The Sun.
London, England, 1864-06-23 00:00:00

The Shoeburyness Competitive Trials,

After so much trying work, though not the less
nteresting, we have at last come to one of the comic
ncidents naturally inherent to all competitions.
When the parallelograms were brought forward,
and communicated to the two competitors, the com-
parison was entirely founded on the methods of
points described in last week's notice, whereby the
Whitworth gun had a slight advantage over the
shunt Armstrong, while the breech-loader was dis-
tanced by both. Then, we have every reason to
believe that, in a certain quarter, the tables were
well received, it was a triumph. But it so happened
hat—led on by our sense of duty, and by a strong
doubt es to the validity of such a method, for it
must obviously disguise when it does not faithfully
convey the truth of the case—we took two quite
distinct lines for own independent investigation,
and thereby came to a very different conclusion as
to the order in which the guns stand by reason of
the parallelograms. Taking the mean ranges as
they are at present erroneously calculated, we made
up the areas, and then their sum for each sort of
ammunition, and each separate gun determined the
order of merit in the minor categories of common
shell, solid shot, and segment shell. It followed
that, by adding for each gun its three category
areas, we were sure of obtaining a correct measure•
ment of their performances, the greatest surface
representing the least merit. Moreover, we deter-
mined on proving this method by a third plan, viz ,
that of enclosing the fractional areas of every degree
into the largest amongst them for each kind of pro,
jectile, thus taking the greatest surface as the
expression of the highest degree of erraticity possible
for each, when firing one particular ammunition.
The result confirmed that of the second me,:nod,
placing the breech-loader iirst, the shunt second,
and the Whitworth third ; and consequently, apart
from the appearance both these methods carry along
with them, as to iogicel soundness, there is indeed
good reason to 'abide by their conclusions. The num-
bers arising from these modes were not given by us,
out of regard to the calculations which might be car-
ried or, by the special committee ; but the facts they
establish were, we trust, explained clearly enough
in our columns of last Wednesday. When this be-
came known, that same party who had rejoiced
at the order of merit first established, and found
nothing to say against the parallelograms, as they
were given, immediately turned round upon them,
and altogether repudiated their correctness. On the
ground of the mode pursued for fixing the mean
range, this determination is not untenable, though
the mean " propel" might bear out just the same
order of merit. Objection may even be taken against
the use of a mean range at all to determine the de-
grees of error. Be this as it may, we have, at any
rate, subject for a warm debate, which, besides caus-
ing merriment, may eventually turn out very useful
wit regard to the scientific points it will necessarily
being under the notice of the committee. What,
however, we sincerely regret is the feeling shown
towards the principal originator of this change in
the reading of the parallelograms. In the discharge
of our duty we have never looked forward to the
approbation of one rival more than of the other;
but to the gratification that springs from the ac-
knowledgment of our doing the country good ser-
vice. Nevertheless, we can only deplore the feeling
which would either smother or corrupt public
opinion, and which then requites impartiality with
a Penalty of childish sulkiness.
Exception is taken to the finding of the paral-
lelograms
on two grounds—viz., that, firstly, the
breech-loader was known to fire unsatisfactorily,
wherefore it cannot stand ahead of the Whitworth ;
ando secondly,reer
two competitive
that the flatness of the trajectory being
more marked
in
the
hexagonal than in either of the
h
guns, it must necessarily fol-
lowot
that the parallelograms of the former will be
longer than those of the latter. Whence, considering
the influence exercised by such desirable flatness on
the question of accuracy, it isobeious that the method
of drawing out areas of comparative error on the
horizontaolfp,l,arnaen,gies
aradically defective for the deter-
mination." Now, in the first:place,
the steel breech-loader was found inferiorin its firing
chiefly as compared to that of the service wrought
iron coil 12 pounder. It is in this sense that both
officers and men, who were need to the practice of
the latter, complained of that made by the former.
On examining into the causes of this relative
inferiority, we soon attributed it to the steel block
not expanding under pressure, in the same way as
the wrought iron coil ; and though this reason was
aot accepted at the time it was
given, yet it has
proved true, and it is pleaded in extenuation of the
first performances made with the breech-loader. In
relation to the other guns, this unforeseen defect of
non-expansion, by increasing the disadvantages due
to lower initial velocity, as well as to the greater
elevation required for target practice, naturally
tended to that of the other two guns ; in fact, with
regard to the number of times it loses, its position
of rank is the worst in all three classes of the pro-
jectiles used. But what retrieves the breech loader
is its greater regularity in point of erraticity; thus,
the sum of the areas made with ccmuion shell by the
breech loader is about 85 times greater than the
smallest amongst them ; while for the Whitworth
the total is about 1 520 times; and for the shunt
125 times greater than their respectively least sur-
f„ee. Witn solid shot, the sum of the measurements
of each gun taken separately is equal to about 81
times the least amongst them ; in the case of the
breech loader it is likewise equal to 81 times its own
minimum area for the Whitworth, and equal to 215

times for the shunt. With segment shell the total
sum for the breech loader is about 99 times its mini.
mum area in this category. For the Whitwettis
is 330 times ; while for the shunt the n'n' of its own
areas is no less than 700 times the smallest amongst
them. The superior tendency to regularity which
we thus find existing in the practice of the breech
loading gun fully accounts, in our mind, for the
advantage it ultimately gains, and for the atomaly
that we meet in its losing more frequently than
gaining, when its parallelograms are taken in detail,
and yet coming out foremost of all when the areas
are summed up. As a proof we are not wrong in
entertaining this opinion we need only examiare the
amount of difference that passes bettsasen the smal-
lest surface of error and the largest, for each gun
and each projectile ecparately. We then find that
with common shell the breech loader makes a maxi-
mum surface equal to about 29 times the mit:Antra,
the Whitworth makes the former 450 times larger
than the latter, while the greatest of the shunt meas
sures 50 times its smallest. With solid shot the
breech loader attains a maximum area 13 times
greater, the Whitworth 21, and the shunt 68 times
larger than their respective minumum area. With
segment shell the breech loader's maximum error is
about 21 times its least, the Whitworth's 78, while
the shunt's largest rises to not less than 200 times
the smallest area it can show with this projectile.
Here again we have numbers which speak for them-
selves, and though the method may be novel yet we
trust its operations, as well as its conclusions, may
appear clear enough to confirm our views of the
case, and explain how it is that the sums of the
parallelograms assign the least amount of error to
the breech loader, though it did certainly lose much
more frequently than either of the other two com-
petitive guns in detail. Thus, by the method of com-
paring the minimum area to the total sum for each
category of ammunition and each gun, be it well
understood that the co-efficients are, for the breech
loader, 85, 81, 99 ; for the Whitworth, 1,520, 81,
330 ; and for the shunt, 125, 215, 700 ; the sum of
the first being 265, of the second 1,931, and of the
third 1,040. By the second method of comparing
the largest to the smallest area for each gun and
projectile used, we find that the coefficients are for
the breech loader 29, 13, 21; for the hexagonal
450, 21, 78; and for the Armstrong muzzle
loader 50, 68, 200; the sum of the first being 63,
that of the second 549, and that of the third 318.
These details may at first sight seem elaborate and
uninteresting, but we feel sure that the question is
of itself so popular, the liability to be misled by
specious arguments so great, and the interests
involved in the choice which public opinion may
help in making eo vital to the country, that we
could not hesitate entering into such explanations,
though endeavouring all the while to render them
in the best shape to convey persuasion, and captivate
the attention of our readers.
In the next instance, it is a serious mistake to
mix up flatness of trajectory with "range aezu-
racy," because, on reflection, one cannot fail to see
that they are, and must ever remain, entirely inde-
pendent the one of the other. In fact, if the flat-
ness of trajectory had anything to do in the crea-
tion of inaccuracy, then we should see the parallelo-
grams getting longer as the angle of elevation
diminishes, and, vice versa, shorter as the angle of
fall increases. In mortar practice we have extreme
curvature, yet we have bad parallelograms, in
smooth-bore practice, where we have flat trajecto-
ries, the parallelograms greatly improve; with rifle
guns the trajectories improve still more, while the
surfaces of error sink down into comparative insig.
nificance. A glance at the Plate E, in the report
on ordnance, fully sets this matter at rest. On the
contrary, far from the flatness of trajectory inter-
fering
with accuracy, it diminishes inaccuracy, for
the simple reason that deviating influences have
less action as the time of flight is shortened, or the
angle of fall is lessened. That, in point of fact,
swiftness is an element favourable to the probabili-
ties of hitting is well known ; indeed round shot at
high velocities and two trajectories give better
results than when fired at low velocities, and cos,.
sequently with higher trajectories to attain a given
range. We cannot therefore see the 'Wisdom of
questioning the merits of low traject
bating to them an evil influenc: pries by attri-
on the length of
parallelograms, when we is
_vow that they are pur-
posely sought not P.:nly on account of their im-
portance RE a me -,,n3 of partly tneking up for the
i mpossibilit; of correctly estimating distances,
but also in -law of the greater chances they give
svi°La regard to accuracy in all respects. If, how-
ever, independently of these considerations, ac-
curacy, as it is asserted, should be determined by
firing exclusively at vertical planes, where low
trajectories are not supposed to be harmful, then
surely it is tacitly felt that the latter cannot affect
the results attained on the hosizental plane.
The causes which do really affect regularity of
fire in rifle guns are many, and it is to them that
reference should be made for the object of under•
standing and explaining the reasons why the Whit-
worth gun does not stand out satisfactorily in the
parallelograms. Firstly, the position of the vent,
whereby the front layers of powder are ignited be-
fore those of the rear, giving a too immediate rise
to motion in the projectile. Secondly, the shape of
the bore, which does not surround the cartridge
with the closeness of a cylinder. It follows that,
through these causes, the density of the gases is
very liable to vary from one shot to another, to
the prejudice of a constant initial velocity. Thirdly,
the smallness of the cross section area entails the
necessity of greatly increasing the length of the
projectile for shell purposes ; this adds to the sur-
face on which the vertical component of resistance,
which is due to the air, acts ; and thereby submits
the projectile more fully than otherwise to the dis-
turbing effects that spring from variations of atmoss
pherical pressure. These causes, two internal and
one external, are of themselves sufficient to cause
serious fluctuations in the height of the trajectory,
and thereby to considerably modify the ranges, par-
t'cularly when firing at high elevations. In the
shunt Armstrong the density of the gases will not
be to an equal extent .iable to oscillate, and thence
the initial velocity will depart less from its normal
amount. Moreover, the projectiles having a greater
sectional area, their length is shorter, the difference
between the solid shot and the shell is reduced to
smaller proportions, and these peculiarities must
necessarily suffice to give the vertical component of
the resistance to flight less disturbing power. The
height of the trajectory will, therefore, fluctuate
within narrower limits than in the case of the
Whitworth, and thus more regularity will be
obtained for the ranges. But, in the breech-
loader,
the retardation to motion due to the slugging
of the shot contributes in the most efficient way to
keep the gases from acquiring various various
degrees of density. The layers are furthermore
ignited from the rear to the front, whereby altoge-
ther the volume within which the gases expand
prior to sensible motion is reduced to a minimum,
and so guarded from variation that it may practi-
cally be considered constant. It follows that this

latter gun will naturally possess great regularity
of ranges, and in this real-met—we mean that of
range accuracy—will stand ahead of its rivals. It
also follows that the Whitworth will be endowed
with the greatest amount of irregularity, especially
at shell practice ; while the shunt will take an in-
termediate position. This is the very order in which
the guns stand, in accordance with the total area of
the parallelograms. So far, then, practice agrees
entirely wilr the conclusions we should have been
led to infer from an accurate examination of the
conditions we have just referred to.
During the first four days of the last week prac-
tice was carried on with the 70 pounders to the
extent of 90 rounds each, and 3 and 6 degrees. The
accuracy of these guns was beautiful, the shots
falling much about the same spot. The shunt seemed
ahead of the breech-loader by about 200 yards
while the lirhiworth at three degrees had the best
by about 60 to 70 yards.

On Tuesday the old 12-pounders were fired for 10
rounds each at 15 degrees elevation, the 'Whitworth
gun attaining nearly 5,000 yards range. The prac-
tieo at 800 yards, through screens so placed as to
explode the shell at 10, 25, 50, and 100 yards dis-
tance from the line of targets, at two series of
heights from the ground, was brought to a close.
The result was, we believe, favourable to Colonel

Boxer's shrapnel ; but until the committee shall