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

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 every one in
this commercial country would prefer knowing the rate
of insurance he has to pay and for what. However, 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 is the navy
(Captain Hood). In speaking of the wet ditch 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 does not
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's 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. Wrottesleyhas 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
require six times three to enfilade six ; because any shot
fired may be expected to hit some one or other. The
same remark applies 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
muck 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
Vauban's bastion system, such as we should probably
use now with a command of 25 feet, a relief of 43
feet, demi-revetments '3o' 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 teet 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 ho 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 1 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 Cormontaignes, 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 he
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
t h rto-ae-
o boat
a of front, so as to render him unfit to cover either men
distancetables
of
°toh
r guns, and so make the assault easy. Now according
(said6o yards, M 0
r.F eauss Ferguson},
shown
fioniid that
Lieutenant shells
Tyler's diagram,penetrate 21 inches to two feet, and in
exploding forma
ter, displacing from small crater four or five feet in diame-
ter,
which falls haer five to eight feet of earth, one-half
its
sides,
except a into the holes, the rest is heaped on
if such a hole werev7orYrisrnall portion blown away. Now
part, a man with a. shovel will in the terreplain of the rani-
seconds, and if followed i replace the earth in a few
dam-age is done. To cal by
one
'with a raitmer no
must first assume that the calculatemotrhe real damage done we
rate of 200 a day, or 500 Shetlasrs throw shells at the
gether • of which 300 will on theeach, or 12,000 alto-
each of five parapets, or one in e:.vryeratte explode in
Now I would ask any one if a number fiofe9t lineal.
'nail craters ,