Amphithe´atre, an ancient Roman building of an oval form without a roof, having a central area (the arena) encompassed with rows of seats, rising higher as they receded from the centre, on which people used to sit to view the combats of gladiators and of wild beasts, and other sports. The first amphitheatre at Rome was that constructed by C. Scribonius Curio, 59 B.C. The Colosseum at Rome is the largest of all the ancient amphitheatres, being capable of containing 100,000 persons, 87,000 of whom occupied numbered and reserved seats. That at Verona is one of the best examples remaining. Its dimensions are 502 feet by 401, and it is 98 feet high. The name means 'both-ways theatre', or 'theatre all round', the theatre forming only a semicircular building.
Amphitri´tē, in Greek mythology, daughter of Oceănus and Tethys, or of Nereus and Doris, and wife of Poseidon (or Neptune), represented as drawn in a chariot of shells by Tritons, with a trident in her hand. In the Homeric poems she is the personification of the Sea, and her marriage to Poseidon is alluded to in a number of scenes depicted on ancient monuments. Such are a bas-relief in the glyptothek at Munich and a mosaic in the museum at Naples.
Amphit´ryon, in Greek legend, King of Thebes, son of Alcæus, and husband of Alcmena. Plautus, and after him Molière, have made an amour of Jupiter with Alcmena the subject of amusing comedies.
Amphiu´ma, a genus of amphibians which frequent the lakes and stagnant waters of North America. The adults retain the clefts at which the gills of the tadpole projected.
Am´phŏra, a vessel used by the Greeks and Romans for holding liquids; commonly tall and narrow, with two handles and a pointed end which fitted into a stand or was stuck in the ground to enable it to stand upright; used also as a cinerary urn, and as a liquid measure—Greek = 9 gallons; Roman = 6 gallons.
Amplex´icaul, in botany, said of a leaf that embraces and nearly surrounds the stem.
Am´plitude, in astronomy, the distance of any celestial body (when referred by a secondary circle to the horizon) from the east or west points.
Ampthill, a market-town of England, Bedfordshire, about 7 miles south-west of Bedford. Pop. (1921), 2269.
Ampul´la, the Latin name for a vessel bellying out like a jug, which contained unguents for the bath; also a vessel for drinking at table. The ampulla has also been employed for ceremonial purposes, such as holding the oil or chrism used in various Church rites and for anointing monarchs at their coronation. The ampulla of the English sovereigns now in use is an eagle, weighing about 10 oz., of the purest chased gold, which passed through various hands to the Black Prince. The ampulla of the French kings, kept at Rheims in the tomb of St. Remy, was destroyed in 1793.