FIELD-ENGINEERING.
_Field-Engineering_ includes the making of military reconnaissances,
temporary fortifications, and military roads; the planning and
construction of military bridges; the attack and defence of military
works;--in fine, all the various duties of engineer troops, either in
the operations of a campaign, or in the dispositions on the
battle-field.
_Military reconnaissance._--By this term is meant an examination of a
portion of the theatre of war, to ascertain its military character and
resources. If the examination be made of a large district of country,
and for an entire campaign, the reconnaissance is _general_; if made for
collecting detailed information respecting a proposed line of march, the
passage of a river, the position of an enemy, &c., it is termed
_special_.
In making a general reconnaissance, great care should be taken to
collect accurate information respecting the general topography of the
country; the character of the mountains, forests, and water-courses; the
nature of the roads, canals, and railways; the quality of the soil, and
the amount of provisions and forage it produces; the population and
character of the cities, towns, and villages, the commercial and
manufacturing resources of every part of the country, and the means of
transportation to be found in each district. The plan of military
operations will be based on the information thus obtained, and any
serious error in the reconnaissance may involve the results of the
campaign, and even the fate of the war.
In a special reconnaissance, not only accurate but minute information
will be required: the character of the roads must be given in detail;
the nature of the water-courses, their depth and velocity; the position
and character of bridges, and fords;--in fine, a full description of all
obstacles to be encountered, and the means that can be made available
for overcoming these obstacles.
A reconnoitring officer may usually derive much valuable information
from the published maps and descriptions of the country to be examined;
additional matters of detail may be obtained from woodsmen, hunters, and
fishermen; and also from the innkeepers and local authorities of the
district. But the officer should always verify this information, so far
as practical, by personal examination. In making a reconnaissance in the
vicinity of an enemy, he must be supported by a strong escort of mounted
troops, and in all his operations the greatest precaution will be
requisite to ensure success.
Some simple instrument, such as a pocket sextant, or compass, will be
sufficient to enable the reconnoitring officer to measure, with
considerable accuracy, the height of mountains, the width of streams,
&c., and an ordinary scale and dividers will enable him to make a
suitable military sketch.
_Temporary Fortification._--It has been stated in the preceding chapter
that temporary fortifications are properly confined to the operations of
a single campaign, and are used to strengthen positions which are to be
occupied only for a short period; and that they are usually made of
earth, thrown up by the troops in a single day. Temporary
fortifications, as a part of field-engineering, may therefore be
regarded rather as an _arm_ than an _art_. The principles of their
construction are derived, of course, from the theory of permanent
fortification, but in applying these principles to practice in the
field, much greater latitude is allowed than in the exact scientific
arrangement of permanent works.
The purpose of field-works (or intrenchments, as they are commonly
called) is to arrest, or at least to impede, the march of the attacking
foe; to shelter the defensive troops from the missive weapons of the
assailants, and to detain them in a position where they will be exposed
to the fire of the defensive force. The numerical and positive strength
of the assailed may be much less than that of the assailant, and yet an
equilibrium exist; the material obstacles compensating for the
difference in numbers. Intrenchments, though inert masses, must
therefore be regarded as most valuable and important accessaries in the
defence of a position.
Intrenchments consist either of _lines_ of works made to cover extended
positions, or of _detached_ works designed simply to defend the ground
they occupy. The former generally present a front against the enemy in
but one direction, while the latter are usually closed on all their
sides.
The following figures have been employed for the plan of simple
intrenchments, viz.: the polygon, redan, lunette, mitre, star-fort, and
bastion.
_Square_ or _polygonal redoubts_ are the most common forms given to
field-works, on account of the ease of their construction. But they have
many defects. There is a sector without fire in front of each salient,
and the ditches are without protection. The latter objection also holds
good against all circular works.
The _redan_ (Fig. 45) is frequently used to cover a point in rear, as a
bridge, a ford, or a defile. When used alone, its gorge should be closed
by palisades. Its ditches are unprotected.
The _lunette_ (Fig. 46) has nearly the same defects as the redan.
The _mitre_, or _priest-cap,_ (Fig. 47,) may be employed with advantage
when a cross-fire is required on the capital of the work. The
_star-fort_ has all the defects, without the merit of simplicity, which
belong to the polygonal redoubt.
The _bastion-fort_ (Fig. 48) more fully satisfies the conditions of a
good defence than any other plan; but it is less simple and easy of
execution. It is usually composed of four or five fronts, but it may be
applied to a polygon of any number of sides.
For the details of the construction of these several works, we must
refer to the special treatises on field-fortification.
Lines of intrenchments may be made either continuous or with intervals.
In adopting either plan, the engineer should avail himself of all the
natural obstacles presented by the position, so as to diminish the labor
of erecting artificial means of defence.
The simplest arrangement for a continuous intrenchment is the
_cremaillière_ or indented line. When applied to an irregular site, or
used to connect together distant and detached works, the indented line
may be regarded as a good disposition. Mitres and redans, connected by
straight curtains, are sometimes employed, as also a combination of
large and small redans, forming alternate salient and re-entering
angles. A continuous line of bastions is preferable to any other
arrangement, when there is plenty of time for their construction.
Lines with intervals are frequently formed of alternate lunettes and
square redoubts. Other detached works may be employed in the same way.
This manner of intrenching a position has several advantages, with
disciplined troops. The first shock of the assailant is sustained by the
detached works, and when he attempts to penetrate in the intervals, his
flanks become exposed to a deadly cross fire. These intervals also allow
the assailed to act on the offensive, by charging the enemy at the
opportune moment. But with raw and militia forces it will be safer to
resort to continuous lines. If cavalry form any part of the defensive
force, it will be absolutely necessary to leave intervals through which
these troops may charge.
A vertical section of all intrenchments is of the same general form; the
dimensions will, of course, vary with the nature of the soil, and the
time and means employed in their construction. The minimum dimensions
that can be used with any considerable advantage are given in Fig. 49.
In laying out field-works advantage should be taken of all available
artificial obstacles, such as hedges, walls, houses, outbuildings, &c. A
thickset hedge may be rendered defensible by throwing up against it a
slight parapet of earth. Stone fences may be employed in the same way.
Walls of masonry may be pierced with loop-holes and arranged for one or
two tiers of fire. The walls of houses are pierced in the same manner,
and a projecting wooden structure, termed a _machicoulis gallery_, is
sometimes made from the floor of the second story, to enable the
assailed to fire down upon their opponents. This arrangement is
frequently employed to advantage in wooden blockhouses against a savage
foe; but it is of little avail when exposed to the fire of artillery.
Some have proposed galleries of this description in permanent works of
masonry, but the project is too obviously absurd to merit discussion.
In addition to the parapet of an intrenchment, a good engineer will
always find time and means for constructing other artificial obstacles,
such as trous-de-loup, abattis, palisades, stockades, fraises,
chevaux-de-frise, crows'-feet, mines, &c.
_Trous-de-loup_ are pits dug in the earth in the form of an inverted
truncated cone, some six feet in diameter, and about the same number of
feet in depth. They are usually placed a few yards in front of the
ditch, and concealed by some slight covering.
_Abattis_ are tops and large limbs of trees arranged along the glacis of
a work; the ends of the branches are lopped off and sharpened.
_Palisades_ are stakes some eight or ten feet long, with one end
fastened in the ground and the other made sharp. They are placed in
juxtaposition and connected together by horizontal riband-pieces. This
arrangement is frequently placed at the foot of the counterscarp. When
the timbers are large and the work is intended as a part of a primary
defence, it is called a _stockade_; when the stakes are placed at the
foot of the scarp, either horizontally or inclined, they receive the
name of _fraises_.
A _cheval-de-frise_ consists of a horizontal piece of timber armed with
wooden or iron lances, which project some eight or ten feet. It is much
employed against cavalry, and on rocky soils serves as a substitute for
palisades.
_Crows'-feet_ are small wooden or iron forms filled with sharp spikes.
They are thrown, with their points upward, on ground which is to be
passed over by cavalry.
_Mines_ are sometimes used in connection with intrenchments, but more
commonly in the attack and defence of permanent works. They will be
noticed further on.
Fieldworks which are to be occupied for a considerable length of time
will usually have their steeper slopes revetted, and be arranged with
scarp and counterscarp, galleries, traverses, blindages, &c. Such works
hold an intermediary rank between temporary and permanent fortification.
As examples of the importance of field fortifications and of the manner
of organizing them, the reader is referred to the celebrated battle of
Fontenoy, in 1745, where the carefully-arranged intrenchments of Marshal
Saxe enabled the French to repel, with immense destruction, the attacks
of greatly superior numbers; to the battle of Fleurus, in 1690, where
the Prince of Waldeck exposed himself to a most disastrous defeat "by
neglecting the resources of fortification and other indispensable
precautions;" to the battle of Malplaquet, in 1709, where Marshal
Villars, by neglecting to occupy and intrench the farm that closed the
passage between the woods of Sars and Lanière, exposed himself to a
disastrous defeat; to the operations of 1792, where General Custine, by
neglecting to intrench the heights that covered Bingen, as the engineers
had recommended, exposed himself to those terrible disasters which
forced him to a precipitate retreat; to the works of Wervike, which, by
a vigorous resistance on the 10th of September, 1793, saved the Dutch
army from total destruction; to the intrenched camp of Ulm, in 1800,
which for six weeks held in check the victorious army of Moreau; to the
intrenched lines of Torres Vedras, in 1810, which saved from destruction
the English army of Wellington; to the field-defences of Hougomont,
which contributed so much to the victory of Waterloo, &c.
_Military communications._--The movements of armies are always much
embarrassed by forests, marshes, and water-courses, and nothing
contributes more to the dispatch of military operations than the means
of opening practical and easy communication through these various
obstacles.
It is not necessary here to enter into any detailed discussion of the
manner of constructing military communications through forests or
marshes. In a new country like ours, where almost every one has had some
experience in road-making, no very great technical knowledge is required
for the construction of temporary works of this character; but much
professional skill and experience will be requisite for the engineers
who make the preliminary reconnaissances, and fix the location of these
roads.
Water-courses may be crossed by means of fords, on the ice, or by
ferries and bridges. When temporary bridges or ferries are constructed
by the army in the field, they are classed under the general head of
_military bridges_, or more properly, _pontoniering_.
Where the depth of the stream is not great, the current slight, and the
bottom smooth and hard, the passage may be effected by _fording_. If the
bottom be of mud, or large stones, the passage will be difficult and
dangerous, even where the depth and current are favorable. Under
favorable circumstances infantry can ford a stream where the depth is
not greater than four feet; cavalry to a depth of four or five feet; but
artillery, and engineer trains, cannot go to a depth of more than two
and a half feet, without greatly exposing their ammunition and military
stores The fords should be accurately staked out before the passage is
attempted, and ropes ought to be stretched across the stream, or cavalry
and small boats stationed below, to prevent the loss of life.
Ice may be crossed by infantry, in small detachments. Its strength may
be increased by covering it with boards, or straw, so as to distribute
the weight over a greater surface. By sprinkling water over the straw,
and allowing it to freeze, the mass may be made still more compact. But
large bodies of cavalry, and heavy artillery, cannot venture on the ice
unless it be of great thickness and strength. An army can never trust,
for any length of time, to either fords or ice; if it did a freshet or a
thaw would place it in a most critical state. Military bridges will,
therefore, become its only safe reliance for keeping open its
communications.
Military bridges are made with trestles, rafts, boats, and other
floating bodies. Rope bridges are also sometimes resorted to by troops
for passing rivers.
_Trestle bridges_ are principally used for crossing small streams not
more than seven or eight feet in depth: they also serve to connect
floating bridges with the shore, in shallow water. The form of the
trestle is much the same as that of an ordinary _carpenter's horse,_
i.e., a horizontal beam supported by four inclined legs. These trestles
are placed in the stream, from twelve to twenty feet apart, and
connected by string-pieces, (or _balks_ as they are termed in technical
language,) which are covered over with plank. The action of the current
against the bridge may be counteracted by anchors and cables, or by
means of boxes or baskets attached to the legs of the trestles, and
filled with stones. A more substantial form may be given to the bridge
by substituting for the trestles, piles, or the ordinary framed supports
so much used in the newer parts of our country.
For examples of the use of bridges of this description we would refer to
Caesar's celebrated bridge across the Rhine; the passage of the Scheldt
in 1588 by the Spaniards; the passage of the Lech in 1631 by Gustavus
Adolphus; the passage of the Danube in 1740 by Marshal Saxe; the great
bridge across the Var during Napoleon's Italian campaigns; the passage
of the Lech in 1800 by Lecourbe; the bridges across the Piava, the
Isonso, &c., in the subsequent operations of the army in Italy; the
celebrated passage of the Danube at the island of Lobau in 1809; the
passage of the Agueda in 1811 by the English; the passages of the Dwina,
the Moscowa, the Dneiper, the Beresina, &c., in the campaign of 1812;
the repairing of the bridge near Dresden, and the passage of the Elbe in
1813, &c.
_Rafts_ formed of timbers, casks, barrels, &c., are frequently used as
military bridges. They may be made to bear almost any weight, and will
answer for the passage of rivers of any depth and width, provided the
current be not rapid.
Where the bridge is to be supported by rafts made of solid timbers,
these timbers should be first placed in the water, to ascertain their
natural position of stability, and then the larger ends cut away on the
under side, so as to present the least possible resistance to the action
of the current. They are afterwards lashed together by strong rope or
withe lashing, or fastened by cross-pieces let into the timbers, and
held firm by bolts, or wooden pins. These rafts are kept in place by
anchors and cables placed up and down stream. The roadway is formed in
nearly the same manner as for a bridge supported on trestles. Empty
casks, and other floating bodies, may be substituted in place of logs in
the construction of rafts.
For examples of the use of rafts in the construction of military
bridges, we would refer to the passage of the Seine in 1465 by Count
Charolais; the passage of the Meuse in 1579, by Alexander Farnése; the
passage of the Vistula in 1704, the Borysthenese in 1709, and the Sound
in 1718, by Charles XII.; the passage of the Adige in 1796; the passage
of the Po in 1807; and the subsequent military operations in the Spanish
Peninsula.
Military bridges are frequently made of _boats_, and the ordinary
river-craft found in the vicinity of the intended passage. Flat-bottomed
boats are the most suitable for this purpose, but if these cannot be
obtained, keel boats will serve as a substitute. When these water-craft
are of very unequal sizes, (as is frequently the case,) two smaller
ones may be lashed together to form a single support; they can be
brought to the same level by means of stone ballast. The gunwales must
be suitably arranged for supporting the balks, or else frameworks should
be erected for this purpose from the centre of the boat. The arrangement
of the roadway, anchors, &c., is the same as before.
A _bridge-equipage_ made to follow an army in its movements in the
field, is generally composed of light skiffs or batteaux, and the
necessary timbers, planks, anchors, &c., for forming the roadway, and
keeping the bridge in its position. All these articles are constructed
especially for this purpose. All the wood-work should be of tough and
well-seasoned timber, so as to impose no unnecessary weight on the wagon
trains. The bateaux should also be made of strong and light materials.
For convenience in transportation, these boats are sometimes made with
hinges so as to fold up. The ribs are usually of oak, and the sides and
bottom of pine. Instead of plank, a covering of tin, copper,
India-rubber, &c., has sometimes been substituted. Floating supports of
this character are often made in compartments, so as to prevent their
sinking when injured by the enemy's projectiles. Indian-rubber pontons
may be folded up into a small space, and their slight weight renders
them convenient for transportation.
On navigable streams a part of the bridge resting on one or two bateaux
should be so arranged that it can be shipped out of its place, forming a
_draw_ for the passage of river-craft. Indeed, it would be well, even
where the river is not navigable, to form a draw for the passage of
trees, and other floating bodies, sent down by the enemy against the
bridge.
An ordinary bridge-equipage of bateaux, or light pontons, for crossing a
river of from three to four hundred yards in width, and of moderate
current, will require a train of from sixty to eighty wagons.[46] Under
favorable circumstances, and with a well-instructed corps of pontoniers,
the bridge may be thrown across the river, and prepared for the passage
of an army in a few hours at most.[47] After the troops have passed
over, the bridge may be taken up, and replaced on the wagons in from a
quarter to half an hour.
[Footnote 46: The number of wagons in a ponton train will be greatly
diminished if it be found that Indian-rubber boats may be used as
supports for the bridge. The engineer department of our army are making
experiments to determine this point.]
[Footnote 47: In 1746, three bridges of bateaux were thrown across the
Po, near Placentia, each fifteen hundred feet in length, and entirely
completed in eight hours. In 1757, two bridges of bateaux were thrown
across the Rhine, at Wesel, in half an hour; again, in the same year, a
third bridge was thrown across this river near Dusseldorf, in six hours.
In 1841, Col. Birago, of the Austrian army, arrived on the bank of the
Weisgerben arm of the Danube, with his bridge-equipage, at a round trot,
and immediately began the construction of his bridge, without any
previous preparation or examination. In less than three-quarters of an
hour the bridge was completed, and three loaded four-horse wagons passed
over on a trot, followed by a column of infantry.]
The following examples will serve to illustrate the use of different
kinds of boat-bridges in military operations:--the passage of the Rhine,
in 1702, by Villars; the passage of the Dnieper and the Bog, in 1739, by
the Russians; the passage of the Danube, in 1740, by Marshal Saxe; the
passage of the Rhine, near Cologne, in 1758, by the Prince of Clermont;
the passage of the Rhine, in 1795, by Jourdan; the passage of the Rhine,
at Kehl, in 1796, by Moreau; and again the same year, at Weissenthurn,
and at Neuwied, by Jourdan; the bridges across the Rhine, at the sieges
of Kehl and Huninguen, in 1797; the passage of the Limmat, in 1799, by
Massena; the passages of the Mincio, the Adige, the Brenta, the Piava,
&c., in 1800; the passages of these rivers again in 1805; the passages
of the Narew, in 1807, by the Russians; the several passages of the
Danube, in 1809, by the French and Austrian armies; the passages of the
Tagus and Douro, in 1810, by the English; the passages of the Niemen,
the Dwina, the Moskwa, and the Beresina, in 1812, by the French; and of
the great rivers of Germany and France, in 1813 and 1814.
A floating body, propelled from one bank to the other by the current of
the stream, is termed a _flying-bridge._ The usual mode of establishing
a ferry of this kind, is to attach the head of the boat by means of a
cable and anchor to some point near the middle of the stream. By
steering obliquely to the current, the boat may be made to cross and
recross at the same point. A single passage may be made in the same way,
by the action of the current without the cable and anchor, but the boat
in this case will be carried some distance down the stream. Rowboats are
employed for crossing over infantry by successive debarkations; but this
process is too slow for the passage of a large force; it may very well
be resorted to as auxiliary to other means.
Steam craft are so common at the present day on all navigable streams,
that an army in the field will frequently be able to avail itself of
this means of passing the larger rivers. But, in a hostile country, or
in one already passed over by the enemy, it will not be safe to rely
with confidence upon obtaining craft of this character. A well-organized
army will always carry in its train the means of effecting a certain and
speedy passage of all water-courses that may intercept its line of
march.
Flying-bridges or rowboats were employed in the passage of the Dwina, in
1701, by the Swedes; the passage of the Po, in 1701, by Prince Eugene;
the passage of the Rhine, at Huninguen, in 1704; Jourdan's passage of
the Rhine in 1795; Moreau's passage in 1796; the sieges of Kehl and
Huninguen in 1797; Massena's passage of the Limmat, and Soult's passage
of the Linth, in 1799; the passage of the Rhine, at Lucisteig in 1800;
the passage of the Po, by the French, just before the battle of Marengo;
and others in Italy, Germany, and Spain, in the subsequent campaigns of
Napoleon.
Military bridges have sometimes been formed of ropes, cables stretched
across the stream, and firmly attached at each end to trees, or posts
let into the earth. If the shore is of rock, rings with staples let into
the stone form the best means for securing the ends of the main ropes.
Plank are laid on these cables to form the roadway. The ropes forming
the "side-rail" of the bridge are passed over trestles at each shore,
and then fastened as before. Short vertical ropes attach the main
supports to these side ropes, in order that they may sustain a part of
the weight passing over the bridge. Constructions of this character are
fully described in Douglas's Essay on Military Bridges. For example, see
the passage of the Po, near Casal, in 1515, by the Swiss; the bridge
thrown over the Clain by Admiral Coligni, at the siege of Poitiers, in
1569; the operations of the Prince of Orange against Ghent and Bruges,
in 1631; the passage of the Tagus, at Alcantara, in 1810, by the
English; the bridge constructed across the Zezere, by the French, in
1810; the bridge thrown across the Scarpe, near Douai, in 1820; the
experiments made at Fêre in 1823, &c.
The passage of a river in the presence of an enemy, whether acting
offensively or in retreat, is an operation of great delicacy and danger.
In either case the army is called upon to show the coolest and most
determined courage, for its success will depend on its maintaining the
strictest discipline and good order.
In the case of a retreat the bridge should be covered by field
intrenchments, called a _tête de pont_, and defended by a strong guard.
If the river be of moderate width, the enemy may be kept at a distance
by heavy batteries on the opposite shore. As soon as the passage is
effected by the main body, the bridge, if permanent, will be blown up,
or otherwise destroyed by the miners, and if floating, will be swung
round to the other shore. The rear-guard will pass over in rowboats, or
the end pontons detached for that purpose. An army retreating in the
face of an enemy should never rely upon one single bridge, no matter
what may be its character: for the slightest accident happening to it
might expose the whole army to inevitable destruction.
The passage of a river by main force, against an enterprising and active
enemy on the opposite shore, is always an operation of the greatest
difficulty, and not unfrequently accompanied with the most bloody
results.
The most effectual method of accomplishing this object is by stratagem.
Demonstrations are made at several points at the same time: bodies of
troops are thrown across, after nightfall, in rowboats or by
flying-bridges, to get possession of the opposite bank. The vanguard of
light cavalry may cross by swimming. The pontoniers should have their
bridge equipage in readiness near the intended point of passage, so that
it can be thrown across with the greatest possible rapidity, while the
advanced guards are still able to keep the enemy at a distance. Under
favorable circumstances the pontoniers will have the bridge in readiness
for the passage of the army before the enemy can collect his troops upon
the threatened point.
Cannon-balls and hollow shot are the most effectual means for destroying
an enemy's bridge when our batteries can be planted within reach. When
this cannot be done, we must resort to fire-boats, floating rafts, &c.,
to accomplish our object. Operations of this kind carried on in the
night, are most likely to succeed.
To protect bridges from the action of these floating bodies, stockades,
or floating chevaux-de-frise are constructed across the stream at some
distance above the bridge; strong cables, or chains stretched directly
across the river, or with an angle up stream, may be used in place of
stockades, or in conjunction with them. Guards should be stationed above
the bridge, with boats, ropes, grapnels, &c., for the purpose of
arresting all floating bodies and drawing thorn ashore, or directing
them safely through the _draw_ in the bridge arrangement.
The troops especially charged with the construction and management of
the various kinds of military bridges, are denominated _pontoniers_. The
duties of these troops are arduous and important, and, in a country like
ours, intersected by numerous water-courses, the success of a campaign
will often depend upon their skill and efficiency.
_Sapping_.--This is a general term applied to the operations of forming
trenches, along which troops may approach a work without being exposed
to the fire of the besieged.
In addition to the ordinary sapping-tools, such as shovels, picks,
gabion-forks, &c., used in constructing trenches, there will also be
required a considerable amount of sapping materials, such as gabions,
fascines, sap-fagots, sandbags, &c.
The _gabion_ is a cylindrical basket of twigs, about two feet in
diameter, and some three feet in length, and without a bottom. It is
made by driving into the ground, in a circular form, a number of small
pickets about an inch in diameter, and of the length required for the
gabion. Twigs are wattled between the pickets like ordinary basket-work,
and fastened at the ends by withs or packthread. Gabions are used in
forming saps, batteries, blindages, powder-magazines, and in revetting
the steep slopes of field-works.
The _fascine_ is a bundle of twigs closely bound up, from nine to twelve
inches in diameter, and from ten to fifteen or twenty feet in length.
The largest are sometimes called _saucissons_. In making a fascine,
straight twigs about the thickness of a man's finger are laid side by
side, and firmly compressed together by a strong rope or chain attached
to the extremities of two levers. While held in this position the twigs
are firmly bound together by withs or cords. Fascines are used in
constructing trenches, batteries, &c., and for filling up wet ditches.
The _sap-fagot_ is a strong fascine about ten inches in diameter and two
feet in length, with a picket inserted through the middle. It is used in
the double sap in connection with gabions.
_Sand-bags_ are usually made of coarse canvass. When filled with earth
they are some six or eight inches in diameter, and from eighteen inches
to two feet in length. From their perishable nature, they are used only
when other materials cannot be procured, and where it is important to
place the troops speedily under cover from the enemy's fire.
Bales of wool, cotton, hay, straw, &c., may be employed in sapping for
the same purposes as the above materials, when they can be procured in
sufficient quantity. Pork and flour barrels, which are usually in
abundance in a camp, are frequently filled with sand and used for
forming magazines, blindages, &c., in field-works.
A trench constructed in ordinary soil beyond the range of the enemy's
grape, is called a _simple sap_, or ordinary trench. The earth is thrown
up on the side towards the place besieged, so as to form a kind of
parapet to cover the men in the trench. The labor is here executed under
the supervision of engineer soldiers, by working parties detached from
the other arms. Fig. 50 represents a vertical section of a simple sap.
When within range of the enemy's grape, the _flying sap_ is resorted to
in order to place the workmen speedily under cover. In this operation,
gabions are placed in juxtaposition on the side towards the besieged
work, and filled with all possible speed by the workmen. Three rows of
fascines are usually placed on the top of the gabions to increase the
height. The most difficult part of the flying sap is executed by
engineer troops, and the trench is completed by the ordinary working
parties. Fig. 51 represents a section of this sap.
The _full-sap_ is employed when the works of the besiegers are within
range of musketry, or when the grape fire of the besieged is so deadly
that the flying sap can no longer be used. This is a difficult
operation, and unless executed with great care and by well-instructed
engineer troops, the construction of the trench will be attended with an
immense loss of life. The work must be executed under cover of a
_sap-roller,_ which is a cylindrical mass of fascines, wool, or cotton,
some two feet in diameter. On very smooth ground a ball-proof shelter on
wheels might be used as a substitute. The sap-roller being placed along
the line of the trench so as to cover the sapper in front, who is armed
with a musket-proof headpiece and cuirass, this sapper commences the sap
by placing a gabion on the line of the proposed trench and fills it with
earth, working on his hands and knees. Having filled the first gabion,
he pushes forward the sap-roller and places a second one next the first,
stopping the open joint between the two with a stop-fagot. The second
gabion being filled in the same manner as the first, others are
successively established. When the first sapper has advanced a few feet,
he is followed by a second, also in defensive armor, who increases the
excavation and embankment; this sapper is then followed in the same way
by a third and a fourth, after which the trench will be sufficiently
advanced to be turned over to the ordinary workmen. The sap-fagots may
be removed when the embankment becomes thick enough to resist grape.
Fig. 52 represents a plan and section of a full-sap.
When the direction of the trench is such that the men are exposed on
both sides, it will be necessary to throw up an embankment both to the
right and left. This operation is called the _double sap,_ and is
executed by two parties of sappers, working side by side. In this sap it
will be necessary to frequently change the direction of the trench, or
to throw up traverses, in order to cover the men at a distance from the
sap-roller. Wing-traverses, on the side of the trench which is least
exposed, some times serve the same purpose as a double sap.
_Mines_.--By _mining_, as a military term, we understand the operations
resorted to for the demolition, with powder, of a military structure of
any description. The term _mine_ is applied both to the excavation
charged with powder for the purpose of producing an explosion, and to
the communications which lead to this excavation.
The place in which the charge of powder is lodged is called the
_chamber_, the communication by which this place is reached the
_gallery_, and the excavation made by the explosion is termed the
_crater_.
The form of the crater caused by an explosion in ordinary soils is
assumed to be a truncated cone, the diameter, _c d_, (Fig. 53,) of the
lower circle being one-half the diameter, _a b_, of the upper circle.
This form has never been ascertained to be exactly correct, but the
theoretical results deduced from a mathematical discussion of this
figure have been fully verified in practice. The radius, _p b_, of the
upper circle is termed the _crater radius_; the line _o p_, drawn from
the centre of the charge perpendicular to the surface where the
explosion takes place, is termed the _line of least resistance_; the
line _o b_, drawn from the centre of the powder to any point in the
circumference of the upper circle, is termed the _radius of explosion_.
When the crater radius is equal to the line of least resistance, the
mine is termed _common_; when this radius is greater than the line of
least resistance, the mine is termed _overcharged_; and when the radius
is less, _undercharged_. A mine of small dimensions, formed by sinking a
shaft in the ground, is termed a _fougasse_. The term _camouflet_ is
applied to a mine used to suffocate the enemy's miner, without producing
an explosion. Small mines made in rock or masonry, merely for the
purpose of excavation, without any considerable external explosion, are
called _blasts_.
From experiments made on common mines, whose line of least resistance
did not exceed fifteen feet, it has been ascertained that the tenacity
of the earth is completely destroyed around the crater to a distance
equal to the crater radius, and that empty galleries would be broken in
at once and a half that distance. It has also been proved by experiment,
that the crater radius in overcharged mines may be increased to six
times the line of least resistance, but not much beyond this; that
within this limit the diameter of the crater increases nearly in the
ratio of the square roots of the charge; and that empty galleries may be
destroyed by overcharged mines at the distance of four times the line of
least resistance.
By means of the deductions of physico-mathematical theory, and the
results of experiments, rules have been determined by which the miner
can calculate, with much accuracy, the charge necessary to produce a
required result in any given soil.
In the earlier stages of the history of this art, mines were only used
to open breaches and demolish masses of masonry; but in later times they
have been employed as important elements in the attack and defence of
places.
An isolated wall, only two or three feet thick, may readily be
demolished by exploding one or two casks of powder placed in contact
with its base. If the wall be five or six feet thick, the charges should
be placed under the foundation. For walls of still greater thickness it
will be best to open a gallery to the centre of the wall, a foot or two
above its base, and place the powder in chambers thus excavated.
Revetment walls may be overturned by placing the charges at the back of
the wall, about one-third or one-quarter of the way up from the base. If
placed too near the base, a breach will be made in the wall without
overturning it.
To demolish a bridge of masonry the powder should be lodged in chambers
excavated in the centre of the piers. When there is not time for
excavating these chambers in the piers, a trench may be cut over the key
of the arch, in which the powder is placed and exploded; or, the casks
of powder may be suspended immediately under the arch, with the same
results. Where a saving of powder is of consequence, small chambers may
be excavated in the haunches of the arch, and the mine carefully
_tamped_ before firing it.
Bridges of wood may be destroyed by suspending casks of powder under the
principal timbers, or attaching them to the supports.
Palisading, gates, doors, &c., may be destroyed in the same way, by
suspending casks or bags of powder against their sides; or still more
effectually, by burying the charges just beneath their base.
To demolish a tower, magazine, or house, of masonry, place charges of
powder under the piers and principal walls of the building. In wooden
structures the powder should be placed under, or attached to the
principal supports. Where time is wanting to effect these arrangements,
a building may be blown down by placing a large mass of powder in the
interior. The powder may be economized, in this case, by putting it in a
strong case, which should be connected with the walls of the building on
all sides by wooden props.
Special treatises on military mining contain full instructions for
regulating the size and position of the charge for the various cases
that may be met with in the practical operations of field-engineering.
As applied to the attack and defence of a fortified place, mines are
divided into two general classes--_offensive_ and _defensive_ mines. The
former are employed by the besiegers to overthrow the scarps and
counterscarps of the place, to demolish barriers, palisades, walls, and
other temporary means of defence, and to destroy the mines of the
besieged. The latter are employed by the opposite party to blow up the
besiegers' works of attack, and to defend the passage of ditches against
an assault. Small mines called _fougasses_ may be employed for the last
named object. The _shell-fougasse_ is composed of a wooden box filled
with one or more tiers of shells, and buried just below the surface of
the earth. Sometimes a quantity of powder is placed under the shells, so
as to project them into the air previous to their explosion. The _stone
fougasse_ is formed by making a funnel-shaped excavation, some five or
six feet deep, and placing at the bottom a charge of powder enclosed in
a box, and covered with a strong wooden shield; several cubic yards of
pebbles, broken stone, or brickbats, are placed against the shield, and
earth well rammed round, to prevent the explosion from taking place in
the wrong direction. These mines are fired by means of powder hose, or
by wires connected with a galvanic battery.
The defensive mines employed to blow up the besiegers' works, are
generally common mines with the lines of least resistance seldom greater
than fifteen feet. All the main galleries and principal branches of
mines for a permanent fortification are constructed at the same time
with the other portions of the work, leaving only the secondary
branches, chambers, &c., to be made during the siege. For the general
arrangement of these galleries, and the precautions necessary for their
protection from the operations of the besiegers, reference must be made
to treatises specially devoted to the discussion of this subject.
Mines can seldom be employed with advantage in works of slight relief,
and liable to an assault. But if judiciously arranged in the plan of
their construction, and well managed during the operations of the siege,
they contribute very materially to the length of the defence.
_Attack and defence_.--This subject admits of two natural divisions:
1st, of intrenchments, and 2d, of permanent works.
I. Intrenchments maybe attacked either by _surprise_, or by _open
force_. In either case the operations should be based on exact
information of the strength of the works and the number and character of
the garrison--information that can be obtained from spies, deserters,
and prisoners, and confirmed by examinations or reconnaissances made by
officers of engineers. By these means a pretty accurate knowledge may be
obtained of the natural features of the ground exterior to the works;
their weak and strong points; and their interior arrangements for
defence.
In an attack by surprise, the troops should consist of a storming party
and a reserve of picked men. The attacking column is preceded by a
company of sappers armed with axes, shovels, picks, crowbars, &c.; bags
of powder are also used for blowing down gates, palisades, &c. All the
operations must be carried on with the utmost dispatch. The time most
favorable for a surprise is an hour or two before day, as at this moment
the sentinels are generally less vigilant, and the garrison in a
profound sleep; moreover, the subsequent operations, after the first
surprise, will be facilitated by the approach of day. Under certain
circumstances, it may be advisable to make false attacks at the same
time with the true one, in order to distract the attention of the
garrison from the true point of danger. But false attacks have, in
general, the objection of dividing the forces of the assailants as well
as of the assailed. In all attacks by surprise, secrecy is the soul of
the enterprise.
In an open assault, if artillery be employed, the troops should be drawn
up in a sheltered position, until the fire of the works is silenced, and
breaches effected in the parapet. But if the bayonet alone be resorted
to, the troops are immediately brought forward at the beginning of the
assault. The attack is begun by a storming party of picked men: they are
preceded, as before, by a body of sappers, provided with necessary means
for removing obstacles, and followed by a second detachment of
engineers, who will widen the passages, and render them more accessible
to the main body of troops who now advance to the assistance of the
storming party. If the assailants should be arrested at the counterscarp
by obstacles which must be removed before any farther progress can be
made, the infantry troops of the detachment display and open a fire upon
the assailed, in order to divert their fire from the sappers. A few
pieces of light artillery, on the flanks of the column, may sometimes be
employed for this purpose with great advantage.
The storming party should always be provided with scaling-ladders,
planks, fascines, &c., for crossing the ditch, and mounting the scarp.
If the counterscarp be revetted with masonry, the troops must either
descend by ladders, or fill up the ditch with fascines, bales of straw,
bundles of wool, &c.: if not revetted, a passage for the troops into the
ditch will soon be formed by the shovels of the sappers. When the ditch
is gained, shelter is sought in a dead angle till the means are prepared
for mounting the scarp, and storming the work. If the scarp be of earth
only, the sappers will soon prepare a passage for the escalade; but if
revetted with masonry, the walls must be breached with hollow shot, or
scaled by means of ladders.
In the defence, the strictest vigilance should be at all times exerted
to guard against a surprise: sentinels are posted on all the most
commanding points of the work; all the avenues of approach are most
thoroughly guarded; and patroles are constantly scouring the ground in
all directions. At night all these precautions are redoubled. Light and
fire-balls are thrown out in front of the work to light up the ground,
and discover the movements and approach of the enemy. Each man should
have his particular post assigned to him, and be thoroughly instructed
in the duties he will have to perform. All auxiliary arrangements, such
as palisades, abattis, &c., should be defended with the utmost
obstinacy; the longer the enemy is held in check by these obstacles, the
longer will he be exposed to the grape and musketry of the main work.
When he assaults the parapet, he will be opposed by the bayonet in front
and a well-aimed fire in flank. While in the ditch, or as he mounts the
scarp, hollow projectiles, incendiary preparations, stones, logs, &c.,
will be rolled down upon his head. But when the assaulting column has
gained the top of the scarp, the bayonet forms the most effective means
of resistance.
The measures resorted to in the attack and defence of the larger class
of field-works, will necessarily partake much of the nature of the
operations employed in the attack and defence of permanent
fortifications.
II. The attack and defence of a fortress may be carried on either by a
regular siege, or by irregular operations and an assault. The latter
plan has sometimes been adopted when the works of the place were weak
and improperly defended; where the time and means were wanting for
conducting a regular siege; or where the assailants were ignorant of the
means proper to be resorted to for the reduction of the fortress. Such
operations, however, are usually attended by an immense sacrifice of
human life, and the general who neglects to employ all the resources of
the engineer's art in carrying on a siege, is justly chargeable with the
lives of his men. In the siege of Cambrai, Louis XIV., on the
solicitation of Du Metz, but contrary to the advice of Vauban, ordered
the demi-lune to be taken by assault, instead of waiting for the result
of a regular siege. The assault was made, but it was unsuccessful, and
the French sustained great losses. The king now directed Vauban to take
the demi-lune by regular approaches, which was done in a very short
time, and with a loss of _only five men!_ Again, at the siege of Ypres,
the generals advised an assault before the breaches were ready. "You
will gain a day by the assault," said Vauban, "but you will lose a
thousand men." The king directed the regular works to be continued, and
the next day the place was taken with but little loss to the besiegers.
But a work may be of such a character as to render it unnecessary to
resort to all the works of attack which would be required for the
reduction of a regular bastioned fort, on a horizontal site. For
example: the nature of the ground may be such as to enable the troops to
approach to the foot of the glacis, without erecting any works whatever;
of course, all the works up to the third parallel may in this case be
dispensed with without any violation of the rules of a siege. Again, the
point of attack may be such that the other parts of the place will not
flank the works of approach; here a single line of _boyaux_ and short
parallels may be all-sufficient.
But for the purpose of discussion, we will here suppose the place
besieged to be a regular bastioned work on a horizontal site, (Fig.
54.)
The operations of the siege may be divided into three distinct periods.
1st. The preliminary operations of the attack and defence previous to
the opening of the trenches.
2d. The operations of the two parties from the opening of the trenches
to the establishment of the third parallel.
3d. From the completion of the third parallel to the reduction of the
place.
_First period._ The object of the _investment of the place_ is to cut
off all communication between the work and the exterior, thus preventing
it from receiving succors, provisions, and military munitions, and also
to facilitate a close reconnoissance of the place by the engineers, who
should always accompany the investing corps, and pursue their labors
under its protection. This corps should be composed chiefly of light
troops--cavalry, light infantry, horse artillery, "brigades of engineers
and mounted sappers,"--who march in advance of the besieging army, and,
by a sudden movement, surround the work, seize upon all the avenues of
approach, and carry off every thing without the work that can be of
service either to the garrison or to the besiegers. To effect this
object, the enterprise must be conducted with secrecy and dispatch.
The investing corps is now distributed around the work in the most
favorable positions for cutting off all access to it, and also to
prevent any communication with the exterior by detachments from the
garrison, and even single individuals are sent out to give intelligence
to a succoring army or to reconnoitre the operations of the besieging
corps. These posts and sentinels, called the _daily cordon_, are placed
some mile or mile and a half from the work, and beyond the reach of the
guns. But in the night-time these posts are insufficient to accomplish
their object, and consequently as soon as it is dark the troops move up
as close to the work as possible without being exposed to the fire of
musketry. This arrangement constitutes the _nightly cordon_.
By the time the main army arrives the reconnoissance will be
sufficiently complete to enable the chief engineer to lay before the
general the outline of his plan of attack, so as to establish the
position of his depots and camp. These will be placed some two miles
from the work, according to the nature of the ground. As they occupy a
considerable extent of ground around the work, it will generally be
necessary to form intrenchments strong enough to prevent succors of
troops, provisions, &c., from being thrown into the place, and also to
restrain the excursions of the garrison. The works thrown up between the
camp and besieged place are termed the _line of countervallation_, and
those on the exterior side of the camp form the _line of
circumvallation_. These lines are generally about six hundred yards
apart. It is not unusual in modern warfare to dispense with lines of
circumvallation, (except a few detached works for covering the parks of
the engineers and artillery,) and to hold the succoring army in check by
means of an opposing force, called the _army of observation_.
The measures of defence resorted to by the garrison will, of course, be
subordinate, in some degree, to those of attack. As soon as any danger
of an investment is apprehended, the commanding general should collect
into the place all the necessary provisions, forage, military munitions,
&c., to be found in the surrounding country; all useless persons should
be expelled from the garrison; a supply of timber for the works of the
engineers and artillery, fascines, gabions, palisades, &c., prepared;
all ground within cannon range around the work levelled; hedges and
trees cut down; holes filled up; temporary buildings demolished or
burnt; and all obstacles capable of covering an enemy and interrupting
the fire of the work, removed.
During this period the engineer troops and working parties detached from
the other arms will be most actively employed. As soon as the investing
corps makes its appearance, bodies of light troops are thrown out to cut
off reconnoitring parties, and, if possible, to draw the enemy into
ambush. To facilitate these exterior operations, and to prevent a
surprise, several guns of long range are placed on the salients of the
bastions and demi-lunes, and others, loaded with grape, in the
embrasures of the flanks, so as to sweep the ditches. About one-third of
the garrison may be employed in exterior operations, and the other
two-thirds in arranging the means of defence in the interior.
_Second period._--As soon as the engineers have completed their
reconnaissances and determined on the front of attack, and all the other
preparations are made, the general will direct the opening of the
trenches. The ground being previously marked out, battalions of light
troops, termed _guards of the trenches_, as soon as it is dark, are
placed about thirty yards in front of the first parallel, (A. Fig. 54,)
with smaller sections, and sentinels about the same distance further in
advance. These guards lie down, or otherwise conceal themselves from the
fire of the work. The engineer troops and detachments of workmen being
first marched to the dépôts and supplied with all the necessary tools
for carrying on the work, now commence their labors under the protection
of these guards. By daybreak the construction of the first parallel, and
the trenches connecting it with the dépôts, will be sufficiently
advanced to cover the men from the fire of the place; the guards will
therefore be withdrawn, and the workmen continue their labors during the
day to give the trenches the proper size and form.
The _parallels_ are the long lines of trench which envelop the besieged
work, and serve both as covered ways for the circulation of the
besiegers, and as means of defence against sorties from the garrison;
they are therefore arranged with banquettes for musketry fire. The
boyaux are trenches run in a zigzag direction along the capitals of the
front of attack, and are intended exclusively for the circulation of the
troops; they have no banquettes. The first parallel is about six hundred
yards from the place, and consequently beyond the reach of grape. It is
constructed by the _simple sap_. After the first night, the guards,
instead of advancing in front of the work, are placed in the trenches.
The second parallel (B) is made some three hundred or three hundred and
fifty yards from the place, and being much exposed to grape, the
_flying-sap_ is employed in its construction. Batteries (H) are
established between the first and second parallels to silence the fire
of the demi-lunes of the collateral bastions, and others (I) near the
second parallel, to enfilade the faces of the front of attack. These are
armed in part with mortars and in part with heavy siege-pieces.
The works are now gradually pushed forward to the third parallel, (C),
which is constructed about sixty yards from the salients of the place.
As the operations of the besiegers are here greatly exposed to musketry
fire, the trenches are constructed by the _full-sap_. The third
parallel, having to contain the guards of the trenches, and being of
less development than the two preceding, is made much wider. The second
parallel now contains the reserve, and the first parallel becomes the
dépôt of materials. _Demi-parallels_ (G) are frequently established
between the second and third, to be occupied by detachments of guards.
The operations of defence during this period are so directed as to
harass the workmen in the trenches and retard the advance of the works
of attack. Garrison pieces of long range and large howitzers are brought
forward on the salients of the bastions and demi-lunes of attack, so as
to fire in ricochet along the capitals on which the boyaux must be
pushed: light and fire-balls are thrown out as soon as it becomes dark,
to light up the ground occupied by the besiegers, thus exposing them to
the fire of the work and to the attacks of the sortie parties. These
parties are composed of light troops who charge the guards and compel
the workmen to abandon their sapping tools and stand upon the defence.
They are most effective when the besiegers commence the second parallel,
as the guards in the first parallel are not so immediately at hand to
protect the workmen. When the sortie detachment has driven these workmen
from the trenches, instead of pursuing them into the first parallel, it
will display itself in battle order to cover the engineer troops, (who
should always accompany the detachment in this enterprise,) while they
fill up the trenches and destroy the implements of the besiegers. When
the guards of the trenches appear in force, the detachment will retire
in such a way, if possible, as to draw the enemy within range of the
grape and musketry of the collateral works. These sorties, if
successful, may be frequently repeated, for they tend very much to
prolong the siege. The best time for making them is an hour or two
before day, when the workmen and guards are fatigued with the labors of
the night. While the besiegers are establishing their enfilading
batteries, a strong fire of solid shot and shells will be concentrated
on the points selected for their construction. The garrison will also
labor during this period to put the work into a complete state of
defence: constructing all necessary palisadings, traverses, blindages,
barriers; and strengthening, if necessary, the covering of the
magazines.
_Third period._--After the completion of the third parallel, the
crowning of the covered way may be effected by storm, by regular
approaches, or (if the work is secured by defensive mines) by a
subterranean warfare.
In the first case stone mortar-batteries are established in front of the
third parallel, which, on a given signal, will open their fire in
concert with all the enfilading and mortar batteries. When this fire has
produced its effect in clearing the outworks, picked troops will sally
forth and carry the covered way with the bayonet, sheltering themselves
behind the traverses until the sappers throw up a trench some four or
five yards from the crest of the glacis, high enough to protect the
troops from the fire of the besieged. It may afterwards be connected
with the third parallel by boyaux.
When the covered way is to be crowned by regular approaches, a _double
sap_ is pushed forward from the third parallel to within thirty yards of
the salient of the covered way; the trench is then extended some fifteen
or twenty yards to the right or left, and the earth thrown up high
enough to enable the besiegers to obtain a plunging fire into the
covered way, and thus prevent the enemy from occupying it. This mound of
earth is termed a _trench cavalier_, (O). Boyaux are now pushed forward
to the crowning of the covered way and the establishing of breach
batteries, (J). Descents are then constructed into the ditches, and as
soon as these batteries have made a breach into the walls of the
bastions and outworks, the boyaux are pushed across the ditches and
lodgments effected in the breaches. The demi-lune is first carried; next
the demi-lune redoubt and bastion; and lastly, the interior
retrenchments and citadel. In some cases the breaches are carried by
assault, but the same objection is applicable here as in the storming of
the covered way; _time is gained, but at an immense expense of human
life._
If the place is defended by mines it will be necessary for the
besiegers to counteract the effects of these works by resorting to the
slow and tedious operations of a subterranean warfare. In this case a
fourth trench is formed in front of the third parallel; shafts are sunk
in this, about six yards apart, for establishing overcharged mines; as
soon as the galleries of the besieged are destroyed by the explosion of
these mines, the covered way is attacked by storm; other mines are
established on the _terre-plain_ of the covered way to destroy the
entrance to the galleries, and thus deprive the besieged of the use of
their entire system of mines.
The measures of defence during this period must embrace every thing
calculated to retard the works of the besiegers. This may be most
effectually accomplished by maintaining a constant fire of grape and
musketry on the heads of the sap, and throwing grenades, shells, &c.,
into the trenches, to harass and destroy the workmen. As the musketry
fire of the besiegers now becomes very destructive to the artillerists
at the guns, strong musket-proof blinds are arranged to mask the mouths
of the embrasures when the guns are not in battery, and also sloping
blindages to cover the men when serving at the pieces. The possession of
the outworks should be disputed inch by inch, and when the besiegers
have reached the ditch of the body of the place, sorties, and every
species of projectile, should be employed to drive off the sappers, and
to retard the construction of their works. In fine, all the resources of
the engineer's art should be put in requisition for the defence of the
breach, and the final assault should be vigorously resisted by the
bayonet, and by a well-sustained fire from all the collateral works.
With respect to the relative strength of the opposing forces it may be
well to remark, that if the fortress is properly constructed the
garrison will be able to resist a besieging army _six times_ as numerous
as itself. Such is the estimate of the best engineers.[48]
[Footnote 48: A good knowledge of the several subjects discussed in this
chapter may be derived from the writings of Vauban, Cormontaigne, and
Noizet de St. Paul, on the attack and defence of places and field
fortification; the several _manuels_ used in the French service on
sapping, mining, and pontoniering; Col. Pasley's experiments on the
operations of a siege, sapping, mining, &c.; Douglas's work on military
bridges; Macauley's work on field fortification; and Professor Mahan's
_Treatise on Field Fortification._ This last is undoubtedly the very
best work that has ever been written on field fortification, and every
officer going into the field should supply himself with a copy.
The following are recommended as books of reference on subjects
discussed in the three preceding chapters.
_Mémorial pour la fortification permanente et passagère._ Cormontaigne.
_Défense des places._ Cormontaigne.
_Attaque des places._ Cormontaigne.
_Attaque des places._ Vauban.
_Traité des mines._ Vauban.
_Mémorial pour la castrametation et la fortification passagère._
Lafitte-Clavé.
_Exercice sur les fortifications._ Davigneau.
_Mémorial de l'officier du genie._ A periodical of rare merit,
containing most valuable military and scientific matter. It is conducted
by officers of the French corps of engineers. It has already reached its
fourteenth number, each number forming a volume.
_Traité complet de fortification._ Noizet de St. Paul.
_Traité d'art militaire et de la fortification._ Gay de Vernon.
_Art de la guerre._ Rogniat.
_Essai général de fortification, &c._ Bousmard.
_Aide-mémoire portatif à l'usage des officiers du génie._ Laisné. A very
valuable and useful book.
_Aide-mémoire de l'ingénieur militaire._ Grivet.
_Cours d'art militaire._ Laurillard Fallot.
_Cours de fortification, &c._ Lavart.
_Le livre de la guerre._ Perrot.
_Journaux des siéges dans la péninsule._ Belmas.
_Journal of Sieges in Spain._ John Jones.
Both of the above are works of great value.
_Cours d'art militaire et de fortification militaire._ François.
_Architettura militare._ Marchi.
_Essai sur la fortification._ Baltard.
_La fortification._ Bar-le-Duc.
_Elémens de fortification._ Bellaire.
_La science des ingénieurs._ Bélidor.
_L'art universel des fortifications._ Bitainvieu.
_Nouvelle manière de fortifier les places._ Blondel.
_Les sept siéges de Lille._ Brun Lavaine.
_Défense des places fortes._ Carnot.
_Mémoire sur la fortification._ Carnot.
_Défense de Saragosse._ Cavallero.
_Mémoires sur la fortification._ Choumara.
_Nouvelle fortification._ Coehorn.
_Théorie de la fortification._ Cugnot.
_Des fortifications,_ &c. &c. Darçon.
_Relation de la defense de Dantzik._ D'Artois.
_Les fortifications._ Deville.
_Péribologie._ Dilich.
_De la fortification permanente._ Dufour. A work of merit.
_Essai sur la défense des états par les fortifications._ Duviviet.
_Attaque et défense des places du camp de St. Omer.
_L'école de la fortification._ Fallois.
_Introduction à la fortification._ De Fer.
_Précis de la défense de Valenciennes._ Ferrand.
_Traité théorique,_ &c. Foissac-Latour.
_Examen detaillé,_ &c. Foissac-Latour.
_Les ouvrages militaires de Fosse.
_Instruction sur la fortification,_ &c. Gaillard.
_Mémoires pour l'attaque et défense d'une place._ Goulon.
_Siége of Peschiera._ Henin.
_Journal du siége de Philisbourg.
_Précis du siége de Dantzick._ Kirgener.
_Deuxième défense de Badajos._ Lamare.
_Fortification, et l'attaque et défense des places._ Lebloud.
_OEuvres de Lefebvre.
_L'architecture des forteresses._ Mandar.
_Traité sur l'art des siéges._ Mazeroy.
_La sûreté des états par le moyen des forteresses._ Maigret.
_Défense d'Ancone._ Mangourit.
_Fortification._ Marolois.
_Siege de Turin._ Mengin.
_Recherches sur l'art défensif,_ &c. Michaloz.
_La fortification de campagne,_ &c. Miller.
_L'art défensif,_ &c. Montalembert.
_Journaux des siéges de Flandre.
_Relations des siéges en Europe,_ &c, Musset-Fathay. A very valuable and
interesting work.
_Relation du siége de Metz.
_Relation du siége d'Anvers.
_Les siéges de Jaffa et de St. Jean d'Acre.
_Les siéges de Saragosse et de Tortose._ Rogniat.
_Siége de Dantzick._ Sainte-Susanne.
_Mémoire sur la fortification permanente.--_Séa.
_Le siége de Constantine._
_Elémens de fortification._ Trincano.
_Des places fortes._ Valazé.
_Essay on Military Bridges._Douglas. A valuable work.
_Guide du pontonier._ Drieu.
_Mémoire sur la guerre souterraine._ Contèle.
_Traité des mines._ Etienne.
_Traité de l'art du mineur._ Geuss.
_Traité de fortification souterraine._ Gillot.
_Traité pratique et théorique des mines._ Lebrun.
_Nouveau traité des mines,_ &c. Prudhomme.
_Manuel du sapeur._ Used in the French service.
_Manuel du mineur._ " ""
_Manuel du pontonier. " ""
_Essay on Field Fortifications._ Pleydell.
_Elements of Field Fortifications._ Lochee.
_Rélation du siége de Grave et Mayence._
_Siéges de Génes._ Thiébault.
_Traité de fortification souterraine._ Mouze.
_Militairische Mittheilungen._ Xilander.
_Die Befestigung der Statten._ Hauser.
_Abhandlung über die Befestigungskunst,_&c. Hauser
_Versuch über die Verschanzungskunst._ Muller.
_Course of Elementary Fortification. _Pasley. This is a work of much
detail--useful, no doubt, to an uneducated engineer soldier, but to an
officer at all acquainted with his profession, it must seem ridiculously
minute.
To the above list might be added a long list of books on that branch of
the engineer's art called _constructions_; but as this part of the
profession is, in some degree, common both to the civil and military
engineer, it is not deemed necessary to include works of this character
in a list of books strictly military.]