mTri^J V^Ik -SUhiy. . Cornell University Library The original of tliis book is in tine Cornell University Library. There are no known copyright restrictions in the United States on the use of the text. http://www.archive.org/details/cu31924030765311 Cornell University Library UG401 .M25 A treatise on tlie attack and defence of olln 3 1924 030 765 311 A TREATISE ON THE ATTACK AND DEFENCE OF Fortified Places : INCLUDING An investigation op the ADVANTAGES which, in POINT OF STRENGTH, SUPERIOR POL'S GONS have over those of an Inferior Order ; AMD An Explanation of the Differences in the Methods of carrying on the Attach, according to the Nature of the POLYGON. WITH ^\' ILLVSTRATION of tub POfVERFOL DEFENCE Which such Parts of a Fortress as may happeo to consist of several Fronts constructed on a straight Line, or on a concave Curve, are capahle of making. Besides various other Matters immediately connected ivitta tlie principal Subject. GENERAL DE MALORTIE, L^ -^<5u MARBCIIAb I}ES CAMPS GT ARMI::ES DU ROI, KNIGHT OF TUEROVAIi MILITARY ORDER OP ST. LOUIS AND OFTHE DECOR ATIO N OF TH E I.VS, AND pnoFBSson of foktjpicjtios jsd aktillbrt in tub roval MILITARY ACdDEDtr, AT WOOLWICH. Author of several oilier Works. LONDON : PRINTED FOR T. EGERTON, liOOKSELLER TO TH E O R D N A NCE, MILITARY LIBRARY, NEAR WHITEHALL. 1824. TO mm (^iBA^iid THE DUKE OF WELLINGTON, PRINCE OF WATERLOO, KNIGHT OF THE MOST NOBLE ORDER OF THE GARTER, &c. &c. &c. iWasster ©enetal of tfie ©tuitartce, This Work is most humbly dedicated by the Author, as a feeble Tribute of his profound Respect and dutiful Attachment ; bs well as of the Gratitude which he feels, in common with all loyal Frenchmen, for the many and highly important Blessings that Europe in general, but the Author's native Country in particular, have de- rived from His Grace's splendid and ever-memorable Achievements. INTRODUCTION. The intended object of this Treatise is to elucidate, as concisely as the nature of the subject and perspicuity in the explana- tion aillow it, the Theoretical principles and practical process relating to the Attack and Defence of Fortified Places in general ; besides various other matters immediately connected with the principal subject. Sub- sequently to a short exposition of the de- fective method of carrying on Sieges which was used before Vauban, and of the man- ner in which this celebrated Engineer im- proved it, the mode of attack suitable for any place supposed to be fortified according vi INTRODUCTION. to the Modern Bastion-System, the Polygon being of an inferior order, is at first illus- trated ; and, after explaining the advanta- ges which, in point of defence, Superior Polygons have over the others, a method of attacking Places also fortified conformably to the Modern bastion-^System, but suppo- sing the Polygon to be of a Superior order, is given. The superior properties of such parts of a fortress as may happen to consist of several fronts constructed on a straight line, or on a concave curve, are next investigated in this Treatise, which also contains a compa- rative view, in respect to strength, of Vau- ban's 1st System and the Modern bastion- System : The process to be followed in at* tacking iPlaCes foftified according to the for- mer System, and such old fortresses as are destitute of Ravelins and Tenailles : Ah illustration of the advantages and defects of Vaubah's Tower-bastion Systems, and Coe- horn's Systems, as well as the methods of INTRODUCTION. vii attacking places fortified after these sys- tems, and the pneans of improyiiig their de- fence: Besides ap investigation of thp de- fects that the Modern bastion-Sy^tejipi stjH retains, an account of the schemes suggest- ed in order to improve it, and some general remarks respecting the requisite arrange- ment of any well contrived system of forti- fication. That Part of the Treatise which relates to the Defence of Fortified Places, contains a general explanation of the preparatory dispositions to be made in order that they may be capable of sustaining a siege ; be- sides a Description of temporary Bomb- proofs and splinter-proofs, which the French call Blindages, and the methods of making them. The construction of Barbet-batte- ries, temporary Covered - batteries. Re- trenchments, Tambours, Traverses, Para- dos, temporary Powder-magazines, Fleches and Counter-approaches, is also explained in the same Part of the Treatise, as well viii INTRODUCTION. as the proper method of palisading the co- vert-way, and the nature of the operations that the besieged troops are to execute, ac- cording to the period of the siege. IX CONTENTS. PART I- On the Attack of Places. CHAPTER I. PACE. Object of a eiege : General oudine of the dispositions usu.ill}' made by the besieger, and definttinns: Metliod of attacking places which was used before Vauban : Defects of (his method ; A summary view of the improvements contrived by Vauban, ns well as of the advantages thait they afibrd to the besieging troops. ... 1 CHAPTER II. First Period of the Siege. Preparatory dispositions requisite before investing a place : Investi- ture of the place: General plans to be drawn subsequently (o the investiture : Parks and Depdt of the Artillery : Lines 1st System and the Modern Bastion— System compared : Observations on Vauban'g CONTENTS. XI PAGE. Snd and 3rd Systems, commonly called the Tower - Bastioa Systems : Method of attacking Places constructed after these Systems : Remarks on Coehorn's Systems, and an explanation of the nature of the attack suitable for a Place fortified according to hia 1st System 135 PART II. On the Defence of Places. CHAPTER VII. A (general investigation of the dispositions to be made, in order to put a fortress in a state of defence : On tlie construction of Bar- bet-batteries, Temporary covered batteries. Retrenchments, I'ambours, Horizontal blindages, Inclined and Double blinda- ges. Traverses, Parados, Temporary Powder-magazines, Fleches and Counter-approaches: On the proper method of palisading the covert-way 119 CHAPTER VIII. On the requisite operations of the Garrison during the 1st period of the Siege SIO CHAPTER IX. On the requisHe operations of the Garrison during the Snd period of the Siege 918 CHAPTER X. On the requisite operations of the Garrison during the 3rd period of the Siege t35 ERRATA. Page 13, line 23. For, thar, read that is. S6, — 3. For, de61ated, read defiladed. 82, — 6 from bottom. For, rather wider and deeper, and its parapet higher, read, rather deeper, and its parapet higher. 102, — 3. For, their epaulments consisting of the parapet of this trench, and their lerrepleins being se- cured by traverses from, read being covered in front by the parapet of this trench, and secured by traverses from 119, — S from bottom. For, In the mean while sappers, read, in the'mean while workmen For, (152) read (151) For, (153) read (152) For, (152) read (151) For, defiled read defiladed. N. B. The asterisk * in line 1, page 197, should be placed after the words 8 iochea thick in the last line of the text in page 196. no. — 15. ibid. — 18. in. — 3. m. — 4. ON THE ATTACK AND DEFENCE OF PLACES. PART I. ON THE ATTACK OF PLACES. CHAPTER I. Object of a siege : General outline of the dispo- sitions usually made by the besieger, and de- finitions : Method of attacking places which was used before Vauban : Defects of this me- thod : A summary view of the improvements contrived by Vauban, as well as of the advan- tages that they afford to the besieging troops. 1. — The object of a siege is to take possession by force of a fortified town, the conquest of which political motives, or military viewSj render impor- tant for the besieger. In order to attain this ob- ject, he constructs various works designated by ihe general name o{ approaches* which, as they * The name of approaches is at present given in the English . service to those trenches which the Author of this Treatise has called Boyaux, according to their original appellation, which B Z ON THE ATTACK. AND consist of trenches secured by a parapet, enable him to advance towards the town under cover of this parapet, and therefore with less darvger. He also erects batteries composed of different kinds of pieces of ordnance, according to the situations in which they are placed, the period of the siege, and their particular purposes ; some of them ar« intended to subdue the fire of the place, and de- stroy other means of defence of the garrison, so that the besieger may carry on the approaches istill more securely: whilst the other batteries serve him for making breaches, through which he penetrates 'into the works, after he has advanced to the ditch in front by means of covered com- munications, called descends, which he constructs, and effected those dispositions across it that are named passages of the ditch. The object of the dispositions in question is to enable the besieger to cross the ditch with as little danger as possible, for the purpose of gaining the; breach, and giv- ing the assault. The approaches, when combined with the bat- teries, generally take the name of attacks. ^' — The, art of attacking places was at all times adapted to the nature of the fortifications in use, as well as to the effect of the weapons • is derived from the French. Particular motives, of no import to the Reader, have led the Author to retain this original ap- pellation. ; DEFENCE op PLACES, 3 which were employed to defend them ; but, like every other branch of the military art, it has been gradually improved. Immediately before Vau- ban, places were attacked as follows : One or two fronts were fixed upon, for the purpose of directing the attacks against them, and forts A (PI. 1. Fig. 1.) were constructed at about 500 or 600 yards from those fronts, in such situations as allowed the besieger to see the works which com- posed them, to greater advantage. A numerous artillery was then placed in the forts in question, so as to keep up a heavy direct fire against the opposite parts of the fortifications ; and ground was broken* under the protection, of the same forts, the approaches being carried on by means of boyaux a. (40) so directed as not to be liable to enfilade from the place. Upon the right and left of each boyau the besieger constructed trenches b called lodgments, the extent of which allowed them to contain 30 or 40 soldiers, posted there for the purpose of protecting against sallies the workmen engaged in carrying on the ap- proaches ; and these soldiers were supported by as many others as could be stationed in the boy-; aux without impeding the communication thjpough; * The expressions to break ground, ori to open the trenches, have both the sara^ meauing, and are used to denote the, actual commencement of the attack. ON THE ATTACK. AND them. After the besieger had gained the sali- ants of the covert-way, and established himself firmly upon the crest of the glacis, he erected batteries c in order to breach the works through which he intended to force his way into the place ; he then executed the descents into the ditches of these -works, crossed the ditches, and gave the as- sault; or else, instead of employing guns to make the breaches, he used mines, which he placed in the escarp of the works to be breached. 3.— Such a method of attacking places un- doubtedly was very defective, as, besides other inconveniences arising from it, the batteries sit- uated in the forts 'A only opposed a direct fire to that of the place, and could not therefore silence it, or even materially impair its £ffect, but with great difficulty ; they feebly protected the ap- proaches, on which account, and because the lodgments b, as well as the boyaux a. did not afford suitable room for a proper number of troops advantageously posted to repel the sallies, these had the means of attacking the approaches in all directions .and destroying a considerable portion of them, before the besieger had time to send such reinforcements as would have been necessary to prevent the sallies from accomplish- ing this purpose. The besieger was also ex- posed to the destructive fire that the works of the place concentrated upon the approaches, and DEFENCE OF PLACES. 5 particularly upon their narrow heads ; so that, independently of his experiencing a great loss of men, much time and labour was requisite to ena- ble him to arrive at the saliants of the covert- way, which work he always was obliged to storm; and when, after several sanguinary conflicts be- tween him and the besieged troops, he had at last succeeded in making and consolidating his lodgments upon the crest of the glacis, he still had to construct the batteries c, and execute every other subsequent operation, under the heavy fire that the place generally was still capable of keep- ing up. 4. — Vauban, having observed the above defects of the process used for attacking places, contriv- ed another method (Fig. 2.) that has the great advantage over the former of rendering the be- sieger far more secure in carrying on the ap- proaches ; for^ the parallels B C, D E, F G, and the demi-parallels H I, K L, M N, which, ac- cording to this engineer's method, are to be con- structed in situations gradually nearer to the place as the besieger advances towards it, can contain strong bodies of troops who are, in those trenches, advantageously posted to oppose the sallies. The parallels and demi-parallels in ques- tion also protect such batteries d, e, f, g as the besieger may have occasion to erect within or near them; and therefore, they allow him to O ON THE ATTACK AND dispose his artillery in a manner more beneficial to his operations. Besides, Vauban's method enables the besieger, as will be shown, to pene- trate into the covert^way and other works by means much less dangerous for him than those previously employed ; and it also has the advan- tage of admitting of any modifications that the ground, or the irregularity of the fortifications, ma}' require. Conformably to Vauban's original arrange- mentj such as represented by Fig. 2*, the batte- ries were still direct, so that their effect was im- proved only by the more advantageous disposi- tion of the artillery in other respects ; but, after this eminent engineer had invented the formida- ble ricochet-firingf, this invention, together with appropriate changes in the situations of the bat- _^_ * At the sieges of Gravelines and Lille, the former in l65S and the latter in 1667, Vanban departed to a certain degree from the process used hy feis predecessors ; but he only attend- ed completely to his own methof], (such as sho\yn by Fig. 2.) at the siege of Mae stricht in 1673. This important place was taken 13 dajs after breaking ground. + The first use which Vauban made of the ricochet was at the siege of Ath in I697. The artillery of this place was sileneepl, in a few hours! Rjcochet firing requires that the direction and charges of the pieces.of ordnance employed for this purpose should be so regulated that the shot, after just clearing the top of the oppo- site parapet, will fall upon that extremity of the terreplcin to DEFENCE OF PLACES. 7 teries, enabled the besieger to enfilade the works, instead of battering them in front; and Vauban's method becoming still more beneficial on that account, as it facilitates the means of placing the ricochet batteries suitably for their intended par- pose, it has ever since been followed, with some modifications suggested by engineers who came after him^ but which are not very material. This method, improved by the use of ricochet firing, will, as well as the above-said modifications, be applied in the present treatise to the attack, first of a regular hexagon constructed according to the Modern Bastion System* and secondly, of a Dodecagon, also regularly fortified after the same system. In this manner, such readers as may not possess a sufficient degree of information respect- ing the operations about to be explained, will be enabled not only to acquire a proper knowledge of them, but also to perceive distinctly the diffe- rences to be observed in attacking inferior or su- perior Polygons ; besides the advantages which, in point of defence, the latter Polygons have over the former. For greater perspicuity, the be enfiladed which is nearest to the attacks, and then rise and come down again several times, until by successive bounds it has passed over the whole length of the terrepleia. * For the particulars of the Modern Bastion System, see the Author's treatise on the General Principles of Peiuianeut Fortification, &c. Parag. V>i). Page 12C. 8 OK THE ATTACK AND nature of the operations which the besieger is to execute on each particular day and-night of the siege (admitting that no unforeseen events or other motives may -render a different arrange- ment advisable or necessary) will be indicated accordingly, and the whole explanation succes- sively applied to three different periods of the siege. The 1st period will include all the prepa- ratory dispositions of the besieger previous to the opening of the trenches, and the 2nd his ope- rations from the time he breaks ground^ to the finishing of the 8rd parallel. To the 3rd period will belong the approaches, &c. carried on be- yond the 3rd parallel^ until the surrendering of the place. The superiority of the Modern Uastion System over those anterior to it in which Bastions are used, of course requires that^ in attacking a place fortified according to the former system, the be- sieger should advance with greater precaution ; the works which he is to construct being there- fore more numerous, and their construction at- tended with greater-difficulty and danger, a lori-ger time is requisite to carry on the attacks. This subject shall hereafter be more particularly eluci- dated, and the process explained for attacking places fortified according to Vauban's 2nd and 3rd systems, commonly called the Tower — Bas- tion — Systems, and to the Systems of Coehorn. CHAPTER II. FIRST PERIOD OF THE SIEGE. Preparatory dispositions requisite before invest- ing a place : Investiture of the place : Gene- ral plans to be drawn subsequently to the In- vestiture : Parks and DepSt of the Artillery : Lines of Circumvallation and Countervalla- tion : Encampment' of the besieging troops : Park and general DepSt of the Engineers : Directing plan : Methods' of determining upon the ground the prolongations of tha Faces and Capitals of the Works : Depdtsfor the Trenches: Last dispositions of the Be- sieger previous to the opening of the Trenches. 5. — The duration of the resistance which a besieged fortress is capable of making, depends not only upon the actual strength of the fortifica- tions, but likewise upon whether the fortress has a proper garrison, and is equally well supplied in every other respect. It is therefore important that any commander of an army, who is decided to lay siege to a place, should keep his intention secret, and at first execute feigned movements so combined as to allow him to preserve the means of effecting his design as soon as he may c 10 OK tBe attack, and think it advisable, whilst, by deceiving the ene- my, or at least rendering him uncertain of the real purpose of those movements, he will per- haps lead him to neglect supplying the place with a sufficient garrison, or such a quantity of artil- lery, ammunition, provisions, &c. as a defence proportionate to the strength of the fortifications would require. According to circumstancesi, the feigned movements in question may be so planned as to persuade the enemy that the place intended to be attacked is secure from a siege ; or, to ex- cite his apprehensions for several places at the same time, and induce him also to believe that the object of the movements may be an immedi- ate attack upon the defensive army.* ^Another precaution materially requisite, before <;oramencing asiege, is to ascertain that the means at hand are sufficient to undertake itjf as, other- wise, the progress of this operation would be re- * By the defensive arnyr is meant in this place the army which keeps the field, for the purpose of protecting, in com- mon with the'fol-tresses, thecountry threatened with an inva- jiiOn. t With respect to the requisite number of troops for the siege of a place, it should be estimated not only according to the strength of the garrison, as well as to the nature and ex- tent of the fortifications, but also in consequence of the means that the enemy may have of sending a consideiable fqrce to attack the beaegta^ and oblige him to raise the siege. DEFENCE OP PLACES. H tarded, and the ultimate result precarious. The artillery, ammunition, tools, &c. necessary for the besieging army, are to be assembled in de- pots cautiously established in such situations be- hind it as may not enable the enemy to draw in- ferences from them with respect to the views of the army, and will however render convenient the conveyance to the latter of the various sup- plies which the dep8ts contain. The carriages, horses, and other means of conveying these sup- plies, as soon as they may be wanted, should of course be secured. 6. — Subsequently to these dispositions, and the commander of the besieging army finding a favorable opportunity to commence his operations against the place, he instantly sends a corps to- wards it, which, when the country round the place is open, should chiefly consist of light ca- valr}-, with some light infantry ; but a greater proportion of the latter is necessary in a country intersected by woods, hedges, ravins, &c. This corps is to be accompanied by horse»artillery, and has for its object to form what is called the investiture of the place ; that is, to occupy sud- denly, at the same hour, and if possible without being expected by the troops of the garrison, all the avenues by which they might receive suc- cours, or give notice of their situation ; so that these troops being deprived of the means of com- 13 , ON THE ATTACK AND municating with the country, may be reduced to their own resource?. The investiture also ena- bles the engineers to reconnoitre the environs of the place, and the fortifications. 7.^The process used for investing a place shall now be explained. The investing corps advances as rapidly as pos- sible towards the place, and when arrived at 5 or 6 miles from it, the commanding officer of this corps divider it into several detachments, each of which, by going round the place, re- pairs to the spot designated for it. At a signal given by means of firing such a number of guns as was agreed upon, all these detachments march forward at the same time towards the plate, seizing, as they advance, upon any per- sons and cattle, &c. that they may happen to meet. They also take possession of the villages, castles, parks, and other advantageous situations. After halting at such a distance from the place as secures them from its fire, the detachments in question take advantage of the cover which the ground may afford, in order to establish as near the place as can be safely done, a line of small posts, so disposed as to be conveniently succoured in case of necessity. The communicationsof these posts, both with each other and the detachments, are kept up by a double chain of patroles; and, for greater security, sentries and videttes are placed at the points most advantageously situated for dis- DEFENCE OF PLACE&. 18 covering whatever may come out of the fortress, or attempt to approach it. If there should happen to be villages, or other important situations, about 1800 yards distance from the place, they are to be occupied, and sometimes intrenched, so as to keep the garrison in check, and prevent it either from seizing upon any of the investing troops, or facilitating the introduction of succours into the fortress, and carrying off' such provi- sions, forage, and other objects, as may he in the neighbourhood. It is to be observed that the de- tachments just spoken of should face towards the country, and the small posts towards the place. The above dispositions are those which the in- vesting corps is to make during the day ; but night being the most favorable time for introdu- cing succours into the place, and also for coming out of it, the investiture should th^»n be more close. In consequence, the detachments ap- proach towards dusk to the distance of about 1200 yards from the fortress, and establish small posts in their front, as before, all the troops facing likewise in the same manner; that the detachments face outwardly, and the posts in- wardly. They observe the greatest silence, and use double vigilance and precaution both against the garrison and any attempts fro n without. Upon the appearance of daylight tiiey retire by de- grees to the positions which they had previously occupied, the engineers examining, as well as cir- 14 ON THE ATTACK AND cumstances permit, the arrangement of the forti- fications, and the ground.* These dispositions are to be repeated every day and night until the arrival of the besieging army, which will gene- rally take place three or four days after the inves- titure ; and this army, whilst advancing, should manoeuvre in such a manner as to secure the in- vesting troops from any movements dangerous for them that the garrisons of the collateral places, or some other troops which the enemy may have in the neighbourhood, might otherwise execute. 8, — The place being invested, the engineers avail themselves of the protection of the troops for the purpose of advancing night and day as near the fortifications as possible, and reconnoi- tring them, as well as the country round them. They carefully observe the form and nature of * If by displacing the whole of the investing corps, in order to station it nearer to the place during the night, positions should be abandoned which afford material advantages to this corps for the purpose of preventing the introduction of any succours into the tovyn, the coinmand"er should endeavour to regulate liis dispositions for the night in such a manner as to contume occupying the positions in question, and yet keep an e^ectual look-out in respect to the garrison. The proper dis- tribution of the investing corps, under those circDmstances, of course depends on the nature of the country, the strength of the garrison, and the number of other troops which the enemy may have in bis power to send, in order to impede the inves- titure. DEFENCE OF PEACES. 16. the ground, and , in short endeavour to procure every information which, by enabling them to ascertain on what side the place may be attacked to greater advantage, puts it also in their power to determine the spots where the parks of the artillery and engineers ought to be established. The engineers likewise examine whether the quantity of wood in the neighbourhood is sufficient for the great number of fascines, gabions and picketSj &c. that the siege will require* ; and, if it should be intended to construct lines of circumvallation and countervallation (10 and 11,) they extend their observations to the dis- position most suitable for each of these linesf. All these details are laid before the commander * Fasciaes a fpl. 3, fig. 11) are composed of straight rods and branches tightly pressed and bound together, in a cylindri- cal form, with withes. Trench-fascines usually are 6 feet long, and 9 in. in diameter. A gabion b consists of a kind of cylin- drical basket, open at both ends, which is made with rods wat- tled between pickets, and secured in several places, so as to form what is called Ihe web of the gabion. The exterior di- ameter of a sap-gabion is I foot 8 inches, and the height of the web 2 feet 9 inches. f When it is intended to construct lines of circumvallation anld countervallation, the engineers commonly make a plan of the country round the place, to the distance of between 3000 and 3000 yards. This plan is called The general plan of the environs of the place, and exhibits an accurate description of the principal parts of the ground, such as the streams, marshes. 16 ON THE ATTACK AND of the, besieging army, who subsequently makes a reconnoisance himself, and then definitively settles the arrangements to be made*. Th« most important roads are likewise to be inspected immediately after investing the place, so as to repair them, if necessary ; whilst the distribution of the besieging troops, in the differ- ent camps that they are to occupy during the siege, should be regulated and such a number of peasants assembled in the adjacent villages, as may be wanted. They should be kept insight. 9. — The parks of the artillery should be estab- lished on that side of the place where the attack is to be carried on, their situations being concealed, if possible, from the view of the garrison. When inundations, woods, steep places, &c. The scale used for it generally is 3-fourths inch, or 1 inch, to 200 yards. * Several French Authors recommend the use of balloons in reconnoitring fortresses, as, by this means, the nature and form of the fortifications, and the manner in which they defend the ground in front, may with good telescopes be correctly ascertained ; as well as the new works that the garrison may have thrown up, the disposition of the artillery of the place, the communications across the ditches, and the situations of the store-houses and other public buildings, &c. Speaking of the use of balloonsj for the purpose of recon- noitring fortified places which it is intended to besiege. Gay de Vernon says in his Traite eUmentairt d'Art militaire, SfC; that the observations mtiy be made at the distance of 1500 metres, (about 1640 yards) from the place. DEFENCE OP PLACES. 17 the country does not afford such situations, the parks are not to be nearer to the fortifications than about 3500 yards, as a shorter distance would render them liable to the fire of large guns. It is also necessary that the roads leading to them should be convenient for carriages, and that an abundant supply of water for horses should be found in the neighbourhood. One of these parks is called the Grand Park, and the other the Litlle Park. The pieces of ordnance of every descrip- tie^n, which are requisite for the siege, are col- lected in the grand park, together with the shot, shells, powder, &c. The little park is about 80 yards distant from the former, and contains the forges, the artificers, and their workshops, the carriages for their tools, the combustible prepa- rations, the materials and implements for making them, and various other objects that the service of the artillery requires. The security of the parks of the artillery is a circumstance of the greatest importance; on which account, those parts of the lines of circum- vallation and coutitervallation that immediately protect them, should particularly be adequate to a suitable defence, besides the parks being se- cured in flank by means of a small number of field-works detached from one another ; or, if it were not intended to construct any lines of cir- curavallation and countervallation, intrenchments 18 ON THE ATTACK AND may be thrown up round the parks^ for the pur- pose of seeuring them. Troops, consisting of in&ntry of the line and light cavalry, are like- wise to be appointed for their defence, and the villages rn front should be occupied by light in- fantry and cavalry. 10. — By Imes of circumvaUation are meant intrenchments which a besieging army occasion- ally constructs round the place, at the distance of about 3600 yards from it. They face towards the country, and have for their object to cover the troops encamped behind themj so that they may be secured from any sudden attack which parties of the enem j might otherwise make upon some of them, in order to force their way into the place. By shutting up every passage leading to the town, the lines in question also prevent the enemy from availing himself of the obscurity of the night, for the purpose of corresponding with the besieged troops, or sending supplies to them ; and they likewise, are sometimes intended to enable the besieger to resist with advantage any attempt of-an army to raise the siege. Lines of circumvallation have of late been little ased, as the custom generally prevailed of covering the operations of the siege with an amy^ of observation, so posted as to watch the enemy's movements, and succour the besieging troops, or receive assistance from them, according to cir- DEFEI^CE OF place;. 19 cumstances. It must be admitted^ -however, that an army of observatioi;\,:^does not render these lines, entirely useless,, allhoagh they m^y.be less necessary ; the r-eason isj.th^t the enemy may de- ceive the army by hisr manoeuvres, and thus suc- ceed in soccouring the- place, ^^egiides, if the army should happen to be attacked, and defeated,: it may retire bebind the lines, so as to recover from the check which it has sustained, and allow the siege to be continued under its protection. This of course supposes that sufficient means of communicating with the country will remain to the army, to enable it to receive any supplies that may be requisite for it. If it be now supposed that any array, which undertakes to besiege a place, is not sufjdciently strong to form a proper corps of observation, be- sides affording the necessary number of troops for carrying on the operations of the siege, lines of circumvallation will in this case be of the greatest utility, if not actually indispensable j* for, parties may at first be kept in advance of * It is evidently supposed in this place, that, akfaougb the army may not be sufficiently numerous to admit of forming two separate corps, yet its strength, and the protection afford- ed by the lines, allow it to oppose an effectual resistance to such forces as the eneniy may be capable of senduig against it. Under different circumstances, it would be much better not to undertake the siege. 20 ON THE ATTACK AND these lines, in brdel* to pt-ocqre information re- specting the feneiny ; aii4 as soon asXh^ have as- cei'tainedthat he is assembling his troops, a kind of vanguard, consisting of a strong detaehment, may he sent for the purpose of observing and harassing him; advantageous fields of battle, between him and the besieging army, may also be reconnoitred, and defensive dispositions made in such situations as will admit of them. Upon being informed of the enemy's approach, as well as of the nature of his movements, the commander of the army will have it in his power to take any measures which circumstances may lead him to think advisable ; either, by forming the whole army in order of battle behind the lines, with the exception' of that portion of it which is necessary to secure the trenches from the garrison ; or, by advancing towards the enemy, with the troops not employed in guarding the trenchesj &c. in order to surprise him in his march, and attack him. The siege may likewise be temporarily raised, and the artillery sent to some neighbouring places, together with the other important objects belong- ing to the army, so that all the troops may be brought against the enemy, and such a victory obtained as will allow the siege to be immediately recommenced. It is certainly to be acknowledged that lines oj cirpuravallation have two material defects j DEFENCE OP PLACES. 21 first, on account of their circular form, the enemy sees their interior in flank and in reverse, imme- diately after he has penetrated through any part of them. Secondly, as in case of their being at- tacked, the action will take place at a short dis- tance from the trenches, it is to be greatly appre- hended (hat the army which defends them will not be able, if defeated, to retreat in such good order as would allow the artillery, &c. used for the siege, to be safely removed, and therefore secured from falling into the hands of the enemy. Consequently, engineers, employed in construct- ing lines of this description, should contrive all possible means of making them adequate to a strong resistance, and particularly endeavour to render a considerable portion of their. circumfe- rence inaccessible to the enemy. For this pur- pose, the engineers are to avail themselves of the steep places, courses of water, and other natur.al obstacles that the ground affords : to render the marshes impassable and the woods impenetrable: to form inundations : and to estabhsh fixed bat< teries in tlie situations most advantageous for thfem, «S;c. Those parts of the lines which the enemy can attack being thus in small number, each of them may be defended by a much greater force than if the whole lines should require to be gju^r^ed ; and, for the same reason, they admit of 22 ON THE ATTACK. AND beinff fortified in a manner more effectttal|nespe- cially if, besides having their extremities termif iiated at the inaccessible parts, which parts shottld be so disposed as to flank them, the «rj ced*. It is to be observed that either the front or the reverse of parallels is not always to be made with steps, but may^ according to circumstances, form a continued slope similar to the slope 6 represented in^^g". 3. 26.— Experience has shown that no soldier of a common size, who stands behind a parapet more elevated above the banquette than about 4 feet 6 inches, can conveniently take pro- per aim, when firing ovet the parapet, if for that purpose th6 muzzle of his gun should re- quire to be depressed as much as ordinary <:rr- cumstances may render it necessary. Therefore^ supposing the height of the parapet of any par^ allel to exceed the abovesaid dimension, it will be requisite to form a banquette highCT than the natural ground, so that -in ease of a sally pre- senting itself, this banquette may enable the * lllore than one step may sometimes be requisite in the front or the reverse of a parallel : for instance, when the fire of the place being very plunging, it becomes necessary to make the trench much deeper than u»ual : or else, when the parallel i& coiislracted on ground sloping downwards in the direction of the plac^,' so that the top of the reverse is much more elevated ahofve the bottom of the trench than it should be in oth«r ground. DEJFENCE OF PLACES. 41 besieging troops posted upon it to keep up an ef- ficient fire against the sally. Admitting that the parapet is not reveted, the arrangement of the banquette may simply consist in cutting a step a (fig. 5) of a proper height and width in the inte- rior slope ; but reveted parapets require different means, and a method suitable for parapets of this kind will be hereafter suggested. It will only be said in this place that the elevation of the crest of the parapet above the banquette may in some instances be so small as 4 feet, and should never exceed 4 feet 6 inches; wherefore, these two dimensions may be considered as the extremes of the elevation in question. 27. — The process generally used in order to trace the 1st parallel b c on the ground (pi. 2, fig. 6) is , such as follows: — The commanding engineer having reconnoitred the ground where it is intended to open the trenches, so as to ascer- tain the direction which the parallel ought to have, he at first describes it in the directing plan, and elucidates, by means of the parallel thus re- presented, the preliminary instructions which he gives to the other engineers ordered for duty, re- specting that portion of the parallel which each of them has to trace. Subsequently to this pre- paratory explanation, the engineers repair to the ground^ at the close of the day : being accompa- nied by a few attendants, and directing themselves 43 ON THE ATTACK. AND towards the pickets c, d, which have previously served to mark out the prolongations of the cap- itals (17). They plant pickets n at the inter- sections of the parallel with these prolongations ; and also to the right and left of these pickets, at such intervals as they think proper in order to in- sure correctness in the direction of the tracing. White lines or tapes, connecting all the pickets, are then stretched, which represent the interior base line of the parapet. The commanding en- gineer of course superintends the whole opera- tion. Whilst the engineers are engaged in tracing tlie parallel, the working parties appointed to construct it should be assembled as secretly as possible in the depots a of the trenches, and supplied with the necessary tools ; these being ta- ken from the general depSt of the engineers. The workmen are divided into detachments, also called brigades, and their requisite number is generally estimated at the rate of one man for each 5 feet of the length of the parallel ; but if it should be wished to accelerate the work, the task of each man may be reduced to four feet. Several officers of great experience, and high- ly distinguished by their professional abilities,- have expressed their opinion that working par- ties should have their guns, instead of being un> armed; as in coniequence of the confidence DEFENCE OF PLACES. 43 ■which this would give to the workmen, they would not disperse on the approach of sallies, as they frequently do when without arms. Be- sides, covering parties less numerous might be employed to protect them against sallies, and this duty would not therefore fall so heavy upon the besieging army ; whilst the casualties among the covering troops would probably be diminish- ed from the number of these troops being small- er. It is also to be observed that as soon as the approaches have been pushed on to the distance of musket shot from the place, it becomes abso- lutely necessary to station part of the guards of the trenches in the boyaux, as they would be eminently exposed in front of them ; and, inde- pendently of other inconveniences, the commu- nication through the boyaux is so much the more impeded by troops being stationed in them, as these troops are in greater number. Howev- er, the apprehension of incumbering the work- men, and especially when besides their tools and guns they would also have materials to car- ry, has hitherto prevented the general adoption of the metliod of arming them ; and this method only was attended to, in some instances*. It was • Speaking of the Flying Sap (48) such as executed in the Meges undertaken by the Allies in Spain, in the years 1811 and l«i2, Lieut. Col. John T. Jones, of the corps of Royal Engi- 44 OM THE ATTACK. AND p^haps apprehended likewise, that, if the work- men should be vigorously attacked by a strong sally, and drivea hack beyond the spot where they are at work, they might leave their tools and only carry away their guns; in whi^h case the sally would not fail seizing upon the tools. The covering party ordered to support the workmen employed for breaking ground, should be assembled in the depots of the trenches, similarly to the workmen. It consists of in- fantry and cavalry, the latter generally exceed- ing the cavalfy of the garrison, and the former being three-fourths or at least two-thirds of their infantry ; but these proportions may undoubt- edly be modified, according to circumstances. Before the covering troops are marchedfrom the depots of the trenches to the ground which they are to occupy in order to protect the work- men, the commander of these troops, accom- panied by his principal officers, should recon- neers, says in page 328 of his highly-iniportant and valuable publication respecting these sieges, that, in marching to the work, every axth man carried the arms of the other five, and he afterwards supplied the place of those put hors de tra- vail. The French have translated the abovesaid publication into their own language. In his report of the opening, of the trenches before Parape- luna, in 1823, Marshal de Lauriston also said that ground was broken at the distance of 200 toises (about 427 yards) from the place, the workmen carrying their arms. DEFENCE Of PLACES. 45 noitre it ; having also with him an engineer who, by explaining the direction that the parallel is to hsL\e, enables hira to fix upon the spot where each separate division of the covering party is to be stationed ; as vrell as upon the roads that the different divisions are to follow for the purpose either of gaining their respective posts, or suc- couring one another in case of necessity. 28.-^ When it has become sufficiently dark for the covering party to advance without being seen by the garrison, each of the divisions which compose it should repair with the greatest silence to the spot assigned to it ; the infantry f being posted in front of those parts of the ground through which the 1st parallel is to pass, and the cavalry g upon the flanks of this parallel. The infantry f, when arrived, are to push for- wards detachments/, forming echelons, with or- der not to fire, unless assured that the enemy is advj latter, or defending by their fire a particular spot where the besieged troops might establish them- selves, and from thence annoy the besieger. In any other boyau, a berm about I foot wide is suf- ficient; and with respect to the interior arrange- ment of the trench, it is, excepting the depth, much the same as in parallels. The profile of the great communications m is similar to that of the 1st parallel. fSee pi. \st, fig. 4.) 41. — Boyaux are for various reasons usually placed upoTi the prolongations of the capitals of the works towards which the besieger advances. First, as these prolongations give the shortest distance from any of the parallels to the next, less time and labour is requisite to construct the bor. yaux. Secondly, the boyaux are generally more secure in this situation than in any other, because the musquetry fire of the works of the besieged place cannot defend their own capitals, unless the saliants are very obtuse ; and, even in this case, the fire must be very oblique, which renders it of little effect* ; whilst only one gun, in each saliant, can * In order not to uncowr themselves, soldiers posted behind a pSrapet generally fire over it straight forwards, without endea- vouring to take proper aim, so that the shot follows a direction DEFENCE OF PLACES. 59 be fired precisely in the direction of the capital prolonged ; and, if to the right or left of this gun, others should be placed along the faces, for the purpose of firing them in a direction parallel to the prolongation of the capital, suitable embra- sures for these guns could scarcely be made, in consequence of the considerable degree of obliqui- ty that the lines of fire would require. Lastly, by placing the boyaux as abovesaid, their para- pet incommodes the batteries in their rear as little as can be done. 43. — In order that the boyaux may not be seen into by the besieged troops, and enfiladed by their artillery placed in the saliants, as might happen if the boyaux were laid out in right lines parallel to the prolongations of the capitals, they obliquely cross these prolongations, to the right and left alternately ; thus forming angles with them, the opening of which is augmented in pro- portion as the boyaux are nearer to the fortress, so that such a direction may be given to the for- mer as will allow their prolongations to clear all the works of the latter, and therefore secure the boyaux from being enfiladed by any of these works. None of the boyaux between the parallels perpendicular to the crest of the parapet, or nearly so. This accounts for the little effect of the musquetry fire whenever it should be kept up in an oblique direction. 6P QN -fHE ATTACH AND sl^Qulcj b? extended farther Uian from 40 tp 50 yards beyond their intersections with the prolongations pf the capitalsjthose which are thefurthest from the place being generally made the longest; and^ si- milarly to the boyau oq, (pi 2, fig. &.) every bo- yau ought to be prolonged 5 or 6 yards beyond its junction with the one immediately behind |t, so as tofprm a return op which not only protects a- gftinst oblique shot the head of the boyau in the rear qf the other^ but affords a sort of recess where one of two parties meeting in opposite directions may retire, until the other has passed. Each return is to be terminated by a slope of 4 or 5 feet, as a passage will thus be formed which may occasionally prove very useful for entering into the boyau, or getting out of it. It is to be observed that the communications made beyond the 3rd parallel are not laid out in the form of zig zags, like the boyaux, as this form would evident- ly not allow them to be defiladed from the works situated on their flanks. This subject will be here- after treated of. 43,— r^oyaux directed according to the usual method just explained, form acute angles a.b c, defipl. 2, fig. 9.) with the parallels ; audit has been suggested, as an improvement of this me- thod, that small returns g-, h (fig. lO.) might be made, having a direction parallel to the prolong- ations of the capitals. Tlhe reason assigned in Defence of pi»aces.' 51 favour of this suggestion is that the angles a be, d ef(fig. 9.J being acute, there is no sui&cient room, at least near the vertices c| these angles, to construct a parapet of a proper solidity. But ijt seems that inconveniences must arise from the short turnings which the returns g and ^ occa- sion ; as well as from the frequent necessity of making the return g much wider than the boyau leading to it^ so that earth may be procured for the purpose of erecting, on each side of this re- turn, a parapet which may protect it against ob- lique shot. Such are probably the motives whicji hare hitherto prevented the returns in question from being commonly made. Indeed^ supposing the besieged fortress to be erected on a polygon of a superior order^ and its works upon the right and left of the boyaux to have a great projection, the besieger may be obliged to secure himself from the fire of these works by a parapet on each side^ before the time when such a disposition is usually requisite ; but this is a different case, which will be hereafter investigated. 44.— Before tracing any boyaux on the ground, they are usually described in the directing plan (15); and, supposing pi. 3, fig. 6, to represent that plan, whilst the boyau mo is to be laid out on the ground, the engineer appointed for this op- eration takes note of the length which, accord- 63 ON THE ATTACK. AND ing to the directing plan, the boyau in qaestion is to have ; as well as of the distance from its in- tersection r with' the prolongation of the capital, to the point n where this prolongation meets the 1st parallel. He also specifies in his note the dis- tance mn, which fixes that part of the parallel from whence the boyau is to be pushed out ; and, in the dusk of the evening, he repairs to the spot for the purpose of determining by measurement, under the protection of troops lying down in front, the situationsof such points on the ground as cor- respond to those m, r, o, in the directing plan. In proportion as the engineer determines the si- tuations of the former points, he plants pickets there, which are subsequently connected by white lines. The other boyaux o q, &c. may evidently be traced out by a similar prociess. The following method might also be used in order to trace the boyau m o on the ground, or any of the other boyaux. According to this me- thod two lines are employed, one of which is equal in length to the distance m r, measured upon the directing plan, and the other to the distance n r ,- the former line being fixed at one end to the pick- et m, and the latter to the picket n, a man at the other end of each line stretches it, and walks tow- ards his companion until those extremities of the lines meet, which the two men respectively hold. It then only remains to lay a line in the prolong- DEFENCE OF PLACES. 63 ation of the line mr, so as to complete the length that the boyau is to have. Whether the engineer employs one or the other of the two methods of tracing boyaux on the ground which were just explaitied, greater security requires that he should endeavour, by looking close to the horizon, to see the saliants from which the boyaux are to be defiladed ; so as to ascertain that the prolongations of the latter will pass at a suitable distance in front of the for- nier(42); whilst Ijefore commencing the operation, he should in the course of the day observe some remarkable objects situated in the proper direc- tions of the boyaux, and which being nearer to them than the saliants, may be better seen at dusk. This means alone may even be occasion- ally sufficient. The working parties who construct the boyaux in the rear of the 1st parallel, or between this parallel and the 2nd, are marched up rank entire, and the workmen distributed at the same distance apart behind the white lines, as those employed for the 1st parallel (27) ; they of course face towards the parapet, and form the trench in the manner explained (30) respecting this parallel. 45. — Unless the besieged troops have made strong and successful sallies, or the besieger has been obliged to delay the construction of several of his ricochet batteries, he will probably be able 64 ON THE ATTACK AND foi gain the spot for the 2nd parallel in the course of the 5th night, and therefore, to commence this parallel in the beginning of the following night. It is usually ^lacedl at about half the dis- tance from the 1st piarallel to the most advanced Valiants of the covert- way, but rather nearer toth«! ^iairaftel than to the saliants, sothaf the ground be- tv^een the 1st and thef 2nd parallels may be more effectually defended by the musquetry fire of the former. The workmen, and particularly those employed at the extremities of the parallel, are covered by detachments, chiefly consisting of gre- nadiers, who take post at 50 paces in their front, or thereabouts ; being also supported by other troops stationed', some of them in the 1 st parallel, and the remainder in the boyaux between it and the 2nd parallel. The troops in front of the work" men should Ite down in the night, and retire at day-break into such portionis of the 2nd parallel as are ready to receive them. If after his arrival duringthe night on the ground Inhere the 2hd parallel is to be established, the besiieg'er should have sufficient time to construct amorces before day-light, that is, short portions of this parallel extending to the right and left of each of the boyaux next to it, he ought to avail himself of this advantage; as troops posted in these amorces will prove very useful, in the event of the garrison making a sally before the parallel is completed. DEFENCE OP PtACES. 05 46. — The Snd parallel is usually made rather wider than the 1st; and its length should in general be such as to allow the latter to overflank it^ at each end, so that it may protect its flanks against any saHy advancing upon them.* Besides, the shot from the b^-tteries erected at the ends of the first parallel, in order to enfilade the faces of the ravelins collateral to the front of attack, will not have to pass over the parapet of the second paral- lel, which advantage may sometimes be very mate- rial. However, if the besieger had been obliged, as may occasionally happen, to postpone the construc- tion of the batteries in question, so as to place them at the extremities of the 2nd parallel ; or, if having constructed them, it should subsequently be neces- sary to remove them to these extremities, then the 2nd parallel ought of course to be longer than above- said, since under the supposed circumstances, it must embrace the prolongations of those faces of the r-av^Iins collateral ^o the front of attack, which the batteries are intended to enfilade. Likewise, with proper precautions, the besieger generally succeeds in concealing from the knowledge of the garrison the spot where he intends to break ground, as well as the time of his breaking it ; con- sequently, this operation is seldom attended with any great danger to him, and, at all events, he is exposed to no musquetry fire from the works of the place, thieir di^t9.nce considerably exceeding the range of * The 2nd parallel should likewise outflank the 3rd, at each extremity, so as to protect its flanks against sallies. K 66 ON THE ATTACK AND a common musquet, and even of a rampart-fusil* ; But the besieger constructs the 3nd parallel under circumstances much less favourable to him ; for, the nature of the ground, the progress of the attack, and the usual distance of the 2nd parallel from the 1st, enable the besieged troops to judge, with al- most a certainty, not only of the spot where the be- sieger will establish that parallel, but also of the time when he will commence it. Besides, these troops will throw light-balls in the night, so as to see the besieger at work, and he therefore has scarcely any chance of proceeding in his oper- ation without being soon perceived ; whilst the ad- vantageous use that the garrison can then make of their musquetry fire, indispensably requires that the besieger's workmen should be secured from it as quickly as possible. Ih consequence, a par- ticular process, called The Flying-sap, is employ- ed for constructing the 2nd parallelf ; according to which process the workmen place a row of gabions in their front, before they commence to dig the trench. They speedily fill these gabions with earth, and are then secured from the fire of common mus- quets. * A rampart-fusil consists of a kind of musquet of much larger dimensions than a common musquet, and which has a greater range ; the bails used for it weigh each 1 l-3rd ounce, and it is laid on a trestle when firing it. t The flyibg-sap is not employed for the 2nd parallel only, but also, at least occasionally, for other works beyond, it, as will here- after be explained. Some of the besieger's lodgmeiits are usually made by means of this sap. DEFENCE OF PLACES. 67 47. — Before giving any detailed account of ^e ordinary method of executing the Flying-sap, the manner of marching up the working party for the second parallel will be explained: As the distance between every two capitals produced is much shorter in this parallel than in the 1st, and the working party proportionally smaller, the workmen may be marched in two divisions only through each set of boyaux d* and each great comn^unication m, both divisions being divided into brigades, as usual, and formed rank en- tire. When arrived on the spot where the pa- rallel is to be established, one of the divisions is to turn to the rights and the other to the left ; so as to advance in opposite directions until the leading brigade of each division, and the other brigades be- hind it, meet the whitelines stretched along such por- tions of the parallel as they respectively have to per- , form. 48. — With respect to the usual method of execu- ting the Flying-sap : — The working party consists of as many men as there are gabions requisite in order that being placed in front of the white lines, close to them and to each other, they may form a * If the besieger had commenced the boyaux D, opposite the ra- velin of the front of attack, later than those in front of the bastions (38), the former may not be completed at the time when he is to construct the 2nd parallel; and, in this case, the two divisions of workmen marched up in the direction of the prolongation of the capital of the ravelin, will have to pass uncovered over part of the distance from the 1 st parallel to the 2nd; but, as it is in the Dight, and the distance ta be passed over without cover will pro- bably be small, the workmen will not be much more exposed (Iwh if the boyaux had been finished. 68 OH THE ATTAGR ANB f o\V of the sahii^ Ibrigth as the trench td be made, Qf ; every tivo Vforkmen, one carries a gabidn and a pick-axe, and the other a gabion and a shovel. The workmen having extended themselves behittct the vvhite lines, place thdr gabions in front of them, as aforigsaid ; after wrhich, the men Who have the shovels lie down at a small distance in the rear of the gabions, whilst each of those supplied with pick-axes breaks the ground behitid his own gabion and that of his companion who has the shovel ; observing tb leave the space for the berm and th^ slope which supports it, and to cut the ground perpendicularly. After he has broken a certain quantity of ground, he lies down in his tarui and the man with the shovel rises in order to throw into the gabioRs the earth which the other man has loosened. The sap is carried on in thisl manner, thjkt is, the men with the pick-axes and those with the shovels alternately working and lying down, until the treneh being sufficiently widie to admit of the whole party^ they enter it and continue the work. The trench being completed to its proper dimensions, the steps and slopes, &c. are formed*. This method of executing the Flying-sap was od- ginally suggested by Bousmard in his Essai gSne~. ralde Fortification, 5fc. 49. — It is customary to revet interiorly with gabi- * If in any particular part of the Flying-sap tlie fire of the garrison should be found yery destructive to the worknien, it would be better to remove them, as that part may subsequently be connected with the others, by mean's of the single-sap (53)v This however should not be done without powerful reasons. 6nS Hoi only Iht p!!fa.pkt of thig Stid p^Mll^l^ biit hh6 th0»ei6^ ihblmieg&t'iVt&nChes beyotidit} and the r6quisit@ affang^metits^ iti order that the guards of thetrehches may conreniently fire and pass Over pa- Eapetg thu« irevetedi whatever their height may be> are different from those which unreveted pa^ rapets admit of, for the same purposes. — For^ according to remarks previously made, a parapet of the latter description which does not exceed 4 feet 6 inches in height, allows the original berm to ht used as a banquette ; and, as the pa- rapet entirely consists of loose earth, the ascent which the interior slope forms is sufficiently easy to enable the guards of the trenches to §ain the top of the parapet vVith a toletable degree of convenience ; whilst, if the height of the unreVeted parapet shotild be more than 4 feet 6 inches, a simple step cut in the interior slopfe, and occasionally supported by fascines, will allo\t the soldiers placed upon this step to fire over the parapet, on the top of which the interior slope also enables them to mount. But even supposing that a parapet reveted with gabions is not higher than 4 feet 6 inches, in which case the ori- ginal berm may serve as a banquette, yet it will be necessary to make steps behind the gabions, in se- veral places along the berm, so that the guards of the trenches may, by means of these steps, mount upon ibe gabions and frotn thence upon the parapet, Vlfithout breaking their ranks; and, if the parapet should be sensibly highet than 4 feet 6 inches, it will be requisite, the berm beihg too low to form the banquette, not only to construct steps for the pur- 70, ON THE ATTACK AND pose of enabling the guards of the trenches conve- niently to pass over the parapet, but also to raise the berm. It is proper too/ under both supposi- tions, that the steps forming the passages for the troops should be sO arranged as to allow a fire to be kept up over the parapet, from the places where they are made; as without it, the ground oppo- site these steps would only be defended by the ob- lique fire of the parapet on each side ; so that, inde- pendently, of other inconveniences, a sally would be able, and particularly in the night, to advance with greater security by marching in the direction of the steps. It is of course to be understood that th& soldiers, whilst firing, ought to be properly covered by the parapet. The two following methods of arranging the steps of a parapet reveted with gabions, as well as the banquette in the intervals between these steps, when it does not consist of the original berm, will be suggested. They are founded on the principles laid down in the preceding paragraph, and either one or the other method may be used, according to the height of the parapet ; observing that in the event of this height being not precisely the same as will be supposed for the sake of explanation, the dimensions recommended for the elevation of the banquette, and consequently of the steps, may be modified. Conformably to rule, the arrange-' ment of the banquette and steps must be such as will allow the soldiers conveniently to mount upon the. DEFENCE OF PLACES. 71 gabions ; whilst the parapet which covers them, when in the act of firing, will not be less than 4 feet in height, nor more than 4 feet 6 inches. First, supposing the height of the reveted parapet to be 5 feet 3 in., or even only 5 ft. like in pi. 2,Jig. 8, the original berm will in both suppositions be too much below the crest of the parapet, to be used as a banquette. Consequently, a banquette b about 9 inches high, and as wide as the berm, may be made upon it for the whole length of the para- pet; being supported, as well as the front of the trench, by the continued slope c, the base of which is equal to its perpendicular height, or rather more.* This banquette will not only allow the guards of the trenches to fire over the parapet, but will give stability to the gabions, by supporting them ; whilst in order to enable the soldiers conveniently to mount upon the tops of the gabions, a step consisting of one course of fascines may be made on the ban- quette, in each of the places where it is intend- ed to form passages for the troops. But, as by oc- cupying a great portion of the width of the ban- quette, these fascines would render it unfit fbruse, if they were fixed, they should be laid loose, so that whenever the soldiers have to fire over the para- pet, they may throw them down into the trench, and * Instead of the continued slope c two steps d may be made, as shewn by the figure ; but they will occupy a larger space ia the trench, than the continued slope. 72 OU THE ATTACK AND afterwards replace them in their former situation upon the banqHctte 6*. This may be done with great ease and expedition^ as trenqh-fasclnee are short and light. It is proper that one course of fas- cines fl should also he placed on the tops of the gar bions, so as to retain the earth of that part of the parapet which is above them, and enable the soldiers to pass over it with still greater facility, by placing their fpot upon the fascines. Secondly, if the height of the parapet should only be 4 feet 6 inches, so that the original berm may be used as a banquette, steps for the passage of the troops, over the parapet, will on- ly be required. In order to make them, the berm may be raised 6 in. in those places where the steps are to be formed ; and, by considering the berm thus raised as being the banquette b in the first eX' ample, the remainder of the arrangement may be jost the same as was explained in that examplef. Although the steps, such as made in the 2nd Ex^ ample, are 3 inches lower than those in the 1st, yet they will allow the guards of the trenches to mount * In order thaf: the ftseines laid on the banquette b may not move from their position, when the soldiers mount upon them, this banquette should be made rather higher in the rear than in the front, so as to have a small inclination towards the gabions, f It is scarcely necessary to observe that since the original berm, between each two sets of steps, does not require to be raised, the fropt of the tjeflch, along this part of the berm, may be formed with one step, like in p(, l',^g, 4. DEFENCE OF PLACES. 73 upon the gabions with sufficient corfvenience. to avoid breaking their ranks; whilst, in firing, they will be covered by a mass of parapet of 4 feet in height. 60. — The arrangements just suggested, for the purpose of enabling the guards of 4,he trenches to fire and pass pver a parapet reveted with gabioqs, scarcely admit cMf its height being smaller than 4 feet 6 inches; for, if it were, and the steps should be made sufficiently high to allow the soldiers to mount upon the gabions with convenience, the pa- rapet in front would not cover them properly when firing over it; and, if the steps should be made lower than abovesaid, so that the soldiers may have a proper cover, they could not n)ount upon the gabions without a sort of confusion. But a besie- ged place needs not to have any great command to require that the parapet of the 2nd parallel, and particularly those of the besieger's works still nearer to the place, should be 4 feet 6 inches high ; whilst the fire of the garrison is seldom so plunging in re- spect to the besieger's trenches, as to render it ne- cessary that any of the parapets which cover them should be made higher than 5 feet 3 inches, or 5 feet 6 inches at most* ; especially such parapets as are af- terwards heightened by crenels formed on their tops, * A parapet 5 feet 6 inches high would of course require (be banquette b (pi. 2, jfig. 8) to be raised 1 foot above the original berm. L T* ON THE ATTACK AND as will be hereafter explained. At all events, ad- mitting that this might happen, it would be much better if iastead of raising the parapet beyond 5- feet 6 inches, the trench should be deepened ; the additional quantity of earth thus procured being employed in thickening the top of the parapet. 51.— Another method of forming steps, so as to en« able troops to fire and pass over reveted parapet* of trenches, {pi. '\:,fig. 22 and 23), has hitherto been used, and consists in carrying up the steps c from, the bottom of the trench to the top of the parapet, in the manner shown hyfig2S. But independently of the grea;t labour which the construction of steps thus made requires, they occupy a considerable part of the breadth of the trench, so that it is neces- sary to widen it behind them. Besides, the great distance at which, the soldiers stand from the crest of the parapet, when firing over it, materially im- pairs the cover which the parapet ought to give them ; and this inconvenience is rendered still great- er by the nearness of the trenches where steps of this description are usually formed, to the fortress.. Indeed, if after making the trench, the gabions a should be removed, and the steps above the berm h cut in the interior slope of the parapet, the front of the trench being formed with a step d, accord- ing to the ordinary method, the labour would be rather diminished, whilst the inconvenience that the steps c have of occupying a large portion of the width of the trench, would also be avoided j but DEFEKCE OF PLACES. n 'Still, the soldiers when firing would not be better covered by the parapet*. 53. — The redoubts i (pi. 2, Jig. 6), at the extrem- ities of the 2nd parallel ought to be traced and commenced in the same night as the parallel itself, the workmen who excavate the ditch being covered by gabions which they place in their front, in the manner of the flying-sap; and, five or six light guns should be placed in each of these redoubts, so as to fire grape-shot upon any «aHy which might approach the flanks of the parallel. 33. — ■ The workmen who on the 6th day relieve in the morning those of the night, bring the fascines requisite for the parallel, and continue the work. 54. — Such batteries as the besieger may have oc- casion to erect under the protection of the 2nd pa- rallel, are to be commenced on the 7th night. They should generally be placed either in the parallel, or (what is still preferable) at a small distance beyond it; and, whilst the besieger is making them, he should also complete every unfinished part of the great communications m; as well as the redoubts i, so that they may be supplied with their artillery at the same time as the batteries. These last will probably be ready to fire on the 8th day. * By the melhod of forming steps represented in pi. 2,^g-. 8, the soldiers stand close to the gabions, when firing over the para- pet; so that being much nearer to its crest than if any of the methods mentioned in the aboVc paragraph should be used, they vi' course are more •effeotuallv covered. 70" ON THE Attack akd 65..*— -The bol-iittx n pushed out from the 2rtd pa- rallel should likewise be commenced on the 7tli nigbt^ generally by Hueans of the single-sap. This sap jadmits of .going «n night aiid day, and may, in very favourable «oil», with expert sappers, prtoceed at the rate of from 16 to 18 feet per hour ; but in order to accelerate the construction of thfe boy aux, advan- tage should be taken of every opportunity which may occur of using the flying-sap tvithoirt any great danger^ for instance^ when the enemy's fire is slackened at intervals, during the night. 56. — -A brigade of Sappers, forming 2 squads of 4 men eacia., is employed for the single^sap, and 1 non -'commissioned officer is attached to each squad. But as only 4 -sappers ca*ry on the sap at one time., thfe 2 squads alternately ^relieve each other, and the men of ihe squad not 'actfaally at •work pass to those of the other the materials ne- ■cessary for the sap, such as gabions, ifa^in^, and fiand'baigs, or occasionally sap fagots. Thie4;:sa(>- pers >at the head of the'sap are supplied each with 1 sap pick^a:xe, 1 sap 'shovel, and 1 3 foot rod. One sap roller and @«ap forksarealso requisite. 57. — Sand-bsrgs d (pi. 3, fig. 1 1) are made of canvas ; and, before using them, they are filled vvith sand or with earth freed from stone. Those employed in saps serve to fill the interstices between each two of the gabions at the head, their length being usually about 20 in. and their width 10 in. 58.— Sap faggots c fpl. 3, Jig. 11,) consist of fas- ipJEFENCB OF PtACES. 77 cines made of stout pickets, which are sometimes used iiD saps for the same purpose as sand bags ; but sand bags are much preferable. The length of a sajp fi^ot is about 3 feet, and its diameter from 9 inches at least to 1 foot, depending on the hard- ness of the wood of which the pickets are cut ; it is ■traversed. in the middle by a picket, pointed at one end, which serves to fix it in an upright position between the gabions. 69. — The sap roller is used for the purpose of covering in front the head of the sap ; and the sappers move it into any requisite direction, by means of the sap forks. It consists of a gabion 6 feet long, and com monJy 2 feet 8 in. diameter, but sometimes less, which is placed within another of the same length, and 4 feet in diameter. These two gabions are concentric, and the space between them is filled with stout pickets of hard wood. The sap .roller was substituted in the British service for Ithe stdffed gabion still used in other services, con- sisting of aigabion 6 feet long and 4 feet in diame- ter, which is filled usually with fascines. 60. — Vauban'e .method of executing the single sap is, with :S0me /modifioations, still employed in iforeign :serYices, where this sap is carried on as follows : — The 1st sapper being covered in front by a stufiFed gabion e (pi. 3, fig. 13 and 13), places a sap gabion g* close to it, in the exact direction of the sap, and throws into this gabion the earth from a trench 18 inches wide, and as many inches deep. 78 ON THE ATTACK AND which he digs ; observing to leave the requisite space for the berm i, between this trench and the gabion. He then enters the trench upon his knees, and moves the stuffed gabion further on, in order to make room for a 2nd sap gabion k, which he places close to the 1st; after which, he fiils with two sand bags laid over each other, or with a' sap fagot I, the interstice between these gabions*, and prolongs his trench, throwing the earth into the 2nd gabion, so as to place a 3rd and subse- quently a 4th gabion, &c. in the manner above ex- plained respecting the 1st and 2nd. The 2nd sapper follows the 1st at the distance of about 5 feet, and augments by 6 inches both the width and depth of the trench that the other has made. The gabions being completely tilled, and partly backed with earth, he lays two courses of fas- cines m on their tops. The 3rd sapper sets to work 5 feet distant from the 2nd, and increases by 6 inches the width and depth of the trench of the latter. His duty likewise is to place one course of fascines o over the tvro courses m previously laid on the tops of the gabions. Last comes the 4th sapper, who commences his work at the distance of 5 feet from the 3rd, and makes the trench 3 feet wide and deep (Jig. 16), by * As soon as the parapet is sufficiently thick to be musket proof, the sand bags or sap fagots which fill the interstices between the gabions may be removed, so as to use tbem in a more advanced part of the sap. DEFENCE OF PLACES. "79 adding 6 inches to the width and depth of the exca- vation made by the 3rd sapper. The sap is contin- ued in the same manner for its required length ; and, as the sappers advance, that part of the trench which they do not occupy is brought to its proper dimensions by a party of workmen usually consist- ing of one man for each two gabions. It is to be observed that the same squad of sap- pers is only employed for 2 hours, during which time each sapper is to be by turn at the head of the sap, and afterwards at the tail. After 2 hours, the squad is relieved by another. 61. — According to the method of carrying on the single-sap which is used in the British service, {pt. ^ifiS- ^^)j the trench made by the 1st sapper has the same dimensions as in the foreign method just explained; but the 2nd sapper augments the width of this Irench by 20 inches, without increasing its depth. The 3rd sapper cuts 18 inches deeper that portion of the trench which the 2nd sapper has dug, thus making it S feet deep ;- whilst the 4th sapper adds 10 inches to the breadth of the trench, or more if he can, and gives a depth of 3 feet to his own ex- cavEltion. The gabions only have one course of fas- cines laid on their tops, or occasionally two courses. 62. — Whatever may be the process employed for executing the siagle-sap, the 1st sapper should - throw the earth from his trench carefully into the gabions, and never work behind the empty gabion ; whilst after finishing to fill the gabions, the 2nd 80 ON THE ATTACK AND sapper ought to throw the remainder of his earth as close to the outside of them as he can. Lastly, the sappers should, in the progress of the sap, endea- vour to preserve their distance of 5 feet from one another. 63.— The nearness of the covert-way to the bo- yaux N in front of the 2nd parallel (pi. % fig. 6), indispensably requires that, in constructing them, the troops who protect the workmen should be post- ed under cover ; on which account they occupy this parallel and such of the boyaux in question a* are ready to receive them. But beyond a certain distance from the 2nd parallel, the troops stationed there might be too far off in the rear of the work- men, to come up in time for securing them and their work, in the event of the garrison making a sally. In consequence, at about half the distance from the 2nd parallel tp the most advanced saliants of the covert-way, the besieger constructs tbe demi-paral- lelsQ, consisting of trenches which intersect the pro- }pngations of the capitals of the bastions and rave- lin, and extend suiBciently to the right and left of these prolongations to meet those of the branches of the covert-way, as well as the prolongations of the flanks of the bastions. Troops chiefly compo- sed of grenadiers are placed in the demi-parallels, ^ho, besides protecting against sallies the trenehesi in front of these works, may also answer the mus- que£ry fire of the place ; being covered by sand bags foritiing crenels on the top of the parapet, in the DEFENCE OF PLACES. 81 manner represented by the crenel d (pi. 3, ^g-. 1 1 ). The reverse of the demi-parallels likewise affords a convenient place for depositing^ the materials that the construction of the works in their front requires; and howitzer batteries s are established at their ex- tremities, in order to enfilade the branches of the covert-way and the flanks of the bastions. 64.' — 'The demi-parallels are generally commen- ced on the ninth night ; the single-sap being used to construct them, unless circumstances allow the flying-sap io be employed at intervals. In the mean while, the sappers continue to push on the bo- yaux opposite the ravelins collateral to the front of at- tack ; and, when arrived at the distance of about 100 yards from the saliants of the covert- way, they make upon the right and left of the last boyan on each side an amorce (45.) which, by being afterwards pro- longed inwardly, will form part of the 3rd parallel; the sappers direct the outward extremity t of this amorce in such a manner that it may be flanked by the redoubt at the end of the 3nd parallel. At day break, the besieger completes such parts of the trenches Carried on in the night as still remain in an unfinished state, and forwards the batteries s at the extremities of the demi-paralleki. During the ninth day, the besieger constructs the boyaux * which cross the prolongations of the cap- itals of the central ravelin and the two contiguous bastions, but does not advance nearer than about 80 yafds to the sallantof the covert-way in front of this M 83 ON THE ATTACK AND ravelin ; then^ towards dusk, he makes amorces ex- tended on both sides of the last boyau of each set, these amorces being-traced in the direction that the 3rd parallel is to have. The single-sap is used to make them, or occasionally the flying-sap, 65 — The requisite materials for proceeding to thfe actual construction of the Svd parallel on the next night, should also be conveyed to the demi-paral- lels and the contiguous boyaux,in the course of the 9th day . In the evening, the guards of the trench- es who'occupy the abovesaid works are to be strong- ly re-enforced, and particularly by grenadiers ; as Tvell as those stationed at the extremities of the 2nd parallel, and in the amorces before mentioned (64) which are to form the ends of the 3rd parallel j these amorces having been made longer and wider during the day. Cavalry should also be posted behind the extremities of the 2nd parallel^ so as to attack in flank and rear any sally which might attempt to penetrate into the intervals between this and the 3rd parallels. 66. — The 2nd and 3rd parallels commonly have the same profile ; however, as the latter being much nearer to the works of the place than the former, is consequently more exposed to a plunging fire from them, it may occasionally be made rather wi- der and deeper, and its parapet higher. In order to construct it, the amorces previously made (64) opposite the central ravelin and the two contiguous bastions are prolonged to the right and left by means of the single-sap, those which face the rav- DEFENCE OF PLACES. 83 elins collateral to the front of attack having their inward extremities produced towards the centre of the parallel. Eight brigades of sappers are there- fore requisite for all these saps, which they carry on one towards another untiHhey meet; and, as they will probably finish them in the evening of the 10th day, the eleventh night and the following day may be employed in completing the parallel*. Crenels should be made with sand bags (63) on the top of the parapet. 67. — The 3rd parallel being completed, and sup- plied with a proper number of troops, the besieger has much less to fear from the sallies : for, if they should venture (o advance from the covert-way op- posite the parallel, they would be exposed to a very destructive fire from this last; whilst, if in order to turn the parallel, they should advance upon its flanks, the guards of the trenches who are posted there would instantly be joined by the troops left for this purpose at the outward ends of the extreme demi- parallels, and at the ends of the 2nd parallel. New batteries a fpl. 4, Jig. 21), the disposition and im- portant objects of which will be hereafter explained, may also be safely constructed under the protection of the 3rd parallel. In short, this parallel facili- tates the means to the besieger of storming the * Supposing that the fire of the place being not very brisk, the besieger has been able to employ the flying-sap occasionally in the course of the 10th night, the 3rd parallel may of course be completed sooner than abovesaid. 84 ON THE ATTACR AND covert*way, whenever partJcular circumstances lead him to etorm it. The reason is that the 3fd paral- lel affords a convenient place where the stormin* paipty, &c. may be apsembled, and from whence the different corps which compose it may repair by the shortest road to those parts of the covert-way that they are respectively appointed to attack. But par- ticularly in this case, such a portion of the parallel as ■ is comprised between the prolongations of the capitals of each two ravelins should be made convex towards the opposite bastion and re-entering place of arms, so as to be nearer to them ; care being ta- ken however that its direction does not render any part of it liable to enfilade. Steps 36 feet long, or thereabouts^ should likewise be constructed in the parallel, upon the right and left of the prolongation of every capital, in order to enable the storming troops conveniently to pass over the parapet, and to form at each passage a front sufficiently extended. It is proper too, that the parallel should be placed rather nearer than usual to the saliants of the to- vert^way in front of the ravelins j whilst the batteries A are to be erected as near the re-entering, parts of the fortifications as can be safely done, so that their fire against theni may prove more effectual. DEFENCE OF PLACES. 85 CHAPTER IV. TUlftD PERIOD, Dispositidn and important purposes of the hatteries erected tinder the protection of the 3rd parallel •• Storming of the covert-way t Circular parts : Dduble-sap : Cavaliers of trenches : 4cth paral- lel: Crowning of the covert-way : Construction of the besieger's traverses: Counterbatteries and breaching batteries: Process for effecting breaches by means of artillery : Descents into the ditches : Passing of the ditches : Assault, 4 c. to the different works requiring this opera- tion : Attack of the retrenchments of the bas- Jions. 68. — The batteries a fpl, 4, ^g-. 21) which the besieger constructs under the protection of the 3rd pjaraliel, might be erected within it ; but it is prefer- able to place them at a small distance in its front, as, in this situation^ they will not impede the move- ment^ of the troops, or be in the way of the ap- proaches ; whilst a direction more suitable for their intended purposes may also be given to them. The disposition of these batteries should allow them to enfilade the branches of the coyert-way, as well as the faces and flanks of the works behind it; and howitzers are to be placed along the faces d, the circular portions e between these faces being occu- pied by mortars and stone-mortars: The fire of the stone- mortars is to be principally directed upon the re-entering place of arms and the branches of the covert-way J and if it should happen that the distance 86 ON THE ATTACK AND exceeds the common range of these pieces of ord- nance, which is about 140 yards, mortars loaded with grenades must be substituted for them. 6^. — In consequence of- the arrangement of the batteries a, such a number of shot may be poured into every work occupied by the besieged troops, as will annoy them at all points, render of scarcely any avail to them the uncovered batteries which they may still have, and even greatly impair the effect of their musquetry fire. The batteries a are also free from the inconvenience which those behind them have of giving uneasiness to the troops in the Srd paral- lel, by firing over their heads ; whilst they immedi- ately protect the approaches in front of this parallel. 70. — The batteriesjust spoken of will probably be ready in the beginning of the 13th day ; and, if it should be intended to storm the covert- way, a brisk fire must be kept up from them for the whole day be- fore that operation is commenced, so as to destroy the paIisades,tambours, and other means of defence which the besieged troops may have in the covert-way, and, if possible, oblige them to quit it. The guards of the trenches posted at the extremities of the Srd parallel should also be strongly re-enforced, in order that they may effectually protect them against any sally which the garrison might send during the at- tack, for the purpose of disturbing the besieger and thus impeding his operation ; and, after collecting on the reverse of the parallel, as well as in the boyaux behind it, the tools and materials requisite to crown the covert-way (71.) the troops for the attack and DEFENCE OF PLACES. 87 the workmen should be assembled, the latter being; supplied each with one gabion. The attack is to be carried on as follows : In the evening, but with still sufficient light to allow the operation to be executed in good order, de- tachments of grenadiers should advance rapidly from the Srd parallel to the crest of the glacis in front of the saliant places of arms, so as to throw a great number of grenades upon such troops of the garri- son as may occupy them. Picked troops, proceeding also from the 3rd parallel, should instantly follow these detachments, and direct a brisk fire of mus- quetry upon the enemy in the branches of the covert-way ; whilst sappers, with engineers at their head, are to cut down the palisades and barriers of this work, so that the storming party may enter it, charge with the bayonet those besieged troops who may attempt to defend il, and oblige them to re- tire into the re-entering places of arms. The storm- ing troops should likewise fire upon any soldiers of the garrison whom they may see along the parapets of the opposite works ; observing to keep watch over the pas de souris or other communications from the ditches to the covert-way, as an enterprising garri- son might venture to return to this work, by means of the communications in question, in order to re- gain it*. 71. — The attack having succeeded, workmen are to set off instantly from the 3rd parallel, .for the * It must be acknowledged that the present disposition of the pas de souris and covert-way scarcely leaves any hope to the besie- ged troops of being able to regain this work, after they have lost it. However, bold troops might make such an attempt. 88 OS THE ATTACK AND purposeof constructing in front of the saliants of the covert-way the lodgements /"aboat 6 yards distant from these saliants, and which embrace them. The flying-sap is used to form the lodgments in question, and the workmen should fill the gabions speedily, in proportion as they are placed. In the mean ■while, other workmen are to execute the communi- cations from the 3rd parallel to the lodgments. As soon as circumstances allow it, part of the storming troops should avail themselves of every cover which they can find behind the traverses of the covert-way, the profiles of the sally-ports and the gabions of the lodgments above mentioned, so that being less exposed, they may more effectually sup- port such other troops as are uncovered. These lodgments will in two or three hours be capable of containing a sufficient number of fresh troops to protect them, who should be sent from the 3rd pa- lallel ; after whichj the troops employed for the at- tack are to retire gradually into this parallel. It is also to be remarked that as the lodgments/ may be enfiladed by the works of the place, and are even exposed to a reverse fire from them, they should be secured by traverses g", erected from dis- tance to distance,* and have their extremities co- vered by strong epaulraents. The besieger is to complete these lodgments during the night, and to forward such other works as are commenced, em- ploying the single-sap whenever he cannot make use * The particirfars relating to the consttuction of , the traverses which the besie^r tnay have occasion to make, will be explained further on. OErENCE OF PLACES. 89 of the ilyingrsap ; but all these operations would be attended with great danger to him, if he were not protected by a brisk fire from the batteries ; on which account, the lodgments should not be at first extended much further along the branches of the covert-way, than is necessary to make them meet the prolongations of the faces of the ravelin and bas- tions; in this manner, their parapet will not impede the fire of the batteries ; and, in order to render this fire more efi'ectual, its proper direction should be ascertained and marked in day time, before the attack of the covert-way is commenced. 72. — The taking of the covert-way, by means of storming it, undoubtedly abridges the duration of the siege; and indeed, various defects in the present methods of fortifying towns, besides the powerful effect of the besieger's batteries in the actual im- proved state of the artillery, afford him a favour- able chance of succeeding in the operation in ques- tion ; but the loss of men on his side will be very great, if independently of the besieged troops being sufficiently numerous, they use proper precautions and defend themselves as they ought to do. There- fore, the storming of the covert- way is not advisable unless the small number and want of determination of these troops, and the feeble state of their means of defence in all other respects, remove every ap- prehension of the considerable danger to which the storming party would otherwise be exposed ; or else. 90 ON THE ATTACl^ AND when the near approach of a season unfavourable for the siege;, or of any army coming up to raise it, in- dispensably requires that the besieger should hasten the operations, let the consequences arising from k in other r-espects be what they may. Under dif- ferent circumstances, it is far preferable that he should advance gradually to the crest of the glacis/ and the process usually employed for this purpose is such as follows : 73. — At the distance of 25 or 30 yards to the rigiitand left of the intersection of the 3rd parallel with the prolongation of the capital of each saliant, two brigades of sappers push out from this parallel the saps tand k, which they carcy on one towards the other until they meet; giving them a curved di- rection, so as to secure them from enfilade. These saps form what is called a circular part, £\nd are subsequently widened so as to have the same breadth as the 3rd parallel ; steps are made within them, in order to pass over their parapet, and crenels are formed with sand-bags on the top of the latter. 74. — The circular parts are generally commen- ced on the 14th night, and completed in the course of the following day. With respect to their use, the troops posted in them see in front the opposite branches of the covert-way, and the fire of each two circular parts crosses upon the ground be- tween them. Besides, the circular parts afford DEFENCE OF PLACES. 91 convenient places for the materials which the ap- proaches beyond them require, as well as room for grenadiers who are within them suitably placed to protect against sallies the sappers &c. engaged in carrying on those approaches. 75. — In the evening of the 15th day (grenar diers being stationed in the circular parts^ and the batteries keeping up an uninterrupted fire upon the covert-way and other works of the garri- son) the sappers advance up the glacis in a direct line, from the middle of each circular part. They make for this purpose a double-sap I, consisting of two parallel single-saps a and 6 (PI. 3. Fig. 17 and 18.) which have the usual dimensions of saps of this kind, but which are separated from each other by a mound of earth c called the tongue. The gabions of one sap are placed on the - right hand, and those of the other on the left; so that after the mound of earth between the two saps is removed,* these form a trench at least 13 feet wide at top (not including the two berms) with a parapet on each side. In order to secure this trench the sappers construct traverses within it, similar to those m or n (PI. 4. Fig. 31 ;f ) by * The tongue c is removed by a working party purposely sent, who also make the trench deeper if this should be deem- ed requisite. f The tiaverses m being constructed with greater conveni- ence than the traverses n, should be preferred to them. They are called lock-traverses. 93 ON THE ATTACK. AND means of carrying on the saps round a mass of earth from 12 to 15 feet wide, and of sucU a length as allows it to cover tke trench ; they augment the height of the traverses by placing gabions on their tops, which they filj with earth. r It should be observed that whenever a double- sap is carrying on, the 1st sapper of each of the two singlp-saps must carefully keep pace with the 1st sapper of the other. 76. — At a smaller distance from thet:restof the glacis than about 30 yards, the head of the dou- ble-sap pushed out from each circular part would not be sufficiently protected by the latter against sallies, besides being exposed to a quantity of hand-grenades which the besieged troops Avould throw upon the sappers from the opposite saliant place of arms.* It is therefore requisite that after the double-sap has been carried on to the afore- said distance, the single-saps which compose it should change their directions, one to the right and the other to the left, so as to form a trench o embracing the saliant of the covert-way, and which is to be extended to the prolongations of the two branches. This trench is intended to con- tain troops, and close to its extremities cavaliers of trenches p are usually constructed, which, by * Experience has shown that any soldier can throw a hand- grenade to the distance of about 2G yards. DEFENCE OF PLACES. 93 raising the soldiers posted there, enable them to plunge their fire into the covert-way, in order to clear the saliant place of arms, as well as the con- tiguous parts of the branches, and prevent the garrison from returning to them. The cavaliers are interiorly secured froto the fire of the colla- teral works by means of returns q the length and height of which are such as to allow them to an- swer the abovesaid purpose.* To construct a cavalier of trenches (PI. 8. Fig. 19.) supposing its requisite height over the glacis to be twice that of a gabion, besides the fascines, one row of gabions a is placed at the bottom of the trench, the tops of which are on a level with the berm, and consequently augment its breadth.f Upon the berm thus widened another row of ga- * It was lately found that batteries, consisting of stone-mor- tars and mortars loaded with grenades, effectually answer the purpose of cavaliers of trenches, whilst much time and labour is saved by substituting the former for the latter. This dispo- sition consequently affords material advantages, and particu- larly, when besides the saliant opposite the trench o being very wide, the collateral works also have a great projection beyond it; for, in this case, the construction of cavaliers of trenches is not only generally attended with considerable difficulties, but is sometimes impossible. t If it should happen that the depth of the trench exceeds the height of the gabions placed at the bottom of it, fascines should be laid on their tops, so as to make them level with the berm. 94 ON THE ATTACK AND hions 6 is formed, close to the row c which sup- ports the parapet of the trench, so that each of the gabions b rests upon the berm and one of thfr gdbions a in the lower row. Therefore, by pla- cing a single row of gabions d over those 6 and c, the cavalier will have its proper height. But if it should be wished to make it one gabion higher, each course of gabions, including that in the trench, must be augmented by one row, and a single row be placed upon the whole. The soldiers appointed to fire over the cavalier mount upon the banquette c by means of steps f leading to it from the bottom of the trench ; and, in order that they may be more eflfectually cover- ed, fascines are laid on the tops of the gabions in the upper row, which support looprhoies made with sand-bags or otherwise. The gabions of every row are of course to be filled with earth. Whenever it is thought advisable that a fire should be kept up over the returns q (PI. 4. Fig^. 21.) which secure the interior of cavaliers, these returns should be made with steps and banquettes, similarly to the cavaliers; but under different cir-, eurnstances, the steps and banquettes are useless. The above method of (Constructing a cavalier of trenches supposes that the single-sap is used to commence it; but if the flying-sap should be em- ployed, gabion^ are at first to be placed in two rows a and 6 upon the berm (PI. 3. Fig. gO-) DEFENCE OF PLACES. 95 atid then successively filled with earth, beginning ■with the gabions in the row a ; after which, the workmen are to throw in front of the gabions the €arth supplied by the widening and deepening; of the trench, until this earth being raised io a suitable height, they lay another row of gabions c upon the two former, and also fill these gabions. The remainder of the operation is to be perform- ed in the same manner as for a cavalier began by the single-sap. If it were found necessary to increase the height of a cavalier commenced by the flying sap, this may evidently be done by subsequently placing a row of gabions at the bottom of the trench, and augmenting each course of gabions by one row, &c. Whatever may be the process used for con- structing cavaliers of trenches, they require a length at least equal to the breadth of the covert- way J whilst their direction should be perpendi- cular to the branches of this work, provided how- ever these branches do not form an obtuse angle, and the cavaliers are not exposed to any very dangerous reverse fire from the collateral works; for, under difierent circumstances, the cavaliera must be parallel to the branches, or nearly so. 77. — Admitting that no impediments may pre- vent the sappers from tracing the trench o (PI. 4. Fig.>21.) in the 1 6th night, as well as the 96 ON THE AtTACK ASD the cavaliers p and the returns q, all tbcse works ■mil be completed at the end of the 18th night,* together with the 4th parallel B C which connects the cavalfers, if the besieger has deemed it expe- dient to construct this parallel; the single-sap is used io trace it, and it is connected with the 3rd parallel by means of the commanications D which follow the prolongations of the capitals of the re- entering places of arms, 78. — Notwithstanding the advantages which under peculiar circumstances the 4th parallel may affi)rd' to the besieger, yet it should not be indis- criminately used ; for, as the parapet of this pa- rallel impedes th« fire of the batteries of the 3rd, they must be transferred from the latter to the former, which operation jiot only occasions the loss of about two days, but enables the besieged troops to avail themselves of the kind of respite which they thus have, in order to make such dis- positions as will allow their own fire to be revived. In general, no 4th parallel is constructed unless the ground between the ravelins being much re- entering, and the besieged troops making a vigo- rous defence, it becomes necessary to press closer upon them ; or else, when the besieger intends * The trench o will be compleled before the cavaliers and returns, namely, on the 16th day ; and grenadiers should be posted in this trench as soon as it is readj- to receive them. DEFENCE OF PLACES. 97 to storm the covert-way ; in this case, as the 4th parallel is nearer to the covert-way than the Srd, the storming party can gain the crest of the glacis in a shorter time, and is also protected from a small distance by the fire of the cavaliers, as well , as by that of the batteries of the 4th parallel, &c. Whenever this parallel is made for the latterpur- pOse, steps should be constructed within it, simi- lar to those described (67.) in respect. to the Srd parallel. The necessary dispositions previously to the attack, and during its progress, are also to be the same for both parallels. 79. — A fire being kept up in the course of the 18th day, either from the cavaliers of trenches or the stone-mortar batteries substituted for them (see note* page 93.) the besieger will be able to ad- vance in the 19th night to the distance of 6 yards from the saliants of the covert-way opposite the ravelin and bastions of the front of attack. He might for this purpose construct double-saps in the same direction as those between the circular parts i k and the trenches o ; but it is preferable that he should make two double-saps r for every saliant, one on each side of the prolongation of the capita], beginning the excavation close to the ceivaliers, qind carrying it on in a straight direc- tion towards the saliant, until the heads, of the saps are at the aforesaid distance of 6 yards from it. The besieger is then to proceed to the crowning 99 ON THE ATTACK AND of the covert-way ; and, in order to begin it, two of the four brigades of sappers employed for con- stracting the double-saps r should turn to their right, and theothers to their left, so as to form four BfRgle-aaps, two of which, namely those inward, are to meet opposite the saliant, whilst the others follow a direction parallel to the branches. 8Q<-^The I9th day and 20th night may enable the besieger to crown a large portion of the covert- way in front of the ravelin ; but the proximity of the re-entering places of arms, besides the action of the ravelins, will render it scarcely possible f(Mr him to extend during that time his lodgments op- posite the bastions, further than the prolonga- tion of the magistral line of the faces of these works. In constructing the traverses g which are to secure these lodgments and those in front of the ravelin, the sappers should cautiously avoid placing any of them in those parts of the lodg- ments where they would interfere with the situa- tions for the guns of the eounter^batteries and breaching batteries that the besieger is subse- quently to erect, as will hereafter be more par- ticularly explained. The epaulments h require such a length, and sueh a height, as will allow them to secure the lodgments from the fire of the collateral works. 81' — The process to be used for constructing the traverses g- is much the same as that described DEFENCE OF PLACES. 99 (75) in respect to the traverses m and n. There- fore the sappers^ after carrjingon the trench as far as the place where any of those traverses is to be made;^ successively change direction^ so as to turn at right angles round' a piece of ground of the same length and breadth that the traverse must have ; and, if the trench should happen to be exposed to a reverse fire, a kind of epaulment s is made in the rear of the traverse, its length and direction being such as to allow it to cover the passage behind the latter, besides answering the purpose of a parados. The height of all the traverses is of course increased by means of the gabions which the sappers place on their tops,&c. ~ 83. — The usual process, for approaching the re-entering places of arms and crowning them, will now be explained : — Supposipg that the besieger has made the 4th parallel b c, he ad» vances from it, towards each re-entering place of arms, by means of a double-sap following the prolongation of the capital of this work, and which he secures by traverses ; whilst after this sap has been carried on to the distance of 6 yards from the saliant, the sappers of one of the two brigades turn to their right, and those of the other to their left, so as to continue their work in a direction parallel to the faces, and thus crown them. But when the besieger makes no 4th pa- rallel, he constructs opposite each re-enteriDg 100 ON THB ATTACK AND place of arms a concave trench e f, connected on both sides with the crowning of the covert- way, and places in the middle part of this trench a strong battery t, consisting of stone mortars and mortars to be loaded with grenades, the fire of which is directed against the re-entering place of arms, its redoubt and the bastion behind ; as yvell as against the ravelin and the redoubt inside of it. Prom this trench the besieger pushes on two double saps u, which he directs straight to- wards the saliantof the re-entering place of arms; and, when arrived at the distance of 6 yards from this saliant, the sappers crown the faces in the manner explained (79) respecting the crowning of the covert-way in front of the bastions and ravelin. It is proper that as soon as the besieger is lodged in front of both the saliant and the re-entering pla- ces of arms^he should establish batteries v composed of one or two howitzers, in order to destroy the tambours* which the besieged troops usually con- struct for ,the purpose of covering the pas de sou- ris at the gorge. 83. — The crowning of the covert-way will generally be completed at the end of the 22nd night, together with the concave trenches e f, in- cluding the batteries < ; and, as the besieger was engaged since the Slst day in making the ne- cessary preparations for erecting the other re- • The description of tambours will be Tiereafter given (ISO). DEFENCE OP PLACES. 101 quisite batteries, he will be able to commence on the 22nd day the counter-batteries w oppo- site the ravelin^ as well as those x and z in front of the bastions; besides the batteries j/ situated in the prolongations of the counter-batteries w, and which are intended to breach the ravelin. The counter-batteries z serve to keep down the fire of the opposite flanks of the bastions, as it would impede the besieger in effecting the pas- sage of the principal ditch, and augment his dan- ger in storming the bastions. They also see the breaches of these works, as well as the tenaille^ the caponier or the bridge leading from it to the gorge of the ravelin, and even part of the cur- tain. In respect to the counter-batteries x, their object is to check the fire that the artillery of the flanks of the bastions collateral to the front of at- tack can keep up in an oblique direction against the counter-batteries z. Lastly, the counter-batr teries w) are intended, first, to silence the garri^- son's artillery placed along thpse parts of the faces of the bastions from whence it enfilades the ditch of the ravelin and the covert-way ; but after ac- complishing this purpose, they should breach the faces through the opening of the ditch in ques- tion. 84. — Unless there should be any particular. rea- sons to the contrary, the counter-batteries and !JreiE^ching batteries just spoken of are usually 102 ON THE ATTACK AKD plaee.d as the Fig. shows ; that is, they are esta- blished in the trench which forms the crowning of the covert-way, their epaulments consisting of ihe patapet of this trench, and their terrepleins IkieiBg secured by traverses from the fire of the place in flank and in reverse. The terrepleins of the batteries y, and occasionally those of the batteries w, are elevated a little above the bot- tom of the trench, go as to allow the gans to be pointed nearer to the foot of the opposite escarp, and therefore in a direction more suita- ble for making a proper breach. But different cireumstances may sometimes require that coun- ter-batteries and breaching batteries should be constructed upon the terreplein of the covert- way, instead of in the crowning; for instance, tbey are to be placed in the former situation whenever the latter would render them liable to a reverse fire, and the besieger cannot construct traverses of such length and height as would be necessary to secure the batteries effectually; or else, when on account of the ditch in front of the v.'ork to be breached being narrow and very deep, it would be requisite, if the breaching battery ■were placed in the crowning of the covert-way, to raise its terreplein immoderately, in order that the artillery men may see the escarp sufficiently low down, to make a practicable breach; foi^ in this case, the guns should of coarse be propor- DEFENCE OP PLACES. 103 tionally depressed, and therefore, their depres- sion would exceed seven degrees; whilst guna loaded with full charges do not admit of being de- pressed more than this number of degrees.* 85. — It was said (S3.) that the besieger begins the counter-batteries id, x, z, and the breaching batteries y on the 22nd day. He also traces on the same day the openings a' of the descents into the ditch of the ravelin, and commences the ex- cavation in the course of the following night; * The following method of breaching a work, by meant of artillery, is generally used when the escarp has a revetment of laasonry : — At first, the guns are loaded with full charges, and all pointed against the same part of the revetment, 6 ftet or thereabouts above tlie bottom of the ditch when it is dry, and on a level with the water if the ditch contains any ; and, as soon as tte earth begins to come out through the opening thus made, the artillery-men gradually lengthen the aperture, by means of concentrating the fire of the guns upon its lateral extremi- ties, until a kind of horizontal groove is formed equal in length to the requisite breadth of the breach ; they then effect several vertical grooves in the same manner, extending from the hori- zontal one to the top of the revetment ; after which, by direct- ing the guns successively agaiust each separate portion of the revetment between two Tertical grooves, and firing all of tbem at once, with smaller charges, the strong commotion produced by the shot in that part renders it loose, and ultimately occa- sions its falling down into the ditch. But if the escarp should onljr consist of a slope of earth, loaded shells are to be thrown into it in a horizontal direction, so thstt by exploding they n^ay spread the earth, and thus fa- cilitate the ascent. 104 OK THE ATTACK AnO besides forwarding the counter-batteries and breachino--batteries, the former of which being completed at the end of the 24th night, and sup- plied with tlieir artillery, may therefore com- mence firing on the 24th day, in the morning; but the breaching-batteries will not be ready for ac- tion before the evening of that da}', or perhaps, not before the next morning.* Whilst the counter-batteries and breaching batteries are firing, the besieger continlies the de- scents into the ditch of the ravelin, and collects near them the necessary materials to execute the works h' which form the passages across this ditch. 86. — By the descent into a ditch is meant a kind of gallery K (PI. 5. Fig. 25.) leading from the glacis to the ditch,f opposite that part of the breach where it is intended that the stormmg party should mount; and, in order that the com- munication through this gallery may be conve- nient, the slope which it forms is not to be greater than about 2 inches per foot; the descent should consequently be begun at such a distance from * It is supposed in the above calculation that the counter- batteries and breaching batteries are placed in the crowning of the covert-way ; but if the besieger should be obliged to establish the latter on the terrepleinof this work, they will only be ready in the course of the 26th night. + The de.sc^nts should meet the bottom of the ditch, or the level of the water, according as the ditch is dry, or wet. DEFENCE OF PLACES. 105 the counterscarp, depending upon the difference of level between the extremities of the former, as will not require the above dimension to be ex- ceeded; or, if the besieger should wish to com- mence the descent nearer to the ditch, and yet, without making it too steep, he may at first carry it on straight towards the counterscarp, as far as the tails of the counterforts, or thereabouts, and then continue it in a direction parallel to the ditch, until he gains the spot just opposite the place where he intends to cross it; after which, this direction is to be changed, so as to bring the de- scent exactly to that place. The descent a! (PI,, 4. Fig. 31.) is supposed to be made according to the former process, , and the descent c' conform- ably to the- latter. With respect to the method ' recommended by some engineers of constructing steps from distance to distance, so that those parts of the descent may be less steep which oc- cupy the intervals between the steps, this method renders the communication through the descent very inconvenient, and should therefore be rc' jected. When it is not requisite that the descent into a ditch should be sunk to any great depth, it may be made in the form of a trench, from 5 to 6 fcfet being allowed for its breadth ;* and, in order to * The coniQiunicatioD tlirough a descent less wide than 5 feet, would scarcely be convenient. The height of the descent retjuires 5 feet 6 inches at least. 106 ON THE ATTACK AND secure it from the stones, grenades, and combus- tibles, which the garrison might otherwise throw into it, it should be covered at top with hurdles and fascines supported by a kind of frames that the French call blindes* and upon which raw hides, or sand-bags and turf, are to be laid, so as to prevent the garrison from setting them on fire. But as a deep descent entirely made in this man-^ ner would require an immoderately large quantity * Blindes serve for different purposes, and are on that ac-. count variously constructed; but tliey all are made of timber; those represented by Fig. 29. PI. 6. are used for the, descents into ditches, and consist of two uprights a, b, generally 7 feet 6 inches long, which are pointed at both ends and connected together by tvfo cross pieces c and d. The uprights and cross pieces are each 6 inches square, and the points of the former project about 1 foot beyond the latter; the width of the blindes, between the uprights, is 3 feet 6 inches. When using these blindes, they are vertically placed in one row along each side of the descent, with an interval of 2 feet € inches betyveen them, and the blindes on the right side exactly facing those on the left. Those parts of the descent ^l;dch correspond to two opposite intervals, are then covered at top with other blindes laid flat, of the same diiiiensions aa the former ; excepting however that the distance between the cross pieces is greater, so that the points of the contiguous, vertical blindes may pass through the angles which thesfe cross pieces form inwardly with the uprights. Ail the blindes are kept steady in their position by means- of pegs and brackets; and, gradually as the hurdles and fascines are placed on tha top blindes, the raw hides or the sand-bags and turf are laid pver them. (See PI, 5. Fig. 25. and PI. 6. fig. 30 agd 31.) bEPEiSrCE Of PLACES. 107 bf earth to be removed, it is far preferable, after using the method in question for such a length a b of the descent (PI. 6. Fig. 35.) as may conve- niently admit of it, to construct the remainder 6 c under ground, like a gallery of mines. For this purpose, frames resembling a common window frame, and the dimensions of which are regulated according to the requisite height and breadth of the descent, are vertically fixed across it, the dis- tance between them being generally 3 feet; and, in proportion as these frames are placed, planks are laid on their tops, as well as between each of their sides and the contiguous side of the de- scent, so that the earth above the frames, and along the sides of the descent, may be retained; It was suggested that an expeditious means Of gaining the ditch might be occasionally employ- ed, without constructing any descent. This means consists in placing amine strongly charged under the banquette of the covert-way, and dis- posing this mine in such a manner as to throw down the counterscarp and join the rubbish to that of the breach ; so that after the explosion, the besieger may descend into the funnel* by sapping, and then gain the ditch. 87. — The descent into a ditch being carried on * The funnel or crater of a mine is the excavation pro- duced by the explosion. 108 ON THE ATTACK AND as far as the back of the revetment of the counter- scarp^ an opening is made through this revetment* for the purpose of entering the ditch, so as to construct the necessary works for passing it. It is proper that a kind of recess of suitable dimen- sions should be made on the right and left of this opening, close to the back of the revetment, as, besides affording a convenient spot for depositing the materials that the construction of the be- sieger's works across the ditch requires, part of the troops appointed for the assault may be as- sembled there. 88. — The nature of the works which the be- sieger constructs for passing a ditch, depends upon whether it is dry, or wet. Supposing the ditch to be dry, a sapper avails himself of the opening made in the counterscarp, in order to throw into the ditch, on the side nearest to those parts of the fortifications which flank it, fascines and sand-bags, &c. which are passed to him from hand to hand. After having thus formed an epaulment capable of affording a safe cover, this sapper commences a single-sap behind it, which, as well the epaulment, is gradually carried on to * If it should be intended to construct a descent, but to use a mine, instead of tools, for the purpose of makin" an opening through the revetment of the counterscarp, the miners should of course establish this mine, and set fire to it, before the descent is carried on so far as to meet the revetment. DEFENCE OP PLACES. 109 the top of the breach. (See the passage d of the ditch PI. 5. Pig. 25.) It has hereto been sup- posed that the ground at the bottom of the ditch admits of being conveniently excavated; but when it does not, either on account of its being rocky, or because water is found at a smaller depth than that which the sap is to have, then the besieger only constructs the epaulment. 89. — Either one or two passages may be made to gain the same breach, according to circum- sljances. The latter disposition is particularly advisable when the besieger expects to be strongly opposed by the garrison during the assault ; for, two passages will allow a more numerous body of troops to mount together upon the breach, and therefore (o carry on the attack with greater ad- vantage.* * Notwithstandifig the reasons which have been urged in favour of assaulting breaches with small successive parties, namely, that no more men are exposed at one time than can enter the breach, whilst the parties, by gradually supporting each other, give as much strength to the attack as if it were carried on by a greater number of troops employed at the snme lime, yet the other method is undoubtedly preferable. For, large bodies of men, animating and encouraging one another, not only carry with them the confidence of success, but make ii greater impression upon an enemy's mind, and therefore derive a double advantage from their number. Besides, ac- cording to the nature and object of au attack with small par- ties advancing one after the other, each of them is to remain 110 ON THE ATTACft ANtJ 90.— It should also be observed that, although particular circumstances may occasionally allow the besieger to give the assault without securing himself in his advance to the breach by means of any works constructed across the ditch, yet this process is very seldom to be recommended, as it will probably fail, or at least be attended with a considerable loss of men to the besieger, if the besieged troops possess determination, and still have the means of keeping up any efiFectual fire from those parts of the fortifications which see the breach.* under cover until those before it have entered the work, or are beaten back ; consequently, the first party has to sustain alone the brunt of the action, and to carry the work; or, if this party is repelled, the second, and successively the other parties, must advance under the discouraging ideas produced by the defeat of those before them ; whilst the besieged troops acquire a new strength from being elated with their success. It is also very probable that although a strong column, capa» hie of attaining its object speedily, might on the outset suffer a heavy loss, yet this loss will not exceed, or even be adequate to that arising gradually from the procrastinated defence which the repeated feeble efforts of the small parties would enable the garrison to -make ; besides the success of the attack being more certain. These arguments hold good in respect to esca^ lading a work, which operation should therefore be executed with a sufficient number of ladders to enable strong parties to ascend at the same time, * It follows from the observations made in the above para- graph, that, if the improper disposition of the fortifications DKFENCE OF PLACES. Ill 91. — The following process is used to pass a ditch containing stagnant water which the gar- rison cannot raise to a higher level : — 4?eginning at the opening of the counterscarp, fascines ar^ ranged in several beds, with small pickets driven through them, are sunk in the ditch by means of laying stones, earth, gravel, and other materials upon them ; and gradually as the kind of bridge thus formed reaches the surface of the water, the epaulment is constructed upon it with sand- bags, fascines, or wool-bags. The two last kinds of materials require raw hides over them, so as to be secured from being set on fire by the gar-, rison.* of any place has allowed a breach to be effected bj a distant battery, and the besieger should venture to advance uncover- ed towards this breach, for the purpose of stormins it, his sue-- cess will be very dpubtful. For, if, notwithstanding all the precautions that he will certainly take, the besieged troops should happen to perceive him in his advance, they will direct a destructive fire ^pon him ; and the confusion likely to arise from it in his coluiijns, will be augmented by the necessity of using ladders, or other means, to descend into the ditch. The attacking troops must then form in proper order, and make the requisite dispositions for the assault, being exposed to the effect of all the defensive means which the garrison may em- ploy ; so that after experiencing great difficulties, and probably a very heavy loss, these troops will have to meet an enemy ready to receive them. * The breadth usually allowed for any bridge which forms tiie passage of a wet ditch, is from 30 to 36 feet; the epaulme?^^ o.cfupies half of this breadth, or thereabouts. it2 ON THE ATTACK. AND The bridge and the epaulment being carried on as far as the breach, the single sap is used to gain its top, as in the case of a dry ditch. 92. — The ditches which present the greatest obstacles to the besieger in constructing the works necessary for passing them^ are those which con- tain running water ; or else, such ditches as the garrison may keep dry, or fill with water, at plea- sure. The impediments arising from the nature of the latter are particularly great when by means of sluices accordingly disposed, a considerable quantity of water may be let in and out several times, in a rapid current. Difficulties also occur in constructing the passages of ditches filled with stagnant water that the garrison can raise to dif- ferent levels ; and all the above ditches require that the bridges used for crossing- them should be floating, besides their strength allowing troops of infantry formed in a column to pass over them, as well as heavy artillery if it should be requisite to convey any. Such of these bridges as are lia- ble to the effect of strong currents, ought like- wise to be rendered capable of resisting that ef- fect. 93. — The method of constructing the floating bridges in question (Pi. 4. Fig. 24.) consists in laying a proper quantity of fascines in beds which cross each other, and are fastened together with small pickets 3 upon every three or four heds^ five DEFENCE OP PLACES. 113 or six rows of joists from 4 to 6 inches thick are placed, in the direction of the length of the bridge; wooden pins 3 feet long, and pointed at both ends, are at every 4 feet fixed through the joists, these pins projecting equally on each side, and being driven into the fascines above and be- low the joists, for the purpose of consolidating the work. In proportion as the bridge advances to- wards the place, the besieger secures it by means of anchors on the side next to the current; and when the force of the water is great, he also drives piles along the other side. The cable of 6ach anchor is folded in two, and fixed at one end to the joists nearest to the current, whilst the other end is fastened to a strong picket upon the tpp of the bridge ; in such a manner, that as these cables may be veered out to any requisite length, the bridge can be raised or let down, according to the level of the water. As soon as any part of the bridge is completed, the besieger constructs the epaulment upon it with fascines, or wool-bags. 94. — It was suggested, as another method of effecting the passage of a wet ditch, that a raft with an epaulment upon it might be constructed along the counterscarp, and then wheeled round, so that one of its extremities being close to the descent, the other may reach to a sufficient dis- tance from the rubbish of the breach to prevent its impeding the manoeuvre for placing the raft in Q 114 ON THE ATTACK. AND the proper direction; the space between the raft and this rubbish is to be passed over by means of beams of a moderate thickness, which are laid across ; and, like the floating bridge just spo- ken of, the raft may in case of a strong current be secured in its position with anchors and piles. In some circumstances a bridge of pontoons, car- rying an epaulipentof a suitable height and which consists of several rows of gabions filled with wool, may also with proper precautions be used to gain the breach ; whilst in others, the besieger will perhaps have it in his power to destroy the batardeaux and'sluices of the garrison with his ar- tillery, or to let the water out of the ditch by means of cutting channels in the ground. In short, the engineer who is to direct the operation of passing a wet ditch, should decide upon the measures which may best answer this purpose, in conse- quence of the localities and the nature of the de- fence that the besieged troops still appear willing to make, and capable of making. 95.— As the particulars explained in the last paragraphs respecting the usual process for con- structing the descents into the ditches, and exe- cuting the works necessary for passing the latter, may have diverted the attention of the Reader from the subjects previously treated of, it is pro- per to remind him in this place, before continu- ing the account of the besieger's operations, that the excavation of the descents into the ditch of the DEFENCE OP PLACE*? 115 ravelin was begun in the 23rd nighty (85.) and afterwards carried on without any interruption, 96. — When the besieger intends to construct recesses (87.) on the right and left of the descents into the ditch of the ravelin, he begins them in the 25th night. He also makes during that night the openings through the'counterscarp, so as to commence the works across the ditch in the 26th night, and complete them if possible in the course of the 26th day ;* which of course depends on their nature, and the manner in which the ditch is defended. It is scarcely necessary to observe that the workmen employed in constructing these works, should be protected by the besieger's fire directed upon the top of the breach, so as to keep the besieged troops from it, and thus prevent them from annoying the workmen. * The besieger is also to reconnoitre the breach during the 26th night ; whilst in the course of the 26th day, he should render the ascent easier by means of throwing a great number- of shells from howitzers upon the top and uneven parts of the breach. It is proper, likewise, that some of the sappers should in the following night smooth the ascent and remove such fragments of the revetment as would be in the way of tbe storming troops. Whenever there is any appearance of the garris wHh double bar- riers.* Besides, as the ground in front of the place should afford no advantageous cover to the besie" ger, the trees, brusliwood, furze, hedges, &c», within J,GOO or 1,200 yards round the town, should be cut down, and the ditches filled up. The waffs of inelosure are also to be destroy- ed, and the houses demolished, unless they are so situated as not likely to facilitate the operations of the enemy, or impede those of the garrison ; ■whilst, if time and other circumstances allow it, sacb temporary works are to be thrown up, as will strengthen some weak fronts, and oblige the besieger to begin his operations further from the place. Lastly, arrangements should be made in order to establish as many baking houses, private hospitals, &c. as may be necessary. Previous to giving any account of the opera- tions of the garrison, at each particular period * Whenever a fortress is to be put in a state of defence, a body of artitkers should be iianicdrdtely established, chjeSy composed of carpenters and smiths, who are to work without any ihtcrmission at the palisades and barriersof the covert-way ; as well as at Ihe Wihdages of every description, which may be necessary. Tbey should also prepare the timbeo for the tam- hcmrs, platfocmsi bridges^ temporary pawdeC^magaaiaesi &c» so that they may afftarwawls b» sps^difiy wmrtructedw 182 ON THE ATTACK AND of the siege, the following methods of constructs ingibarbet-batterieSj temporary covered-batteries, retrenchments, tambours, blindages, traverses, parados, temporary powder-magazines. Baches and counter-approaches, will be explained; as well as the manner in which the covert-w^y should be palisaded. 168.— The barbet-batteries c (pL 6, Jig, S3 and 33^ are usually placed at the saliants of the works which contain them ; and, as the guns are to fire over the parapet, the terrepleins of these batteries should of course be raised above those of the works, in a proportion determined by the elevation of the guns when mounted upon their carriages*. In regulating the length of a barbet- battery, about 15 feet are generally allowed for the distance between each two guns, the breadth of the terreplein being from 20 to 24 feet. One or two ramps a 12 feet wide, with a slope equal \q six times the height of the t^rreplein of the battery over that of the principal work, serve to ^ The travelling carriage raises the gun 3 feet 1 1 inche;,. and the garrison carriage 2 feet 9 inches : the former admits of the terreplein of the barbet-battery being 3 feet 6 inches below the crest pf the parapet, and the latter 2 feet 4 inches, Guns placed on traversing platforms can be fired over the pa- ispet, without standing on a terreplein purposely raised ; hiut tlitse platforms are chiefly used against sliipping. DEFENCE OF PLACES, 183 Communicate from one terreplein to the other* the disposition of these ramps allowing the ban*- - mates of timber, whilst firing ; and /^Z. 7, (fig. 34', 35, 36, 37, 38. J shows the arrangement of a casemate of this description which the French Engineer Carnot caused to be made at St. Omer, some years since, for the purpose of ascertaining the best method of constructing them. This casemate was established upon the terreplein^ and contained two 24 pounders mounted upon ship-carriages; its dimensions being 1^ feet in length, 23 feet in breadth, and 8 feet in height- It was covered at top by beams 1 foot square, which were placed close to each other and had earth laid over them to the height of 6 feet. Other beams, also 1 foot square, and fixed in an up^ right position, supported the former along the sides of the casemate; as well as in the middle, between the two platfortns. The embrasures were both oblique, and pierced through the whole thickness of the parapet ; being covered at top by beams and earth like the casemate, and the cheeks having a revetment of thick planks nailed to uprights ; the embrasures were 2 feet wide at the neck, and the same dimension was allowed for tjieir height ; whilst, at the mouth, the dis- 184 ON TME ATTACIfc AND taace of iacb cbeek from the line of fire or cen- tral line of the embrasure, was eqjual tol-fourth of the length of this line. Both embrasures bad tlidimig^ shutters*. In the course of the expetiment, neither the case- mate, northe embrasures, were materially iiijared by the explosion, as only a very small number of the planks used forreveting the cheeks gave way, besides tlie soles being slightly affected near the silk; and, altbongh a ca»s;iderable portion of tbe smoke was repelled into the casemate, yet it went otf in two orthree minutes,anid did not incommode tbe aritillery-men who were working the guns; it was even observed tltat the return of the smoke into the casemate coald be prevented by closing the shatters of the embrasures^ imntediately after the explosion. Notwithstanding tbe favourable results which Garnet's experiment afforded ia several respects^ yet his method of eoustructing casemates of tim^ * Ib order that casemates of timbec constructed according to Camot's method may be made with greater convenience and expedition, it was proposed, subsequently to his experiment, to substitute trunks of trees 12 inches in diameter, with the bark on, for the squared beams which he employed ; and also to revet the cheeks of the embrasures with strtiDs; piles, so as to remove every apprebensioaof tbe eheeks being damaged by th« firing of tbe guns. (Sie pi. 7, Jig. 59. J DEFENCE OP PLACES. 1 85 ber for artillery is not to be followed^ as the great width which the embrasures require, facilitates the means to the besieger of firing into them, and also has the inconvenience of weakening the para- pet between the embrasures, so that it is liable to be destroyed by the fire of any heavy guns bear- ing upon it in an oblique direction ; whilst on ac- count of the casemates being placed on the terre- plein, they are exposed to be struck by the shot proceeding from the besieger's ricochet batteries. 170. — -Indeed the defect which Carnot's case- mates have of requiring very wide embrasures, might be to some degree diminished by means of making the latter similar to the embrasure A (Fig. 40.) which allows the muzzle of the gun fired through it to be nearer to the exterior line ab of the parapet ; so that the embrasure may be made narrower; but such a rectification could evidently not be carried to any great length, and besides, the casemates would be equally liable to ba' struck by the shot from the ricochet-batteries of the besieger. 171 . — The following process, for constructing casemates of timber intended to secure artillery, is far preferable to the method of Carnot. Ac- cording to the process in question, the casemates A (FigAland4:2.) should be made in, the para- pet, as this situation will secure them from rico- chet fire ; they are to be covered at top in the same 2 c 186 ON THE ATTACK AND manner as Carnot's cjtsematCB, but, for each gum, the front is to consist of beams b (Fig. 41.) 15 ft. long, and 1 foot square, or rather more, forming an epaulment about 4 ft. 6in. thick throtigh which the opening c is to be cut, so that the muzzle Of the gun mayprojeetbeyond this epaulment. The neck d of the embrasure d e, which is pierced through the exterior slope of theparapet, should as well as its mouth e not be larger Ihan is neces- sary to allow the gun to be fired in such direc- tions as may be requisite, in consequence of the particular purposes which the fire from the case- mate is intended to answer. If instead of a gun, an howitzer should be {)Iaced in the casemate, or a mortar mounted on a carriage which allows it to be used as an ho- witzer, the embrasure must of course be larger than for a gun, and its dimensions are therefore to be regulated accordingly. 172. — The use of casemates of timber, in or- der to secure the artillery of a besieged plafee, is to be recommended whenever the garrison has the means of constructing them ; ^nd under diffe- rent circumstances, traverses and parados should be substituted for these casemates. 173. — Bastions may be more or less effectually retrenched, according as they are full or empty, ~ vlride Or narrow. The time, as well as the quan- tity of materials and number of workmen, tbat DEFENCE OF PLACES. 187 the besieged troops may have in their power to em- ploy for constn'scting the retrenchments, should likewise be considered. It is scarcely possible to erect any effectual re- trenchment within an empty bastion;* on which account the besieged troops sometimes only con- struct a coupure in the direction a b {Fig. 45.) that is, from one angle of the flank to the other; or else, they pierce crenels through the walls of the nearest houses c, and make coup.ures d across the streets or other intervals which separate them ; besides tambours e in front of these coupures, the height of the former being such as to allow the fire of the latter to pass over them ; passages /"are established, for the purpose of communica- tion. The crenelled houses c may likewise be connected with the adjoining curtains by means of coupures g* crossing their rampart, and which should be defiled from the fire that the besieger would otherwise direct upon their terrepleins, from that of the bastion. 174. — Pull bastions admit of being more ef- fectually retrenched than the preceding ; and, when they are small, their retrenchments com- monly have the same disposition as either one or the other of the retrenchments ab c and defgh * See the Author's Treatise on the General Principles of Permanent Fortification, &c.; paragraphs 98 and 99, 188 ON THE ATTACK AND represented by Pig. 46 and 47. But if the bas- tions should be very large, a front of fortification composed of two half-bastions and a curtain, may be constructed on the line ah (Fig. 48.) which connects those parts of their faces where the jirolongation of the exterior line of the parapet of the ravelin on each side, meets them. Or else, a work consisting of two, faces c d and ef, con- nected by a curtain d e, may be thrown up, with a redan g him front, from which it is separated by a ditch k; the communication between this ditch and such a part of the terreplein of- the bastion as the work c d ef covers, consists of a postern Z, and steps or ramps m serve to gain the interior of the redan, from the ditch ; whilst, in order to communicate with the other part of the terreplein, steps or ramps n are made, lead- ing to it frotri the ditch of the redan ; besides bridges of timber o which the besieged troops lay across the ditch of the work cdef, and should preserve in this situation as long as can be done without danger.* It should be observed that in order to have the means of affording a flanking defence to the * In order to secure for the longest possible time the com- munication through the bridges o and otlier similar bridges, they msy be covered by a kind of traverse p consisting of gabions, and which is so placed as to allow a "free passage round it. DEFENCE OF PLACES. 189 ditches of the redoubts which the ravelins contain in the modern bastion system, as, well as to the terrepleins of the ravelins, a clear space q r, 54ft. long at least, I's to be left between the retrench- ments and the shoulders of the bastions, what- ever the dimensions of these works may be. 175. — The most effectual method of retrench- ing a wide bastion, provided the besieged troops have the necessary means to employ it, is to con- struct, -besides the works on the terreplein, a front of fortification A [Fig. 48.) sufficiently re- tired to stand in the rear of any breach that the besieger may make, not only in the fkces of the retrenched bastion, but also (and particularly if the ditch in front of the bastion is dry) in the adjoining curtains s, t, through the openings be- tween the flanks of the bastion and the tenailles. This front must of course be placed behind the gorge of the bastion, and terminated at both ends upon the curtains, beyond the points where the profiles of the tenailles, if prolonged, would meet them, A postern u forms the communica- tion from the place to the ditch of the retrench- ment, and this ditch is traversed by a caponiers leading to steps w which are made at the re- entering angle of the counterscarp, for the pur- pose of gaining the terreplein of the bastion. It must be admitted that the above method of retrenching wide bastions requires a great quanti- 190 ON THE ATTACK AND ty of timber, besides such a number of work- i»en as the garrison may sometimes not be able conveniently to afford ; therefore, if any fortress should happen only to have one or two fronts liable to be attacked,the retrenchments A might be permanently constructed, and those on the terrepleins made during the siege. 176. — No retrenchment constructed oh the terreplein of a bastion should have a greater com- mand over it than 3ft. or 3ft. 6in, ; and from 15 to 18ft. are usually allowed for the thickness of the parapet, the slope of the escarp being regu- lated according to the relief of the retrenchment; the breadth' and depth given to the ditch chiefly depend on the quantity of earth necessary to con- struct the retrenchment, and, supposing the latter to be made during the siege, both the escarp and counterscarp are supported by fascines a and b (Fig. 49.); or else, fascines are only employed for supporting the escarp, whilst th^e earth on the side of the counterscarp is retained by means of posts c (Fig. 50. ) about 10 in. square, besides planks d2\n. thick, which are placed over each other, between the posts and the ground. Palisades and fraises are used to render the retrenchment more secure. 177.— Supposing a ravelin to be full, and sup- plied with a permanent redoubt G, (PL 4. Fig. 21.) this work, together with the two coupures DEFENCE OF PLACES. 191 to' and x' which the besieged troops construct during the siege, unless permanent ones were previously made, form the retrenchment of the ravelin ; so that it only remains to cover, by means pf a tambour, the communication at the gorge of the redoubt. But if a full ravelin should happen to contain no permanent redoubt, a temporary one, con- sisting of earth, is to be constructed, besides a coupure on each side; the extent of this redoubt should be regulated according to the interior space of the ravelin, and its profile arranged conformably to the directions just given (176) re- specting that of the retrenchments of bastions; only, the command of the redoubt over the ra- velin is generally made equal to half the command of the body of the place over this work. With respect to an empty ravelin, nothing can be usefully done to retrench it, except construct- ing a tambour which covers the communication at the gorge, and thus facilitates the retreat of the troops who have defended the ravelin, ]78. — The smallness of the saliant places of arms not allowing any works of earth to be con- , structed within them, tambours are simply made which answer the same purposes as the tambours placed in the empty ravelins, &c. 179. — A re-entering place of arms -which con- tains a permanent redoubt, requires no other re- trenchment ; with the exception however of a 192 ON THE ATTACK AND tambour, to cover the communication at the gorge of the redoubt. But supposing that a re-entering place of arms has no permanent redoubt,, whilst its dimensions and every other circumstance allow one of earth to be constructed within it during the siege, this redoubt ought to be made. In short, if a re-entering place of arms, destitute ©f a permanent redoubt, should also happen to be so small as not to admit of one ofearthj, or, if the be- sieged troops had not the necessary means to con- struct the latter, their only resource is to erect a tambour; or else, a work composed of strong palisades planted close to each other, with a ban- quette behind them, the sort of parapet which they form being thickened above the banquette by means of turf, or of clay intermixedwith chop- ped straw. 180. — A tambour consists of pieces of oak a (PI. 7. Fig-. 43 andU.) 12 feet long, and from 6 to 7 or 8 in. thick, which are vertically fixed in the ground, close to each other, so as to be left about 7 feet high. It is secured in front by a ditch b, besides fraises c in the escarp ; and loop-holes d are made in the tambour, at every 3 feet of its length, passages being left at its ex- tremities, near the counterscarp of the ditch behind, with gates to shut them up when circum- stances require it. The tambour of a saliant place of arms usually follows the direction of the DEFENCE OP PLACES. 19S ■ ciJ'cular part of the counterscarp in question, and is terminated by two small flanks, one at each end, in which the passages are made j whilst that of a re-entering place of arms has the form of a redan ; but in whichever situation the tambour may be placed, a sort of shed e 6 feet wide, consisting of platiks 2 inches thick, is fixed on its top, and supported at every 6 feet by pieces of timber jf fastened to it. The object of this shed is to secure the troops in the tambour from the besieger's grenades, and, as it slopes inward- ly, it follows that in the saliant places of arms the grenades falling upon it roll down into the ditch of the ravelin or the bastion behind; but, in the re-entering places of arms, a small ditch should be made behind the tambour, for the pur- pose of receiving the grenades, the nearest side of this ditch to the tambour being placed exactly ixnder the interior edge of the shed. 181.— The traverses a (PI. 7. Fig. 51.) which the besieged troops construct upon the terre- pleins, in order to render them less liable to en- filade, usually consist of gabions 4 feet 6 inches long and 3 feet in diameter, which are placed in 4 rows close to one another, with 3 other rows oter them. All the gabions are filled with sand- bags, and connected together by means of fas- cines, &c., so that the traverses may be firmer.* * Traverses have sometimes been made with wool-bags, so 2 D 194 ON THE ATTACK AND The object of the Parados is to secure the be- sieged troops from any reverse fire to which they may be exposed. The method of constructing them is the same as that used for traverses. 188. — The blindages made in a besieged town may be variously disposed according to the parti- cular ttse of the bomtb-proof that they are in- tended to form. Cormontaingne suggested the faU^wing method of constructing those which have for their object to secure buildings inwardly, and which, similarly to any other blindage having a horizotital roof, are called horizontal blinda- ges:, or timber bomb-proofs. Conformably to this methodl, and the interior breadth of the building not exceeding 21 fee*, uprights, a (PI. 8. Fig. 52.:) are placed in a row within the building, in the divectioa of its length, with their lower end: firmly fixed in a sill b, and the distance from the centre of each upright to that of the next being H or 13 feet. ' The Up- rights are connected tngelher by means of beams c horizontally laid on theirtops, and which the cleats d retain in their position ; these beams, and conser quently the oprights,, support girders e which ex- tend across the building andihave tJieir extremitieB fixed in the walls ;* beams^/'are placed close to one that being composed of lighter materials, they might be more conveniently removed from one place to another; but this method is very uncommonly used. * CormontaiBgnc recommends that the uprights, girders. DEFENCE OF PLACES. 195 another upon the girders, in the direction of the length of the building, so as to support the beams g", which, similarly to the former^ are close to each other, but have a contrary direction ; two rows h and i of logs of wood arranged as the Fig. shows, are laid over the beams g-, and the places where the extremities of the logs in the row i meet, are covered by other logs k. The upper part I of the blindage consists of about 3 feet thick of dung; or, when the strength of the walls allows it, of 6 or 6 feet of earth. The doors and windows of the building are se- cured by means of beams m which are for this purpose obliquely fixed opposite them, against the exterior faces of the walls ; and for greater precaution, fascines and earth, with turf over them, are laid against these beams, to a thickness of S or 4 feet. (See Fig. 55 and 56.) 183. — As an improvement of Cormontairigne's method of making the abovesaid horizontal blind- ages, another process was of late years suggest- and other beams used for a blindage of this nature, should be 1 foot squate ; and also, that the girders and the beams over them should be proped at every 10 or 1 1 feet ; therefore, any building wider than 21 feet between the walls, will require several rows of uprights. The diameter of the logs of wood is to be from 6 to 8 inches, or thezeabouts. 196 ON THE ATTACK AND ed. According to this process, the upright? a and the girders h (Fig. 53.) only are 12 inches wide and 8 inches thick, the breadth of the beams, o and d being ,13 inches, and their thickness 4 in- ches ; but these beams, as well as the girders, are to be laid on their narrower face, with an interval of 4 inches between each two beams ; and short pieces either of planks or joists should be from distance, to distance tightly fixed in this interval, their number depending upon the nature of the wood of which the beams are made, and. its smaller or greater elasticity. At each end of the girders, inside of the building, an upright e 8 inches wide arid 6 inches thick is placed close to the wall, and those parts of the walls against which the dung or earth is laid are lined with strong planks /. The remainder of the work, within the building, is to be executed conforma- bly to Cormontaingne's method, but, for greater security, the exterior faces of the walls shpiild be supported, opposite the extremities of each girder, by two props g and A 12 inches wide and 3 inches thick, which are fixed together by means * The width of the props g- and A may be reduced to 8 inches, and their thickness to 6 inches, without materially im- pairing the .strength of the blindage. Trunks of trees with the bark on, and which have suitable dimensions, may also be UWd for these props, instead of squared timber. DEFENCE OF PLACES. 197 of two joists i and k 4: inches square ;* these props of course require diiferent lengths, the prop h being intended to support the upper part of the wall, whilst the prop g- is to strengthen the lower part; both props have their lower extremities fixed in a piece of timber I placed in a horizontal direction, and which also retains in its situation the foot of another piece m standing vertically against the wall; the upper ends of the props are kept steady by means of cleats n fastened to this piece. The above new process has the material advan- tage of requiring much less timber than Cormon- taingne's method; and, as the smaller dimensions of the various pieces of timber used render them ligh- ter, the work can be executed with greater conve- nience and expedition ; but neither one nor the other method admits of the thickness of the walls being under 2 feet 8 inches, or thereabouts. 184.-^Such buildings should be selected, for the purpose of securing them by means of ho- rizontal blindages, as extend lengthwise in the presumed direction of the enemy's fire, and have their walls concealed from his view. Buildings of this kind having only one story are still to be preferred to those of a greater height, as the operation of securing them will be more simple, and will require less time and expence ; and if the height of the story is such that it may 198 ON THE ATTACK AND bq conveniently divided by a kind of loft, advan- tage should be taken of this circumstance, which will afford the means of having double the room, with but a trifling additional expence. If the garrison should however be obliged to se- cure a building which is more than one story high, the blindage i$ in this case to be placed qn the up- per floor, as such a disposition will allow a much larger portion of the building to be secured, with- out the requisite quantity of timber being on that account proportionally increased, or the carpen- try and walls much more affected by the weight of the blindage, than if it had bjeen placed low- er; besides, the necessary number of secured buildings VI ill be smaller. With respect to the method of constructing the blindage, the up^ rights a and eon the groundi- floor (Fig. 53.) should at first be fixed, and the girders b laid upon them ; after which, other uprights and girders are to be placed precisely over the forrcier, so as to corre™ spond exactly with them. The blindage is then to be completed according to the process ex- plained. (183.) 18r>. — Wlienever a horizontal blindage is placed on the upper-floor of a building several stories high, and the building happens to be much exposed to the fire of mortars, or situated within a fortification of a Small extent, such as a fort, &o, the stacks of chimneys are to be taken down DEFENCE OF PLACES. 199 to the level of the floor upon which the blindage is constructed ; and stoves, with their pipes pas- sing through the windows, should be established in those parts of the building which are inhabited by troops ; or else, the stacks of chimneys may ac- cording to circumstances be demolished for only such a height as will allow the remaining portion to be secured by means of bhndages made within the loft of the building, and so disposed as to leave issues for the smoke from the chimneys; so that it may afterwards pass through the sky-lights, or other apertures in the roof. Strong pieces of timber may also be vertically and tightly fixed in the windows of the upper- stories, each piece being 3 or 4 inches distant from the next. 186. — The roof of any building which con- tains a horizontal blindage should be preserved, as, if it were demolished, the dampness occa- sioned by the rain-water would injure the build- ing, and render it unhealthy for troops ; besides spoiling many of the articles of subsistence and ammunition that might happen to be placed thei^e. But if, on account of the roof being suf- fered to remain, any accident by fire should be apprehended, the body of firemen which it is ne- cessary to establish in every besieged town, and to distribute in the most exposed quarters, should be ordered to observe very carefully such build- SOO ON THE ATTACK ANB ings in particular as are secured by medns of blindages. ' 187.— The lamentable scarcity of permanent bomb proofs, in th6 fortresses hitherto construct-, ed, rendering temporary ones highly useful, and particularly in small fortresses, it is undoubtedly requisite that the methods of making these bomb- proofs should be explained in any work intended to elucidate the operations relating to the defence of places ; but it should be observed that walls have not commonly such a thickness as would en- able them to support horizontal blindages ; whilst the considerable quantity of timber of large di- mensions which these blindages require may be inconvenient in procuring ; their use is therefore necessarily limited, notwithstanding their great utility. 188. — Independently of the horizontal blindages just spoken of, others may be constructed which are called inclined blindages; or splinter protfs. They consist of pieces of timber a (Fig. 54, 55, 66, 57.) placed close to each other, in an inclined direction, against walls either vertical or sloping. The smallest diameter which these pieces of tim- ber should have, not including the bark, is from 12 to 15 inches when their situation does not ren- der them liable to the direct percussion of the shells, but 18 inches under different circum- stances J they only require to be squared on two DEFENCE OP PLACES.' 201 opposite sides, so that one piece may fit the next, and their lower end h is to be sunk into the ground to a sufficient depth to make them steady; whilst the upper end c should be cut slanting, in ordeif to apply it exactly to the wall. The blindage is then strengthened by means of fascines d (Fig^, 55, B6.) laid close to the exterior surface of the pieces of timber, these fascines and the chinks between the pieces in question being covered with clay and chopped straw mixed together, upon which turf e may also be placed. In respect to the length and inclination of the pieces of tim- ber, they should be such that the distance from their lower end b to the wall being 6 feet at least, the height of the blindage may be neither less .than Ij that distance, nor more than double. Besides other purposes, inclined blindages serve to cover the doors of powder-magazines, the entrance from the ditch into a postern, or to form places of security for troops; and particu- larly along the front of attack, and the col- lateral fronts, as the troops stationed under the blindages being at a short distance from the attacks, can rapidly advance to any spot where they may be required. Dry ditches afford a con- venient situation for blindages of this kii.d, on ac- count of the facility which they. give of fixing the timber against the revetments; but it is still preferable to construct the blindages along such E 2 202 ON THE ATTACK AND walls as may happen to support inwardly portions of the rampart. In short any walls properly si- tuated, and which are sufficiently strong to sup- port the blindages, may be employed for this pur- pose. It is to be observed that inclined blindages should generally face towards that «ide where they will be the most secure from the enemy's di- rect fire. An inclined blindage may also be advantage- ously made against the exterior walls of a build- ing interiorly secured by a horizontal blindage, ^ as besides its utility in other respects, it will af- ford a safe communication round the building; as well as the means of establishing under cover of the blindage temporary fire-places similar to those which the French call cuisines de cam- pagne. Passages about 2 feet 6 inches wide should be left from distance to distance between the pieces of timber which form the blindage, be- ing placed opposite such parts of the walls as do not contain either a door, or a window. 189. — Fig. 58, 59, 60, show the construction of another kind of blindages; these are called. double blindages, and have two opposite faces, either upright or slanting, besides two vertical ga- ble-ends. The timber for the faces requires 18 inches diameter at least, and the gable-ends are made with joists 3 or 4 inches thick, being se- DEFENCE OF PLACES. 203 cured on the outside ^y means of an inclined blindage « (Pig. 59.) when their situation renders them liable to the direct fire of the besieger. It is proper, when timber sufficiently long for this purpose can be procured, to give such height to the blindages as will allow a loft h to be con- structed within them, provided however that this height will not improperly expose them to any di- rect fire. Double blindages are chiefly employed when there is no building in tlie place which admits of being made secure; or, in order to lodge safely under them part of the defenders of such detach- ed works as are destitute of permanent bomb- proofs ; and if these blindages are to serve at the same time as guard-rooms and redoubts at the gorges of the works where they are situated, both their faces and gable-ends should have loop- holes, with inclined palisades in front for greater security. 190. — Inclined blindages and double blindages may no doubt answer very useful purposes, simi- larly to the horizontal blindages; but like the lat- ter, they require for their construction a consi- derable quantity of timber of large dimensions, as well as a long time and a great labour. Be- sides, the places of security established by their means are not sufficiently extensive and commo- dious to afford advantages capable of overbalan- sot OS THE ATTACK AND cing in all circumstances the abovesaid inconve- niences wliich the blindages in question have; there- fore, they should not be indiscriminately used. 191.— Temporary powder magazines may be' formed by means of galleries A lined with timbef (Fig. 61, and 6t,) which are made in the ram- palrts; their requisite dimensions of course de- pend the latter containing the entrance, which is se- cured by a barrier. In order that fleches may be more speedily constructed, their parapet is usually traced by means of two or three rows of gabions, and after- wards thickened. With respect to the direction of the faces, they are made parallel to the glacis, whenever the localities allow it, so that the fleches * If there should be any advanced glacis, flecJies n)ay also be placed at the foot of this woik. 206 ON THE ATTACK AKD may be effectually flanked by the covert-way b&- hind them, as well as by the bastions and ravelins. Fleches may also be made behind an advanced ditch, or an advanced covert-way, in order to protect them; but they should in this case be placed at the foot of the glacis in front of the re- entering places of arms, as this situation will enable them to afford a very useful flanking de- fence upon their right and left, and to be flanked by the covert-way and ravelins from a small dis- tance which allows even a musquetry fire to be effectually kept up for this purpose; whereas, by placing the fleches opposite the bastions and ravelins, those in the latter situation would be feebly protected, and would afford no flanking defence from which any material advantage might be derived. It is to be observed that whenever fleches are constructed in the rear of an advanced covert-way, the directipn of their faces should be such as not to allow the besieger to enfllade them from the crest pf the advanced glacis. 194. — In order to enfllade the boyaux, the be- sieged troops frequently construct upon the flanks of the attacks works called counter-approaches, which they place on soine advanced spot advan- tageously situated for this purpose. A. counter- approach sometimes only consists of a trench where troops are posted to keep up a musquetry DEFENCE OF PLACES, 207 fire, but it is more commonly intended for artil- lery ; a communication, in the form of a trench, leads from the covert-way to the counter-ap- proach, being defiled from the attacks, and co- vered by a parapet either on one or both sides, as may be necessary in order to secure it; this communication is called a line of counter-ap- proach. As soon as a counter-approach is no longer use- ful, the besieged troops destroy it. 195. — The palisades which serve to protect the covert-way, should be vertically planted in ane row upon the banquette, 10 pr 13 inches distant from the foot of the interior slope of the glacis, and with their points projecting from 13 to 15 inches over the crest of this work; the usual distance from each palisade to the next is 3 inches, and their lower extremity is sunk 2^ or 3 feet into the banquette, the band which secures then) at top being placed on the side towards the covert-way, about 2 feet 6 inches below the points. It is proper that a pointed piece of iron should be fixed in the band, between every two palisades, so as to prevent the besieger from stepping upon it, in order to leap down into the covert-way. It was suggested that independently of the row of palisades just mentioned, another row should be planted behind it, between each two traverses, the palisades in this row being 2 feet distant from 208 ON THE AtTACR AND the foot of the slope of the banquette, and their project>on above ithe crest of the glacis equal to that of the palisades in front. According to the same scheme, the palisades in. the second row are to meet at one of its ends those placed on tb^ banquette of the contiguous traverse; whilst a passage, secured by a harrier, is to be left at the other end, close to the traverse on that side, for the purpose of establishing a communication be- tween the two portions of the covert-way which the palisades in the 2nd row separate. A ban- quette is to be made behind these palisades, with steps to mount upon it; and, in order to secure the soldiers from the musquetry-fire of the be- sieger, fascines are to be vertically fixed in the in- tervals between each two^palisades, so as to form with them a kind of parapet which, for greater security, should be thickened above the banquette by means of turf, or of clay mixed with chopped straw. The object of this method of palisading the co- vert-way is to^ugment the difficulty of storming it, and to facilitate the retreat of the troops who have defended it ; but it should be observed that inde- pendently of the much greater number of pali- sades which such a method requires, those in the 2nd row cpnsiderably impede the manoeuvres of the garrison in the covert-way, and the commu- nication within it; they also augment the quantity DEFENCE OF PiACES. 209 of splinters produced by the enemy's ricochet- nre, and, as they must be planted atan early period of the siege, most of them will be destroyed before the covert-way can be attacked ; so that after gain- ing the crest of the glacis, the besieging troops will be able to direct a plunging fire upon those posted behind the palisades which remain,as well as an en- filading and a reverse fire ; whilst the sappers will cut down these palisades in safety, being covered by them from the fire of the place. It follows from" the above observations that^ besides the in- conveniences of the method in question, it doeS' not afford effectual means to keep off the enemy from the covert-way ; and also, that after he has penetrated into this ,work, the 3nd row of pali-, sades will actually be of advantage to him, in-- stead of being useful to the garrison. 2 F 210 ON THE ATTACK AN» CHAPTER VIIJ. On the~requisite operations of the Garrison,, du- ring the 1 st period of the Siege. 196. — As soon as it appears from tbe prepara- tions and movements of the enemy that he will very shortly lay siege to the place,* the garrison should forward, without any intermission^ such dispositions requisite to put it in a state of de* fience, as are not yet completed. The bai4)et- batterieSj together with the cavaliers v/hich the place may happen to have, are to be instantly supplied with heavy artillery, so as to impede the enemy in forming the investiture; whilst arrange- ments should be made to remove into the interior of the country the women, children, and old men, whocan be of no service during the siege. The cat- tle, forage, dry vegetables, wine, liquors and other articles of this kind, which may be found in the neighbouring country, are to be brought into the town, and a plan concerted in order to keep up intelligence with that country, either by signals or otherwise, so that the enemy's posts may be * Whenever a fortress is Lable to be very soon besieged, par-f ties should be sent from it every day, for the purpose of ob-s setwig the enemy. DEFENCE of: PLACES, 211 broken through with greater facility, and such succours introduced into the place as may be sent to the besieged troops. 197. — The garrison should in day time also have posts in advance of the place, for the pur- pose of keeping off the enemy, and thus obli- ging him to reconnoitre the fortifications from a greater distance, as well as the ground imme- diately before them ; but care should be taken, in establishing these posts, to place them in situa- tions which will allow the troops to retire safely with any artillery that they may have, whenever their retreat is to be effected * 198.— Besides the aforesaid dispositions, the garrison should be organised suitably for the de- fence of the place, and particular companies formed, consisting of grenadiers and other sol- diers of known bravery* who may be depended upon in those circumstances which are the most dangerous, and require the greatest exertions. Horse-artillery, with light field pieces, are like- wise to be appointed for the exterior operations, and all the troops trained to the various manoeu- vres that they may have to perform during the siege, either in the day or the night ; the officers * In or'der to keep off tb€ enfemy's reconnoitring parties sttU nioite efftdtually, small' drtaichnients, concealed from their view, ni»y be stationed in the intervals between the posts. 212 ON THE ATTACK ANfr being made acquainted with the properties of e psed to denote such carriages as allow the mortars mounted upon them to be fired in a horizontal direction. gl6 ON THE ATTACK AND CHAPTER IX. On the requisite Operations of the Garrison during the 2nd Period of the Siege. 203.— The besieged troops having ascertained that the enemy is manoeuvring or at work on some particular spot not far distant from the place, a direct and a ricochet fire should instantly be directed upon that spot: from the whole of the artillery conveniently situated for this pur- pose. This fire is to be briskly continued until patroles, with engineers at their heads, and sup- ported by proper detachments, advance as near the enemy as possible in order to reconnoitre whether h,e actually is opening the trenches, or about any other operation. 204. — If the engineers should report that the enemy is breaking ground, lighl-balls are to be thrown in every direction where they may allow bis trenches to be seen, so as to open a direct and a ricochel-fire upon them and the troops who cover the workmen, from the artillery of all the fronts suitably placed.* This artillery is * By observing the disposition of the enemy's trenches, and particularly their length, the besieged troops will also DEFENCE OF PLACES. 217 to be imraediatdy Ke-enforced by means of pie- ces brought from the other fronts and the reserve. Besides, light guns and howitzers, with in- fantry and cavalry to support them, should take an advanced position towards the extremities of the enemy's trenches, so that their fire may bear in flank upon the covering troops, as well as in an oblique direction,* and also answer the pur- pose of throwing the workmen into confusion. A sally is likewise to be made, with two thirds of the garrison, about two hours after the artillery has opened its fire. The principal object of this sally, and indeed, of the manoeuvre in general, is to induce the workmen to disperse, by creating^ alarm among them ; and, in order to execute it, the cavalry and horse-artillery, supported by the light infantry, are to advance towards the ends of the trenches, from the collateral parts of the fortifications, so as to oppose the cavalry of the besieger ; at the same moment the other infantry, with light artillery upon its flanks, is to attack the covering troops in front; this infantry, as be able better to judge whether he actually is commencing bis operations, or only cairying on a feigned attack, in order to draw their attention to the spot where he is at work, and then really break ground with greater safety on auother spot. * The oblique direction of the fire ajjove alluded to is what the French call en echarpt. 3g 218 ON THK ATTACK AND well as the artillery attached to it, sh ould make several discharges, the artillery being loaded with •grape-shot ; but they ought not to advance in- considerately, and must retire before they are at- tacked by the troops who will undoubtedly be sent to re-enforce the covering party. The artillery of the place and the advanced batteries towards the extremities of the besie- ger's trenches should of course discontinue their fire during the time of the sally, but are to re- commence it with as much activity as before, in- stantly after the troops have retreated. 205. — The 1st parallel being completed, the immediate object of the besieged troops must be to impede the besieger in constructing his 1st batteries and the boyaux pushed out from the 1st parallel ; for this purpose, the artillery placed in the barbet-batteries of the front of attack and the adjacent fronts, or on traversing platforms if any should be used, is to keep up a lively direct fire on the besieger's batteries and the heads of the boyaux ; the large mortars are to occupy the curtains of the same fronts, and to be fired al- ternately in different directions ; whilst the rico- chet fire of the pieces established in the covert- way, and which should chiefly consist of howit- zer'*, as well as of mortars mounted upon gun- carriages, is to be, so distributed that part of it will cross over the prolongations of the capitals. DEFENCE OF PLACES. 219 and the remainder follow the direction of those prolongations.* 206, — Previous to the siege, the garrison should be provided with a correct plan representing the whole fortress, as well as the surrounding country, and where the principal works are distinguished by particular names and numbers. This plan is called the general directing plan of the defence^ and the prolongations of the faces and capitals of the works belonging to the front of attack, &c. are to be drawn upon it, subsequently to the opening of the trenches. The engineers should every morning also mark on the same plan the work of the besieger during the preceding night. But independently of the general plan in question, a particular plan upon a larger scale is to be made, representing no other part of the fortifications except the front of attack and those works collateral to it, the situation of which allows their fire to bear upon the approaches. The prolongations of the faces and capitals should be very accurately described in this plan, with the position and extent of the 1st parallel; besides * TJie besieged troops ought not to direct an equal portion of the fire of their artillerjr upon each of the spots vvlierc the besieger is constructing his batteries, but should concentrate a larger quantity of it alternately upon one or two batteries, 90 as to augment the effect. 220 OIJ THE ATTACK AND every other work which the besieger may after- wards construct, the first disposition and succes- sive changes of the garrison's batteries, the tem- porary works intended to be made for the pur- pose of improving the defence, and all othep material details of this kind. 207. — Such arrangements previously com- menced as may still remain in an unfinished state, should also be completed as soon as the trenches are opened. The powder, ammunition, loaded shells, provisions and other important supplies, which the garrison cannot otherwise secure, are to be removed to the spots least exposed to the besieger's fire, being distributed into several quarters. The small magazines for the ammuni- tion used in the course of each day should like- wise be established along the fronts opposite the attacks, as well as places of security for the troops on guard there, and the supplementary troops that these fronts may' require in various circumstances; whilst the quarters most suitable for the other troops should be assigned to them, and the order precisely regulated in which duty is to be done, either in presence of the enemy, or with respect to any work which the garrison may have to perform. In short, the filches and counter-approaches ought to be constructed, together with the requisite retrenchments, cou,- pures, caponiers, bridges, &c. DEFENCE OF PLACES. 2S1 SOS. — Besides the aforesaid preparations which the hesieged troops are to make immediately after the opening of the trenches, they should at the same time also construct such embrasures, tra- verses and parados, as will be requisite for the greater security of their artillery when in con- sequence of the besieger's batteries being ready for action, it will become necessary to remove the largest portion of it to those parts of the fortifications which are the least exposed, and from whence its fire can effectually bear upon the attacks.* 209. — Whatever precautions the besieged troops may use, for the purpose of securing their artillery, part of it will be silenced before the 2nd parallel is commenced; therefore, they should replace as many pieces as possible, in or- der to impede the besieger in constructing this parallel and any new batteries which he may have occasion to make in or near it. Those parts of the collateral fronts which their situation has secured from the effect of the besieger's 1st bat- teries, and from whence the attacks are properly seen, should particularly be supplied with such a * If it should be wished to employ any guns mounted on traversing platrorms, embrasures may be made for them by means of raising the merlons with sand-bags placed upon the top of the parapet. 322 ON THE ATTACK. AND number of pieces as will allow them to keep tip a lively fire with direct as well as ricochet shot. 210. — The manoeuvres which the garrison, should execute, in order to retard the construc- tion of the 2nd parallel, are similar to those ex- plained (204.) with respect to the 1st; but they will be performed under more favorable circum- stances, as the proximity of the 2nd parallel to the place not allowing the workmen to be cover- ed but by a small number of troops^ who also are much exposed to the musquetry fire of the co- vert-way, it is next to a certainty that a strong sally properly led will very soon drive back those troops, and disperse the workmen. The sally is then to form in order of battle between the par- allel and the enemy, so as to oppose any re-en- forcements that might be sent against it, and give time to those workmen of the garrison who follow the sail}', with engineers at their head, to destroy that portion of the parallel which is con- structed, including the redoubts at the extremi- ties. 211. — It should likewise be observed that with- in the distance from the 2nd parallel to the place, it is in the power of the besieged troops to make such an advantageous use of their musquetry fire, as will to some degree compensate for the loss of that portion of their artillery which the besieger's batteries have rendered unserviceable j for this DEFENCE OF PLACES, 223 purpose expert marksmen, supported by the fire of the covert- way, should advance upon the flanks of the attacks, in order to enfilade the boyaux, &c. and also annoy the troops in the trenches by their oblique fire ; whilst parties of light infantry should lie in ambush in the night, who are to fire upon the workmen engaged in executing any fly- ing-sap, and to attack them unexpectedly, so as to disperse them ; besides, marksmen stationed in the saliants of the covert-way, and supplied with rampart-fusils, should constantly keep up a well directed fire on the heads of all the saps, the pro- per direction of this fire being marked during the day by means of iron forks fixed in the glacis , so that it may be preserved in the night. In- deed, by suitably employing their musquetry, the besieged troops will not only impede the besieger in his advance beyond the 2nd parallel, but per- haps oblige him to use the single-sap for tracing this parallel, although the flying-sap is generally employed. It is to be remarked that the effectual defence of a fortress does not so much depend on the number of pieces of ordnance that the besieged troops may have in their power to employ, as upon the judicious arrangement and use of the artillery, and the care which is taken not to ex- pose it inconsiderately. The same argument holds good in respect to the musquetry, as the 2g4 ON THE ATTACK AND besieger soon despises even a heavy fire without effect ; whereas, on the contrary, a smaller quan- tity of fire will induce him to advance with greater precaution, if the fire is judiciously dis- tributed and properly kept up. 212. — Sallies consisting of a small number of troops should very frequently attack the besieger whilst he is advancing beyond the Snd parallel, and^ particularly after he has gained the spots where the derai-parallels are to be constructed. The only object of these sallies is to alarm and disperse the workmen, but as soon as it is pre- BDmed that their frequency must have led the be- aeger to relax in his precautions against more; serious operations, a strong sally is to be made, in order to destroy hfs trenches, carry away some of bts pieces of artillery and spike the rest, &c. DEFENCE OF PLACES. 225 CHAPTER X. On the requisite , operations of the Besieged Troops during the 3rd Period of the Siege. 213.^-At this important period of the siege, the defence of the place should be carried on with redoubled energy ; the besieged troops avail- ing themselves of the material advantages afford- ed to them by the disposition of the fortifications and their small distance from the approaches, in order to defend inch by inch the ground through which the besieger is to advance, and render the construction of his works on that ground more dangerous and more difficult for him. 214. — The garrison should make every possi- ble effort to retard the tracing and constructing of the 3rd "parallel. If the besieger should ven- ture to trace it by means of the flying-sap^ any small sally will disperse his workmen, as, on account of the short distance from this parallel to the place, no troops can be safely stationed in front of the workmen, for the purpose of cover- ing them ; but it is probable that the besieger yvill employ the single sap, and as soon as the sappers have set to work, the fire of pieces of ord- nance chiefly placed i« the collateral parts of the fortifications, and the positions of which were 2 H 226 ON THE ATTACK. AND previously concealed from the besieger's know- ledge, should be directed upon the heads of all the saps (66.); whilst howitzers, established in the collateral ravelins and the saliant places of arms, are to bear obliquely upon the parallel. Most of the artillery brought into action should be loaded with grape-shot, expert marksmen be- ing posted in the covert-way, to keep up an un- interrupted fire upon the heads of the saps. Light-balls are of course to be thrown, so as to see the enemy at work. 215. — The besieged troops having ascertained that, notwithstanding the above dispositions, the besieger has succeeded in carrying on the saps for some length, a strong sally should be made in order to destroy all the work which he has exe- cuted. For this purpose, infantry and cavalry are to advance from those parts of the fortifica- iions which are collateral to the extremities of the 3rd parallel, so as to take such a position as will enable them to protect the flanks of the sally. Picked troops should at the same time repair from the covert-way opposite the parallel, to every portion of the latter where the besieger is at work, and stand firm at the ends of each por- tion whilst the workmen who accompany them are speedily throwing down the gabions and the parapet; but they all should retire as soon as the besieger's troops advance from the demi-pamllels, &c. in order to repel the sally. DEFENCE OF PLACES. 22? Independently of this strong sally^ small ones should be repeatedly made, which will generally prove sufficient to disperse the sappers. Feigned sallies may also be occasionally executed for the mere purpose of alluring the besieger out of his trenches, so as to direct upon him from the place a destructive fire which was previously prepared. 216. — The fire of the besieger will probably be slackened for a couple of days, after he has completed the 3rd parallel, as relying no longer upon the effect of his batteries behind it, he will be engaged in constructing new ones. The gar- rison should therefore avail themselves of this circumstance, to re-place at all points as many pieces of ordnance as possible, and convey to the re-entering places of arms mortars which are to be loaded with grenades, &c. A very brisk fire is to be continually kept up, that of the howitz- ers and mortars being principally directed on the spots where the besieger is constructing batteries. The parapets, palisades, tambours, and such other defensive means as may require repairing, should also be put in good order, and the retrench- ments completed, as well as the coupures ; whilst casemates of timber for the artillery are to be made in the saliants of the collateral works, un- less they were previously constructed. The fire of these batteries, if properly kept up, will have a very great effect upon the 3rd parallel and the approaches beyond it. 328 ON THE ATTACK AND 217. — If the garrison should have any reasons to suspect that the besieger intends storming th6 covert-way,* picked troops oughtto be stationed in the re-entering places of arms, besides reserves in the ditches ; grenadiers should also be distributed in the latter, for the particular purpose of throwing a great number of grenades into the covert-way, after the defenders have retreated from it. The parapet of this work, as well as those of the works behind it, are to be lined with soldiers, and de- tachments of grenadiers should be posted in the collateral parts of the covert-way. Besides the abovesaid defensive dispositions, the artillery should be loaded with grape-shot in all the batteries the situations of which allow their fire to bear upon the covert-way, and those portions of the 3rd parallel to be seen, from whence the storming party is to advance. Light- balls are likewise to be thrown for the- whole night. 218. — As soon as the storming troops advance from the parallel towards the covert-way, a brislc fire of artillery and musquetry is to be opened upon them from all the works; but after they have gained the crest of the glacis, those troops of the garrison who occupy the saliant places of * Inferences in this respect may be drawn from the besieger constructing steps {67.) in the parallel, and placing stone-mor- tars within it, &c. BEl^ENCE OF PLACES. 229 arms and the branches of the covert-way, should make a discharge and then immediately retire, some of them into the re-entering places of arms, and the others through the tambours of the salianl places of arms ; unless the covert-way hap- pening to have a second row of palisades, (195) these troops endeavour to make a short stand be- hind the palisades in this row, so as to continue firing. After they have retreated, the fire of the place is to be directed against the besieger's work- men and such of his troops as have entered the covert-way ; a profuse quantity of grenades should also be thrown upon them, and, as soon as any confusion among them is perceived, the troops in the re-entering places of arms are to charge those of the besieger in the covert-way; whilst the grenadiers posted in the collateral parts of this work rapidly advance upon the glacis, in or- der to turn the lodgment which the besieger has commenced for the purpose of crowning the co- vert-way, and thus enable the workmen who fol- low them to destroy that lodgment. 219. — If instead of storming the covert-way the besieger should gradually advance towards it, as many howitzers and mortars as the besieged troops can bring into action should continually fire upon his approaches and batteries. Stone mortars are also to be conveyed to the saliant places of arms, and expert marksmen posted for SBO ON THE ATTACK AND the pOFpese of keeping up an uninterupted fire with raftipari^fosils against the heads of the satps; whilst sallies, sometitnes small and at other times consisting of a greater number of troops, should repeatedly attack the sappers in the night. Ob- lique embrasures are likewise to be pierced through the parapets of the curtains of the front of attack and contiguous fronts, as well as through that of the ravelin on each side of the former front; so that being feady when the besie- ger commences the cavaliers of trenches, the fire kept up through them may impede the construc- tion of these works. 220. — Although the troops posted in the saliant places of arms will not be able to remain there after the besieger has erected the cavaliers of iPefiches, yet some of the soldiers should endeavour to return odcasionally to these works in the nighty by keeping close to the palisades, so as to throwas many grenades as possible into the saps that the besieger is pushing on in order to gain the crest of the glacis and then crown the covert-way. The requisite disposition of the artillery of the place, for the purpose of impeding this 6peration, is snch as follows : 221. — Batteries with oblique embrasures should be made upon the curtaiti of the front of attack and those of the adjacent fronts^ so that their fire may be directed against the besieger's lodg- ments before the bastions ; whilst other bat- DEFENCE OF PLACES. 231 teries, with oblique embrasures also, and secured if possible in casemates of timber, are to be formed in the collateral ravelins and their re- doubts, so as to direct their fire upon every part of the crowning which they see to advantage. The flanks of the bastions of the front of attack should likewise contain batteries, intended for the same purpose as those along the curtains, and which may be inclosed in casemates of timber: when circumstances allow it * Besides, the gar- rison should endeavour to construct casemates of this kind in the flanked angles of the bastions, so that a fire may be kept up by the artillery placed there, upon the lodgment of the besie- ger in front of the central ravelin. The above mentioned disposition of the artil- lery allowing it to see the spots where, after crowning the saliants of the covert-way, the be- sieger is to establish his counter batteries and breaching batteries, an uninterrupted fire should be directed upon those spots, wliilst the besieger is en^-ao-ed in constructing the counter batteries and breaching batteries in question. « It is proper that the flanks of the bastions collateral to the front of attack should also be supplied with artillery, so as to direct its fire upon the besieger's lodgments opposite the bastions of this front ; but no casemates of limber are re- quisite to secure tlte artillery of these flanks. 332 ON THE ATTACK AND 222. — The besieged troops being obliged to retire from the covert-way, with the exception of those in the re-entering places of arms, the traverses should be destroyed one after another, either with cannon or by means of fougasses previously prepared, so that they may not afford any cover to the besieger in executing the de- scents into the ditches, and constructing batte- ries on the terreplein of the covert-way. The traverses of the re-entering places of arms are of course to be excepted. As soon as it is perceived that the enemy is commencing any descent, shot made of combus- tibles should be thrown upon the spot where he is at work, as well as shells from mortars and howitzers. 223. — The kind of defence which may be afforded to ditches depends on their nature. Snpposinga ditch to be filled with stagnant water, the only means that the garrison has of defending it consist, first, in directing upon the opening through the counterscarp, the fire of a battery so situated as to see that opening, this battery being covered, if possible ; and second- ly, in keeping up a fire of artillery and mus- quetry upon the besieger's works across the ditch, from the flank which protects it. 224. — The besieged troops may on the contra- DEFENCE OF PLACES. 233 ry employ for the defence of a dcy ditch, not only the fire of their artillery and musquetry, but also sallies. Supposing for instance that the ditch to be defended is the principal ditch ; iadependently of the fire kept up from the place, troops assembled behind the tenaille of the front of attack, or in the ditches of the col- lateral fronts, may from thence sally upon the besieger whilst he is engaged in constructing the epaulment for the passage of the ditch. Such sallies as in this case have only for theic object to disturb the enemy's sappers, so as to delay the progress of their work, should con- sist of a small number of men, and be very fre- quently repeated ; but if any favourable oppor- tunity should offer itself of destroying the e- pa,iilment and carrying away the sappers, &c. a strong sally ought to be immediately made. 325. — Those ditches which by means of slui- ces the garrison may at pleasure keep dry, or fill with water, admit of being defended more eflfectually than any others j and particularly when the sluices are so disposed as to allow a considerable quantity of water to be let in and out several times, in a rapid current ; for, be- sides the difficulty which the besieger has iu constructing the works suitable for passing a 2i 3^4 ON THE ATTACK AND ditch of this description, and the danger of their being set on fire by the besieged, troops, these troops may at first keep the ditch dry, in order to avail themselves of all the means which the nature of such a ditch affords to defend it : af- ter which, the sluices may be opened when the besieger is nearly arrived at the foot of the breach, so that the water rushing with great force against his works,' and passing over them in a large body, may carry them avyay, toge- ther with the rubbish from the breach ; and, if this manoeuvre should happen not to succeed the first time, it may be repeated until it hag at least produced the effect of rendering the breach unsuitable for the assault, by clearing away the rubbish. 226. — The requisite preparations for the de- fence of any breach consist in covering it with crows-feet, and collecting a great quantity of combustible matters at its foot, such as tarred fascines, &c. in order to set fire to them on the approach of the storming troops^ besides throw- ing grenades and rpllhig down loaded shells upon these troops. Mines placed undpr the breach, ai)d which are to be fired as soon as the stormmg party gams its top, will also prpve very beneficial to the defence. , 227. — With respect to the dispositions to be DEFENCE OF PLACES. 235 made at the time of the assault, the nature of them depends upon whether the work intended to be stormed is or is not retrenched. Suppo- sing that it has no retrenchment, troops supplied with musquets and grenades should occupy the top of the breach as soon as the enemy gains the ditch, so as to keep him off for the longest possible time ; being supported by other troops composed of strong men wearing cuirasses, who are to be formed in close order, and armed with pikes and other long weapons. Upon the appearance of the enemy on the top of the breach, the troops posted there should imme- diately retire sideways, in order to make way for the others who then should attack the ene- my with impetuosity, for the purpose of dri- ving him back into the ditch. This manoeu- vre is to be repeated with fresh troops, as many times as the enemy renews the assault. 226. — But when the assaulted work is re- trenched, grenadiers and other troops should be posted on each side of the breach, and facing it ; they only are to resist the first efforts of the storming party, and should speedily retire with- in the retrenchment, after making a close dis- charge, as soon as the enemy has forced his way to the top of the breach ; the whole fire of the 236 ON THE ATTAtat ANI^ retrenchraentj intludJng that of some pieces of light artillery loaded with grape-shot, is then to be directed upon the enemy's ttwbps and such wOtkrtien as are^ngagfed in cbfiStrutsting a dqdg* inent tinder tiieir protection ;* (and if any con- fusion amongst themshould he ^bs&rved, troops must immedi^tdy sally tipbn thar flaasfcs frolA the retrendhmentj afld charge tiieni with the bayonet, &c., "Without firing. Ih case «)f this manoeuvre obliging the enemy to retire, 'his lodgment should be instantly flestroyed, and such preparations recommenced again^ a new assault, (226) as were previcmSly imade. 229. — In storming a work which is not re- trenched, the besiegeJ- evidently has this great advantage over the 'troops who defeiid it ; name- ly, if he should happen to fail in the first assault, he may retire with security, so as to make 'dis- positions for a second attack ; proceeding in the same manner, until he has succeeded ,• ^wheiseas even admitting that the defenders of the -work * The mines placed under the breach of a Work, in order to defend it (226), are more likely to answer that purpose When the work is retrenched, than when it is not. The 'reason is that, in the former ease, the garrison