A treatise on field fortification : containing instructions on the methods of laying out, constructing, defending, and attacking intrenchments, with the general outlines also of the arrangement, the attack and defence of permanent fortifications

Front matter

ON

FIELD FORTIFICATION,

CONTAINING f INSTRUCTIONS ON THE METHODS OF LAYING OUT, CONSTRUCTING, DEFENDING, AND ATTACKING

Preface

In preparing the work now laid before the public, which is chiefly designed for the use of the Cadets of the United States’ Military Academy, the aim of the writer was to make a book which should also be generally useful,—one that should contain all the principles and important details of that branch of the Art of Fortification of which it specially treats, developed in a manner to be within the com¬ prehension of any person of ordinary intelligence,— a book not for the study alone, but one which the officer can take with him into the camp, and consult at any moment.

With respect to the contents, the writer has col¬ lected his information from every source within his reach; rejecting all unnecessary discussions, and admitting no results, which have not either been submitted to a rational analysis, or tested by fair experiment; preferring, in all cases, the views of persons who wrote from their own experience, to the conjectures of others whose theories, however plau¬ sible, rested on a less solid foundation.

In arranging the matter, the writer has endea¬ vored, as far as it was practicable, to confine the text to the principles alone, reserving the minor details for the plates, and the explanations appended vi

PREFACE.

to them; and on this point he would hazard one or two remarks.

Much that appertains to the Engineer’s Art is but an affair of feet and inches ; facts which are the results of long usage, holding, in many in¬ stances, the important position of principles. His experience has taught him that those authors are the clearest who enter into the minutiae of their subject; and that with pupils of superior minds, a thorough knowledge of details is an invaluable aid in unravelling the difficulties, and retaining the principles of the Art; whilst, with those of limited capacities, a want of such detail leaves them with the most vague and unsatisfactory notions.

Having said thus much of the plan of the work, a few words, respecting its object, may not be mis¬ placed. The importance of a knowledge of Field Fortification, to officers of all arms in the regular army, need not be insisted upon; the daily occur¬ rences of a campaign demonstrate this too clearly. To the militia officer, this knowledge is even of more importance than to the regular; for called upon, in many cases, to act without the co-opera¬ tion of regular troops, in the defence of his own fire-side, he will require all those conservative means which add strength and confidence to irregu¬ lar forces when brought for the first time before an enemy.

To suppose irregular forces capable of coping on equal terms with disciplined troops, is to reason, not only against all probability, but against a vast weight of testimony to the contrary. It is not indeed that discipline confers individual courage; certainly a greater proportion of this essential military virtue will, in all cases, be found among the militia, composed as it must be of men of a

PREFACE.

vii

nigher grade of moral and intellectual qualities, than is to be met with among the common soldiery of any country. But these men, with all the supe¬ rior advantages that must actuate the volunteer, necessarily want that indispensable element of suc¬ cess, in pitched battles, which results from disci¬ pline and habitual training. Called out on a particular emergency, with little or no previous exercise in the services they are required to render, militia cannot have that shoulder-to-shoulder cou¬ rage, by which men are animated, who have served long together, which begets a reliance on each other, and a confidence in their chiefs, and which is one of the surest guaranties of victory. But place the militia soldier on his natural field of battle, behind a breastwork, and an equilibrium between him and his more disciplined enemy is immediately esta¬ blished ; with a feeling of security in his position, his confidence in his own exertions is restored ; with a full certainty that his enemy cannot close upon him, before he can retire beyond his reach, he does his duty coolly, and with an execution so terri¬ ble, as to have placed the achievements of our mili¬ tia, from the day of Bunker Hill, to the dosing scene of our last war at New Orleans, on a line with the most brilliant military exploits of the best disci¬ plined troops in the world.

But were not these reasons in themselves suffi¬ cient, others of greater cogency could be adduced, in favor of intrenched positions for militia. Its ranks are filled with all that is most valuable in so¬ ciety. The farmer, the mechanic, the merchant, the members of the learned professions, must all quit their peaceful avocations to meet the foe. The father of the family jeopards its future prosperity, the son exposes his widowed mother to the chances

PREFACE.

• • •

Vlll

of an old age of penury, to bare their breasts to a mercenary band, without other home, without other ties, than the camp affords. Surely nothing but a reckless disregard for the best interests of society could urge men, under such circumstances, to forego the advantages of every possible conservative means.

The chapters of the work on Military Bridges, Reconnaissances, and Permanent Fortification, are necessarily incomplete. A full discussion of these subjects did not come within the limits of the writer’s plan. The Military Art, in all its branches, is founded upon a comprehensive and thorough knowledge of the exact and physical sciences; and in no one branch is the importance of this know¬ ledge more felt, than in that of Engineering. In adding, therefore, these chapters, a clear compre¬ hension of which supposes an advanced state of scientific attainment in the reader, it was far from the writer’s intention to lead his fellow citizens into error, by spreading a knowledge necessarily of a superficial kind amongst them ; but he rather hopes it may serve the purpose of fixing their attention more strongly and minutely upon a profession, which requires the season of youth to be spent in thoroughly acquiring its elements, and the devotion of mature age to an incessant study of its princi¬ ples, and their applications.

The author is indebted to Lieut. J. E. BLAKE , 6lh Infantry, for the very correct and handsome execution of the original drawings , from which the plates were engraved.

Table Of Contents

INTRODUCTORY CHAPTER.

On the Effects of Musketry and Artillery, and the means of directing their fire to obtain the best results, . . . xv

CHAPTER I. Page

Art. 1-2. Art of Fortification, . . . 1

“ 3. Permanent and Field Fortification, . 1

“ 4. Intrenchments, ..... 1

“ 5-7. General Conditions of Intrenchments, 1

“ S. General form of the Profile, . . 2

“ 9. General Arrangement of the Plan, . 3

“ 10-11. Flanked Disposition, . . 4

“ 13. Sector without Fire, ... 4

“ 15. General Outline of the Attack of In¬ trenchments, .5

“ 16. General Measures for the Defence, . 5

“ 17. General Principles of the Plan and Pro¬ file, . . . . . . 6

CHAPTER II. Art

18. Site, Command, and Relief,

. 11

19. Line of Direction of Fire, .

. 11

cc

20. Directing Line of the Plan,

. 11

21. Elements of Intrenchments,

. 11

22. The Redan, ....

. 12

a

23. The Lunette, ....

. 12

t€

24. The Cremaillere,

. 12

25. The Priest-Cap, ....

. 12

26. The Redoubt,

. 12

X

Contents

Pag*

Art. 27. The Star Fort,.13

“ 28. The Bastion Fort, .... 14-

Chapter III

Art. 31. General Dimensions of the Parapet, . 18

“ 32. Command of the Interior Crest, . . IS

“ 33. Thickness of the Parapet, . . .19

“ 34. Inclination of the Superior Slope, . 21

“ 35. Inclination of the Exterior Slope, . 21

“ 36. Inclination of the Interior Slope, . 21

“ 37. Tread of the Banquette, . . .21

“ 29. General Dimensions of the Ditch, . 22

“ 40. Slopes of the Scarp and Counterscarp, 23

“ 41. Approximate method of regulating the

dimensions of the Ditch, . . 23

Chapter IV

Art. 42, 43. Influence of the Site on the Plan

and Relief,.24

“ 44. Defilement from a Direct Fire, . . 24

“ 45-48. Defilement from a Reverse Fire, . 25

“ 49-51. Method of determining the dimen-

♦ sions of the Traverse, for Reverse

Defilement,.28

“ 52. Defilement of Enclosed Works, . . 30

“ 53 General Remarks on the Defilement

of Works,.30

Chapter V

Art. 56,57. Method of Profiling, . . .32

“ 60. Estimate of the daily labor of a Man

working on an Intrenchment, . . 33

CONTENTS.

XI

Pag«

Art. 61. Distribution of the Working Parties, . 33

** 62-64. Manner of forming the Excavation

and Embankment, . . . .33

“ 65. Precautions to be taken in stony soils, 34

“ 66. Drainage of the Terre-Plein, . . 34 “ 67. Time required to construct a work, . 34

Art.

Chapter VI

68, 69. Revetments, .

• ii

70-72. Sod Revetment.,

• ii

73, 74. Pisa Revetment, .

• •

H

75-79. Fascine Revetment,

• • ii

80. Hurdle Revetment,

• • ii

81-83. Gabion Revetment,

• • ii

84. Plank Revetment,

• • ii

85. Sand-bag Revetment, .

• • ii

86-99. Timber Revetment of the Ditch, .

Art.

Chapter VII

100-4. Remarks on Obstacles on

the Exte-

• •

105. Artificial Obstacles, .

• •

106-8. Troups-de-loup,

• • ii

• • ii

112-14. Palisades, .

• • ii

115-16. Fraises

• • a

117. Stoccades,

• • a

118-20. Chevaux-de-frise,

• • a

121. Small Pickets, .

• • a

122. Crows-feet,

• • a

123-26. Artificial Inundations,

• • a

• •

Chapter VIII

Art. 129, 130. Interior arrangements for the

Defence, . . . .51

CONTENTS.

Pag®

Art. 131, 132. Armament of Musketry and Ar¬ tillery, .51

“ 133, 134. Remarks on the employment of

Artillery, . . .52

“ 136-39. Barbette Battery, . . 52

“ 140-47. Embrasure Battery, . . .54

“ 154-61. Powder Magazines, . . 58

“ 163-65. Enclosures for Gorges and Outlets, 60

“ 170. Safety Redoubt, . . .62

Chapter IX

Art. 193. Classes of Lines, . . . . 69

“ 194. Principles regulating the Plan of Lines, 69

“ 206,207. Lines with Intervals, . . 72

“ 20S-11. System of General Rogniat, . . 73

“ 212-15. General Observations on Lines, . 74

Chapter X

Art. 216-23. Intrenchments of Mountainous

Sites,.76

“ 224. Intrenchment of Forests, . 78

“ 225. Intrenchment of Marshes, . . 79

“ 226-36. Intrenchment of Rivers, . . 79

“ 237,238. Intrenchment of Villages, . . 82

“ 242,243. Arrangement of Hedges for De¬ fence, . .85

CONTENTS.

Page

Art. 244-47. Arrangement of Walls for De¬ fence, . . . . .86

“ 250-56. Defensive arrangement of Houses, 87

“ 257-65. Military Positions, . . .89

Chapter XI

Art 266-68. Operations preliminary to the At¬ tack of Intrenchments, . . 92

“ 269-73. Attack by Surprise, . . .93

“ 274-87. Attack by Open Force, . . 95

“ 288-99. Measures to be taken in the De¬ fence, .99

Chapter XII

Art. 300-2. General Observations on Water- Courses, &c., . . . .

“ 303, 304. Reconnaissance of the Locality

for a Bridge, .

“ 305-8. Floating Military Bridges,

“ 309-18. General Observations on Boat-

Bridges, . . . . .

“ 319-38. Construction of the Bateau Bridge,

** 339-41. Operations in breaking up the

Bateau Bridge,

“ 342-45. Bridges constructed with ordinary

“ 346-56. Construction of Raft-Bridges,

“ 353-70. Flying Bridges, ....

“ 371-77.'Trestle Bridges, . . . .

“ 378. Temporary Bridges, .

“ 384-87. Passages on Ice, .

“ 388-99. Preservation and Destruction ©f

Bridges,.

“ 400-6. Passage of Rivers,

106 109

115 118 121 122 xiv

CONTENTS.

CHAPTER XIII. Pa*e

Art. 407-22. Military Reconnaissance,

Chapter XIV

Art. 423-25. Permanent Fortification, . . 135

“ 426-30 General Properties of Permanent

Works, ..... 135 “ 431-36. General Principles that Permanent

Works should satisfy, . . 136

“ 437-46. Description and Properties of the

Outworks, .... 138 “ 447-4S. Object of Interior Retrenchments, 140

“ 449. Arrangement of the Crest of the Glacis 141

“ 450. Object of Traverses in the Covered

“ 451. Communications of Permanent Works, 141

“ 452. Relief and Command of the Outworks, 141

“ 454. Uses of Counterscarp Galleries, . 142

“ 457. General Outline of the Attack of Per¬

manent Works, .... 142 “ 496-505. General Outline of the Defence

of Permanent Works, . . 152

“ 506. Uses of Permanent Works, . . 156

Note A. Relation between the Terre-plein and

Interior Crest of the Square Redoubt, 16 1 Note B. Method of Equalizing the Excavation

and Embankment of a Field Work, 164

INTRODUCTORY CHAPTER

ON THE EFFECTS OF MUSKETRY AND ARTILLERY,

AND THE MEANS OF DIRECTING THEIR FIRE TO OBTAIN THE BEST RESULTS.

As the object of all defensive arrangements, whether artificial objects be raised, or the natural features only of a position be seized upon for the purpose, is to place troops under cover from the enemy’s fire, and to enable them to deliver their own with effect, some knowledge of the chances of hit¬ ting a mark of given dimensions at various distances, as well as the influences which the undulations and character of the ground, and the physical and mental state of the party firing, may have upon their aim, are essential elements in estimating the advan¬ tages which they present. The object of this intro¬ ductory chapter is to present, from the most recent and authentic sources, some of the facts arrived at by experiment , which beai on the question.

I. Remarks cm Target Practice of Small Arms. There is no fact more striking than the great dis¬ proportion between the number of combatants put hors de combat and the amount of ammunition ex¬ pended, even in the most bloody engagements. Hundreds of instances might be cited in support of this. Military writers estimate that not more than

XVI one ball out of ten thousand attains its mark; and it is estimated, for example, that in the Expedition of the French to Algiers, in 1830, which lasted but 15 days, upwards of three millions of cartridges were consumed. The causes of this disproportion¬ ate application of means to an end, may be found partly in a careless use of his ammunition by the sol¬ dier ; partly in the want of good instruction and fre¬ quent practice, particularly in those men who have not been familiar with the use of fire-arms from their youth ; partly in the haste with which a fire against an enemy is delivered, wffiich destroys calm¬ ness and good order, and impairs the aim ; but chief¬ ly by the over estimation of distance caused by fear, smoke, and the moveable character of the mark.

Much depends upon the attention to his duties paid by the officer to prevent this. The men should be frequently practised at target firing, and be taught to note the influence which the firmness with which the piece is pressed against the shoulder, its depression or elevation, according to the distance of the target and the character of the ground, both as to the hardness of its surface and its undulations, have upon the accuracy of the aim. This practice should not be confined to the open field, but be also extended to the various positions in which soldiers may be placed behind breastworks and other shelters, such as palisades, stoccades, loopholed walls, abattis .arranged for defence, &c., in order that the soldier may feel himself perfectly at home under all circum¬ stances, and not be called upon to cast about for the best way of managing his piece in every new emer¬ gency. So far from urging the men to load and fire ra¬ pidly, every pains should be taken by the officer to im¬ press upon them the necessity of not hurrying, of keeping perfectly cool, o' loading steadily and aiming

XVI1 deliberately. Volley firing is admirable practice for this purpose ; that by files is apt to give a slovenly and hurried action to the soldier. The fire of troops in line should be kept, as far as possible, under the control of the officer. His position and means of estimating distance enable him far better to judge of the proper moment than the men generally can. It is generally admitted that not more than four or five rounds can be fired in two minutes, allowing the men time to aim deliberately; three may be fired in one minute, but at the expense of a good aim.

As all infantry now are instructed as well in the duties of skirmishers as in the ordinary service of the line, they should be practised at firing both at a small mark, like the ordinary round target, and at a large square one, with black bands made across it, showing the ordinary height of the knees, centre of the body, the breast, shoulders, head and top of the cap.

As the point blank of the musket fired with the bayonet off is at about 120 or 130 yards, to attain a point at this distance, it must be directly aimed at; when it is at a distance short of this the aim must be below it; and when at one over this the aim must be above it. With the bayonet fixed the musket has no point blank, and to hit a point the aim must always be above it.

The following rules for aiming are given by Robert, a recent French author of high standing, in a work on artillery, as drawn from the practice of the French.

To hit the centre of the body, at all distances up to 110 yards, with bayonet fixed, aim at the breast.

To hit the same point, from 110 to 150 yard* distance, aim at the shoulders.

xvin

To hit the same point, from 150 to 200 yards distance, aim at the head.

To hit the same point, from 200 to 220 yards distance, aim at the top of the cap.

To hit the same point, from 220 to greater dis¬ tances, aim according to circumstances.

II. Probable Effects of Small Arms. Beyond 220 yards the effect of the fire is very uncertain. Beyond 450 yards the ball seldom gives a danger¬ ous wound, although the musket, fired under an elevation of 4°, or 5°, will carry from 600 to 700 yards, and under greater elevations over 1000 yards.

The nature of the surface of the ground, as has already been stated, has considerable influence upon the efficacy of the fire. In broken, or ploughed ground, fire is less effective than on an even firm surface, since in the former the balls that strike it are embedded, whereas in the latter they ricochet, and thus attain their mark; it being estimated that, under favorable circumstances, about one-seventh of the balls produce their effect in this way.

Table of effects of fire on a target 5 feet 9 inches high, and 95 feet in length.

No. of balls out of 100

Distance to the Target

that hit the mark.

in

yards.

On even ground by direct and ricochet shots.

On broken ground by direct shots.

Penetration into pine, &.C., in inches at same distances.

2.2

1.2

0.7

0.4

0.1

Do. into oak same distances.

_____

4 in.

2.3

0.6

0.4

0.1

In rifle practice with the ordinary rifle, owing to the greater length of time requisite to load this arm, xix there is some compensation for the more uncertair aim of the musket in short ranges and large targets. When the distance is under 170 yards and the mark large, the effects of the two arms are nearly equal. But for distances of 220 yards, and beyond, the bal¬ ance is greatly in favor of the rifle. This superi¬ ority of the rifle is more particularly observable in the latest improvements of this arm, by Hall, in loading at the breach.

Decker, a German author of reputation, lays down the following, as the probable number of balls out of 100 which will attain their aim, when fired by well instructed troops, making full allowance for the over-estimation of distances in firing on an enemy.

Troops firing in line at 300 paces, out of 100 balls 1 will touch.

a a

200 “

it it

it a

100 “

a it

“ as skirmishers

400 “

u it

it it

300 “

a it

a a

200 “ it

a a

100 “ it

Rifle practice

400 “

a u

a u

300 “

a g

u a

200 “

u a

The firing of skirmishers is the more effective from the greater deliberation in aiming and in seiz¬ ing upon the opportune moment. Volleys produce a tremendous staggering effect, by the simultaneous fall of numbers, when they are coolly thrown in at short ranges. To produce this effect they ought not to be delivered at greater distances than 200 paces.

Decker condemns file firing except for the pur¬ pose of occupying new troops when first brought before an enemy.

III. Ranges and 'probable effects of Field Artillery. —In artillery practice, the greatest deliberation and

XX coolness must be exercised to obtain good results, There are so many circumstances which affect the aim of artillery, that nothing but the most careful attention to the effects produced by the first few rounds will enable the officer to manage his guns with advantage.

The point blank range of six pounder field guns is about 600 yards, and that of twelve pounders about 700 yds. The chances of hitting a mark are less with pieces of small than of large calibre, ow¬ ing to windage, the effect of wind, &c. The ranges of all calibres vary more when the pieces are fired under small angles of elevation than under large angles.

The following Tables of the number of balls out of 100 which will attain a target 6 feet high, and 95 feel in length, at various distances, is taken from Piobert :—

Distances in yards.

No. of 12 pdr. shot (French) out of 100

U 0 u u u u

Table of the number of balls out of 41 in a can¬ ister which attain a butt 6 feet high, and fifty feet in length.

Distances in yards

12 pdr. canister (French)

4.5

g U l< ((

8.3

7.4

The usual diameter of grape is about one-third that of the ball. To produce a good effect at a dis¬ tance, grape ought not to be less than one inch in diameter. Smaller balls produce greatest effects at

XXI short distances. Grape of one-third the diameter of the ball has sufficient velocity at 880 yards with 12 pounders, and 760 yards with 8 pounders, to dis¬ able men. Whe.i the distance is within 500 yards, the fire of grape is superior to that of ball against troops.

In howitzer practice the shells are fired with small charges, as they break easily when they strike an obstacle with a great velocity. The point blank of the howitzer varies with the charge. The greatest range of the twenty-four pdr. howitzer is about 2200 yards ; that of the six inch about 2600 yards.

The chances of hitting a mark with the howitzer diminish with the length of the bore, the calibre and weight of the shell. The deviations with small charges are nearly double those with heavy charges.

The shell of the howitzer produces no effect when fired against masonry, as it invariably breaks. It imbeds itself in earth and wood, and bursting pro¬ duces a considerable crater. The fragments of the shell are often thrown to distances over 600 yards, and they do great damage to objects near. The wounds from them are very dangerous. The shells loaded with incendiary composition are used to fire buildings.

The rate of firing for field guns is from 35" to 40" for six pdrs., and one minute for twelve pdrs. But when the enemy is close at hand, and deliberate aim not necessary, two rounds may be fired per minute.

IV. Selection of positions for field batteries. The position taken up on the field for a battery must be looked at in a double point of view. 1st, as to its suitableness for annoying the enemy and xxii

2d, as to its being favorable for limiting the effects of the enemy’s fire aimed at the battery.

As a general rule artillery should overlook all the ground over which an enemy might advunce, the pieces of heaviest calibre being placed on the most commandiiig points. The batteries, however, should not be within musket range of w’oods, or of any ground where the enemy’s sharpshooters might find cover to annoy them. The slope of the ground on which the gun rests must not be too oblique to the line of fire, otherwise the shot will not tell; the de¬ clivity of the ground should never exceed one per¬ pendicular to fifteen base. When the ground be¬ tween the battery and the enemy is horizontal and firm, it will be best to take a position near the ene¬ my, as the ricochet shots on such ground do not rise much. If the ground is uneven a distant posi¬ tion may be more favorable to obtain a grazing fire. Positions should be so chosen that hollows, woods, villages, &c., on the front, or flank of the line occu¬ pied by the troops, may be thoroughly swept, to prevent the enemy’s columns from approaching un¬ der cover.

Advantage should be taken of any unevenness of ground to place the artillery under cover until called into action. But all broken ground occupied by batteries should be thoroughly examined, and the avenues Jeading to it, by which the enemy’s cavalry might fall upon the batteries, should be obstructed. Stony ground is a bad position for a battery, owing to the effect of the enemy’s shot in scattering the stones. Very even ground is unfavorable, as well as uneven ground which opens in a funnel shape outwards from the battery, as the enemy is enabled in either case to concentrate his fire from an ex¬ tended front upon the battery. Rough ground xxiii

Dreaks the effects of the enemy’s ricochet shots, and when it presents bluffs or perpendicular faces to¬ wards the enemy it will stop the balls that strike those parts. Undulating ground hinders the enemy from observing the effects of his fire. If the ground in rear of the battery is hidden the enemy will ge¬ nerally aim too high ; but if the battery is relieved against the sky it will assist his aim. It must be borne in mind that in taking advantage of undula¬ tions to cover a battery it will not do to fire from behind the covering ridge, as the aim and range will be rendered very uncertain. Batteries should never be placed directly in front of other troops, since they necessarily attract the enemy’s fire to them, and would therefore cause great damage to the troops in rear.

V. Management of the fire of batteries. The management of the fire with regard to the projectile to be used is very important. It has been observed that the ball and howitz produce a greater moral effect upon troops than grape. When it is taken into consideration that a six pdr. shot will take off twenty-four ranks at a distance of 500 to 600 yards, the tremendous effect of a smashing fire of ball upon a column may be readily understood. A fire of ball or shells should, therefore, be opened upon troops at a distance, when they are in mass, in several lines, or when an enemy’s line can be enfiladed. When an enemy’s column is advancing a fire of ball should be opened on the head of the column; and if it be in retreat the aim ought to be directed on the centre. The fire of shells is good against cavalry, as it produces disorder from the explosion of the shell.

A fire of grape or canister should be opened on troops in line, or in open order, but not at distances xxiv greater than 600 or 800 yards. In an attack upon troops in line, a battery may advance to within 400 or 500 yards before opening its fire of grape; and even nearer if the ground is unfavorable to ricochet, and there is but little danger from an attack of thd enemy’s skirmishers on the flanks of the battery. When an enemy’s battery advances nearer than point blank range, a fire of grape should be opened upon it, just at the moment when having com¬ menced the movement to place the pieces in bat¬ tery, the flanks of the horses will be offered to the fire.

As a general rule, the aim should be rather low, as ricochet shois produce considerable moral effect. For this purpose, when the ground is favorable to this fire, the aim should be at the mark, but rather under it for distances within 1200 yards; beyond this, and up to 1800 yards, when this fire becomes inefficacious, the piece may be fired with an eleva¬ tion of one degree between its axis and the ground.

Our fire should be concentrated on several points in succession ; but the pieces of the battery should be separated at wide intervals, when the position will admit of it, to offer fewer chances to the diver¬ gence of' the enemy’s shot. It is seldom of any use to fire a single piece at a small mark, as a group of a few individuals ; if it be suspected that any important personage may be in such a group we should let them have the discharge of an entire battery at once.