Part 30

Wisdom and discretion in council point out the form necessary for the first establishment of a warlike enterprise, or disposition, afford the means of bringing it to a conclusion, and assimilate all the various parts so as to unite the whole.

The following maxims are in the memoirs of general Montecuculli.

1. _Deliberate leisurely, execute promptly._

2. _Let the safety of your army be your first object._

3. _Leave something to chance._

4. _Take advantage of circumstances._

5. _Use all the means in your power to secure a good reputation._

The disposition or arrangement of a warlike enterprise may be universal, or particular.

An universal disposition or arrangement of war implies every thing which relates to that system upon an extensive scale; such as the combination of many parts for the ultimate benefit of the whole, &c.

A particular disposition or arrangement of war signifies the detail of minute objects, and the appropriation of various parts, one with another, for the purpose of effecting a general combination. This disposition, (without which the other must prove abortive,) consists in an observance of the strictest discipline by every individual that belongs to a troop or company. To this end, general officers should be scrupulously exact in attending to the inspection of particular corps; specific instructions for regimental œconomy and discipline should be given, and the strictest regard be paid to the execution of orders.

DISTANCE, in military formation, signifies the relative space which is left between men standing under arms in rank, or the intervals which appear between those ranks, &c.

DISTANCES. Inaccessible distances may be found several ways; the most correct of which of course is by means of proper mathematical instruments; which, however, are not always to be had in the field.

The following different methods are laid down by several authors, where instruments cannot be had.

1. Wishing to know the distance of the object A from B (fig. 1.) place a picket at B and another at C, at a few fathoms distance, making A B C a right angle, and divide B C into 4, 5, or any number of equal parts: make another similar angle at C, in a direction from the object, and walk along the line C D till you bring yourself in a line with the object A, and any of the divisions, (say _o_) of the line B C. Then, as C_o_ : C D ∷ B_o_ : B A.

VAUBAN.

2. To gain the distance between two objects C and D (fig. 2.) from any point A, taken in the line C D, erect the perpendicular A E: on which set off from A to E, 1 or 200 feet, more or less, according to the distance between the points C and D; set off from E to G in the prolongation A E, one eighth or one tenth of A E; at G raise the perpendicular G F, and produce it towards I; plant pickets at E and G, then move with another picket on G F till it becomes in a line with E and D: and on the prolongation of the perpendicular F G place another picket at I in the line with E and C; measure F I, and it will be as G E : A E ∷ F I : C D.

3. To gain the inaccessible length A B, (fig. 3.) of the front of a fortification; plant a picket at C, from whence both points may be seen: find the lengths C A and C B by the method just given (No. 1.) make C E ¹⁄₄, or any part of C B, and make C D bear the same proportion to C A: measure D E, then it will be as C D : D E ∷ C A : A B.

See _Am. Mil. Lib._ Article FIELD FORTIFICATION.

Nearly after the same manner may be ascertained the distance from B to A when the point B is accessible; for having measured the line C B, and made the angle C E D equal to C B A, it will be, as C E : D E ∷ C B : B A.

4. The distance of a battery, or other object, may be ascertained by the tangent scale on the breech of a gun. It is however necessary in this case to know the height of the object, the distance of which is required. Lay the gun by the upper line of metal for the _top_ of the object, then raise the tangent scale till the top of the scale and the notch at the muzzle are in a line with the bottom of the object, and note what height of the tangent scale is required: then say, as the length of the scale above the base ring of the gun is to the length from the base ring to the swell of the muzzle, so is the height of the object to its distance from the muzzle of the gun.

5. The breadth of a river, or other short distance, may be taken thus: take two pickets of different lengths, drive the shortest into the ground close to the edge of the bank; measure some paces back from it, and drive in the other till you find, by looking over the tops of both, that your sight cuts the opposite side--Then pull up the first picket, measure the same distance from the second, in any direction the most horizontal, and drive it as deep in the ground as before. Consequently, if you look over them again, and observe where the line of sight falls, you will have the distance required.

6. The following simple method of ascertaining the breadth of a river may be sufficiently correct for some cases: Place yourself at the edge of one bank, and lower one corner of your hat till you find the edge of it cuts the other bank; then steady your head, by placing your hand under your chin, and turn gently round to some level spot of ground, and observe where your eyes and the edge of the hat again meet the ground: your distance from that point will be nearly the breadth of the river.

7. DISTANCES ascertained by the difference between the true and apparent level. See LEVELLING.

8. DISTANCES measured by sound. See SOUND.

9. The following simple micrometer may be so usefully applied to military purposes, that we shall extract it verbatim from the Philosophical Transactions for 1791, where it is described by Cavallo. This micrometer consists of a thin and narrow slip of mother of pearl, finely divided, and placed in the _focus_ of the eyeglass of a telescope, just where the image is formed. It is immaterial whether the telescope be a reflector, or a refractor, provided the eye glass be a _convex_ lens and not a _concave_ one, as in the Galilean construction. The simplest way to fix it, is to stick it on the diaphragm, which generally stands within the tube, and in the locus of the eye glass. When thus fixed, if you look through the eye glass, the divisions on the scale will appear very distinct, unless the diaphragm is not exactly in the focus: in which case the scale must be placed exactly in the focus, by pushing the diaphragm, backwards or forwards, when this is practicable; or else the scale may be easily removed from one surface of the diaphragm to the other, by the interposition of a circular bit of paper or card, or a piece of sealing wax. This construction is fully sufficient when the telescope is always to be used by the same person; but when different persons are to use it, then the diaphragm, which supports the micrometer, must be so constructed as to be easily moved backwards or forwards, though that motion need not be greater than about the tenth or eighth of an inch. This is necessary, because the distance of the focus of the same lens appears different to the eyes of different persons; and therefore whoever is going to use the telescope for the mensuration of an angle, must first unscrew the tube which contains the eye glass and micrometer, from the rest of the telescope, and, looking through the eye glass, place the micrometer where the divisions of it may appear most distinct to his eye. The mother of pearl scale may be about the 24th part of an inch broad; its length is determined by the aperture of the diaphragm; its thickness that of writing paper. The divisions on it maybe the 200th of an inch, which may reach from one edge of the scale to about the middle; and every fifth and tenth division may be a little longer, the tenths going quite across. When the telescope does not magnify above 30 times, the divisions need not be so minute. For the sake of those not conversant in trigonometry, the following is an easy method of determining the value of the divisions on the scale. Mark upon a wall or other place, the length of 6 inches; then place the telescope before it so that the 6 inches be at right angles to it, and exactly 57 feet 3¹⁄₂ inches distant from the object glass of the telescope. This done, look through the telescope, and observe how many divisions of the micrometer are equal to it, and that same number of divisions will be equal to half a degree, or 30′; and this is all that need be done to ascertain the value of the scale. The reason on which it is founded is, that an extension of six inches at the distance of 57 feet, 3¹⁄₂ inches, subtends an angle of 30′, as is easily calculated by trigonometry. To save the trouble of calculation, a scale may be made requiring only inspection. Thus, draw a line equal to the diameter of the field of the telescope, and divide its under side into the same number of parts as are on your micrometric scale, and, by the above operation on the wall, having determined the value of 30′, which we will suppose to correspond with 16 divisions on the scale, mark 30′ on the opposite side of the line, opposite 16 on the lower; 15 opposite 8, and so on.

By the following table the results may be ascertained by inspection only: thus, suppose an extension of 1 foot is found by the table to subtend an angle of 22′, the distance will be 156.2: and suppose at the distance of 171.8 an object subtends an angle of 20′, its height will be found to be 1 foot; or, suppose an object of 6 feet high to subtend an angle of 20′, the distance is 1030.8, by multiplying 171.8 by 6.

_Table of Angles subtended by 1 Foot, at different Distances._

+------++-----+------++-----+------++------------ | Dis- || | Dis- || | Dis- || | Dis- |tances|| |tances|| |tances|| |tances Min-| in || Min-| in || Min-| in || Min-| in utes.| feet.||utes.| feet.||utes.| feet.||utes.| feet. -----+------++-----+------++-----+------++-----+------ 1 |3437.7|| 16 | 214.8|| 31 | 110.9|| 46 | 74.7 2 |1718.9|| 17 | 202.2|| 32 | 107.4|| 47 | 73.1 3 |1145.9|| 18 | 191.0|| 33 | 104.2|| 48 | 71.6 4 | 859.4|| 19 | 180.9|| 34 | 101.1|| 49 | 70.1 5 | 687.5|| 20 | 171.8|| 35 | 98.2|| 50 | 68.7 6 | 572.9|| 21 | 162.7|| 36 | 95.5|| 51 | 67.4 7 | 491.1|| 22 | 156.2|| 37 | 92.9|| 52 | 66.1 8 | 429.7|| 23 | 149.4|| 38 | 90.4|| 53 | 64.8 9 | 382.0|| 24 | 143.2|| 39 | 88.1|| 54 | 63.6 10 | 343.7|| 25 | 137.5|| 40 | 85.9|| 55 | 62.5 11 | 312.5|| 26 | 132.2|| 41 | 83.8|| 56 | 61.4 12 | 286.5|| 27 | 127.2|| 42 | 81.8|| 57 | 60.3 13 | 264.4|| 28 | 122.7|| 43 | 79.9|| 58 | 59.2 14 | 245.5|| 29 | 118.5|| 44 | 78.1|| 59 | 58.2 15 | 229.2|| 30 | 114.6|| 45 | 76.4|| 60 | 57.3 -----+------++-----+------++-----+------++-----+------

DISTANCE _of files_. Every soldier when in his true position under arms, shouldered and in rank, must just feel with his elbow the touch of his neighbor with whom he dresses; nor in any situation of movement in front, must he ever relinquish such touch, which becomes in action the principal direction for the preservation of his order, and each file as connected with its two neighboring ones, must consider itself a complete body, so arranged for the purpose of attack, or effectual defence. Close files must invariably constitute the formation of all corps that go into action. The peculiar exercise of the light infantry is the only exception. See _Am Mil. Lib._

DISTANCE _of ranks_, open distances of ranks are two paces asunder; when close they are one pace; when the body is halted and to fire, they are still closer locked up. Close ranks, order or distance is the constant and habitual order at which troops are at all times formed and move; open ranks, order or distance is only an occasional exception, made in the situation of parade, or in light infantry manœuvres.

DISTANCES _of files and ranks_, relate to the trained soldier, but in the course of his tuition he must be much exercised at open files and ranks, and acquire thereby independence and the command of his limbs and body.

DISTANCE _of the bastions_, in fortification, is the side of the exterior polygon. See FORTIFICATION.

DISTRIBUTION. In a military sense, generally applies to any division, or allotment, which is made for the purposes of warfare. Thus an army may be distributed about a country. In a more confined sense, it means the minute arrangements that are made for the interior œconomy of corps; as distribution of pay or subsistence, distribution of allowances, &c.

DISTRICT, in a military sense, one of those parts into which a country is divided, for the conveniences of command, and to secure a ready co-operation between distant bodies of armed men.

DITCH. See FORTIFICATION, MOAT.

_To drain a_ DITCH, is to make the water run off into lower ground, by means of small trenches cut for this purpose.

DIVERSION, in military history, is when an enemy is attacked in one place where he is weak and unprovided, in order to draw off his forces from making an irruption somewhere else; or where an enemy is strong, and by an able manœuvre he is obliged to detach part of his forces to resist any feint or menacing attempt of his opponent. To derive advantage from a diversion, taken in an extended acceptation of the term, it is necessary, that one state should have greater resources than another; for it would be absurd to attack the territories of another before you had secured your own.

It is likewise requisite, that the country you attack by stratagem or diversion, should be easy of access, and the invasion you make must be prompt, vigorous and unexpected, directed against a weak and vulnerable quarter. A little good fortune is however essential to render a diversion perfectly successful, as all the ways and means by which it ought be made, cannot be reduced to rule.

The most memorable instance of a diversion well executed, which we meet with in ancient history, was performed by Scipio in Africa, whilst Annibal carried the war into Italy. In 1659, a diversion no less remarkable, was practised by the imperial and allied armies against the Swedes.

DIVISIONS _of a battalion_, are the several platoons into which a regiment or battalion is divided, either in marching or firing; each of which is commanded by an officer.

DIVISIONS _of an army_, are the number of brigades and squadrons it contains.

The advance, the main, and the rear guards are composed out of the several brigades, and march in front, in the centre, and in the rear of an army. Each army has its right wing, its centre, and its left wing. When armies march they advance in column, that is, they are divided into several squadrons and battalions of a given depth, successively formed upon one another. If an army be drawn out or displayed in order of battle it is usually divided into the first line, which constitutes the front, the second line, which makes the main body, and the third line or reserve.

DODECAGON, in geometry, is a regular polygon, consisting of 12 equal sides and angles, capable of being regularly fortified with the same number of bastions.

DODECAHEDRON, is one of the platonic bodies, or five regular solids, and is contained under 12 equal and regular pentagons.

The solidity of a _dodecahedron_, is found by multiplying the area of one of the pentagonal faces of it by 12; and this latter product by ¹⁄₃d of the distance of the face from the centre of the _dodecahedron_, which is the same as the centre of the circumscribing sphere.

The side of a _dodecahedron_ inscribed in a sphere, is the greater part of the side of a cube inscribed in that sphere, cut into extreme and mean proportion.

If the diameter of the sphere be 1,0000, the side of a _dodecahedron_ inscribed in it will be .35682 nearly.

All _dodecahedrons_ are similar, and are to one another as the cubes of the sides; and their surfaces are also similar, and therefore they are as the squares of their sides; whence as .509282 is to 10.51462, so is the square of the side of any _dodecahedron_ to the superficies thereof; and as .3637 is to 2.78516, so is the cube of the side of any _dodecahedron_ to the solidity of it.

DOG-_Nails_. See NAILS.

DOLPHINS. See CANNON.

DOMMAGE, _Fr._ in a general acceptation of the term, signified in the old French service, the compensation which every captain of a troop, or company was obliged to make in consequence of any damage that their men might have done in a town, or on a march. If any disagreement occurred between the officers and the inhabitants, with respect to the indemnification, a statement of losses sustained was sworn to by the latter, before the mayor or magistrates of the place, who determined the same. But if the officers should refuse to abide by their decision, a remonstrance was drawn up and transmitted to the secretary at war, with a copy of the same to the intendant of the province. Officers have frequently been displaced or degraded on this account. Hence the term dommage is supposed to have been derived from the latin words _damnum jactura_, and signifies the loss or privation of a step.

DONJON. See DUNGEON.

DOSSER, in military matters, is a sort of basket, carried on the shoulders of men, used in carrying the earth from one part of a fortification to another, where it is wanted.

DOUBLING, in the military art, is the placing two or more ranks, or files into one.

DOUBLE _your ranks_, is for the 2d, 4th, and 6th ranks (when so drawn up) to march into the 1st, 3d, and 5th; so that of 6 ranks they are made but 3; which is not so when they double by half files, because then 3 ranks stand together, and the 3 other come up to double them; that is, the 1st, 2d, and 3d, are doubled by the 4th, 5th, and 6th, or the contrary.

DOUBLE _your files_, is for every other file to march into that which is next to it, on the right or left, as the word of command directs; and then the 6 ranks are doubled into 12, the men standing 12 deep; and the distance between the files is double what it was before. By this method 3 files may be doubled into 6, &c.

_To_ DOUBLE _round_, in military movements, is to march by an inversion of a second line, on the extremity of a first line, thereby to outflank an enemy.

DOUBLE _tenaille_. See TENAILLE.

DOUILLE, _Fr._ a small iron socket which is at the heel of the bayonet, and receives the extreme end of the musquet, so as to be firmly united together.

DOUILLE likewise signifies, the cavity which belongs to the round piece of iron that is fixed to the end of the ramrod, by means of two nails through two small holes, called _yeux_ or eyes, and to which the worm is attached.

DRAGON et DRAGON VOLANT, _Fr._ some old pieces of artillery were anciently so called. The _Dragon_ was a 40-pounder; the _Dragon Volant_ a 32. But neither the name nor the size of the calibre of either piece is now in use.

DRAGONNER, _Fr._ According to the French acceptation of the term, is to attack any person in a rude and violent manner; to take any thing by force; to adopt prompt and vigorous measures; and to bring those people to reason by hard blows, who could not be persuaded by fair words.

DRAGOONS, in military affairs, are a kind of horsemen, or cavalry, who serve both on horseback, and foot; being always ready on every emergency, as being able to keep pace with the horse, and to do infantry duty. In battle, or on attacks, they generally fight sword in hand after the first fire. In the field they encamp on the right and left of the lines. They are divided into brigades, regiments, and squadrons. Their martial music is the clarion or trumpet. The first regiment of dragoons in England was raised in 1681, and called the royal regiment of dragoons of North Britain. This name is derived from the Latin word _Draconarii_, used amongst the Romans. The standard of the Roman cavalry bore as its device a dragon; as that of the infantry bore an eagle.

_To_ DRAGOON, is to persecute by abandoning a place to the rage of the soldiery.

DRAG-_ropes_. See ROPES. See BRICOLE.

DRAIN _or_ DREIN, in the military art, is a trench made to draw water out of a ditch, which is afterwards filled, with hurdles and earth, or with fascines, or bundles of rushes and planks, to facilitate the passage over the mud. See TRENCH.

DRAKE, a small piece of artillery.

DRAUGHT, a plan or delineation of any place; a body of troops selected from others.

_To_ DRAUGHT, to draw forces from one brigade, &c. to complete another; to select a proportion from brigades, regiments, or companies for any particular service.

DRAUGHT-_hooks_, in a gun-carriage, are fixed to the transom-bolts on the cheeks of artillery carriages, near the trunnion holes and trails: they are used to draw the guns backwards and forwards by men with drag ropes fixed to those hooks.

DRAUGHTED, the soldiers of any regiment being allotted to complete other regiments are said to be draughted.

DRAUGHTSMEN, a body of men educated to assist the engineers in drawing plans, fortifications, and surveying; every officer should endeavor to be a good draughtsman; and every corps ought to have a master to teach in camp or quarters.

_To_ DRAW, to delineate or make a sketch.

DRAW RAMROD, a word of command, used in the drill exercise, on which the soldier draws his ramrod half from the pipes, and seizing it back handed by the middle, waits for the signal for the next motion, when he turns it round, and with an extended arm, places the butt of the rod about one inch in the muzzle of the firelock, in which position he waits for the command _ram down cartridge_.

DRAW SWORDS, a word of command in the sword exercise of the cavalry.

The drawing of swords is performed in 3 motions. 1st, Bring the right hand smartly across the body to the sword knot, which being placed on the wrist, and secured by giving the hand a couple of turns inwards, seize the hilt of the sword. 2d, Draw the sword with an extended arm; sink the hand till the hilt of the sword is immediately against the left nipple, the blade of the sword perpendicular, and the back of the hand outwards. 3d. Bring down the hilt till in a line with the bridle hand, the blade perpendicular, the edge turned towards the horse’s left ear.

Officers of infantry, when the men are under arms, draw their swords without waiting for any word of command.

_To_ DRAW _off_, to retire.

_To_ DRAW _on_, to advance.

_To_ DRAW _out_, to call the soldiers forth in array for action.

_To_ DRAW _up_, to form in battle array.

DRAW _bridge_. See BRIDGE.

DRAWING, in a military sense, is the art of representing the appearances of all kinds of military objects by imitation, or copying, both with and without the assistance of mathematical rules.

DRESS-_military_. The clothing of the army is generally called regimentals, every part of which should facilitate, and not hinder, the various motions of the manual exercise. A soldier, without regard to fashion or taste (to use the words of a modern author) should be dressed in the most comfortable and least embarrassing manner possible; and the keeping him warm, and leaving him the entire use of his limbs, are objects always to be had in view.

_To_ DRESS, in a military sense, is to keep the body in such a relative position, as to contribute towards, and form a part of, an exact continuity of line, upon whatever front, or in whatever shape, the battalion may be formed. Soldiers dress by one another in ranks, and the body collectively dresses by some given object.