The Sun.
London, England, 1862-08-25 00:00:00

degree of interest than the one relating to
No question is invested at present witliiigrear
pro-
duction of plate armour for ships of war. That the
Lords of the Treasury and the Admiralty are fully'
alive to the vast importance of the subject has long
'l^en evident. Scientific committees, assisted by the
first metallurgists of the day, have been employed
to conduct all kinds of experiments and report upon
them. A vast fund of information must also have
been forwarded by Capt. R. S. Hewlett, C. 8., re-
garding the experimental firing at Portsmouth; and
testing sample plates still proceeds there as fast as
they can be attached to the target ships. In testing
these sample plates the knowledge gained of the
structure of different kinds of iron has been- great.
Some of the plates, on being struck by several 68-
pounder shot, in nearly the same plate, so as to com-
pel a fracture, have exhibited a peculiar silvery~
appearance in the separated parts of the metal ,
which at the same time have shown an extra-
ordinary length of fibre. This was parti
cularly the ease with the rolled plates
made at the Parlegate Works for the experimental
angulated target of Mr. J. Jones of Liverpool. In
these plates, however, as in most other rolled plates
manufactured at that time, the greutcst injury by
the shot was found to be inflicted on the reverse
side of the plate, next the timber backing-, where
the layers of the metal being opened by the saidden
shock of the GB pound shot, they spread out with
radiating cracks, and penetrated the timber to an.
average depth of from 4to 5 inches. The Atlas
Works rolled plates were equally faulty with the
Parkgate plates, but constant man ufacture aud the
plates from both works .
constant practice at sample
on the sides of the target ship irn Dorchester Creek
which are witnessed by a representative from the
firms, have supplied such an amount of valuable
data to the manufacturer that they have recovered
for rolled plates the prestige they at first had in
sabeir competition with hammered plates. It he's
'now become a moot point which kind can be mann-
, factured that shall to a certainty possess greater
allot reeieting powers than the other. Of hammered
plates the Thames Iron Shipbuildiog Company arc
undeniably the best makers ; in fact, it seems at
present quite impossible, if their best saople plates
tested at Portsmouth be selected, to manutiacture a
more 'perfect armoar plate. Other makers azsain,
have not been so successful, owing, no doubt, to want
of experience in manufacture, but they
evidently
improve in each succeeding plate sent for testing.
Of the condemned plates, some have broken clear
through, line cakes of ice, with through rents in
all directions. Others have separated into layers,
so that the 41 inch solid plate has been transformed
into half a dozen thin sheets. In both cases, any
ship covered with such armour would be more easily
destroyed by shot than any common wooden ship
could be. We have selected the best and worst de-
scription of plates as an illustration, but there Arc
many other makers who have supplied plates which,
although they may not stand in the first rank, de-
cidedly do not in the last. It also happens at
times that a plate of a very inferior quality is
tested which has been supplied from a firm
noted for the general excellence of theiz plates.
In fact, this has happened with each of the three
firms quoted above, and not in every instance earl the
cause of the plate's defect be satisfactorily accounteo
for. The vast establishment which have been formed
by private individuals for the manufacture of iron
plates by the roller and by the hammer, and in some
instances by both combined, and the fine specimens
of the manufactured and unmanfactured metal in
the International Exhibition, all prove that the
great iron workers of the country are equally alive
with the Lords of the Treasury and the Admiralty
to the daily increasing importance of iron in ship-
building and in the manufacture of heavy ordnance.
Perhaps if one part of the question is more open
than another to a definite settlement at the: present
moment, it is the description of iron most sa;table
for the manufacture of the armour plate. 'll.his
appears to lie between the " puddled'' and " scrap,"
Both have their advocates. There are, however,
now being manufactured in the smithery of Ports-
mouth Dockyard, under the large steam hammer,
two plates, expressly to settle this question for the
present, as far as may be possible. One is being
made exclusively from the dockyard scrap iron, and
the other from the beet Shropshire " puddled."
Each plate is being made hilt. in length, 3ft. 6iii.
in breadth, and SA-in. thick, but will be afterwards
cut in two parts, one to be annealed and the other
not. When completed they will be tested in the
usual manner by the Stork's 6S-pounder in Por-
cheater Creek, and the results cannot fail to be very
interesting and important. Several plates Were
forged some time since in this same smithery,whial
proved on being tested at Shoeburyness, to be of
very good quality, and in the forthcoming trial a
Goverment establishment may possibly take the
first position on the list for the manufacture of
ship's armour.
The screw steam frigate Shannon, 35, Capt.
Oliver I. Jones, from Spithead,arrived in Plymouth
Sound on Saturday morning, and sailed in the after-
noon for the Mediterranean.
The War Department screw steamer Lord Pan-
mure, T. Moore, master, left Plymouth Sound on
Friday evening for Woolwich.
The screw steam sloop Rattler, 17, Commander
Howard, from Spithead, arrived in Plymouth Sound
on Friday. She is having defects made good, pre-
vious to sailing for China, her destination.
The corvette Niobe, 25, one of the vessels pur-
chased for the Prussian Government, was towed
from Hamoaze into Plymouth Great Western Docks
on Saturday, to be fitted up by Mr. Moore, ship-
builder, of Friary-yard.
The paddlewheel steamer Monkey went down to
Sheerness on Saturday, from Woolwich, conveying
B(lianc k t
h Eagle, agle
of
mos.
Henry D.
absence,
90 supernumerary seamen for the fleet.
tSearTr.rheaeot paddlemmaans tdeer in steam-yacht
Polley, commando
nspecial duty
in the ser-
vice of the Viceroy of Egypt), went down the river
on Saturday, from Woolwich, on a trial of her ma-
chinery after repairs. The Black Eagle is under
orders to embark her Majesty's baggage and car-
riages for conveyance to Ostend.