The Sun.
London, England, 1853-05-20 00:00:00

UNITED SERVICE INSTITUTION.

The members of ' the above institution assembled,
pursuant to adjournment, in the theatre at the insti-
tution, Scotland-yard, on Wednesday, for resuming the
discussion on Mr. Fergusson's system of fortification ;
Lieut.-Col. W. H. Sykes, V.P.R.S., in the chair.
Amongst the distinguished officers present were—
Generals M'lnnes, Aitchison, Sir C. Pasley, Sir R.
Doherty, Briggs, and Horne ; Admirals Lord Rostock,
Crofton, and Sir Charles Napier ; Sir Charles Cuyler,
Sir J. Dunlop ; Colonels Fletcher, Colville, Torrens,
Codrington, Hope, Lemon, Markham, Townsend, Sir A.
Murray, Paget, Buen, James Jones, Angelo,
Somers, Palliser, Jebb, RE., Abbott, C.B. (of the East
India College, Addiscombe), Wortham, R.E., and Fer-
gusson, R.M. ; Majors De Winton, Baron, Agnew,
Montagu, and Whitfield ; Captains Sutherland, Ford,
Warren, Evans, Elwyn, Crofton Key, RN., Dinor,
R. A., Lefroy, -Eardley Wilmot, R. A., Sinclair,
King, R.N., Gardiner, R. N., Blythe, Roxburgh,
Fearon, Anderson, Williams, Hood, Simmons, Mac-
laurin, Nixon, Desborough, Barnett, RN., Ward,
R.E., Shaw, Johnson, R.N., A. Lane Fox, Kelly,
Stuart, Addison, Yorke, Rawlinson, Baker, R.E., Grif-
fiths, R.A., Galton, R.E., Ruddiman, Phillimore, Robb,
R.N., H. Reynolds, Dunlop, RN., Hogg, Hand, R.N.,
Fitzroy. RN., Gambier, Mansell, Appleton, R.M.,
Gordon, R.N. ; Codrington. R.N. ; Timbrell, Watts,
Strong, Tower, Bague, W. H. Hall, R.N. ; Hammond,
R!N. ; and Hoseason, R.N.; Lieutenants Pasley, ' R.E •
Tyler, R.E. ; Lumley, Henderson, R.N.; D'Aguilar,
Goose, R.N. ; Dr. Thomson, Dr. Kerr, Dr. Lloyd, Dr.
Baird, Dr. Adolphus ;E. Hawkins, ' Esq. • H.ac;
Knight, Esq.; J. S. Kennedy, Esq. ; S. Lon, sq.
&c., &c.

The CHAIRMAN, in opening the business, said this dis-
cussion had already run to a length far greater than had
been anticipated, having now occupied four nights ; and
as he understood that Mr. Fergusson was about to leave
town, it was desirable that the discission should be
closed that night.
Captain WARD, of the Royal Engineers, then rose,
and spoke to the following effect :—I would not have
intruded myself on your notice at this late period of the
discussion, had I not felt that it was the duty of an engi-
neer officer to reply to the arguments used by the gal-
lant captain who last spoke (Captain Younge), and
which had probably a strong impression in favour of cir-
cular concentric lines, as applied to Gosport. I shall
first proceed to examine the strength of those lines. It has
been proposed to throw a salient curve across the. isthmus,
and I will proceed to see if that plan of defence is the best.
Captain Younge has, I think, very satisfactorily demon-
strated to us that in such a position, embraced with
a curve of such a radius (two miles), it would be a mat-
ter of difficulty, if not of impossibility, to effectively
enfilade 'the. proposed work. He has also dwelt upon
that important fact as the great, the essential recom-
mendation of the proposed work for Gosport. Indeed,
to use his own words, " enfilade is the very foundation
of an attack of a fortress." But let us examine for a
moment where the merit of this absence of enfilade lies.
If I, have understood rightly, the reason why .systems on
the circular principle are not open to enfilade is on-ac-
count of their circularity. A circle possesses the advan-
tage of limiting the number of guns a besieger can.
attack by enfilade fire ; and it is evident that greater the
curve, or, in otner words, the less the radius of the cir-
cle the less would•be the number of guns open to enfi-
lade. It may be a matter of opinion how many. can be
so attacked in each case—but there can be no doubt
that the degree of curvature is 'but one limit to that
number, however much it may be. . But the gallant
captain feeling, I presume, that some case had been
established by Sir Charles Pasley and Mr. Wrottesley,
when they argued on the possibility of enfilading the
model fortress before us, says at all events the proposed
lines of Gosport are not open to this description of fire,
if the others are. I have admitted all this. But bow
has he gained this extraordinary additional strength—
how has he limited enfilade ? Not .by increasing
the curvature, but by flattening the arc ; in fact by
approaching to a straight lime. The protection against
that most important fire in this case must not then be
put doWn to the merits of the circular system, for in the
position before us we are increasing in strength the more
we depart from the circle, and we shall find ourselves
still less vulnerable when we have arrived at a straight
line. In the. particular position before us, the straight
line— with tiers of parapets one behind another if you
please, but I will come to that point presently—would
possess many advantages over the salient curve. I. In
the first place, it would be of less extent. 2. Next, it
would be easier of construction, for curved lines are
always more difficult to lay out or build up. Both these
facts diminish the cost of the works. 3. More fire
could be. concentrated on any particular point of the at-
tack if desired. 4. And, as is easily seen, the enfi-
lade, "that foundation of the attack of a fortress,"
could not be attempted, as the prolongations go to in-
accessible positions. Both these facts add materially to
the strength of the fortress. If, then' the cost of con-
struction is diminished, and additional
by this modification, I may conclude it is superior to
the salient curve. Having arrived at this conclusion I
think it may reasonably be matter of opinion whe-
ther in similar positions a slight concave curve is not
stronger than either. The degree of curvature in this
case would be regulated by circumstances ; for instance,
it might be so arranged as to perMit 'the whole garri-
son to concentrate their fire at the most effective range
of their guns, or on some vulnerable point of the be-
sieger's ground, as over that by which he must approach.
If such a plan was adopted it might be called a modifi-
cation of the circular system ; it certainly may be con-
sidered as a modification, but I.,think you will admit
that it is arrived at by turning it inside out. However,
to return to' the 'straight line, which I think I have
shown, in the situation under consideration, possesses
advantages over the proposed salient curve. To any
who think the straight line an evident modification of
the circle, I would say it is a very simple one, and it
does not say much for the ingenuity ofengineers hitherto
to suppose that the idea of a straight line of ramparts for
a defence never occurred to them, and *that we are in-
debted for this valuable suggestion to 'the ingenuity of
the present day. A little consideratiOxi; 'will, I think,
show the contrary. Engineers not 'may saw that a
straight line of ramparts across an isthmus was' a very
strong mode' of keeping an enemy at a distance, when
they could afford to construct it, but they also found
that at 'a very small increase of expense they could
materially improve —oil ,that system, if it' may be
called one. They therefore preferred' to fortify thus :
By inclining the, beginning of the lines at the
extreme • ends' a' little inwards, then 'adding two
small lengths— of ramparts, capable of holding five
or six guns each, and joining these by 'a .strait;ht line.
The expense of constructing this, over and above the
straight line, was about the cost of the. two'flanks. See
what these flanks did for them in return for the expense.
Each fired along the face of the rampart in its front, and
when these latter were much elevated above the plain of
the country, this service was of no small importance, for
it prevented certain sappers and other burrowing under
them like rabbits, and so blowing up the brave defenders.
They also protected by musketry fire the foot of each
other's ramparts, and each undertdok this duty for the
other's half of the remaining straight line called the
curtain. Now, these little additions- to -the cost of a
straight line added materially to the strength of the
ramparts,- so much so that engineers of those days ar-
rived from practice- at the conclusion that they were
well worth their cost, and always applied them to their
fortifications. Nor have any that have seen service

from that time to this differed from them in opinion.
Flank defence is essential, if for no other purpose, to

protect the foot of the escarps from the mining propensi-
ties of sappers, as I have mentioned. And though to he
flanked is to be outflanked, to be not flanked is to be
blown up, and so the choice is left us. I think then that

I, and others like myself, who have not had the experi-
ence of battles, do right to incline to the opinion that
flank defence is desirable, and that we should prefer add-
ing it to any system of fortification, even if carried across

an-iithmus. I think now lam justified in concluding-
1. That the broken bastioned line is, in the Gosport po-
sition, superior to a straight one in its capability of re-
sisting attack, and I have shown before that the straight
is superior to the salient curve ; 2. That, though the
first cost of the bastioned line would be slightly superior
to the straight one, it would amply repay the extra ex-
pense, and therefore be cheaper in the end ; and 3.
That the first oost of the bastion line would not exceed
that of the salient curve, as it would not exceed it in

length, and certainly not in difficulty of construction. I

am-willing, however, to go yet further with those who
still admire the circular salient curve, and examine its
comparative value. I do not think there can be a sha-

dow of a doubt in any one's mind that a straight line
across the Gosport isthmus would be preferable to a sa-
lient curve of a similar profile, for I cannot imagine one
objection to it. The question then lies between the

straight line and the bastion front. Now, by breaking
the straight front into faces and flanks, you do not deprive
yourself of one gun, you command the same extent of
fire to your front as before—you may say that I make

flanks to be enfiladed. Admitting for a moment that they
are easy of enfilade, if I was on that account to decide on

putting no guns there at all I should be no worse off than

if I had a straight line ; but, inasmuch as by putting these
guns so, I am doing great service to the defence by flank
fire, and I oblige the besieger to throw up batteries,
and bring guns to destroy these flanks, before he can
come up to the face of the bastions—l am making a
stouter resistance, and it requires a longer time for the
besieging force to overcome me than would otherwise be
the' case. I hardly think, however, that I shall be told
by the admirers of the circular system, that five or six
guns in a row are worthy of, or easy to, enfilade, when
they generally resist the possibility of eight or
nine of
them beingser
so treated
clearly in that system. For Mr. Wrot-
tesley has
being
shown in his diagram that this number
ei
are capable of
an
ge up in one line. However,
even against such enfilade, it would be easy to pro-
vide a remedy by placing a traverse, or putting the guns
or leaking tha
in case-mates,
flanks somewhat lower than
the faces, or making them
.circular and concave—this
latter, and indeed all thesemerriv
tlaoedc;.l have been tried,
but engineers have generally a
at this conclusion
respecting them, that insomuch as these flanks are very
short, and so difficult to enfilade, that
do not
care about making the attempt, it is better to besiegers
a
straight flank to systems, the curve or case.matesly a
being worth the expense or trouble. I think not
ten
we may come to the conclusion that if it is hnecessary,
Si
tro'
throw a continued line across the Gosport isthmus,
it had far better be a broken bastion line than
salient curve, and that if the circular system apos-
sesses advantages they are applicable to the site for
which they have been proposed. With respect to the
proposed plan of putting parapets and guns one behind
another, I will examine that presently, but it can in no
v invalidate the arguments I have used. Such para-
poi, cif they possess an advantage adequate to the ex-
pense of their construction) can be equally well applied
to the faces and curtains of the bastion system for Gos-
port, as to the salient circular one. Whether throwing i

a continued fortification across the isthmus at Gosport
is the most effectual mode of defending the harbour, is
another question. After all the object of fortification is
but to ensure our lives and property, and ever, one in
this commercial country would prefer knowing the rate
of insurance he has to pay and for what. How ever, let
me first remark shortly on some of the points lluded to
last evening by the advocates of the circular system.
One was mentioned by a gallant captain i the navy
(Captain Hood). In speaking of the wet dit h and Sir
Charles Pasley's plan of crossing it by Colonel Blan-
shard's or by India-rubber pontoons, he says if the
besiegers attempted to do so he would let the water
out, and then he appealed triumphantly to know
where the besiegers would be then. Now, gentle-
men, in order to master this grand conception, I
must remind you that the ditch is not permitted to
be less than fifteen feet deep in water, 200 feet broad,
and is about four miles long ; that it must be filled
by the tide and cannot well be sustained at a level
above high water. It is then no matter of difficulty to
tell you where the besiegers would be ; if they attempted
a passage across they would do so at high at water,
when the water would simply refuse to go out ; but even
supposing a passage to be attempted at a time most
favourable for the gallant engineer to indulge his long-
ings, he might, with the most approved sluice-gates;
probably lower that immense body of water a few inches,'
in an hour, by which time it would be all over with the'
fortress. A few words on the recommendations of this
system by a brother officer (Captain Simmons). I can
speak for myself, and I am sure I can for the corps, how
pleasing it was to find one of ours arising in defence of
this system. It showed that we had but one feeling in
coming to this discussion, not that of a determined oppo-
sition, but for the public good. I may, as lam on en-
filade, allude to what Captain Younge said last evening,
that "no enfilade can properly be so called that doesnot
follow the line of parapet or ditch against which it is
directed, and that it is a palpable contradiction of terms
to say that a shot which only passes along a chord
enfilades the arc." Now, sir, an engineer does not care
to set guns to enfilade the arc, but the guns in that
arc, and if some part of each of the guns in any arc
are on an alignment with a besieger fire they will
be equally effectually enfiladed; whether the parapet
in front of them is an arc or a straight line. Mr.
Wrottesley has shown, .by his diagram, how many guns
are so open to enfilade in the circular system, drawn on
the scale proposed by the ingenious projector. I will now
Proceed, sir, to notice some of the defects of the circular
system. The art of fortification, then, has arrived at its
greatest perfection when it enables a fortified place to hold
out with the least expense for a certain period against
the greatest force. It cannot be expected that a fortress
of 1,000 guns is compared against one of 200 ; that it is
necessary to prove the former must fall quicker, or even
as quick, before the same besieging force, to establish the
point that the larger fortress is not so good as the smaller.
Besides, in this circular system, Mr. Wrottesley has shown
that 55 guns are the most that can be brought to bear on
any besieger's battery, and he uses three batteries, em-
ploying 165 guns, to oppose him, out of the whole fortress.
Here, then, we find in the height of the siege 835 guns at
least standing idle, and that number must continually
stand idle supposing we were to commence fighting now,
and continue doing so till the world's end, supposing the
siege to last so long. But, expecting as we do to have
some peace, it will not be over-estimating it if I say that
900 guns of every 1000-gun fortress must be continually
idle. Is it judicious to fortify so ? Are 900 platforms,
guns, and carriages to be exposed from year to year, the
platform to rot, the guns and carrriages to be continually
re-painted and re-lacquered; the extent of parapets they
occupy to appear continually for repair in our arsenal
estimates ? Really, sir, this would be paying a high in-
surance for protection ; and even that insurance, it has
been admitted, will not give us undoubted security. I
have said that I do not think it can be for a moment
supposed that six tiers of guns are not stronger than
one ; but I intend to show that guns and parapets so
placed do .not yield a protection equivalent to their cost.
I have no doubt it is evident to all that the besieger, if
he requires say three guns to enfilade one face, does not
reqtfire sit times three to enfilade six ; because any shot
fired may be 'expected to hit some one or other. The
same t °mark applied to counter batteries ; and it is also
evident, that with such extent of parapets the besieger
can continue firing all night, with guns that in attacking
the old system would have remained silent. Here,
then, the comparison, gun for gun, is at once in favour
of the besieger. Now, the expense of constructing every
tier of guns increases in a much greater ratio than the
number of tiers, for every succeeding parapet is placed
higher, requires more earth to construct it, and is
supplied from a deeper and more distant source than
the one below it. This supply has therefore to
travel further to be properly appropriated, and will
cost more to appropriate. It is evident, therefore,
on the first view of the case, that this system is
much more expensive in its construction than has
generally been supposed, and that the comparison is
here again in favour of the besieger. But I am sure
very few could have formed any idea of the proportion
of this additional expense as compared with a single
line. I have estimated this with some care, and I will
explain the proceedings. As it might be a matter of
opinion at what prices certain works could be executed,
I cannot give you the actual cost of the construction ;
but as there can be no doubt that the proportional cost
of any construction depends on the amount of work to
be done in each case, I have made a section by which
you at first sight guess that proportion, and a calcula-
tion by which you can at once arrive at the true com-
parison. I intend to compare the cost of such a line as
has been proposed for Gosport, and a simple bastioned
line, as I have been speaking of, applied there—you can
then arrive at your own conclusions—first, whether it
is worth our while to go to the expense ? and, second,
if it is, whether the money cannot be more advan-
tageously expended in the defence ? I have drawn a
section on a scale of twenty feet to an inch of the
proposed lines for Gosport, as laid down in the
" Perils of Portsmouth ;" and also one of a simple
Vauhan's bastion system, such as we should probably
use now with a command of 25 feet, a relief of 43
feet, demi-revetments 30 feet high, &c. In. each case
the mass of earth for throwing up the parapets,
must go from the ditch, and I have employed the usual
way of calculating the labour required to move the
quantity of earth. The distance of the centre of gravity
of the mass before moving, to that of the same when
finally settled into its new position, multiplied by the
number of cubic red moved in each case, gives, of course,
an accurate comparison. (He then went into a com-
parison, by figures, to show that the proposed system of
Mr. Fergusson would be more expensive than the sys-
tem of Vauban.) Now, since, under the most favour-
able comparison, the circular fortification for Gosport
would cost ten times as much, it becomes a matter of
consideration whether four parallel tiers are worth the
expense. For the same money ten such systems as Vau-
ban's could be constructed ; one in front of another, all
requiring to be passed, or it could be very advantage-
ously distributed in outworks, containing say double the
amount of labour as the main line, and at one-third the
price of the circular work. I have endeavoured to show
you the comparative cost of the four tiers it has been
proposed to apply to Gosport. I do not know that I
need say anything more ; the facts speak for them-
selves. There are certain principles in this system
which experience has shown us will not answer. It
is no matter of opinion that casemates 40 feet
high will not stand in made ground 60 feet
high ; that wet ditches 60 feet will not permit of
such steep unrevetted sides as we see recommended for
them ; and that if a quantity of earth has to be taken
ten times the distance it must be at ten times the cost.
If such is the comparative expense of the Gosport lines,
With ditches 30 feet deep and- a command of 48 feet,. I
must leave you to conclude what it will be for ditches 60
feet deep and corresponding commands. We must, how-
ever, all feel thankful to Mr. Fergusson for the attention
he calls to fortification, and the interest in our defences
he has excited in the public generally by publishing his
works. We should thank him for what he has done,
not blame him for what he did not do. It is not to be
expected that he who has been a useful member of society
in other ways should be as well versed in practical details
as we who spend our lives in that service.
Lieut. PASLEY then at some length reviewed the pro-
posed system, contending that it would not meet the ex-
pectations that its projector anticipated.
Colonel JEBB, of the .Royal Engineers, considered
that, without wishing to detract from the great merits
of Mr. Fergusson's system, its great defect was because
there were neither effectual flank, defence, or outworks,
nor the possibility of forming retrenchments.
Mr. FERGUSSON, in answer to the call of the chairman,
then rose to reply to the objections that had been urged to
his system. He said--If I were to attempt to answer all
the objections that have been made to me and to my sys-
of fortification I fear I should far exceed the time that
can be allotted me for such a purpose. It requires only
a few words to make an assertion, but often a great
many to rebut it. I believe, however, this meeting will
not think I am 'shirking a difficulty if I put on one side
at once all ob)ections- and remarks personal to myself.
It is not I who am on trial here, but my system of for-
tification, and to this I would confine my remarks, and
would not even notice Lieutenant Tyler's jokes about
the gas, nor Captain Wrottesley's misrepresentation of
my reasons for wishing the national store of naval guns
being transferred to Portsmouth when fortified instead
of being left in an open arsenal at Woolwich. I will
also pass over all such objections as those made to show
that there was nothing original in my proposal. That is
a question, I conceive, in which I. only am interested,
and it will be time enough to dispute about the ori-
ginality when we have determined what there is of good
in the proposal. At the same time, if any one chooses
to assert that this model of my system represents the
same thing as that model of Coimontaignes, Or that this
drawing of the Gosport lines is like that one of a fire of

the ordinary construction, I can only say that his eyes
are formed on a different system from mine, and that be
sees resemblances where I only see differences. Mr Fer-
_ .

gusson then recapitulated the main features of his plan;
and, in answer to Lieutenant Tyler's mode of attack,
said it appeared to him to be more scientific than Sir
Charles Pasley's. His proposition was that 24 mortars
could in 60 hours destroy his parapets over say 200 yards
of front, so as to render him unfit to cover either men

or g-uns and so make the assault easy. Now according
to the best tables (said Mr. Fergusson), I find that shells
thrown a distance of 600 yards, as shown on Lieutenant
Tyler's diagram, penetrate 21 inches to two feet, and in
exploding.form a small crater four or five feet in diame-
ter, displacing from five to eight feet of earth, one-half
of which, falls back into the holes, the rest is heaped on
its sides,. except a very small portion blown away. Now
if such a hole were formed in the terreplain of the ram-
part, a man with a shovel will replace the earth in a few
seconds, and if followed by one with a rammer no
damage is done. To calculate the real damage done we
must first assume that the mortars throw shells at the
rate Of 200 a day, or 500 shells each, or 19,000 alto-
gether • of which 300 will on the average -explode in
each of' the Ave parapets, or one in every two feet lineal.
NOW 1701114 ask any one if a number of small craters