=Arcis-sur-Aube.= A small town in the French department of Aube; here a battle took place on March 20, 1814, between Napoleon and the allied forces under Prince Schwartzenberg. The battle, beginning with several skirmishes on the first day, and ending in a general engagement on the second day, when the French retreated over the Aube, was not in itself very important. But Napoleon now formed the plan of operating in the rear of the allies, and left the road to Paris open; assuming that they would not venture to proceed without attempting first to secure their rear. The allies marched, nevertheless, on the capital, and thus decided the campaign. =Arco.= A metal composed of 70 parts of pure copper, 27 of zinc, and 3 of lead; used for the brass-work of small-arms. =Arcola= (Lombardy). The site of battles between the French under Bonaparte, and the Austrians under Field-Marshal Alvinzi, fought November 15-17, 1796. The Austrians lost 18,000 men in killed, wounded, and prisoners, 4 flags, and 18 guns. The French lost about 15,000, and became masters of Italy. =Arcot= (East Indies). This city (founded 1716) was taken by Col. Clive August 31, 1751; was retaken, but again surrendered to Col. Coote, February 10, 1760; besieged and taken by Hyder Ali, when the British under Col. Baillie suffered severe defeat, October 31, 1780. Arcot has been subject to Great Britain since 1801. =Arcubalist.= See ARBALEST. =Ardalion.= A river in Algeria. On the banks of this river in 398, Mascezil, a Roman general, defeated Gildo, a Moorish chieftain, then in rebellion against Rome. =Ardebil.= A city in Persia; its citadel was constructed by French officers; captured by the Turks in 1827. =Ardres.= A city in the department of Pas-de-Calais, France, it was dismantled in 1850. This city was captured by the Duke of Burgundy, brother of Charles V., from the English in 1377; a treaty was concluded here between Francis I. of France and Henry VIII. of England June 7, 1546; captured by the Spaniards in 1596; returned to France in 1598. =Area.= In a military sense, is the superficial contents of any rampart or other work of a fortification. =Areoscope.= An instrument used for analyzing the air of rooms; used in English medical corps. =Ares.= The god of war in Greek mythology, corresponding to the Roman Mars (which see). =Argaum.= A village in the Deccan, near to which Gen. Wellesley (afterwards Duke of Wellington) totally defeated the army of Dawlut Rao Scindia in October, 1803. =Argelinos=, or =Algerinos=. The Spaniards so named the foreign legion, which was sent to them from Algiers by France, during the reign of Louis Philippe. =Argent.= This word means silver in French, and is always used in heraldry to designate that metal. In engraving English shields the part designated as argent is left white. =Argentaria= (now _Colmar_, Northern France). Where the Roman Emperor Gratian totally defeated the Alemanni and secured the peace of Gaul, 378.