_Field Fortification_ is the art of forming temporary works of defence, such as trenches, redoubts, breastworks, epaulments, _chevaux de frize_, _trous de loup_, &c. See FIELD FORTIFICATION. _Naval_ ARCHITECTURE, is the art of building the hull, or body of the ship, distinct from her machinery and furniture for sailing; and may properly be comprehended in three principal articles. 1. To give the ship such a figure, or outward form, as may be most suitable to the service for which she is intended. 2. To find the exact shape of the pieces of timber necessary to compose such a fabric. 3. To make convenient apartments for the artillery, ammunition, provisions, and cargo: together with suitable accommodations for the officers and men. ARCHITRAVE, the master beam, or chief supporter, in any part of a subterraneous fortification. AREA, the superficial content of any rampart, or other work of a fortification. ARIGOT, _Fr._ a fife or flute. ARM--Military writers use this word to signify a particular species of troops--thus the artillery is an arm, and the cavalry, and infantry, and rifle men are each called an arm; but this use of the word is now deemed quaint. ARM, in geography, denotes a branch of the sea, or of a river. ARM is also used figuratively to denote power. _To_ ARM, to take arms, to be provided against an enemy. ARMADA, a Spanish term, signifying a fleet of men of war, applied particularly to that great one fitted out by the Spaniards, with an intention to conquer England in 1588, and which was first dispersed by a terrible storm, several of the ships wrecked on the coasts of England and Ireland, and many overtaken and defeated by the English fleet, under admirals Howard and Drake. ARMADILLA, a Spanish term, signifying a small squadron. ARMATURA, in ancient military history, signifies the fixed and established military exercise of the Romans, nearly in the sense we use the word exercise. Under this word is understood, the throwing of the spear, javelin, shooting with bows and arrows, &c. ARMATURA is also an appellation given to the soldiers who were light-armed. Aquinus seems without reason, to restrain _armatura_ to the _tyrones_, or young soldiers. ARMATURA was also a denomination given to the soldiers in the Roman emperor’s retinue. ARMED, in a general sense, denotes something provided with, or carrying arms. _An_ ARMED _body of men_, denotes a military corps or detachment, provided with arms and ammunition, ready for an engagement. ARMED, in the sea language. A cross-bar-shot is said to be armed, when some rope-yarn, or the like, is rolled about the end of the iron bar which runneth through the shot.