in all
instances, been effectual to avert its insidious development,
or to arrest its destructive progress. The tree which is in-
tended for a timber ship is no sooner felled than the oxygen,
which, during vegetation, is held in harmless combination,
begins its work of decay. The gradual combustion and de•
ter•ioration of the woody fibre supervenes ; carbonic acid i!
evolved ; and the wood, becoming carbonized, loses its flex•
ibility and strength. The progress of this decay is sure
though, by care, its effects may be retarded ; but, from 'l—
numerous instances of its rapid increase, even in well-1
vessels, we are led to conclude that no human foresight
prevent its poison from spreading. like a baleful epide
into every portion of the ship. How many statek,
are now mauldering away under this destructive
while their fine and graceful forms conceal the treachero
enemy within !"
On the question of repairs, our author states—
" It is a great mistake to suppose that iron vessels a
more difficult to repair than wooden vessels ; and, in purs
ance of this error, it is often urged, as an oblection to the,
that, should accidents occur to them in a foreign country,
one could be found capable of making good the damage. Bu
so far is this from being the case, that it is found that nothing
is easier of accomplishment; for the injuries are generally
xternal, and confined to a single spot, and may in most
ntly repaired by any ingenious man, if the

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