The daily exchange. [volume] (Baltimore, Md.) 1858-1861, 1861-08-20
TEST OF TIE NINE-INCH GUN COMPLETED
ONE THOUSAND ROUNDS FIRED

A'AN - GOU NDS FIXED.
Inc PlttsouTg Dispatch of the I7th gives the
'o'o"i"g account OF new gun, the first, if ap-
P'o'eu OF Dy the Government, of heavy order:
IL Dahlgrcn, extremely heavy at the breecb
neing something over calbre thick of metal, INIT
beglrs to taper back of the trunninns and tonars
quickly to the muzzle, being much lighter in pro-
portion TO the weight OF the proiectile than tha
coiumblad. 1t was cast solid and Of Bloomfield
metal, the same used for some years in the mann
iscture OF counbiads. Fer the purpose of FIRING
the gun was swung up by iron straps in q trianpIe
thnS avoiding the necessity of correcting the re-
col' al each discharge, which would follow the use
OF d carriage mounting. The triangle is formed of
tour uprights of heavy timber about thirty feet in
iehgth. Each pair of uprights is framed at the
loot into heavy timbers and oined at the tnp in
the shape OF letter A, the base spreading ncarIv
thlrty feet. The pairs are set up on each sds Gf
tue gun, ABOUT ten feet apart at the base and in.
Ginning together at the top, where thew are separa
ted ABOUT tour feet. log is fitted to roll nj tbo
top, and from it depend four iron rods in y birb
the gun Is swung on heavy iron bands. To check
the VIBRATION OF the gun, which would continue for
some minutes after each discharge, a heavy cable
was hltched to the breech, passing around = erub
hlng post about one hundred feet distant Four or
hVe men were required to attend the cable srd nv
actVe movements generally caught the piece on
the second vibration, bringing it to a rest 4
oomh-proof shelter had been constructed AT abo,,t
Qne hundred feet distant from the triangle to 80
tsct the men from accident il case of tie bnrstin
OF the gum but the shelter was never IIsed rn
men were employed in loading and firing the gan.
VINO retreated to the SGubbng post where the end
OF the iandyard for firing the friction tubps was
carried a stout pen bad been built to receive the
oaiIs and preserve them far as possible but tho
hTst lew rounds knocked the pen to nieces and
bevond it. ~ ''''
The firing was carried on with extracrdinarv
rapldity, the only full days work, on Friday, civ
ing two hundred and two rounds The IaboT of
hrlng Is very severe on the gum ers, recurring
tnem to retreat nearly one hundred feet at eann
discharge. ~ od
Ihe measurements at every twentieth round
were made with extreme care, the star rusge usnd
feaGlDg to thousandths of inch, and showing the
slghteSt enforcement of the bore. An impression
OF the inner extremity OF the vent was taken at the
same time, and alter the six hundredth round the
nISt vent was closed and the second drilled The
hity Impressions thus taken of the vents are a
curiosity IN themselves, as showing the rradual
enlargement of the opening in certain directions
from first to last.
Ia hnishlng the bore Of the gun, the finishing
'oo accdentally split, charging the bore behind TIE
seat OF the ball, O26 in. and scoring up the surface
considerably. At the close Of the proof, ona tbou
sand balls having been fired the greatest rniarga
ment OF the bore was found to be but O52 in or
.OZo by hrlng-but little more than one-fftieh at
a" snch The result proves that the material
used in the casting of the gun has never been
equalled
The proof charge of powder is ten pounds. and in
the test therefore, ten thousand pounds or five
tons, OF powder were expended MANY Of the hal.
we're recovered and fired repeatedly and but ahoul
hVe hundred We're expended in the prnof The
slells Welgh seVenty-twO pounds, making an ag.
gregate of thirtysix thousand pounds, or eighteen
tons of iron fired.