, 1864-02-17


from time to time, In order 70 light the gus
which escaped from the sand through ths
smal vent-ho1e in the dask Az the rods with
which this process was effected struck the
sides Of the mould, a ahoWer. of tire-1akes
descended into the cavity, and shot ont scin-
ullahons npon the assembled crowd. The
gas cecaptng from within, the iron pipe sur-,
rounding the core-barrel IVES in q constant
state Of ignition, and formed pale, luu,fn-
on therey' "Out Of the road!" &c, aud
the constant excitement Of the scene, al1cd
to the vivtdncss Of the new foundry view.
=, ENDING OF TIE CASTING.
The official report Of Capt. Benct states
that the furnaces were opened at precisely
twenty-four minutes atter twelve; that the
last furnace was closed Ut fort7-firc and q
4uentiy. the time occupied in the casting
ute8. ,. = i
= TIE 1KMrEEArunE or THE WATER. ~
The temperature. OF tho stream Of water
which at one minute after twelve commenced
running into, the core, stood at the COM
menccment at thtrty-six degrees; at tho mo-
ment the casting was over it stood at forty.
two degrees; four minutes after the casing
was over 1t was at titty-two degrees; eight
minutes alscr the casting was over at seventy
fire and half degrees; fourteen minutes af-
ter the casting ut eighty-one and half de-
grees; twenty minutes after tho c,6ting at
e1ghty-n1ne and quarter degrees; tWonty-
i've minutes after the casting at ninety one de-
grees, and thirty minutes after the casting ut
ninety-one and three quarters degrees.
THE CASTING AnuHpAHTLy SATISFACTORY
The casting ssns perfect SUCCESS No re-
suit could possibly lave been more satlsfac-
tory. Nothing went wrong. Furnace No. 6
was the first to be stopped, and the others,
Nos 4 and 5, were stopped almost: inmedi-
ately after. When the casting was complet-
ed blnckfug, consisting Of ground coal, was
strewn over the top to prevent chilling.
from The vent holes in the fask, which Is
perforated in n thousand places with these
necessary accommodations, haf an inch in
diameter. Three furnaces only we're en-
ployed. A fourth furnace WIZ In reserve, in
case Of any accident, but the necessity for its
use vas wholly. precluded. :. Only; two or
was completed, eviucing ! eaieniation Of M ni.
:, The fourth tnrnace in reserve had SUPPLY
Of ten tons, and nth twelve .tona, which in
any exigency might hare been, drawn upon.
After tie casting was over, the mould not
being completely filled, owing to the gradual
with freah,liqnid iron; Or, in other words:
was filled up with s. shanks. ~: ALL the fuel
employed Tas the Pittsburgh bitumtnous
coal. :. :
THE DRAWING OF TIE cone
was to take place about twcnty-four hours.
after the casting. !. In this operation the Rup-
ply Of water is suddenly stopped Oft The
barrel is much expanded by heat. A 1arge
strain is put On BY the steam crane, almost
cools quickly, shrinks. rapidly, the strain of
the crane springiug it out about two feet, and
it is then drawn ont. -.
WHEN THE 20-1Ecu VIII. uE COMPLETED. s..
The gun Is expected to be ready In the
latter part OF May Tho solid shot will
weigh 1,C0o pounds. The. range cannot, Of
course, at this early date, be determined,
but will at least be equal to the 15-inci, gun.
THE VALUE or TIE FORT rlrr GUN.
Tic Talne Of this stupenlous piece Of ar
til}ery which. on Thursday, was cast at the
Fort Pitt Foundry, is estimated ut thirty
thousand dollars. Tho outlaT ID ut least that
las, Us necessity, been expensive. Future
castings Of guns Of the same titncl5toas will,
Of course, incur tho expenditures Of a much
less amount. ;
TIE WEIGHT or TIE SHOT.
The 20-inch is not intended for long. range
gun, but rather to do terrible execution
within the range Which it will POSSESS. In
-
question Which arises Is, "To whic', shall
greatest attention be devoted-to the increase
Of velocity or TO the bulk of the cannon bau:"
The weight Of the shot has III this 1nstance
cngrossed confederation. Shell will be almost
exclusively used. Both shot and shell will be
spherical, of great weight and enormous ex~
plosivc force. The solid shot will weigh one
thousand pounds, and the shell seren hun
drcd and scyenty-lye pounds, allowing for
windage. No information Of co1rsc can be
given at present IN regard to the range Of the
gun, Whatever Its range may be, It is Ger
tain that its execution wlll be unparalleled in
its extent and devastation.
TIE KIND OF POWDER EMPLOYED.
Two kinds Of powder arc employed In gun
service, VIZ: cannon and mammoth. Can
non powder, invented by Major Rodman, will
be employed in the 2t-inch gun. It Is the
same variety as that used IN 1d-inch guns, and
its E7uins aIo stxteenths OF an inch In diatno-
ter, or about the size Of hickory nuts. The
gun will burn not less than ono hundred
pounds Of powder.
THE Grs's pEsrrsAr1os. .s...
New York Is the destination Of the sDiuch-
It will be mounted In the NarroWs, ,buloW Fort
Hamilton twill be mounted and In ser
vice probably within three months, certainly,
within SIX. =. . ,
TIE GUN CARRIAGE . <-
does not dcyiatc in Its general construction
from the wrought iron carriages Of the l5-
inch guns No distinctive title has ben de-
yised for the gua,, 1t viii merely be charac.
terized as 20-snch gun, constructed on the
Rodman principle. The carriage 1s now-bc'
ing manufactured at the Watertown' Arsenal,
near Boston. -,
|. PEcC1IlRIT1Es OF THE BORE. -.
The length Of the bore will be two hundred
and ten inches. The bore will Terminate in
semi:el1ipsoia, whose mnforitfcs will be
thirty inches, and whose minor axis Will be
twenty inches.
Z, = =. COST FER CHARGE
Tie cxpeusc for each charge Of the gun
may be rougIy placed at about sevrnty-nve
dollars, allowing twenty-five dollars for pow.
der md fifty for proIectiles. Fifteen or six
teen men will be required to manage the gun
when completed, nine being employed In the
loading, and six or seTen in .trayersinss tht
gun. No formula con ut present. be- gtTeI
respecting the tenacitf and hardness OF TIN
| meial. Tic Lydrometer determines its spe
| cifc gravity. It is to: be remarked, that bJ
| the interior cooling principle adopted, th.
hardest and best iron IS that ncarcsf the sur
| lace Of the bore. The feet Of. the gun being
| cast hollow secures this.
- TIE e0-1Son TESTED. ;.
Tic iron OF which the run is cast was thor
ougl,ly tested, by Major kodman, In the sam
manner as That Of tue first 15-inch. The sam
Die by which tie gun Ia to be proved Ii to b
/ taken from the sinksng-head, or the Toug
| end cut off from the muzzle.