ARCHIME`DES OF SYRACUSE, the greatest mathematician of antiquity, a
man of superlative inventive power, well skilled in all the mechanical
arts and sciences of the day. When Syracuse was taken by the Romans, he
was unconscious of the fact, and slain, while busy on some problem, by a
Roman soldier, notwithstanding the order of the Roman general that his
life should be spared. He is credited with the boast: "Give me a fulcrum,
and I will move the world." He discovered how to determine the specific
weight of bodies while he was taking a bath, and was so excited over the
discovery that, it is said, he darted off stark naked on the instant
through the streets, shouting "_Eureka! Eureka!_ I have found it! I have
found it!" (287-212 B.C.).

ARCHIMED`ES SCREW, in its original form a hollow spiral placed
slantingly to raise water by revolving it.

ARCHIPEL`AGO, originally the AEgean Sea, now the name of any similar
sea interspersed with islands, or the group of islands included in it.

ARCHITRAVE, the lowest part of an entablature, resting immediately
on the capital.

AR`CHON, a chief magistrate of Athens, of which there were nine at a
time, each over a separate department; the tenure of office was first for
life, then for ten years, and finally for one.

ARCHY`TAS OF TARENTUM, famous as a statesman, a soldier, a
geometrician, a philosopher, and a man; a Pythagorean in philosophy, and
influential in that capacity over the minds of Plato, his contemporary,
and Aristotle; was drowned in the Adriatic Sea, 4th century B.C.; his
body lay unburied on the shore till a sailor humanely cast a handful of
sand on it, otherwise he would have had to wander on this side the Styx
for a hundred years, such the virtue of a little dust, _munera pulveris_,
as Horace calls it.

ARCIS`-SUR-AUBE (3), a town 17 m. N. of Troyes, in France,
birthplace of Danton; scene of a defeat of Napoleon, March 1814.

AR`COT, the name of two districts, N. and S., in the Presidency of
Madras; also chief town (11) in the district, 65 m. SW. of Madras;
captured by Clive in 1787; once the capital of the Carnatic.

ARCTIC OCEAN, a circular ocean round the N. Pole, its diameter 40 deg.,
with low, flat shores, covered with ice-fields, including numerous
islands; the Gulf Stream penetrates it, and a current flows out of it
into the Atlantic.

ARCTU`RUS, star of the first magnitude and the chief in the N.
constellation Booetes.

ARDECHE, an