The Sun.
London, England, 1867-10-22 00:00:00

THE DEFENCES OF POR7SIIIO LI TH.

If the opinions of the officers of our own Royal
Engineers, from Sir John Burgoyne down to the
youngest officer, were taken with regard to the
triple lines of fortifications now rising up in bristling
array around the dockyard and naval arsenal at
Portsmouth, with their advance guards at the east
and west ends of the Isle of Wight, it is more than
probable that the majority would pronounce all the
works as perfect as human skill or foresight, under
the circumstances of their design and construction,
could possibly render them. Still many of our
Engineer officers hold contrary opinions, and con-
tend, in common with many military men and civil
engineers, that scarcely a work can be inspected,
finished, or in the course of construction, that does
not exhibit some fatal defect, either original in de-
sign, or arising out of the conditions of its construc-
tion. No other nation has certainly in times of
peace enwred upon a work of such magnitude as in
the great scheme for the " Defence of the Dock-
yards and Naval Arsenals." The work is vast if the
failures have been pretty numerous. ft is better for
our strength, however, to discover and point out all
such defects as may exist ourselves than to allow
our foreign friends (who are constantly and won-
derfully inquisitive in the matter) to point them out
for our special edification, and thus lead them to
suppose that the people of this country are content
to repose in fancied security upon a false estimate
of the country's defensive power in the shape of its
coast and harbour fortifications. It would also be
as well to confess at once that even up to the pre-
sent moment we have nothing as the fruits of mili-
tary engineering of which we can very loudly boast,
or that is likely to excite the admiration of our
American brethren, or of our many friends from the
Continent of Europe, unless, indeed, it is the mag-
nificent way in which we spend our money on such
matters, the " eccentricity " with which we make
many of our greatest works look uncommonly like
failures, and the incomparable coolness with
which we do all these things. It is certainly
impressive enough to take one's stand on
the highest point of the crest of Ports-
down-hill and look downwards to the south, the
west, and the east, over scores of square miles of
land and water which are being covered with forts
of every size, description, colour, and material, red,
white, green, brown, and grey ; iron, granite, clay,
chalk, and sand—a grand school for the education
and practice of the Royal Engineers. In all this
vast plan the Portsdown-hill forts and the marine
forts at Spithead have naturally outweighed all
others in general interest, and will continue to do so
from their extent and peculiarities of position. Let
the reader, in imagination, step with us on the
highest elevation of Portsdown, in the centre of the
line of the five gigantic forts which are ranged
along the seven miles' length of the crest of Ports-
down. Now, if we can only give, for the time, un-
limited faith to the professional skill and provisions
of the great department in tall Mall that designed
those works, and in its subordinate officers who
carried out the details of their construction, wo
should find Widley, Southwick, Nelson, Walling-
ford, and Purbrook assume an appearance of
grandeur, strength, and efficiency that should last
for ages, as they stand in their elevated solicitude
with their backs turned upon Portsmouth Dockyard
and arsenal, and their empty embrasures looking
towards London. If, however, we lay down this
faith on the glacis of these forts, and look boldly
down into their deep white ditches, their empty em-
brasures, or over their grass-covered ramparts, re-
miniscences will arise of main magazines collapsing
b 0 feet below the level of finished parade-grounds,
of escarp walls falling down into and filling up the
ditch, of retaining walls giving way from excess of
weight behind them, of arches and vaulted passages
in brickwork split and gaping under superincumbent
and miscalculated weights, and a thousand other
" eccentricities" of the kind. But, as we have
already observed, the work has been vast if the
mistakes or failures have been pretty numerous.
As a rule also, all the mistakes, or nearly all, which
have occurred, have been due to ell curastances
under the control of the officer in local charge
rather than to the heads of the engineer
department at the War- office ; or, to the
immense progress made in the manufacture
and calibre of rifled artillery since these
and all other works around Portsmouth were
designed. There is also certainly nothing on the
heights of Portsdown nor in any part of the triple
bands of fortification that stretch out from its base
which can be said to exhibit such a miserable fiasco
as may be seen on the banks of the Medway.
" The Portsdown forts," Colonel Jervois remarks
in referring to objections that have been raised to
their construction, " render it impossible for an
enemy who may have landed on the coast of Sussex
to seize the bill by any force detached from his
main body without a regular siege." To this it may
be replied that no enemy must ever be allowed to
land in England. He must be met on the beach
and driven back into the sea he has ventured to
cross. Too much has been made of Portsdown-hill,
but as the work is nearly done it is useless to grumble
too persistently over the £600,000 it will have cost.
Southwick, Widley, and Nelson, the three forts
holding the central position of Portsdown, and
which loom up so grandly in their elevated seat
600 ft. above sea level, are complete so far as their
construction by the contractor is concerned ; but
the Artillery Department have yet to lay the
" racers " on the gun-platforms on the terre-plein
and in the caponnieres, and supply the guns and
mortars for their armament. These three works
may be generally described as earthworks of extra-
ordinary size and horse-shoe form, with deep and
wide ditches cut in the chalk, and flanked by weak
caponnieres. The front of each work, or the toe of
the horseshoe, faces north, the heel of the shoe, or
gorge of the work, being on the south face of the
hill, and toward Portsmouth. Tho gorge is closed
by massively built barracks in brickwork, with
stone dressings. From the edge of the huge chalk
ditches down to the long and deep valley north of
the position the entire face of the hill has been
cleared of all timber or hedgerows, and all inequali-
ties in the ground levelled, so that it now forms a
vast glacis swept in all directions by the fire of the
forts. From the valley below, in which lie embosotied
in foliage the villages of Purbrook, Southwick, and
Waterloo, the ground gradually rises in a succession
of swells, mostly well covered with timber, until
it culminates in the far distance in lofty spurs from
the great range of downs which extends along the
coast of Sussex. So far we have seen the central
strength of the great position of Portsdown. We
have now only to glance at the east and west ends.
On the eastern end of the hill stands Fort Purbrook,
with its two extensive outworks—a lion couchant,
keeping watch over the low-lying land below and
the great eastern highway leading toward Chiches-
ter and Brighton. Purbrook is very similar in form
to the three central forts, only differing in its two
outworks, which embrace the north-east and east
slopes of the hill. It is still in course of construc-
tion, Fort Wallington, on the west end of Ports-
down, and overlooking the slope of the hill to the
N.W., is partly built on clay, and has revetments
of massive brickwork on the escarps and counter-
scarps. It is complete with the exception of its
armament. Fareham Fort is separated by the village
of Fareham from the west base of Portsdown, but
it is part of the Portsdown line of defence, com-
manding as it does the approaches to the hill in the
advance of any enemy from the westward or the
Solent. It is an earthwork, with bomb-proof brick
caseinates under the ramparts. The armament of
all the Portsdown forts is intended to comprise a
total number of about 200 heavy guns and mortars,
besides light pieces for the caponniere. These guns
may possibly be all mounted in the forts in about two
years' time—October, 1869—if the authorities bestir
themselves in the matter with requisite energy.
Looking south from Portsdown, and in the direc-
tion of Portsmouth, may be seen at the very foot of
the hill,with only the village of Coshain intervening,
the northern section of the second circle of fortifi-
cation; as Portsdown is the northern section of its
first or outer circle, which engirdles Portsmouth—
the Ililsea lines, defending the only entrance to
the iOrtnd of Portsea by road from the mainland.
The Hilsea lines have been uncommonly fruitful
in their crop of " eccentricities." These lines

are nearly 3,000 yards in length, and their right
may be seen resting on the mudlands of Langston
harbour and their left on the mudlands of
Portsmouth harbour. They consist of long earth-
work curtains, with casemated batteries on the
flanks of each curtain, the batteries intended to
cross fire with each other, and sweep the whole
front of the work. There are embrasures for 90
guns. The channel between Portsmouth and Lang-
ston harbours, connecting the two tidal waters,
runs in front of the lines, and an inner moat sepa-
rates this tidal channel, in which a certain depth of
water is to be retained at all times' of tide, from
the base of the line of ramp. A new road has also
been constructed for the use of the public entering
or leaving the island from the mainland, which is
to supersede the old highway, and the outer tidal
water channel was to have been so designed, to use
the exact words made use of in Colonel Jervois's
report on the " progress made in the construction
of the fortifications for the protection of the dock-
yard and the naval arsenals," dated February, 1867,
"to give it sufficient dimensions to allow of the
passage of floating batteries." The Hilsea lines
have become a sand-covered ruin, with their case-
mates cracked and tottering over quaking bog and
permeating chalk springs. The embrasures are
choked with the falling earth intended to cover the
brick face of the casements on the flanks, and the
revetment walls throughout are kept in their places
by an elaborate system of timber shoring. The
work of construction has been for years in hand,
and successive contractors have been driven from it
by ruin or despair ; but still the locomotive with its
long train of earth trucks may be seen toiling up-
wards and along the line of rampart depositing its
earth coverings. Ihe difficulties met with in the con-
struction of this line of defence have been immense,
but in time they will no doubt be finally overcome
and the work finished. The embrasures have all
been placed so closely together, however, that every
alternate one must be built up, and thus the Hilsea
lines will only mount one-half the number of guns
for which they were designed. No one imagines it
possible that the Hilsea lines will ever be subjected
to an attack by an enemy, and, therefore, in
common with the huge forts on Portsdown, pos-
sibly, it can matter very little whether guns
are placed in them or not. The ecentricities of the
Hilsea lines, which appear to be of the greatest
public importance at the present moment, relate to
the construction of the new public highway, and the
tidal channel connecting the waters of Portsmouth
and Langston harbours. The new highway has
been carried by the Royal Engineers over the tidal
_channel referred to by a bridge, moving over central
wheels by double rails, of such restricted dimensions
that the local authorities —the Sheet Bridge High•
way Trust—refuse to accept it, and a new bridge
must therefore be constructed at the expense of the
Government. The tidal channel is a still more seri-
ous matter. When the Helsea lines at present being
constructed on the south bank of the tidal channel
were first designed at the War-office, to supersede
the old bit of fortification then standing there, the
Admiralty communicated with the War-office, and
desired that in any future alteration of the old tidal
channel the width of the tidal water at high-water
mark should not be less than 300 ft., that two open-
ings for the passage of war vessels should be avail-
able in any new bridge, and that the tidal channel
should be made of sufficient depth and width to ad-
mit of the passage through from Portsmouth to
Langston harbour, or vice versa, of floating batteries
and gunvessels to assist in the defence of the island•
The Admiralty authorities also called special atten-
tion to the fact that in their taking a large amount
of water space from Portsmouth harbour for the ex-
tension of the dockyard there would very probably
be a corresponding decrease in the total volume of
tidal water in the harbour, which must be restored
by other adopted means ; that those means existed
in the known flow of the tide from Langston into
Portsmouth harbour for two hours after the tide had
made its ebb from the mouth of the latter; and that
to secure the full benefits of this additional flood into
Portsmouth harbour, it was imperative that the new
tidal channel should be of sufficient width and depth,
and that retaining gates should be fixed at the Langs-
ton end of the channel to prevent any back-flow of
the title. It was also of the highest importance that
the " scour" of the ebb tide should not be lessened
out of Portsmouth harbour under any circum-
stances, but rather increased, owing to the existence
of two immense banks of shingle formed inside the
harbour itself, and the known deposit of shingle on
the Channel bar outside the harbour. The very
existence of Portsmouth as a naval port, therefore,
seemed to depend upon the Royal Engineer Depart-
ment constructing the new tidal channel in good
faith, with the expressed wishes of the Admiralty,
but the work now stands on the verge of completion,
with the important suggestions of the Admiralty
ignored in every important particular. Instead of
the channel giving a water space of 300 ft. in width
at high water mark, with a depth sufficient for float-
ing batteries and gun vessels and a double passage
under the bridge, it has now a breadth of water of
only about 120 ft., has not a depth of water suffi-
cient for the passage of such vessels, and only one
available passage between the piela of the bridge,
and will afford no material tidal addition to the
ebb of Portsmouth harbour. Some correspondence
has naturally ensued upon this matter between the
Admiralty and the War Department, which has
been so far closed by the latter, stating that the
new tidal channel served all the purposes required
of it for the strength and security of the fortifica-
tions, and that if the Admiralty desired a deeper or
wider channel than the one made, the Admiralty
could obtain a fresh estimate and do the work by
its own officers. If we did not happen to know
that the facts connected with the construction of
this bit of water channel are just as we have related
them, we should look upon them as far too absurd
in their nature to deserve a moment's credit.

Leaving Hilsea lines at our feet, and looking out
further to the southward, we can trace the sweep of
the three lines of defence, until the eye rests upon
the stagings and stone foundations for the marine
forts at Spithead, or further still upon the great
mound of earthworks on the summit of Bembridge-
down, which forms the " keep" to the various forts
on Sandown cliffs and sands, and commands the
approaches to its beautiful bay with the anchorage
inside the east end of the Wight at St. Helen's. The
Spithead works, however, frem their paramount
importance and their present backward stage of pro-
gress, are of greater interest than any or all the
others at the present moment. The " Horse" and
"Noman" shoal forts will be the largest, and they
will also be the most successful in their work of con-
struction of the Spithead forts. The Horse fort has
the base ring of its foundations standing on the
shoal at lift. below low water of ordinary spring
tides. The Noman has its base ring 20ft. below low
water of ordinary spring tides. The foundations of
each are formed of rings of granite, Portland, Run-
corn, and concrete blocks, the rings decreasing in
diameter as the foundation grows in height. The
interior space of this layer of rings, in the centre of
which an iron cylinder has been sunk from 50 to
60ft., and remains available for future borings for
water, is filled in with concrete. The top of both
the foundations for these two forts thus form a cir-
cular and solid base on which the future fort must
be built, 210 ft. in diameter. On this base all that is
yet being done towards the construction of the forts
themselves is building up their basement wall each
16ft. in height above the foundation summit, and
14ft. Gin. thick, of granite and Roach Portland
stone. These walls are set back from the edge of
the foundations 18in., to admit of a facing of ar.
motir-plaiing being given to it. The top of these
walls will be level with the interior of the work or
the floor of the lower gun battery. They will in-
close the magazines, shell stores, provision stores,
water tanks, &c. The Spithead forts were at first
intended to be of stone alone. Soon afterwards a
granite structure faced with iron was adopted, but
subsequent experiments at Shoebury demonstrating
the inability of such a structure to receive the im-
pact of heavy shots, without shaking its "heart"
into fragments, the idea of a fort built up entirely of
iron was entertained. This latter alternative, how-
ever, frightened every one by its evident excessive
costliness, and the present adopted and some-
what composite plan was at length substituted.
The forts are now to have au outer casing of