M/I - mustered in

M/O - mustered out

Magazine - A place in which military stores, arms, ammunition, provisions, etc., are deposited.

Main-Body - The body of troops which march between the advanced and rear guards. In a camp, it is that part of the army which is encamped between the right and left wings.

Main Guard or Grand Guard - A body of cavalry posted in front of a camp for the security of the army. In garrison, it is a guard mounted generally by a subaltern officer and twenty-four men.

Malingerer - A soldier who feigns illness to avoid his duty.

Mammelon A round hillock of easy ascent, rising upon the surface of the ground. The word in French literally signifies a nipple.

Maneuvers - Military evolutions. To maneuver troops, is to habituate them to a variety of evolutions, accustom them to different movements, and to render them familiar with the principles of offensive and defensive operations. The term also signifies the management of an armed force, so as to derive sudden and unexpected advantages before an enemy.

Manual Exercise - A regulated method of rendering troops familiar with the musket, and of adapting their persons to military movements under arms. Platoon Exercise is the method of drilling soldiers in small numbers of sub-divisions. Sword-bayonet Exercise is that in which riflemen are taught to use their swords when fixed to the rifle.

Mantlets - Wooden fences, on rolling wheels, used during a siege to protect the sappers from the enemy’s fire.

March (Dead). The strains of music played during the procession of a military funeral.

March (Rogue’s). The beats of a drum when a criminal offender is expelled or drummed out of a regiment.

Marching - Is either in slow time, quick time, or double-quick time. In slow or quick time, the length of the step or pace is thirty inches, except in stepping out, when it is increased to thirty three inches, and in stepping short, when it is reduced to ten inches. In double-quick time, the step or pace is thirty-six inches. In slow time, seventy-five steps or paces are taken in a minute; in quick time, one hundred and eight, and in double-quick time, one hundred and fifty. The side or closing step, which is taken when it is necessary to move a small distance to either flank, is ten inches, and is always taken in quick time; but when taken to clear or cover another soldier, it is twenty-one inches. In stepping back, the step or pace is thirty inches.

Marching By Files - To march with the narrowest front, except that of rank entire or Indian file, of which bodies of troops are susceptible.

Marching, or Billet money - Money paid to officers and soldiers, for covering their expenses incurred when marching for the purpose of changing quarters.

March Regiments - A term given to those corps who have not any permanent quarters. Latterly, they have been denominated regiments of the line or line regiments.

Marines or Marine Forces - Troops raised for the naval service, and trained to fight either in a naval engagement, or in an action on shore.

Mark (To) Time - Is alternately to throw out each foot, bringing is back square with the other, without gaining ground, so that the cadenced step may be preserved until the obstacle is removed which required the necessity of marking time. Changing the feet in marching, by quickly bringing up the ball of the rear foot to the heel of the advanced one, and instantly making another step forward, is to recover the cadenced stop which has been lost.

Matial Law - The law of war.

Martinet - A strict disciplinarian, who gives officers and soldiers unnecessary trouble. The term is supposed to have had its origin from an adjutant of that name, who was in high repute, as a drill-officer, in the reign of Louis XIV.

Masked - Concealed.

Matériél - The appurtenants of an army, such as horses, cannon, ammunition, stores, provisions, etc.

Med-Surg - Medical-Surgical History of the Civil War

Melée - A confused hand-to-hand fight.

Mess - A kind of ordinary table d’hote, at which the officers of a regiment dine.

Military Fever - Humorously called the Scarlet Fever; an overweening fondness for the outward appendages of the soldier.

Military Messengers - Confidential men who are sent on messages, or with letters to and from head-quarters, etc.

Military Regulations - The rules and regulations by which the discipline, formation, field-exercise, and movements of the army are directed to be observed, according to a uniform system.

Militia - Citizen soldiers. Each State has its separate military organization, by which all citizens liable to bear arms are enrolled, and mustered into divisions, brigades, regiments, companies, etc. In most States, even the commissioned general officers are elective, each division electing its commanding officers, who are commissioned by the Governor on their certificates of election. The Governor nominates the adjutant-general, quartermaster-general, inspectors, etc., as well as his own staff. The militia, in time of peace, are only required to attend the various annual or semi-annual musters ordered by State laws. In event of war, the general Government issued its proclamation announcing war and its causes, when the Secretary of War makes his requisition on the Governors of the States for the needed troops. The Governors then accept volunteers for their quota, and send them forward at command of the War Department. If volunteers do not offer in sufficient numbers, then the requisite force is obtained by drafting - The militia are mustered, and the white and black bean, drawn from a box, indicates the men. These either go, or find substitutes—there is no other course. By this admirable system our Government is saved the expense of a large standing army, yet has, upon short call, several millions of troops. The facility of the organization has been made manifest in our recent internecine troubles. An army of very effective men 250,000 strong, was ready for the field in six weeks’ time.

Minié Rifle. A rifle invented by Captain Minie, of France, carrying a conical ball, hollowed at its base. The powder exploding, expands the base of the ball closely into the grooves of the rifle-barrel. Additional force is thus gained for the ball.

Mining - The making of subterraneous passages under the wall or rampart of a fortification, for the purpose of blowing it up with gunpowder. Counter-mining, the making of galleries and mines by the besieged, to counteract the mines of the besiegers.

Missing - The expression used in military returns, especially in field-reports, after an engagement, to account for the general loss of men.

Mitraille - Small pieces of old iron, as heads of nails, etc., with which pieces of ordnance are loaded, commonly called grape-shot.

Mobilize (To). To embody or incorporate. Used in the French service vocabulary.

Mortars - Short brass or iron cannon, of a large bore, for throwing shells.

Mount (To) Guard - To go on duty.

Mount (To) Cannon. To put a piece of ordnance on its frame, for its more easy carriage, and the management of it in firing. To dismount cannon, is to remove it from its serviceable position.

Mount (To) a Gun - Is either to put the gun into its carriage, or when in the carriage, to elevate the mouth, or raise it higher.

Movements - In military parlance, signify the different evolutions, marches, counter-marches, and maneuvers made in tactics.

MUSCN - Musician

Musketry Range - Effective musketry range of fire is when delivered against infantry from 200 to 250 yards, and against cavalry from 30 to 60 yards. The reasons that the range of a cannon or a musket-ball is limited when fired from rifled artillery and musketry, or from the smooth-bored cannon and musket, are, that its momentum gradually diminishes in its range or flight, and is subject to the friction of the air in its passage through it. A ball fired in vacuo would have thirty-four times the range which it was when fired in air. Another reason that musketry fire does so little execution when delivered by troops aligned, is, that owing to the curvature of the earth, at the distance of 800 yards, a man of ordinary stature, presents a mark of only one-tenth of an inch in altitude or height, and at 1,000 feet, but little more than a twelfth. Colonel Schliminback, of the Prussian service, from a number of calculations extending over a series of battles during the wars which sprung out of the French Revolution, ascertained that a man’s weight in lead, and ten times his weight in iron, are consumed before he is put hors de combat! At the battle of Vittoria, nearly four millions and a quarter of ball cartridges and 6,570 round shot and shell were fired by artillery, but the killed and wounded of the French army, consisting of 90,000 men, did not amount to 8,000. The same was true in the Crimean struggle. Notwithstanding the terribly destructive nature of the contest, it is proven that two hundred and eight shots were expended for every man killed! This makes no account of the vast amount of shot and shell used. If even one in ten shot proved fatal, an army would soon be annihilated.

Muster-Roll - A nominal return of the officers and men in every regiment, troop, or company in the service, forwarded monthly to the War Department.

Muting Act - A statute specifying military offenses, and by virtue of which the English army is continued on a peace or a war establishment.

MWIA - Mortally wounded in action

Naval Camp - A fortification consisting of a ditch and a parapet on the land side, or a wall built in the form of a semi-circle, and extending from one point of the sea to the other.

Necessaries (Regimental). The boots, shirts, stockings, et cetera., issued to soldiers.

Non-commissioned Officers - Are those officers elected by the men, or those not served with commissions, either by the general Government of by the State authorities. See Officers. In infantry regiments are, the sergeant-major, the quartermaster-sergeant, the sergeants, corporals, and drum and fife majors.

None-effective - The negative of effective.

Oblique (To). To move forward to the right or left, according to the word of command.

Oblique Deployment - Is when the component parts of a column extending into line, deviate to the right or left, for the purpose of taking up an oblique position; in which operation sits movements are termed obliqued deployments.

Oblique Fife or Defense - A fire under too great an angle.

Oblique Step - A step or movement in marching, taken gradually to the right or left, at an angle of about twenty-five degrees.

Obstacles - In a military sense, are narrow passes, or any impediments which present themselves when a battalion of other body of men is marching in front or rear.

Officers - Are commissioned or non-commissioned. Commissioned Officers are either general, field, staff, or subaltern. Staff Officers are the quartermaster-general, the adjutant-general, brigade officers, and aides-de-camp, etc.

Off-Reckonings. The account of money issued by Government to colonels of regiments, for the clothing of the men.

Opening of Trenches - The first breaking of ground by the besiegers, for the purpose of carrying n their approaches toward the place.

Order of Battle - The arrangement or disposition of the various component parts of an army for battle.

Orderly .A non-commissioned officer or private who attends an officer for the performance of orderly duty.

Orderly Book - A book into which the sergeants of companies transcribe the general and regiment orders, for the specific information of the officers and men.

Orderly Officer - The officer of the day.

Orderly Room - A room in barracks used as a regimental office.

Orders - In a military acceptation, are the lawful commands of superior officers relative to military affairs, and are:

General Orders, which are those issued by the commander-in-chief, for the government of the army at large, or for any specific purpose; Abbreviated G.O.

Garrison Orders, those issued by the governor of a garrison; Abbreviated Gar. O.

District Orders, those issued by a general commanding a district; Abbreviated D. O.

Brigade Orders, those issued by a general commanding troops brigaded; Abbreviated B. O.

Regimental Orders, those issued by the commanding officer of a regiment, arising out of general or garrison orders: Abbreviated R. O.

Standing Orders, general rules and instructions which are to be invariably followed, and are not subject to the temporary intervention of rank. Of this description are those orders which the colonel of a regiment may judge fit to have inserted into the orderly books, and which can not be altered by the next in command, without the colonel’s concurrence; Abbreviated S.O.

Pass Orders, written directions to sentries, etc., belonging to outposts, etc., to allow the bearer to go through the camp or garrison; Abbreviated P. O.

Beating Order, an authority given to an individual, empowering him to raise men by beat of drum, etc., for a particular regiment, or for general service.

Ordnance - Heavy artillery, as cannon, howitzers, mortars, etc.

Outfit - The necessaries, uniform, etc., which an officer provides when appointed to a commission.

Outpost - A body of men posted beyond the grant guard, or the limits of a camp.

Outworks - The works constructed beyond the enceinte or body of a place, as revelins, half-moons, tenailles, horn and crown-works, lunettes, etc.