The Sun.
London, England, 1856-09-30 00:00:00

THE STEAM FRIGATE MERRIMAC.

The United States screw steam-frigate Merrimac, now
lying in Southampton Water, is 300 feet long. The
length of her spar deck is 281 feet. Her breadth of
beam is 611 feet, and depth of bold to gun deck 26 feet
3 inches. Her capacity at load line is 4,587 tons, and
draught of water 231 feet. She has two 10-inch, 24
9-inch, and 14 8-inch guns. Her 10-inch guns weigh
12,0001bs each, and the 24-inch guns 9,ooolbst. each.
The former would throw 130-p ainders, the latter 84-
pounders, and her 8-inch guns 64-pounders. Although
Sir Howard Douglas is a great authority amongst
American naval men, they differ, it appears, from him
as to the comparative merits of solid shot and shell ;
for they intend that the Merrimac shall fight with shells.
The weight of the 10 inch shells on board the frigate
when unloaded is 1011bs. ; of the 9-inch shells, 69lbs. ;
and of the 3-inch one', 49ilbs. The weight of metal
front a broadside from the Merrimac, in solid shot,
would be 1,7161b5., and in shells, 1,3821b5. One of the
peculiarities of Dahlgren's guns, which are on board the
frigate is the enormous disproportion between the
thickness of the breech, where the first shock of the
explosion takes place, and that of the chase of the gun.
Thus the breech metal in the pivot guns is 10 inches
thick, while the thickness of the chase is not above 21
inches ; - yet, notwithstanding this, when Dahlgren's
guns are purposely put to the extreme test, they burst
at the breech, and not at the chase, which shewa that
the disproportion in thickness is not too great. The
local variation of compasses is counteracted on board
the Merrimac by three magnets, whose powers and posi-
tion are adjusted by some secret calculation} to the
variable attractive powers of the different parts of the
ship. The method of calculation is the invention of
an American, who has not divulged his secret. His
adjustment has answered extremely well in the Merri-
mac. Hoisting arrangements are attached to the screw
of the frigate. The screw is 26 feet 2 inches in pitch,
and 17 feet 4 inches in diameter. The frigate has a 2-rod
steeple engine, with a 72-inch cylinder and a 3-foot
stroke. The pressure of steam is 20lbs. to the square
inch. Toe revolutions are 50 per minute. The
engine department is furnished with independent auxi-
liary engine for coaling the ship, and with four of Mar-
tin's patent vertical flue boilers, and a steam engine
register and chronometer clock. The two latter are
rare and costly instruments for an engine room. The
consumption of fuel is 35 tons a day, full steam. The
chief engineer's room is fitted up with every requisite for
itna, inable accident that may occur. The length of the
main mast of the Merrimac is 123 feet ; the fore mast is
111 feet, and the miaen 1091. The size of the mainsail
is 51 square feet, of the foresail 40 square feet, of the
maintop 45 square feet, and of the jib 24 square feet.
The whole area of the Merrimac's sails is 566 square feet.
In ordei to carry an enormous armament, and to fight
the heavy ships and batteries that she would be pitted
against, she has been constructed of very great strength.
She has iron transept braces 41 inches wide, and of an
inch thick between the outer and inner planking ex-
tending from the sheer plank to the keel. Her knees
are of prodigious strength and solidity. In war time she
would carry a few more guns of the same calibre as those
she has now on board, and about 100 more men than sh•
now musters. There are many things in this frlgate de-
serving the attention of Englishmen. Her quarters for
fighting are very roomy compared with these of English
line-of-battle ships, crowded as the latter are with guns
and men. Thus, in battle, there would be far less de-
struction of life on board the Merrimac than on board
an English ship. The paucity of guns on board the fri-
gate is compensated for by their large calibre, and the
frigate being more easily managed than our three-deckers,
she would with her artillery—superior both in length of
range sled powei a of mischief--do fearful damage to
the largest line-of-battle ship before the latter could
approach her. These have been the reasons that
have induced the Americans to build and arm such
frigates as the Merrimac, and the 'practice of a nation
so shrewd, go ahead, and brave as America undoubtedly
is, ought not to be despised. The Merrimac took two
years building. She is the smallest of six frigates, built
on the same plan, the names of the others being the
Wabash, Minnesota, Colorado, Roanoke, and Niagara.
The Merrimac was stationed a short time at Havana
before she came to S nithampton. On Friday last, Capt.
Prendergast, her commander, and some of his officers,
dined with the 0 ,untess of Hardwicke, at her beautiful
seat on the banks of Southampton Water, close to where
the frigate is lying, and th• Americans were charmed
with her ladyship's graceful hospitality. The Earl of
Hardwicke, who is a captain in the British navy, is from
home. The officers are quiet, gentlemanly, and well-
read men, and, like English sailors, take pride in their
profession. They of oJurse believe Americans quite
equal, if not superior, in pluck, in science, and in fight-
ing, to Englishmen, and apparently would not be indis-
posed to have a brush with us. With all this, it is
curious, however, to notice the deep regard they betray
for Old England, and the numerous inquiries they make
as to the distance from Southampton of Stratford-on-
Avon, Abbotsford, and other places connected with
England's peaceful worthies. The arrival of the Merri-
mac is a godsend for Southampton, on account of the
money the men and officers will spend in town. Bum-
boats and boats laden with provisions and visitors are
continually going off to the frigate. Since Mr. Croskey,
the American consul, brought the first United States
mail packet to Southampton, half a million sterling has
been spent in that town in American dollars from Ibe
various men-of-war and mail packets belonging tq the
United States that have called at the port.