A Thunder of Cannon
Archeology of the Mexican-American War Battlefield of Palo Alto
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AIDE-DE-CAMP—Junior staff officer attached to a general.

ARM (of service)—Cavalry, infantry, artillery, etc.

BALDRIC—A shoulder belt, worn diagonally from shoulder to hip.

BALL—Musket ball or musket CARTRIDGE.

BALLISTICS—Science of projectiles in motion.

BATTALION—A military unit of two or more companies, but smaller than a regiment.

BATTALION COMPANY—"Center" company of an infantry battalion.

BATTERY—Originally a gun emplacement. By the mid-nineteenth century, this term referred to a company-size artillery unit equipped for mobile warfare with a variable number of guns, usually four to eight, depending on standardized method of artillery organization of a nationality or availability and expediency. See FIELD BATTERY.

BLOUSE—Smock-type garment.

BOMB—Mortar shell; loosely applied to all explosive projectiles.

BORE—Interior of a firearm and cannon barrel.

BREASTPLATE—Small badge worn on the shoulder belt.

BREECH—Rear or closed end of a firearm and cannon barrel.

BREECHLOADER—A firearm that receives its load at the breech.

BREVET—A commission to an officer that entitles him to a higher rank without higher pay.

BRIGADE—Military unit larger than a regiment and smaller than a division.

BRIQUET—An infantry sword; a type of HANGER.

BROWN BESS—Nickname applied to Long Land Pattern British muskets and later patterns, including the India Pattern musket.

BULLION—Gold or silver lace.

BUTT—Rearward portion of the stock of a firearm.

BUTT CAP—A metal cap used to cover and protect the butt of a pistol.

BUTT PLATE—A reinforcing plate used to cover and protect the butt of a shoulder arm.

CAISSON—Ammunition wagon accompanying mobile artillery.

CALIBER—Diameter of the bore of a cannon and firearm. For a cannon, this is expressed either as the weight of the solid shot, inches of diameter of the bore, or the diameter of the bore divided into the length of the tube. For a firearm, caliber is usually expressed in hundredths of an inch.

CANISTER SHOT—A tin projectile containing small shot.

CANNON—All tube artillery; includes guns, howitzers and mortars.

CAP—A small metal device containing a percussion-ignited compound designed to ignite the main charge of a firearm.

CARBINE—A shortened form of musket or rifle used by mounted troops.

CARRIAGE—Wheeled mount for a cannon.

CARTRIDGE—For firearms, the paper tube containing the lead ball and gunpowder, the paper used as wadding once its contents were poured into the musket or rifle barrel; for a cannon, the bag or case containing the propelling charge.


CAZADORE—Spanish term, same as light cavalry.

CHARGE—The propellant and round in a firearm and cannon.

COATEE—A short military coat, cut to the waist in front, with short tails that just covered the buttocks.

COCKADE—A rosette of national colors worn on hats and helmets.

COLOR SERGEANT—A top-rank, noncommissioned officer.

COMMISSARY—A supply officer; a military supply depot or dump.

COMPANY—Military unit smaller than a battalion.

CONE—A small tube of a percussion firearm on which is placed the PERCUSSION CAP.

CORPS—A tactical unit consisting of several divisions.


CYLINDER—The part of a multi-firing firearm holding a number of cartridges presenting the loads successively for firing, by revolution about an axis.

DIRECT FIRE—Fire against a visible target.

DIVISION—Military unit larger than a brigade.

DRAGOON—Mounted infantryman and forerunner of American cavalryman, the latter in use by the Civil War.

DUCK—A fine, bleached linen canvas, used for summer wear.

EPAULETE (Epaulette)—An ornamental shoulder piece. During this period, its shape, size and color were used to indicate the wearer's grade and branch of service.

ELEVATION—Angle formed between the axis of the cannon bore and the horizontal.

ELEVATION SCREW—Handscrew under the cannon breech for adjusting elevation.

ENFILADE—Fire from a flank, raking the entire length of a formation.

ESCOPETTE—A short musket with a bell-mouthed or sawed-off barrel, used by Mexican mounted irregulars; also called a "scuppet" by U.S. soldiers.

ENSIGN—Infantry second lieutenant; a BREVET rank at the time of the Mexican-American War in the U.S. Military.

FACINGS—Lapels, cuffs and collars of a uniform coat that were covered or "faced" with a different color than the coat. The colors used often indicated the regiment or service branch of its wearer.

FIELD BATTERY—A company of artillery equipped with guns, horses and vehicles to serve as field artillery; a specific term used to emphasize the difference between such a unit and a conventional, less mobile BATTERY.

FIELD OFFICER (or Field Grade Officer)—A major, lieutenant colonel or colonel.

FIXED AMMUNITION—Propellant and projectile complete as a single unit; artillery projectile with a wooden SABOT affixed.

FLINT—A hard quartz variety stone, possessing fracture properties for a sharp edge, and for producing sparks when the edge was struck against steel.

FLINTLOCK—A firearm equipped with a gunlock in which the impact of a piece of flint against steel produced sparks to set off the priming.

FOOT ARTILLERY—An artillery unit in which only the officers, senior noncommissioned officers (NCOs), trumpeters and drivers were mounted, the other enlisted men marched on foot.

FOREARM—The part of the stock in front of the trigger guard extending under the barrel towards the muzzle.

FORAGE CAP—A light soft leather or cloth cap worn with the undress uniform; same as a barracks cap.

FRIZZEN—The upright, pivoted part of the flintlock mechanism against which the flint struck to produce sparks; also termed "battery".

FROG—A short sheath attached to a belt, designed to hold a scabbard.

FULL DRESS UNIFORM—The showy uniform worn for parades and other military ceremonies.

FURNITURE—Metal fittings on a musket or rifle.

FUSE—Device to detonate a shell or other weapon.

FUSIL—Light musket.

GAUGE—The diameter of the bore of the firearm expressed in the number of spherical balls of corresponding size to the pound. For example, 16 gauge indicates a diameter that would take a round ball of the weight of 16 such balls to weigh a pound.

GRAPESHOT (Grape)—A type of artillery ammunition consisting of metal balls, the number and diameter depending on the caliber of the gun, placed in a canvas bag and tied to form a rough cylinder that fitted the gun's bore. The metal balls used in canister rounds also were informally called grapeshot, although of smaller caliber and greater number. By the early nineteenth century, true grapeshot was reserved for use by Navy and coastal artillery since it was found that CANISTER was more effective for field artillery.

GREAT COAT—An overcoat. During this period, it was usually long and had a cape.

GUN—Long-barreled cannon with a characteristic high muzzle velocity and flat trajectory.

HANGER—A short, heavy cutting sword with a curved blade; generally an infantry weapon.

HAVERSACK—A canvas or heavy linen bag used in the field for carrying rations. Soldiers usually carried the bag over the right shoulder so that it rode the left hip and thus did not interfere with the cartridge box.

HORSE ARTILLERY—An artillery unit in which all men had personal mounts. It, therefore, could move rapidly enough to keep up with cavalry.

HOUSINGS—Horse trappings.

HOWITZER—Short-barreled cannon with a characteristic high angle of fire.

INDIRECT FIRE—Fire against a target not visible from the cannon.

JACKET—A term synonymous with WAISTCOAT or VEST; also a short coat with sleeves.

KERSEY—A coarse woolen cloth, usually ribbed.

KNAPSACK—A infantryman's pack; in the Mexican Army, it was made of cowhide with the hair left on the outside; in the U.S. Army, the knapsack was made of heavy canvas, varnished to make it waterproof.

LACE—Flat braid used for trimming lapels, cuffs and other portions of the uniform.

LANCER—Light cavalryman armed with a lance.

LIGHT ARTILLERY—During this period, a very loose term applied to either foot or horse artillery; field artillery as compared to fortress or siege artillery.

LIGHT INFANTRY—Troops selected for agility, marksmanship, courage and reliability; used for advance guard operations, raids and skirmishing. In some cases, they were issued lighter weapons and equipment.

LIMBER—Two-wheeled, horse-drawn vehicle for pulling gun carriages or caissons.

LINE—A term describing ordinary infantry, cavalry, etc.; meaning "infantry of the line of battle".

LINE OF SIGHT—Straight line from the muzzle of a piece to the target or point of impact.

LINSTOCK—An artilleryman's implement; a staff three feet long with a forked iron head to hold a slow match; used to fire a cannon.

LOCK—The mechanism of a firearm; the function was to ignite the explosive.

LONGARM—A classification name for the longer type of smallarms, such as muskets, rifles and carbines.

MAGAZINE—Storage space for munitions; a supplementary container for musket or rifle ammunition carried on the individual soldier.

MINIE BULLET—An elongated bullet with a cup-shaped hollow in the base which, when expanded by the action of the gases, causes the bullet to take the rifling. Named after C.E. Minie, Captain of Infantry, French Army, to whom the invention of the system is credited. The minie was adopted by the U.S. Army in 1855.

MORTAR—Very short-barreled cannon with a low muzzle velocity and a very high trajectory.

MUSKET—A smoothbore barrel shoulder arm.

MUSKETOON—A shortened musket, commonly used by artillerymen and some mounted units.

MUZZLE—The end of the barrel from which the bullet leaves the arm.

PAN—The receptacle for holding the priming charge for a flintlock.

PARK—Artillery reserve.

PATCH—A leather or cloth wrapper, usually greased, used around the bullet of rifled muzzle-loading arms to facilitate loading.

PERCUSSION CAP—A small metal, cup-shaped device charged with fulminate or other percussion-ignited compound, and placed on the cone of a percussion arm. When struck by the hammer, the explosive compound was ignited by the blow, and the flash was transmitted through the hollow cone to the main charge in the barrel.

PERCUSSION WEAPON—A firearm with a gunlock that fired by striking a percussion cap, a small metallic cap containing a fulminating powder. It replaced the flintlock during this period.

PIECE—A firearm, including any cannon.

PICKET (derived from the French piquet)—Infantry or light cavalry outpost.

PLASTRON—Colored chest-panel on a jacket.

POINT-BLANK—Coincident point of the TRAJECTORY and LINE OF SITE.

PORTFIRE—A tube, usually of thin metal, containing a quick-burning PROPELLANT, such as alcohol mixed with gunpowder. It gradually replaced the linstock during the late eighteenth and early nineteenth centuries.

PRICKER—Wire needle used for clearing musket touch hole.

PROJECTILE—Portion of a ROUND intended for delivery to the target; cannonball, musketball.

PROPELLANT—Explosive charge; gunpowder in a ROUND of ammunition.

RAMROD—A wooden or metal rod used for ramming down the charge of muzzleloading arms.

REGIMENT—Military unit larger than a battalion and smaller than a brigade.

REGULAR ARMY—The permanent Army of the United States, maintained in peacetime as well as during war; the "Standing Army".

RIFLE—A shoulder-fired longarm with a rifled small caliber barrel.

RIFLE MUSKET—A term used by the Ordnance Department in mid-nineteenth century to designate the new musket size rifled arms and long slim rifle caliber barrels.

RIFLING—Grooves cut in the sides of the bore, or the process of cutting such grooves.

ROUND—One complete load of ammunition for one piece.

SABOT—Wooden block on artillery FIXED AMMUNITION.

SABRE (or saber)—A curved cavalry sword; a cavalryman, for example, "a regiment of 800 sabres".

SAPPER—Originally one who dug narrow siege trenches; later the generic term for engineers; see ZAPADORE.

SCALES—A type of shoulder knot made of brass scales. During this period, worn only by mounted troops.

SCHABRAQUE (Shabrack)—A cloth cover fitting over the saddle and saddle blanket; ornamental HORSE FURNITURE. In the United States mounted service it was used mostly for full-dress ceremonies, but the Mexican mounted service used them in the field.

SEMI-FIXED AMMUNITION—One complete round with adjustable components, such as a powder charge.

SEPARATE LOADING AMMUNITION—Powder cartridge and projectile independent of each other.

SHAKO—A cylindrical military cap, made of felt and leather. It originated in Austria and was adopted by England, France, Spain, the United States, Mexico and other nations as standard infantry headgear by the early nineteenth century.

SHELL—Hollow PROJECTILE containing powder and fused to detonate.



SIEGE TRAIN—Heavy artillery, for besieging fortresses and fortified towns, accompanying an invading army. It normally marched with the baggage train.

SMOOTHBORE—A firearm whose bore is not rifled.

SPADROON—Light, straight bladed sword.

STANDARDS—The flags of a cavalry regiment.


STOCK—The wooden part of a firearm; also a wide, stiff neck covering.

SWIVEL—A mechanism permitting motion on a part of an arm so that it remains a part of the piece, for example, a "swivel ramrod", a ramrod attached to the arm yet capable of the movement required for loading.

TRAIL—That part of a CANNON CARRIAGE resting on the ground.

TRAIN—Troops responsible for driving transport, artillery, etc.

TRAJECTORY—Path of a PROJECTILE in flight.

TRIGGER GUARD—The frame placed about the trigger to minimize the possibility of accidental discharge by unintentional pressure on the trigger.

TRIGGER PLATE—The metal part of the firearm through which the trigger projects.

TUBE—The cannon, synonymous with barrel.

UNLIMBER—Unhitch from LIMBER and prepare to fire.

UNDRESS UNIFORM—A uniform worn for normal military duties; less showy but more comfortable than FULL DRESS.

VALISE—A leather case carried behind the cantle on the saddle to hold a horseman's cloak and other articles.

VENT—A small hole, tube or channel used to convey the flash of the ignited priming from the exterior of the BREECH to the main CHARGE in the chamber.

VOLTIGEUR—A French term for a light infantryman, introduced during the Napoleonic Wars. The name was borrowed for the Tenth Infantry Regiment with one horse for each two men, permitting doublemounting for rapid movement. Early plans to give it a special organization, uniform and equipment fell through. Eventually, this regiment actually differed from other regular U.S. infantry regiments only in its name.

WAD—The paper, felt or other material used to retain the CHARGE in the barrel of a firearm and cannon, or in a cartridge.

WORM—A twisted, corkscrew-shaped metal device used on the end of a ramrod in withdrawing the CHARGE in muzzle-loading arms.

ZAPADORE—The Spanish word for "sapper". Zapadores were elite troops in the Mexican Army.

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Last Updated: 25-Feb-2009