Chap. XV.

ROMAN.

1S7

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HARBOUR.

Fig. 146. CIVITA VECCHU.

All these ports have long become useless, and the modern one of Civita Vecchia , which isnow at the mouth of the Tiber, is forty miles from Rome , and fourteen leagues distant fromOstia ; it was the ancient Cen-tocella;, so called from its havingan hundred arcades, to which asmany vessels could be moored.

Tlie Roman ships were calledTriremtey Quadriremis , and Quin-queremisy as they exceeded eachother by a bank of oars: therewere vessels still larger, as thehexereSy the hepteres, the octeres,

Sec. ; and the ship Philopater, Plu-tarch informs us, had forty banksof oars; three banks of oars wereraised in a sloping direction oneabove the other, consequently thosewith the greatest number were themost lofty vessels; when in portthey were placed often under ar-cades, and protected from the wea-ther, as we see represented in an ancient picture.

Ttrracina. The size of this port and the walls which surround it show that its establish-ment was calculated for commerce, as well as for the protection of a numerous navy. Twostraight sides united by a gentle curve form this harbour, the entrance to which is 367feet in width ; the length of the other three sides, or its perimeter, is 3705 feet. Itsgreatest diameter is 1319 feet, and the least, which is perpendicular to the pass on theland side, is 1247 feet. Its total area is estimated at 128,107 square yards. Near theright bank of the port is an accumulation of earth, called Monte Cello, collected from thefrequent cleansing. The canal, which now communicates with the port, and which bringsdown the waters from the Pontine marshes, enters through a breach made in a rectilinear partof the enclosure. The wind, which blows directly into the mouth of the harbour, is the north-east, but its force is destroyed by the heights of Pisco Montano, on which, probably, was

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"Fig. 147. ~ ARCADES AT OSTIA.