The new method of fortification, as practised by Monsieur de Vauban, Engineer General of France with an explication of all terms appertaining to that art / made English.

A NEW TREATISE OF Fortification•• BOOK II. (Book 2)

CHAP I. Of the Maxims of Fortification.

SInce it is impossible to build a Fortress, without having considered before-hand what Reasons there are to induce an Enginier to do it after such a manner, that there is no great matter to be ob∣jected against it; there are some certain Maxims established, according to which, when a Fortification is raised, there can be but little said against its Advantages to those that are within; as you may easily examine it your self by the following Obser∣vations.

I.

All the Parts which are to enclose a space of Ground, ought to be flank'd, that is to say, view'd on every side, that so there may be no shelter about the place where the Enemy may lodge himself, but what may be discovered by those within, not only from the front, but from the sides, and even from behind, if it be possible.

II.

Whatsoever encloses a durable Fortification, must be either Flank, Face, or Curtain, and built after such a manner, that the first Discharges of the Cannon may not be able to pierce its thickness.

III.

Regular Fortification is much to be preferred be••ore that which is Irregular.

IV.

It is impossible to fortify a Triangle after the Regular way, because the Angle of the Gorge is always less by 90 Degrees.

V.

The straighter the Angle of the Center is, the Place is by so much the stronger, and consequently better, because gains more Side••.

VI.

The Angle of the Bastion must never be greate•• than 100 Degrees, nor less than 60, for being bigger, the Face cannot be defended as it ought to be, and being less, it

is not able to resist the Injury of the Weather, or the Efforts of the Mines and Cannon. See Chap. 1. Sect. 4. of Book IV.

VII.

The greatest Angles are best to fortify.

VIII.

The Angle of the Curtain ought never to be less than 90 Degrees, nor greater than 110; because, if it be larger, 'tis too much subject to the view of the Enemy. See Chap. 1. Sect. 5. of Book IV.

IX.

The great Demi-Gorges are to be preferred before the small ones, as well because there is more space to retrench in, as because one may make retiring Flanks, which adds very much to the strength of the place.

X.

Great Flanks are best.

XI.

The Face ought to be never less than the half of the Curtain, if it be not in an Irregular Fortification••

XII.

The Faces of the Bastion ought to be defended by the small Shot of the opposite Flanks.

XIII.

The shortest Faces are best, because they are not so sub∣ject to be attacked, as when they come ou•• a great way in the Country. See Chap. ••. of Book IV.

XIV.

The Curtain ought never to be shorter than 60 Fathoms, which is 360 foot English, nor longer than 100, if it be not in an Irregular Fortification.

XV.

The Line of Defence must not be of greater length than 120 or 125 fathoms, because a Musquet can carry no far∣ther to do execution: Holdman goes contrary to this Axiom, when he says, that it may be 150 fathoms; and likewise George Pascha, who believes it may be 136 fa∣thoms long.

XVI.

The Talu•• or Level ought by no means to be forced or streightened, but o••ght to have sloap enough, that the Ground or Earth may settle of itself.

XVII.

Large and deep Trenches are to be preferred before those that are narrow and hollow, or large and less deep, because the Enemy will find more difficulty to get over the first sort. See Chap. 10. of Book I.

XVIII.

Dry Trenches are to be esteemed before those that are full of Water, especially in great Places, where Sallies, Retreats, and Succors, are necessary.

XIX.

Trenches full of Water that cannot easily be drained, ought to be preferred before those that are dry in small

Fortresses, where Sallies, Retreats, and Succors, are not so necessary.

XX.

The Outworks ought always to be lower than the Body of the Place, and those that are at the greatest distance ought to be the lowest.

CHAP. II. Of the Situation of Places.

AS it is very rarely permitted to make choice of that space of Ground which is to be fortified, but on the contrary the Place is almost always determined, whether we design to repair an old Fortification, or surround any Town with Bastions, and other kind of Works; or whe∣ther we are to make ourselves Masters of the Passage of a River, of any strait Place, or an Eminence, that is of advantage to command the flat Country, or an Island in a River; or of one or more jettings out of Land into the Sea for the making a Port; and lastly, for several other Uses, the recital whereof would be too tedious; It is necessary upon these Accounts to understand, what kind of Situations are best for the Erecting a strong Hold, and to know the Opinions of others concerning this Matter.

I.

What are the Advantages of a Fortress situated upon a Mountain.

• (1.) This Fortification is not easily Ruined by Mines.
• ...

• (2.) The Enemy will be at a great deal of difficulty to bring their Machines to batter down this Fortifica∣tion.
• (3.) Those of the place may discover the Enemy at a great distance, and so hinder them from making their Approaches nearer.
• (4.) The Horse or Batteries of the Enemy, which are planted either on plain or rising Ground, can no ways do any damage to this Fortification, it being always lower.
• (5.) Upon an Eminence, the Air is always more heal∣thy than in Vallies or lower Places.
• (6.) The Enemy will but very rarely be able to take such a Place by Assault.

What are the Disadvantages of a Fortress built upon a Rock.

• (1.) They commonly want Water in such a place.
• (2.) It is difficult to bring thither Materials, Provisions, ••nd other Ammunition.
• (3.) These Fortifications are for the most part not very durable, having only a sandy or gravelly Earth for Foun∣dation.
• (4.) Places so situated, are not to be succoured but with great difficulty.
• (5••) Such a Place cannot well be defended, becau••e what is done by the Cannon from top to bottom, is but of little consequence.
• (6.) Sallies are there very dangerous, especially if they be at any distance from the Counterscarps.
• (7.) These Fortifications are almost always Irregular.

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It is to be observed, that these kind of Situations are good for Cittadels, Castles, and other small Forts, in order to command the Country thereabouts.

II.

The Advantages of a Marshy or Fenny Situation.

• (1.) The Enemy cannot come near it without danger of being lost.
• (2.) This Fortification is not easily blown up.
• (3.) These Places may be fortified for little Charge.
• (4.) They have there no need of a great Garison.

The Disadvantages of a Marshy Situation.

• (1.) It is almost impossible to relieve it.
• (2.) It must be strengthened with Piles driven in.
• (3.) Sallies thence are commonly unsuccessful.
• (4.) The Air is there always unhealthy, which is the occasion of frequent Distempers, because the Water there is always corrupted.
• (5.) These Places may be attacked without any great loss of Men, provided they stay till the Frosts.

III.

The Advantages of a Place encompassed round with Water.

• (1.) It cannot be undermined.
• (2.) There is no occasion for any great Works••
• (3.) The Enemy cannot always discharge their Cannon with any certainty, because the Water abates much of their force.
• (4.) The Besieged may very easily set fire to the Ene∣mies Shi••ping.
• (5.) ••he Naval Army is too much exposed to the ••iew of the Artillery of the Place.

The Disadvantages of a Place surrounded with Water.

• (1.) The En••my may ••asily stop their Provision, and hinder their Succors.
• (2.) Boats alone are sufficient to attack such a place, and so there is no occasion for Horse.
• (3.) These Places are more subject to Diseases than othe••s.

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We may affirm, that these Places that are encompassed all round with Water, which cannot be quite drained, or at least with great difficulty, are the best notwithstanding, because they are, as it were, fortified by Nature.

IV.

The Advantages of Places situated upon an open Rising Ground.

• (1.) There is great Plenty of good Earth.
• (2.) They are never there in want of Water.
• (3.) Almost all these Places are commonly Regular.
• (4.) They have there Earth enough to make Retrench∣ments, in case the Enemy make their Attacks with great fury.
• (5.) The Enemy had need to have two or three Armies, if they would intercept the Provision and Ammunition coming to those of the Place from all Parts.

The Disadvantages of Places erected upon Rising Ground.

• (1.) The good Soil that there is about such a Place, serves only for the Enemy to make Retrenchmen•• 〈◊〉〈◊〉 Batte∣ries, Approaches, Redoubts, and other Works, from whence they may do great Damage to the Besieged.
• (2.) The Enemy may form their Camp, as those of the Place did their Fortification, that is to say, they may give

• it a Regular Figure, and encompass it with a good Trench and a good Rampart.
• (3.) The Ground is very good to make Mines under such a place.
• (4.) The Enemy may seize all the Fruits growing about these places.

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These Places however are best, because those of the place will take double the Advantage that the Enemy can have.

V.

The side of a Mountain is a very ill place to fortify, and it must be avoided as much as may be, because the top of the Mountain almost always commands the Place within.

VI.

The Valley is is no good place to fortify, because the Enemy may discover them from the top of the Moun∣tain.

VII.

The Advantages of Places situated on the Sides of any Great River.

• (1.) You may bring thither by Water, whatsoever is necessary for Building, and for the Soldiers.
• (2.) You may fortify the Circumference after the Regu∣lar manner, or at least very near it: The side towards the Water is fortified with small Charge.
• (3.) It may be easily Relieved.
• (4.) Earth is there very plentiful for repairing th•• Works, and for making Retrenchments.
• (5.) You may there make Sluces to put all the Country thereabouts under Water.
• (6.) They never want there any Water.
• (7.) The Enemy must have a great many Troops to ••ay Siege to such a Place, by reason of the distance of the Q••arters.
• ...

• (8.) If it be attacked only by Land, nothing hinders but that the Besieged may pass the River at pleasure, and re∣ceive Succors by Boats.
• (9.) If it be attacked both by Land and by Water, there must be two great Armies, which will be very Chargeable.

The Disadvantages of Places situated on the Sides of a Great River.

• (1.) The River serves the Enemy for transporting what∣soever is necessary for a Siege.
• (2.) The Enemy may cast up great heaps of Earth to Command the Place.
• (3.) The Enemy may easily shelter themselves from the Firing of the Besieged, having great plenty of Earth.

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'Tis not to be denied, but that these Places are to be preferred before any of those that we have now mentioned, in case they are Masters of the Pass, by which the Provi∣sion and Ammunition is to come in.

CHAP. III. Of the Quality of the Earth.

WHen you have once made choice of a Place for the erecting a Fortress, before you Engage yourself in so expensive an undertaking, you must examine the Qua∣lity of the Earth, and consider whether it be Good or Bad: For there are very Advantageous Situations, the Earth whereof is good for nothing; and on the contrary, there are Ill Situations that have a very good Soil, but they lie subject to be Commanded after such a rate, that

it would be great folly to settle there: As may be evident by the following Observations.

Sect. I.

MOuntains commonly have a stony Ground, which is the worst of all, as well because it will not stick together as because the Parapers made thereof are good for nothing: But if you are compelled to fortify in such a place, you must make choice of the best Veins of Earth to make the Parapet, and cause it to be brought from else∣where. 'Tis true, this sort of Earth is of some advantage, in that the Besiegers will find it difficult to cover them∣selves in their Approaches for want of good Earth.

Sect. II.

THE Gravelly or Sandy Earth is likewise very bad, by reason that it wants a binding Quality, being always apt to tumble down; when you are forced to make use of this, you must mix some good Earth therewith, or some old Dung, and the Ramparts must be well lined with Ston••s or Bricks, and the Parapets with Turfs.

Sect. III.

THE Marshy Ground is better than the two former sorts, although generally 'tis not very good, because when it comes to dry, being raised into Ramparts and Parapets, it is subject to fall to pieces; besides, 'tis diffi∣cult to find Earth enough about a Marshy place for raising Ramparts, Parapets, and Glacis, of a reasonable height; and moreover, the Foundation of these Works must be always strengthened with Piles. But if there b•• a necessity of raising Fortifications in these places, it must be during the Heats, that so the Earth may have the greater Consistence.

Sect. IV.

THE best kind of Earth for Fortifying, is that which they call Fat or Fertile Ground, because 'tis pliable; and you are not obliged to strengthen the Foundation with Piles, nor to line the Ramparts, unless you will.

CHAP. IV. Of Provision, and other Necessaries.

SEing a Place cannot be able to endure a long Siege, if it has not wherewithal to make resistance, therefore there must be Provision made of whatsoever is necessary for a Soldier; under which Head is to be understood, Money to pay the Troops, Meal, Corn, Hay, Wine, Beer, Brandy, Butter, Salt, Wood, Powder, Lead, Match, Bullets, Cannon or Great Guns, Musquets, Pikes, Sulphur, Pitch, Brimstone, Palisadoes, Chevaux de Frise, Hand-Mills, Horse-Mills, and Wind-Mills, that so, if the Enemy should cut off the Water, they might not be without something to Grind their Corn. A good Commander will take care of all this. An able Physician, Chirurgeon, and Apothe∣cary, are there likewise very necessary. To these there might be added, some other Things requisite, in order to keep the Soldiers in good heart.