Chapter XVIII: Air Craft and Motor Vehicles in War (1)

While other branches of the service have hundreds of years of precedents back of them, there is very little past experience to guide us in the use of air craft in war. Portable observation stations, captive balloons, and man-lifting kites still form part of the equipment of all modern armies, but the two principal classes of air craft today are air ships and aeroplanes.

That air craft will play a very important part in future wars is no longer questioned, but the development of both air ships and aeroplanes is proceeding so rapidly that it is difficult to say today what they will be capable of doing tomorrow. There are many possible uses for this new arm of the service, but a number of these are still largely matters of speculation. Others, however, are now well determined and these in themselves are of sufficient importance to require the adoption of air craft as an indispensable part of the equipment of any army.

There is a natural tendency on the part of those who are engaged in the development of a new instrument of war to exaggerate its power and minimize its limitations. Air craft at the present moment are capable of rendering most valuable service, and with the improvements that are bound to come, their value for military purposes will be greatly increased; but the claims of certain enthusiasts that aeroplanes and air ships have rendered cavalry obsolete and revolutionized the art of war have no foundation of fact.

_Characteristics._ _Aeroplanes_ can travel about 350 miles and have a maximum speed of 80 or 90 miles an hour, or more. Service machines normally carry a pilot, an observer, and fuel and oil for from four to six hours. Aeroplanes can start and can land without assistance. They can be handled on the ground by three or four men. They can remain in the open for short periods without serious deterioration. When flying at normal working altitudes they are difficult to hit. Their chief use is for reconnaissance. On the other hand, aeroplanes cannot always be depended upon to be ready for work whenever they are needed. Compared with most war equipment, both aeroplanes and aeroplane engines are extremely fragile. Flying round an aerodrome where landings can be made on suitable ground, an average pilot will rarely injure his machine. But in war, pilots will be required to fly in all sorts of weather and will be forced to land on all sorts of ground in order to deliver promptly the information they have obtained. Minor breakages are bound to result and machines will be so badly strained that frequent overhauling will be necessary. Moreover, the engine, even with the best of care, should be overhauled after running twenty or twenty-five hours. It will be necessary, therefore, to provide large quantities of spare parts and to deliver these wherever needed. The care and repair of aeroplanes and engines require a highly trained commissioned and enlisted personnel.

Types are in active process of development and they vary with different nations. It seems certain that for the immediate future, no single type of aeroplane will suffice for all purposes but that air fleets will be composed of craft suited to different functions as is the case with sea craft. Examples of the variety of types are: The _destroyer_, a pusher biplane, armed with a machine gun in front and arranged to carry bombs and a wireless equipment but without armor. The _battleplane_, of great size, speed and offensive power, has a pilot with two soldiers each operating a machine gun that fires in all directions. The _artillery spotter_, carries armor, operates at a low height and has low speed; it carries an observer and a wireless equipment. The _scout_, a one man craft capable of great speed up to 80 or 90 miles per hour, or more, and great climbing power. It is equipped with rifle or revolver and is unarmored.

The principal problems remaining for solution in aeroplane development are concerned with obtaining a dependable motor and a propeller able to withstand the very great centrifugal stresses.

In several countries, and depending upon the nature of the duty, aeroplanes are organized and operate in squadrons of 6 to 8 machines. These squadrons are served by motor trucks that tow them from place to place. Some machines have wings that fold when being towed.

_Air Ships._ Air ships have a radius of action of about 1000 miles and a speed of from 40 to 50 miles an hour. They can remain in the air for many hours at a time, can hover over a selected spot, and can be used safely at night and in mist or rain. They afford a good field of view and can carry a number of observers. Their chief use is for distant reconnaissance which is greatly facilitated by their long range wireless equipment. Compared with aeroplanes, they offer an easy target and require a large number of trained men to handle them on the ground. The difficulty of maintaining them in the field makes it necessary to operate them from fixed bases established in time of peace.

Balloons are still used. Captive balloons are employed for tactical reconnaissance, and for observation of artillery fire; they are usually equipped with telephones.

Hydroaeroplanes are employed with navies, but have not come into extensive use.

_Armor and armament._ The weight of armor reduces the speed and the lifting capacity of aeroplanes. At present, armor is in general limited to a bullet proof seat for the pilot, and bullet proof protection to the fuel tank. Airships are able to carry more extensive armor. Aeroplanes are not very vulnerable to fire; to bring one to earth it is in general necessary to disable the pilot or to puncture the fuel tank. Even these accidents do not necessarily involve the destruction of the craft; pilots volplane successfully to earth without the use of the motor. Aeroplanes are frequently riddled with bullets without interfering with their operation. The principal armament of the aeroplane is the machine gun. The rifle and revolver are also used, as also small calibre guns. The armor and armament of a particular type depend upon the use to which that type is destined.

_Duties._ The primary duty is reconnaissance, both strategic and tactical. Reconnaissance consists usually in the location of troops and artillery positions.

Strategic reconnaissance by aeroplane is practicable for a distance of 150 miles; it endeavors to ascertain the position, strength, directions of movement, and dispositions of the larger elements of the enemy and also knowledge of the terrain in the theatre.

Tactical reconnaissance by air is used in both attack and defense. It is necessarily general in nature because the height of observation prevents close view. It endeavors to discover movements of the enemy, location of his reserve, his cavalry, artillery, movements of wagon and auto trains, camps, lines of communication, the nature of terrain, etc. Air reconnaissance extends and supplements that of cavalry but does not supplant it. Often verification of reconnaissance must be secured by actual contact.

The duty of reconnaissance involves the corresponding prevention of hostile reconnaissance. This duty has resulted in developing in most armies special types of fighting craft, the aim of which is to secure command of the air within the military theatre. There is in this a close analogy with the domination of the military theatre by sea power or by cavalry. Another important duty of air craft is that of directing artillery fire. For this purpose air craft are usually assigned one to each group of batteries, and operate directly under the orders of the artillery commander. Their information is conveyed by wireless, by smoke bombs, by visual signals, and by dropping messages. These methods are all in active process of development and vary with the different nations.

Hostile artillery in position, is discovered by the flash of its guns, by telltale wheel tracks to the artillery position and by activity in the position. For mid-range firing, aeroplanes can frequently direct the fire from a position directly above or even behind the friendly artillery.

Another duty of air craft is that of air raids. This duty is less important than the others. Like most other raids, those by aircraft are likely to have but little direct bearing on the military situation; but within special range they will continue to be performed. The objectives for air raids are capitals of states, military bases, hangars, lines of communication, depots, arsenals, etc. Raids are usually ineffective against troops or fortifications.

Another important function is the carrying of staff officers, of maps, dispatches, etc., as also reporting promptly the positions and movements of friendly troops.

_Practicable heights for observation._ Satisfactory reconnaissance from air craft requires low flying height and low speed. These two elements increase greatly the vulnerability of the craft. Air craft are comparatively safe from all kinds of fire, at 6000 feet elevation and are entirely safe at 10,000 feet. In clear weather the observer, at an elevation of about 5000 feet, can detect bodies of troops for a radius of four to six miles. Aeroplanes are practically safe from rifle fire at 2000 yards range or at an elevation of 3000 feet. They are reasonably safe from field artillery fire at 4000 yards range or at an elevation of approximately 4500 feet. It is difficult to reconnoiter in a wooded country. Timbered areas, therefore, have a new importance in the concealment they afford from overhead observation.

The safe heights above mentioned are in general too great to afford detailed observation, the necessity for close observation will, therefore, lead bold airmen to a closer approach to the enemy. By swerving, changing velocities, diving, soaring, etc., the airman reduces the risk involved in a close approach to the enemy. He will have added protection from hostile fire when he can soar directly over the anti aircraft guns, none of which is able to fire vertically upwards; also by operating where hostile projectiles will be likely in their fall to damage other hostile troops, and also by utilizing the protection of hills, etc. The vibration of the machine prevents satisfactory use of field glasses. The observer is restricted to observation with the naked eye.

Airships because of their greater size and slower and more regular motion, must remain at greater altitudes for safety than aeroplanes. Accordingly they will be less frequently employed for battlefield reconnaissance or wherever exposed to rapid fire of anti aircraft artillery.

_Defensive measures._ The principal defense against air craft is command of the air by superior air fleets. The tactics of air reconnaissance are, therefore, largely similar to those of cavalry or of sea power. The secondary defense against air craft consists of anti aircraft artillery. For elevations up to 3000 feet, the machine gun is effective. For greater elevations land forces must protect themselves by artillery. Special types of guns of great rapidity of fire are used as is also the standard light field types. The special types of anti aircraft artillery are usually employed in the protection of capitals, lines of communication, etc. They have a lesser application to mobile forces, because the need is less and the economy of road space greater. Light field artillery to be effective against air craft must be capable of firing at an elevation of 45 to 50 degrees. This calls for special types of trail and the necessity of digging pits for the trail.

Range finders are in general of little efficacy in locating the fast moving target. Artillery fire seeks its object in speed and volume of fire, rather than in attempted accuracy. Volume of fire may keep air craft away even if hits are few. Tracer shells emitting smoke are much used to assist observation of fire. To bring down an aeroplane it is almost absolutely necessary to disable the pilot or the fuel tank. The airship is much more vulnerable. The target is the gas bag, rather than the pilot.

_Powers and limitations._ From the very first it has been obvious that air craft would be of enormous value for all kinds of reconnaissance work. Some of their advantages for this purpose are:

1. Speed. It will often be possible for air craft to obtain in a few hours, information that it would require days to secure by any other means.

2. Ability to surmount both natural and artificial obstacles.

3. Ability to determine depth of enemy’s troops as well as front.

4. Having once obtained the desired information, it is comparatively easy to ascend to a reasonably safe altitude and bring the information back.

Some of the limitations of air craft in reconnaissance work are:

1. They can accomplish but little in heavy rains, gales, fog or darkness, though they are steadily improving in their ability to travel in heavy weather.

2. Inability to reconnoiter at night makes it impossible for air craft to keep in continuous touch with the enemy.

3. They cannot be depended upon to be ready for duty whenever they are needed.

4. Observing downwards from a considerable height, detailed knowledge of terrain cannot be obtained.

The European war has given the greatest stimulus to the development of aerial navigation. The art is doubtless destined to the widest expansion in the future. At present it has many limitations, and the absurd claims made for it should be carefully discounted. It has become another arm in warfare.

Like other inventions it is indispensable to the conduct of warfare. A relative preponderance in this arm confers on a belligerent an immense advantage.

(See also “Anti Aircraft Artillery,” Chap. VIII.)

_The motor car_, as lately applied to military purposes, has influenced practically every phase of campaign. As affecting _tactics_, it permits the rapid transport of troops over short distances where rail transport, even if available, might be slower than marching. The loading, dispatch and unloading are very rapid and flexible in arrangement. Even where the railroad is available, the motor car or truck is a valuable adjunct, provided suitable roads are available. The railroad can reach only its various stations, but with a system of good highways the motor vehicle can load or deliver at or very close to any designated point. Whereas a very slight accident will interrupt rail traffic the automobile can be stopped only by the destruction of the road (a comparatively rare occurrence) and sometimes even this will cause very little delay. The transportation begins at almost any point, such as camp, bivouac, or barrack, and is complete to the final destination without resorting to marches at either or both ends of the line.

The routing is not confined to any one prepared road bed. Moreover, the transport is not confined to short distances. The European war shows instances of transporting large bodies of troops over distances as great as 100 miles.

In effecting tactical concentrations of bodies of troops, such as reserves at critical points on the battle field itself, the motor car is very useful. The rapid concentration of forces at critical points of the field is the aim of all tactical operations and the secret of success in battle. The motor vehicle rapidly brings the troops to the desired point, fresh for action.

Motor vehicles are useful in the transport of troops pursuing a defeated enemy and correspondingly useful to the retreating force.

Heavy field artillery is utilizing motor transport to an ever increasing extent. The motor truck also lends itself admirably to use as swift, powerful armored cars, which are virtually small, movable forts. Motor trucks have demonstrated their ability to rapidly transport siege howitzers to threatened points along undefended portions of a coast line and thus greatly aid the mobile army in resisting landings. In operations on land the heaviest types of guns and howitzers are successfully transported.

For overseas operations the motor is useful, as it needs less room aboard ship and dispenses with much of the care and attention that animals require.

For _Staff_ uses the motor is specially adapted to the transportation of general and staff officers over the field of battle. It also assists greatly in the distribution of orders; for this purpose the motorcycle also is much used. Officers can thus cover vastly greater territory than by the use of a horse and with practically no fatigue. The result is that officers of ripe experience and advanced age, whose failing physical powers would formerly have prevented their riding horses are now employed in the field. The scope of staff service is greatly increased.

For the _Supply_ of an army the motor truck is particularly valuable. Its speed will vary with the condition of roads but on even mediocre roads it will cover daily several times the distance covered by the horse-drawn vehicle. It needs no halts for rest, operates in a country without regard to green forage areas, is hardier than the animal and is but little affected by weather. Nearly its total carrying capacity is available for cargo, whereas the necessity for carrying forage reduces that of the horse-drawn vehicle.

The motor truck is well adapted to use as a mobile soup kitchen; one small truck will serve a meal for 500 men.

Motor transportation now permits the army to operate at a distance from the base or railhead several times greater than is possible by the use of wagons or, conversely, it permits the supply of the army at moderate distances from a base with a much less number of vehicles; thus it shortens the total road distance of a force and tends to make armies less dependent for subsistence on the military theater. The increasing numerical strength of the modern army requires more and more independence of subsistence drawn from the country in which it operates.

In line of communication service, the armored car greatly assists in thwarting hostile attempts to cut the line.

The greater the capacity of motor trucks the more economical they are as carriers if the roads are satisfactory. In many theaters where American forces will continue to operate for some time to come, indifferent roads will be the rule; the economic size of the truck is accordingly restricted to a cargo capacity of about 1½ tons.

Motor trucks equipped with flanged steel wheels may be used on railroads in lieu of or in addition to the regular rolling stock. If both kinds of wheels (road and railroad) are carried, or interchangeable sets of demountable rims, the same truck may be used on both road and railroad. The change of wheels or rims can be made in a few minutes.

The motor vehicle is extensively employed in the ambulance service. In addition to its superiority from an humanitarian point of view, it has a very great capacity for the evacuation of sick and wounded, thus contributing to the increase of tactical efficiency of the army.

For the service of _information_, the motor is useful in patrolling; its speed and carrying capacity is great; it is in many ways less likely to attract notice than is a group of horsemen. It has been used for the prompt occupation of important points weakly defended. It is a useful adjunct to the aero service; aeroplanes organized into divisions of 7 or 8 machines are served by motor vehicles which transport the aeroplanes; the wings of the latter being folded for transport. The aeroplanes, which would otherwise be very vulnerable in camp, have thus some protection against the risk of sudden capture.

The motor car, in short, aids in strategic and tactical concentration of troops and heavy guns and in the defense of isolated points, lessens fatigue, and extends the theater of command, inspection and reconnaissance. It greatly increases the scope of operations by increasing the mobility of an army and making it largely independent of local food supplies; its humanitarian service is very satisfactory.

No army devoid of good motor transport service can thus hope to maintain itself against an adversary well equipped in that respect. All trained armies will be equipped with motors; therefore the motor will not permit a diminution of effort by a belligerent; to impose one’s will upon a trained adversary, the effort must in fact be greater than ever.

For efficiency of service, motors are employed where practicable in groups of the same type. This facilitates training of personnel, interchangeability of parts, repairs, etc. In armies generally, the field and combat wagons continue to use animal power.

The motor can enter every department of military activity, increasing the efficiency of operation therein. It is as applicable to campaign as to most other phases of modern life.

GLOSSARY
of
Military Terms Employed in the Text
(Consult also Alphabetical Index)

=Abatis.=--An obstacle consisting of felled trees,
often interlaced with wire. The trees are felled or
placed with their tops toward the enemy, the butts
often remain attached to the stumps, or are secured
to the ground by stakes.

=Adjutant.=--The executive officer of a command.

=Advance cavalry.=--_See Cavalry._

=Advance guard.=--A body of troops which marches
in front of a command in column of route to
facilitate the march and protect the main body from
surprise. _See Chap. IV._

=Advance party.=--The leading formed element of an
advance guard.

=Advance supply depot.=--A station for the issue
of ammunition, rations and other supplies, where
the trains attached to the combatant troops are
sent to refill. _See Chap. XVII._

=Advanced position.=--A defensive position in
advance of the main line of defense.

=Aiming point.=--_See Artillery fire._

=Ambuscade.=--A surprise attack delivered by a
body lying in wait for its enemy.

=Angle of site.=--The inclination or slope of the
ground as affecting the angles of elevation of
artillery.

=Applicatory method.=--A system of military
peace training by means of the solution of
practical problems in strategy and tactics. These
problems are solved on a map or on the terrain,
and are called =map problems=, =terrain
exercises=, =war games=, etc. _See Chap.
I._

=Artillery.=--The heavier pieces of ordnance, as
distinguished from small arms and machine guns.
Artillery includes guns, howitzers, and mortars of
various calibers, and the troops attached thereto.
All modern artillery is rifled. Mobile artillery
is habitually mounted, both for transport and use,
on wheeled carriages, and accompanies the mobile
troops. _See Ordnance._

=Artillery fire.=--_See Chap. VIII._ The
usual method of fire of modern artillery is that
which employs =indirect laying=. The guns are
concealed and the target is usually not visible
to the gunners. The officer directing the fire
ascertains the range and direction of the target
from one of the guns of the battery, called
the =directing gun=. He also determines
the difference in azimuth or direction (at the
directing gun) between the target and some
conspicuous object visible to all the gunners. This
point is called the =aiming point= and the
angular difference of azimuth of the target and the
aiming point is known as the =deflection=.
This is set off on the gun sight in such manner
that when the sight is directed on the aiming
point the gun will be directed on the target.
Due to their different positions the deflections
at the other guns will vary slightly from that
at the directing gun. This variation is called
the =deflection difference=. By varying the
=deflection= and =deflection difference=
the officer in charge may distribute the fire over
the front of the target. The range is determined
by the process known as =bracketing=. The
approximate range having been estimated or
determined by a mechanical =range finder=, a
shot or group of shots is fired at the estimated
=range=. They burst on impact, and from
observation of the smoke it is possible to
determine whether the shots are =short of= or
=over the target=. The range is then increased
or decreased and the firing continued until two
consecutive bursts are obtained, one on either
side of the target. Thus if a shot at 3,000 yds.
bursts short of the target and one at 3,400 bursts
over, it is known that the target lies between
these ranges. Two shots at known ranges, one over
and one short, form a =bracket=. The length
of the bracket may be reduced by interpolating
intermediate shots. Bracketing need not be done
by a single piece. To save time a number of shots
on both sides of the estimated range may be fired
simultaneously by different pieces.

=Barrage.=--A zone or belt of the terrain more
or less continuously swept by the fire of field
artillery, with the purpose of preventing or
discouraging the passage of hostile troops across
the fire swept space. Such a barrage or =curtain
of fire= might be designed to break down the
fighting power of a line of battle by preventing
the forwarding of ammunition, supplies and
reinforcements. It may also be established in front
of hostile line for the purpose of checking or
breaking up an assault or counter-attack, etc.

=Base depot.=--_See p. 365._

=Billeting.=--Quartering troops in the homes
of local residents, who may be required also to
furnish food. The practice is common in Europe but
has seldom been employed in this country.

=Bivouac.=--A camp of very temporary nature, such
as that of troops on the open field of battle. The
shelter and bedding are such as the troops carry on
their persons.

=Bracket.=--_See Artillery fire._

=Bomb-proof.=--A shelter, usually subterranean,
against high explosive shell.

=Caisson.=--A carriage for artillery ammunition.
It consists of two parts, the =body= and
=limber=, each mounted on wheels. The two
parts may be separated. The limber is the forward
portion to which the team is attached, and is
identical with the limber to which the gun is
attached on the march. The separation of the
caisson body and limber, or of the gun and limber,
is called =unlimbering=.

=Cantonment.=--A camp of rather permanent nature
where the accommodations are more elaborate than in
the ordinary camp under canvas. The shelters often
consist of rough huts or simple frame buildings
erected for the purpose. The term is also applied
to portions of towns occupied by troops for a
protracted stay.

=Cavalry.=--Cavalry, according to its uses, has
several classifications:

=Advance guard cavalry.=--Attached to the
advance guard.

=Advance cavalry.=--That portion of the
advance guard cavalry which precedes the point of
the advance guard.

=Independent cavalry.=--Cavalry operating
independently of all save the supreme commander.

=Outpost cavalry.=--Attached to the outpost.

=Rear cavalry.=--Attached to the rear guard.

=Chevaux-de-frise.=--An obstacle in the form of a
saw-horse with several legs.

=Clinometer.=--A small hand instrument used to
measure the inclination or slope of the ground, or
the angle of elevation of a gun.

=Column.=--A formation of troops in which the
elements are placed one in rear of the other, as a
column of route.

=Combined sights.=--_See p. 331._

=Communications.=--The prepared routes by which
troops move from one part of a position to another;
also their lines of supply and reinforcement. The
term is also applied to telegraph, telephone, and
other signaling apparatus.

=Connecting files.=--_See p. 61._

=Conscription.=--The act of impressing men for
compulsory military service; the draft.

=Contact squadron.=--_See p. 149._

=Containing.=--The act of restraining or delaying
the movements of a hostile force, by attack or
threatened attack, with the object of preventing
its junction with other hostile forces. _See p.
91._

=Convoy.=--_See p. 95._

=Cordon system of outposts.=--_See p. 184._

=Cossack post.=--A group on the line of
observation of an outpost. It consists of four men,
and places one sentinel.

=Counter-attack.=--Offensive operations by troops
whose general attitude is or has been defensive.
_See p. 236._

=Counter-mining.=--The subterranean operations
of troops on the defensive for the purpose of
frustrating the efforts of the attack.

=Cover.=--Protection from fire or view, or both.

=Crest, geographical or topographical.=--The
highest part of a ridge or elevation.

=Crest, Military.=--A line or position on the
front slope of a hill or ridge which affords a good
view of the whole or of some special portion of
the foreground. Depending on the configuration of
the terrain, it may or may not coincide with the
geographical crest. _See Fig. V, p. 135._

=Curtain of fire.=--_See Barrage_.

=Danger space.=--That portion of the trajectory in
which the height of the projectile above the ground
is less than the height of the target. The length
of the danger space varies with the flatness of the
trajectory and the height of the target. Thus, for
a man standing, the danger space is that portion
of the trajectory in which the height of the
projectile above the ground does not exceed about 5
ft. 8 in.

=Dead space.=--A portion of the terrain,
especially in front of a defensive position, not
covered by fire; a defiladed area.

=Defensive position.=--A line or zone of the
terrain occupied by troops and prepared for defense
by means of field fortifications.

=Defilade.=--Vertical cover from view or from
fire. Troops behind a crest are said to be
defiladed if shots which skim the crest also pass
over their heads. =Flash defilade= is a mask
of sufficient height to conceal the flashes of guns.

=Defile.=--A narrow passage, such as a bridge or
mountain pass, that prevents or embarrasses the
deployment of troops passing through it.

=Deflection.=--_See Artillery fire._

=Delaying action.=--A combat entered into for the
purpose of temporarily delaying the enemy.

=Demolition.=--The destruction of material objects
by any means.

=Deployment.=--An extension of the front, usually
for the purpose of forming line of battle.

=Deployment, depth of.=--_See p. 349._

=Depth.=--Space measured from front to rear.

=Detonator.=--A small charge of explosive used to
ignite a larger charge.

=Diagrammatic analysis.=--_See p. 29._

=Direct laying.=--_See Artillery fire._

=Directing gun.=--_See Artillery fire._

=Distance.=--_See Depth._

=Dispersion.=--A separation of the elements of a
command, especially when combat is imminent; the
opposite of concentration.

=Division.=--A unit of army organization, the
smallest which includes all branches of the
service. In the United States Army a division has
a strength of about 20,000. It includes infantry,
cavalry, and field artillery, and the necessary
special troops such as engineers, signal, sanitary,
etc., with all the requisite wagon or motor
transport.

=Draft.=--_See Conscription._

=Echelon.=--A term applied to lines or groups that
are stepped or “staggered” with respect to one
another.

=Elongation.=--An increase in the usual road space
or length of a column of troops, due to fatigue,
poor discipline, or other causes.

=Enfilade.=--Fire from the flank, parallel or
nearly parallel to the line against which it is
directed. It is peculiarly effective and demoralizing
to troops against which directed, and is therefore always
carefully guarded against.

=Envelopment.=--An attack directed obliquely
against the flank of a position. _See Fig. IX, p.
219._

=Estimate of the situation.=--A mental review of
a military situation made as a preliminary to and
basis for a plan of action.

=Examining post.=--An outpost station at which
persons endeavoring to pass through the lines are
examined and identified.

=Fascine.=--A long cylindrical bundle of brush
used as a flexible log in a revetment.

=Feint.=--An attack made primarily for the purpose
of diverting the enemy’s attention from more
important operations.

=Field maneuver.=--A practical problem in tactics
prepared for solution on the terrain, with troops.
Both combatants may be represented by real troops
or one by imaginary troops.

=File.=--A single soldier; an element consisting
of one front rank and one rear rank man. A
=column of files= is one having a front of one
or two men.

=Fire superiority.=--Superior moral or physical
fire effect as compared to that of the adversary.
Fire superiority is implied if the assailant
can advance or force back the defender. Fire
superiority for the defender is implied if he
can hold his ground and check the advance of the
assailant.

=Firing data.=--_See p. 116._

=Fixed ammunition.=--Ammunition in which the
projectile and propelling charge are a single
piece, the charge being contained in a cylindrical
metal case with the projectile fixed in the end
like a rifle cartridge. It is used in all small
arms and machine guns and in practically all of the
smaller field guns and howitzers.

=Flanks.=--The extremities of a line of battle,
outpost, etc., and the terrain in their vicinity.

=Foraging.=--The process of obtaining supplies,
especially food, from the local inhabitants, force
being used when necessary.

=Forced march.=--_See p. 89._

=Fortification.=--Any engineering work or
accessory device which increases the fighting power
of troops by affording shelter or concealment or
increased fire effect, or which restricts the
tactical maneuvers or fire effect of the enemy.

=Fortification, field or hasty.=--Those works
executed by combatant troops in the field to meet
immediate tactical needs.

=Fougasse.=--A small land mine with a charge of
explosive and broken stone. It is fired by powder
fuse or electricity, as the enemy approaches.

=Front.=--The known or supposed direction of the
enemy; the theater of active military operations as
distinguished from the country in rear.

=Frontage.=--The extent of front of a command
deployed for battle, of an outpost, etc.

=Fuse.=--A device used for detonating the
explosive charge of a shell or shrapnel. Fuses
are classified as time, percussion, combination
(percussion and time), and delayed action. Time
fuses detonate at the end of a given time,
percussion fuses on impact. A delayed action fuse
is one which delays the explosion of the charge
until the projectile has penetrated the structure
which it strikes. The term fuse is also applied
to powder trains used to ignite placed charges of
explosive in demolition. Electric fuses are devices
which detonate a charge by means of the heating
effect of an electric current. They are also called
primers.

=Gabion.=--A hollow cylinder of brush or other
material which is filled with earth and used as a
revetment.

=General Staff.=--A corps of highly trained
officers charged with the study of the conduct
of war and the detailed methods of military
operations. In time of war they direct and
administer the operations of mobilization,
concentration, supply, transportation, etc.,
and assist the field commanders in planning and
executing their operations.

=Grenade.=--A charge of high explosive in a
container hurled a relatively short distance by
hand or by means of a catapult, rifle, or small
mortar. The charge explodes by time fuse or
concussion. Large grenades are called air mines or
air torpedoes. They are distinguished from high
explosive shell by their relatively short range,
which ordinarily does not exceed 500 yards.

=Guerrillas.=--Irregular troops, not belonging to
the organized combatant forces of a belligerent
state, and not recognized by the laws of civilized
warfare.

=Gun.=--A piece of ordnance fired from a platform
or wheeled mount. A gun, as compared with a
=howitzer=, has a relatively long barrel,
flat trajectory and high velocity. Its effect is
produced largely by the vigor of the blow struck
by the projectile, which is usually combined
with the action of a charge of explosive. Guns,
according to their size and uses, are classed
as =mountain=, =light= or =heavy
field=, =siege= and =seacoast=. All
modern guns are breech-loading rifles.

=Head cover.=--A vertical or nearly vertical
shield of any material which protects the heads of
troops from flat trajectory fire. _See Overhead
cover._

=Heliograph.=--An instrument used for signaling by
flashing the rays of the sun from a mirror.

=High explosive shell.=--A projectile containing
a charge of high explosive fired from a gun or
howitzer. The charge explodes by time fuse or upon
impact. It is used to demolish material objects,
such as fortifications, but is often employed also
against living targets.

=Howitzer.=--A piece of ordnance having, as
compared with a gun, a short barrel, low velocity
and curved trajectory. Its effect is produced
chiefly by the explosion of the charge contained
in the projectile. _See Mortar._

=Hurdle.=--A revetment of woven brush.

=Initial point.=--A point of the terrain from
which the starting times for all elements of a
command are calculated for the commencement of a
march. _See p. 58._

=Initiative.=--A commander is said to have the
initiative when he carries out a preconceived plan,
dictating and controlling the course of operations
and forcing the adversary to meet his lead. The
initiative is ordinarily, though not always,
possessed by the attacker, inasmuch as he usually
selects the time, place and manner of attack, and
forces the defender to adapt his measures to meet
it. A vigorous counter attack, which forces a
suspension of the attack, transfers the initiative
to the original defender.

=Interval.=--An open space between adjacent men
or adjacent organizations on the same line. It is
measured parallel to the front.

=Latrine.=--A dry sewage pit or trench; a cesspool.

=Leading troops.=--The advanced elements of a
command; more specifically a less formal substitute
for an advance guard, employed in retreat or other
situations where a regular advance guard is not
required.

=Limber.=--A portion of an artillery carriage
consisting of an ammunition chest mounted on two
wheels, with a pole for the attachment of the
team. For the march the field guns are attached to
the limbers by engaging the eye at the end of the
trail with a pin or pintle on the limber. _See
Caisson._

=Line.=--A general term applied to all combatant
troops as distinguished from the non-combatant;
a position occupied by troops, as a defensive or
outpost line, etc.; a military formation in which
the elements are placed alongside or abreast of
each other. _See Column and Echelon._

=Line of columns.=--A number of parallel columns
of troops with their heads on the same line.

=Line of communications.=--_See p. 363._

=Line of investment.=--A cordon of troops drawn
around a fortress for the purpose of cutting off
its supply and communication; usually the first
step in siege operations for the reduction of the
fortress.

=Line of observation.=--The line occupied by the
sentinels and observing groups of an outpost.
_See Fig. VIII, p. 195._

=Line of resistance.=--Specifically, the prepared
line of defense of an outpost, usually occupied by
the supports. _See Fig. VIII, p. 195._

=Listening galleries.=--Subterranean galleries
driven to the front for the purpose of detecting
the mining operations of the enemy.

=Listening posts.=--Sheltered positions in
advance of a defensive line for the purpose of
early detection of the enemy’s movements. They are
connected with the main line by a communicating
trench or subterranean gallery.

=Loopholes.=--Openings in a parapet or head cover
through which fire is delivered.

=Machine gun.=--An automatic or semi-automatic
gun of small caliber, capable of great rapidity
of fire. It uses fixed ammunition, preferably
identical with that employed in small arms. The
ammunition is fed automatically from a hopper, clip
or belt. Machine guns are of various sizes and
types, but all are characterized by rather light
construction and great mobility. Some require a
crew of several men for their operation, others are
operated by a single individual. There is hence no
sharp line of demarcation between machine guns and
automatic rifles. _See p. 304._

=Maneuver.=--A movement of a body of troops.
Strategical maneuvers include movements of troops,
on a relatively large scale in preparation for
prospective battle, but usually at a distance from
the enemy. Tactical maneuvers include movements
executed on the battlefield or in the near presence
of the enemy. As compared with strategical
maneuvers they are usually on a smaller scale, in
closer proximity to the enemy, and more immediately
related to battle tactics.

=Map distance.=--The horizontal interval between
contours (on the map) corresponding to a given
slope or gradient.

=Map maneuver.=--A tactical study or exercise
followed out on a map.

=Map measure.=--A recording or counting device
used for measuring distances on a map.

=Map problem.=--A real or imaginary tactical
problem solved on a map. _See Chap. I._

=March outposts.=--Temporary outposts placed by
a marching column during a halt or at the end of
a day’s march. They are withdrawn on resuming the
march or when the regular outpost is in position.

=Marginal distribution.=--An outline of the
dispositions of troops placed in the margin of a
field order. _See pp. 40 and 342._

=Mask.=--A cover from hostile view or fire.

=Matériel.=--The equipment and non-expendable
supplies of an army; any material object.

=Melée.=--Specifically, the confusion following a
cavalry charge, often characterized by hand to hand
combat.

=Mil.=--A unit of angular measurement, the inverse
tangent of one thousandth. _See p. 109._

=Mine.=--A subterranean charge of explosive, used
to destroy hostile fortifications.

=Mining.=--The operations of subterranean attack
and defense.

=Mission.=--The aim or purpose of a commander on
which his decisions and plans are based.

=Mobility.=--The power of rapid movement. Mobile
troops are those capable of quickly changing their
location and dispositions to meet tactical needs.
Non-mobile troops are capable only of passive
defense. It is therefore essential that first line
troops shall be highly mobile. Otherwise they cannot
seize or retain the initiative. Even in defensive
operations mobility is essential to meet the movements
of the assailant.

=Mobilization.=--The change from peace to war
footing. An army is said to be mobilized when it is
assembled, organized, armed, and equipped to take
the field.

=Morale.=--The collective psychological condition
or spirit of troops, especially combatant troops
engaged in battle. High morale is implied when
troops respond readily to the will of their
commander. Morale is therefore measured by the
extent to which troops submit to the control of
their officers.

=Mortar.=--A piece of ordnance having a very short
barrel, low velocity, and curved trajectory. It
throws a projectile containing a large charge of
high explosive, at angles of elevation varying
from 45 degrees to 60 degrees so as to drop the
projectile on top of its target.

=Mutual support.=--Two or more portions of a
firing line which can cross fire on a part of the
front of the position are said to afford mutual
support.

=Obstacle.=--Any natural object or artificial
device which retards the enemy’s movements without
affording him shelter from fire. _See p. 216._

=Orders, field.=--Written or verbal orders
covering the tactical dispositions and operations
of combatant troops. _See Chap. II._

=Ordnance.=--A collective term applied to all
firearms which hurl projectiles. As generally used
the term excludes small arms, such as rifles and
pistols, and applies especially to the heavier
pieces. _See Small arms and Artillery._

=Outguard.=--One of the observing groups of an
outpost. _See p. 183._

=Organization.=--_For the organization of all
tactical units in the U. S. Army, see p. 10 et
seq._

=Outpost.=--A line of observation and resistance
established between a body of troops and the known
or supposed position of the enemy, to guard against
surprise attacks.

=Overhead cover.=--A horizontal or inclined shield
of any material which extends over the heads of
the troops and protects them from grenades or high
angle fire. _See Head cover._

=Pack train.=--A train of animals, usually
mules, carrying packs on saddles. This form of
transportation is used in mountainous country or
where roads are very poor.

=Parados.=--A bank of earth in rear of a trench to
protect the occupants from the back draft of shells
bursting behind the trench.

=Parapet.=--A bank of earth or other material
in front of a =trench= or emplacement which
protects the occupants from fire.

=Patrol.=--A small body of troops, foot or
mounted, sent out from a larger body for the
purposes of observation and reconnaissance. _See
Chap. III, pp. 165, 185, 212, etc._

=Percussion.=--_See Fuse._

=Picket.=--A large outguard.

=Pioneer.=--A member of the mobile engineer forces
of an army.

=Platoon.=--A division of a company, troop or
battery.

=Platoon column.=--A platoon in double column of
files. This formation is much used in advancing
under fire, especially in rough country.

=Point.=--The extreme forward element of an
advance guard, or rear element of a rear guard.

=Ponton.=--A portable boat used as a support or
pier for a floating bridge.

=Ponton equipage.=--The portable floating bridge
equipment of an army.

=Position fire.=--_See p. 325._

=Position in readiness.=--_See p. 308._

=Pusher.=--An aeroplane in which the propeller is
placed in the back of the machine.

=Railhead.=--The forward limit of rail transport
for the supplies and reinforcements of an army.

=Range finder.=--Any device for determining
distances.

=Ration.=--The daily food allowance of a soldier.

=Reconnaissance.=--A rapid examination of a
hostile body of troops, structure, locality,
district, etc., for the purpose of noting features
and gathering information of military value.

=Re-entrant.=--A more or less sharp projection
from a line toward the rear. _See Salient._

=Reinforced brigade.=--A brigade of infantry
with attached auxiliary troops, usually on an
independent mission.

=Relay post.=--_See p. 53._

=Rencontre.=--_See p. 295._

=Requisition.=--A demand for supplies made by an
army upon the local inhabitants.

=Reserves.=--Troops temporarily withheld from
action for the purpose of reinforcement at critical
times and places, to meet emergencies, etc. As
distinguished from =supports=, the place
of their employment in combat cannot always be
foreseen. Also, individuals who have undergone
military training and are available for service but
not at the time a part of the standing army.

=Revetment.=--Any device used to retain earth or
other material at a slope steeper than the natural
slope.

=Road space.=--The distance covered by an
organization in its usual marching formation or
column of route. _See p. 16._

=Salient.=--A more or less sharp projection from a
line toward the front.

=Salvo.=--_See p. 114._

=Sap.=--A zigzag trench dug for the purpose of a
covered advance against the enemy.

=Screen.=--A feature of the terrain which favors
concealment. A disposition of troops designed to
prevent the enemy from obtaining information.
_See p. 165._

=Sentry squad.=--A group on the line of
observation of an outpost. It consists of eight men
and places a double sentinel.

=Shrapnel.=--A projectile containing a number
of small bullets or fragments with a propelling
charge. It explodes in the air and scatters
the bullets and fragments of the case over a
considerable area, being in effect a flying
shotgun. The shrapnel of the 3-inch, U. S. field
gun, when properly burst, will sweep an area 200
to 300 yards in depth and 20 to 25 yards in width,
killing or seriously wounding any man or animal in
the area. It has little effect on fortifications
and is used only against troops. Shrapnel is hence
known as the “man-killing projectile.”

=Siege.=--The formal investment and attack of
a fortress. A fortified place may be reduced by
cutting off its supply, by assault, or by both
methods. Occasionally the actual reduction of the
fortress is not attempted, it being simply covered
by a force of sufficient strength to prevent the
garrison of the fortress from interfering with the
operations of the invader.

=Situation, general and special.=--The (real or
imaginary) circumstances or conditions confronting
a body of troops at any stated time. A military
situation has two parts which are described
as =general= and =special=, or with
respect to time and place, as =distant=
and =immediate=. Past events and future
possibilities or probabilities usually form part of
the situation. _See p. 20._

=Small arms.=--Firearms, such as rifles and
pistols, carried by individuals. The term is
occasionally applied also to machine guns which use
small arms cartridges.

=Spar bridge.=--A type of military bridge in which
the support consists of two trestles which are
tilted toward each other and locked together.

=Splinter-proof.=--A shelter similar to a
bomb-proof but designed to afford protection
only against rifle bullets, shrapnel and shell
fragments. It is not proof against penetration by
large projectiles.

=Squad.=--A unit consisting of eight men, four
files in double rank. The commander, usually a
corporal, is called the squad leader.

=Squad column.=--A squad in double column of
files. _See Platoon column._

=Staff.=--A number of highly trained officers
attached to the larger units who are charged with
the administration of special departments and
who constitute an advisory board to the supreme
commander. _See General Staff._

=Strategy.=--The application of the broad
fundamental principles of the art of war. The
object of strategy is to place troops in the most
favorable or least unfavorable position for battle,
which is the logical culmination of strategy.
Strategy deals with questions of national policy,
national resources, geography, mobilization and
concentration of troops, supply, transportation,
etc.

=Successive bounds.=--_See p. 50._

=Successive thin lines.=--_See p. 328._

=Supporting point.=--_See p. 251._

=Supports.=--Troops held in rear of the firing
line for the purpose of replacing losses, so as
to maintain the firing line at proper strength;
the large groups on the line of resistance of an
outpost; one of the formed bodies of an advance,
rear or flank guard.

=Tactical walk (or ride).=--Tactical instruction
given upon the terrain with imaginary troops.

=Tactics.=--The methods employed in handling
troops in battle or in immediate preparation
therefor.

=Terrain.=--An area of ground considered as to its
extent and topography in relation to its use for a
specific purpose, as for a battle or the erection
of fortifications.

=Terrain exercise.=--A practical problem in
tactics prepared for solution on the terrain, with
imaginary troops.

=Theater of war.=--The territory covered by the
operations of belligerent forces.

=Time fire.=--_See Fuse._

=Trains.=--The supply wagons accompanying an army.
=Combat= and =field= trains are attached
to battalions and squadrons and carry respectively,
the ammunition and rations of the troops.
=Ammunition= and =supply= trains are
attached to the larger units such as a division.
There are also a number of special trains,
including =sanitary= and =engineer=
trains. _See Chap. XVII, Division Supply._

=Trajectory.=--The path of a projectile. Guns of
high power are said to have a flat trajectory, that
is to say, one which approaches a straight line.

=Traverse.=--A bank of earth or other material
in rear of and perpendicular to the parapet of a
trench for the purpose of protecting the occupants
from oblique or enfilade fire and to localize the
effect of shells bursting in the trench.

=Trenches.=--The purpose of trenches is to protect
the troops occupying them from hostile fire.
According to their use they are classified as fire,
support and communicating trenches.

=Troop leading.=--The practical art of commanding
troops. =Troop leading= is often used in
contradistinction to =decision=. The latter
involves the formulation of a plan of action, the
former the practical technique by which the plan is
executed.

=Turning movement.=--The attack of an enemy,
usually on a flank or in rear, by an element of the
command widely separated from the remainder of the
attacking force.

=Visibility problems.=--_See p. 24._

=War game.=--A competitive game conducted on a
map and involving the tactical handling of troops.
The two-sided war game is the usual form, and is
carried on by two individuals or groups under the
direction of an umpire. In the one-sided war game
the umpire dictates the operations of one of the
imaginary combatants.

=Wire entanglement.=--An obstacle of wire or
barbed wire strung on posts or other supports; the
most commonly employed artificial obstacle.

INDEX

TECHNIQUE OF MODERN TACTICS

Practically all the tactical principles and methods discussed in the
text are copiously illustrated by concrete cases in the examples of
orders. These illustrations are taken from carefully selected problems
of the Army Service Schools and constitute a valuable adjunct to and
illustration of the discussions. It is recommended that the student in
each case examine the appropriate examples of orders and supplement
the references sought in the text. The orders are indexed under the
caption--“ORDERS, examples of.”

A