The New Orleans crescent. [volume] (New Orleans, La.) 1866-1869, 1868-07-26

ExpERI,lKETs AT sHoEBURYNEss,

Tie London Times reports the results OF some
important trials Of some iron structures applicable
to land fortifications. They had excited great in
terest, and the attendance at Shoeburyness was
very large. The structures to be fred at were
erected about 100 yards within the low embank-
ment protecting the ground from the Thames, the
front Of the works facing inland. The plymouth
target and the other classmates were in the center,
fanked on either hand by the experimental walls
and plates. The appearance of the larger struc.
lures was massive and imposing, but their elect
wss somewhat marred by the large black surfaces
of iron wall being divided of into squares by
white painted lines. The details of construction
were TO a considerable extent hidden by the close
fitting of the external parts; but ample iDfOrma-
ton was supplied on this point by the exhibition
of autographed plans and sections OF the struc,
tures, showing all their parts in full detail. Red
ard blue lines also painted on the targets TO
indicate the places Of the joints and other impor-
tant features in the construction, and printed de-
scriptioDs prepared for the purpose, were circu.
lated among the visitors. Diagrams we're also ex-
hibited, showing the various data Of the artillery,
and a notice Of the gun charge and proJectle was
posted up before each round.
The chief object was the Plymouth shield, and
the only gun used, with the exception Of two
rounds from the American Rodman, was the largest
rined gun viz: the twenty-three ton gun OF twelve
inches bore, carrying Pslliser pointed shot oil
Goo pounds. The charges were originally intended
t. be such as would represent the effects at dis
tances of 500 and 1000 yards but as it was con.
sdered desirable to test the strength OF the shield
with the full power of the guns, the bate ing
charge Of seyentysix pounds of powder was used
every round.
There were in all eight rounds fred against the
shield, five of which were directed against the
part to the right of the portfolio, strengthened by
| an extra fvench plate in front, giving in this
place twenty inches thickness of IRON. The other
three were fired at the thinner or ffteen-iDeh side
| of the shield.
The first shot hit the fve.inch strengthening
plate about three feet from the ground and iftee
inches from the right-hand edge, tearing open the
narrow strip outside the shot. One bolt was
| driven several inches inwards, and the inside
plates and the vertical standard behind them were
slightly bulged; the shot penetrated about foot
| and broke up.
| The second round was shell Of tie same weight
| from the same gun, with bursting charge Of la
| pounds This struck about six inches above the
port. and exactly on the left edge OF the strength
| enipg plate so that half the proiectile acted on
this plate and the other part on the thinner part
adjoining. In front no damage was seen, bat al
the back it was found that the horizontal irOr
'.plankn over the portfolio was broken in two on
the right hand side of the port and partly thrus
| backward. The bolts near the part strucl
we're strained. bnt not broken. The she'll did no
bury itself deep enough in the iron TO do more
mischief than a shot, as the bursting charge ex
ploded in the rear.
The third round was shot from the grea