The Sun.
London, England, 1869-02-20 00:00:00

INTERESTI2VG OPERATIONS.'

One of the large plates which Sir John Brown and
of Sheffield, have made it their special business to pro-
duce was manufactured only a day or two back at the
famous Sheffield manufactory. Under any system what'
ever lines of joints between the armour-plates are admit'
telly lines of weakness, and it was in view of this well'
known fact that the late Iron-plate Committee, in their
examination of practical men, appeared to keep so Proms
;
neat the important point of whether the entire face of
the shield or casemate could be constructed of one entire
plate ;in fact, with an unbroken front. The eminentnleu
who replied hesitated on this subject, and even the
principal practical men of this great Sheffield firm gave
an absolute denial to the practicability of producing
perfect plate 12 feet by 8 feet in superficial area and sonic
five or six inches in thickness. The fact is now more thsa
accomplished. The immense slab was produced in till°,
wise. From eight o'clock on Thursday evening until pot
noon on the following day the huge pile of iron, consisting
of five slabs superposed, each 7 feet by 6 feet and 3# incbO
thick, or a mass of GO cubic feet, weighing 14 tons, ""
gradually heating during the 16 hours to welding point in
the glowing furnace. At 25 minutes past 12 the furnace
door was opened, and the faint outlines of the pile could be
indistinctly seen through the white rolling flames ; the toegs
were fixed on,and the rolling mill began winding at the head
chain to pull the glowing mass on to the trolly. A sronr.a
of workmen stood by, and the pile, dripping with het
steams of molten metal, was quickly under the huge rollers'
Then came the dull rumble of the mill, and the 001
pile was seized in the iron jaws and passed rapidly
easily through. Then followed the clatter of the revel°
of the mill, and again the rollers grip the yellow IV's!:
and bring it back to view. Busy hands broom and !Viet
its surface, clean off scales ; and backwards and forwer:
it passes some four times, until a length equal to
future width is attained. The traveller overhead OW
brings up the crane, the dogs are attached, and the 131a54,,,
lifted and swung half round. Now, again, through
mill the glowing mass of iron passes and repasses,
now and then a conflagration of brooms, and a little
watering, to assist the scaling, and now and then Of
manoeuvring of the place to secure its proper wi'
Little by little the length increases, and the thickne:
diminishes, until at ten minutes to one n'eleo
exactly twenty-five minutes from the commencetnent
of the operation, the orange-coloured plate is repot
finished, whole and perfect, upon the trolly on the r:
side of the rolls, slowly to cool and straighten, before
it is thrown on the floor and weighted for final want
The size of the shield-plate rolled in its finished state
16 feet long, 8 feet 6 inches wide, and 5 inches thick. 0e
result of Friday speaks highly of the continued advance
English establishments so constantly make to meet ever".,
coming requirement. A year ago a plate of such superm'
cial dimensions was deemed and asserted to be inalY, ec'
ticable. The wish of an important public body is imPree'w-
and quickly is realised. To-day in Sheffield theY
prepared not only to make plates of the size den3anclea
12 feet by 8 feet ; but to go beyond, and make plates
8 feet wide by 20 feet in length.