CATARACTA
CATARACTA (καταρράκτης).1. A portcullis, so called because it fell with great force and a loud noise. This contrivance for guarding against the surprise of a fortified town was in use in Italy in very early times (Dionys. A. R. 8.67); and the Romans had no occasion to borrow the thing itself, as they borrowed its name in classical Latin, from the Greeks. Vegetius (de Re Mil. 4.4) speaks of the cataracta as an invention of great antiquity; and something like it is found in very primitive buildings, such as the lake-dwellings of the Paeonians
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| Plan of a gate at Pompeii. |
（καταπακτὴ or perhaps κατεπακτὴ πύλη, Hdt. 5.16, with Stein‘s note). As early probably as the 4th century B.C. the simple portcullis had been improved in order to obviate the placing by the enemy of an obstruction in the line of its groove (Aen. Tact. Poliorc. 39); the ropes by which it was raised or lowered were called [p. 1.385]ἀνσσπαστήρια and χαλαστήρια (App. BC 4.78). Vegetius (l.c.) says that it was hung outside the regular gate: and this statement is confirmed by a narrative in Livy (27.28) as well as by existing remains. In the above plan of the principal entrance to Pompeii, now called the Porta d'Ercolano, there are two sideways for foot-passengers, and a road between them, fourteen feet wide, for carriages. The gates were placed at A, A, turning on pivots [CARDO], as is proved by the holes in the pavement, which still remain. This end of the road was nearest to the town; in the opposite direction, the road led into the country. The portcullis was at B, B, and was made to slide in grooves cut in the walls. The sideways, secured with smaller gates, were roofed in, whereas the portion of the main road between the gates (A, A) and the portcullis (B, B) was open to the sky. When therefore an attack was made, the assailants were either excluded by the portcullis; or, if they forced their way into the barbican and attempted to break down the gates, the citizens, surrounding and attacking them from above, had the greatest possible facilities for impeding and destroying them. (Liv., App., Veget., ll. cc.）
2. A boarding bridge, something like the corvus of Duilius [CORVUS], so called because it descended like a portcullis (App. BC 5.82).
3. A sluice, or perhaps rather a weir with hatches or sluices in it for regulating the height of water in a running stream (Plin. Ep. 10.69; Rutil. Numat. de Reditu suo, 1.481, “Tum cataractarum claustris excluditur humor;” cf. Amm. Marc. 24.1,11; 3, 10; 6, 2: Heliod. Aeth. 9.8).