Year: 1864

constant state of ignition, and formed a
pale, luminous crown of blue flame The
cries of "Hold on there (" "Out of the
road /" etc., and the constant excitement
of the scene, added to the vividness of the
new foundry view. : =


The official report of Captain Benet
states that the furnaces were opened at
precisely twenty-four minutes after twelve;
that the last furnace was closed at forty
five and half minutes past twelve, and
that, consequently, the time occupied in
the casting included exactly twenty-one
and half minutes.


The casting was perfect success. No
result could possibly have been more sat
isfactory. Nothing went wrong. Fur
mace No. was the first to be stepped, land
Nos. and were stopped almost imme-
diately after. When the casting was com
pleted, backing, consisting of ground
coal, was strewn over the top to prevent
chilling. During the operation the gas
escaped freely from the vent holes in the
flask, which is perforated in thousand
places with these necessary accOmmOda-
tions, half an inch in diameter. Three
furnaces only were employed A fourth
furnace was in reserve, in the case of any
accident, but the necessity for its use was
wholly precluded. Only two or three tons
were left over, after the casting was COM
pleted, evincing a calculation of unusual
nicely.


The fourth furnace IN reserve had sup
ply of ten tons, which in any exigency
might have been drawn upon. After the
casting was over, the mould, not being
completely filled, owing to the gradual
settling of the liquid mass, was supplied
with fresh liquid iron, or, in other words,
was filled up with "shanks.' All the
fuel employed was the Pittsburgh bitumin-
Gus coal


The drawing of the core was to take
place about twenty-four hours after the
casting. In this operation the supply of
water is suddenly stopped off The bar
rel is much expanded by heat. A large
strain is put on by the steam crane, al
most sufficient to draw the barrel out.
The barrel cools quickly, .shrinks with ra.
pidity, the strain of the crane springs it
out about two feet, and it is then drawn
out. .


AFTER THE CASTING.


The casting of the great 20 inch gun
having been satisfactorily accomplished,
congratulations became the order of the
day. Delegations and committees shook
hands. "Bosses" and puddle stickers
alike dispersed. The Fort Pitt Foundry
was, for the time, left to itself to reflect
in leisrre on the greatest gun the world
has yet witnessed. The gun is expected
to be ready in the latter part of May.


Preparations for manipulation are so
complete it will be as easily handled as a
smaller gun. The steam cranes and the
other facilities at the proving ground for
testing it, are of the most complete and
thorough description. The enormous
framework, by means Of which the gun
is slung up by trunnions, is the largest
structure of it's kind in the known world,


The value of the stupendous piece of
artillery which, on Thursday, was cast at
Fort Pitt Foundry, is estimated al. thirty
thousand dollars.


The 2O.nch is not intended for a long
range gun, but rather to do terrible exc
cution within the range which it will pos
sess. In the manufacture of guns of large
calibre, the question which arises is, "to
which shall ths greatest attention be de-
voted, to the increase of velocity or to the
bulk of the cannon tall?" The weight of
the shot has in this instance engrossed
consideration. Shell will be almost ex-
clusively used. Both shot and shell will
be spherical, of great weight and enor-
nous explosive force. The solid shot will
weigh one thousand pounds, and the shell
seven hundred and seventy-fve pounds,
allowing for windage. No information of
course can be given at present in regard
to the range of the gun. Whatever its
range may be, it is certain that its execu-
ton will be unparalleled in it's extent and
devastation.


Two kinds of powder are employed in
gun service, viz: cannon and mammoth.
Mammoth powder, invented by Major
Rodman, will be employed in the 2O-inch
gun. 1t is the same variety as that used
in 10-inch guns, and its grains are six
tenths of an inch in diameter, or about the
size of hickory nuts. The gun will burn
not less than one hundred pounds of pow
der.


New York is the destination of the 90
inch. It will be mounted in the NarrOws,
below Fort Hamilton. It will be mounted
and in service probably within three
months, certainly, within six.


The length of the bore will be two hum
dred and ten inches. The bore will ter
inmate in a semi-ellipsoid, whose major
axis will be thirty inches, and whose minor
axis will be twenty inches.


The expense of the charge Of each gan
may be roughly placed at about seventy
five dollars, allowing twenty-five dollars
for powder, and fifty for projectiles. Fif-
teen or sixteen men will be required to
manage the gun when completed, nine be.
ing employed in the loading, and six OF
seven in traversing the gun.