HISTORY OF ENGINEERING.
Rook I.
142
mm
Fig. 152.
MOLE.
SECTION.
The Island of Nisida, or Nesis, is situated at a small distance from the eastern promontory,and on it is now placed the modern lazaretto to the Bay of Naples .
Misenus with its port occupied the opposite promontory or the western side ofthe bay; among the ruins may be traced many hollows in the rock, which probablyserved as docks for shipbuilding. The double port of Miscnus had but one entrance,guarded by a mole, in the usual manner of the Roman ports. Near this part of the coaststood the mansion of Lucullus, afterwards occupied by Tiberius : the poet Phcedrus observes,“ that from its summit might be seen the shores of Sicily.” Pliny the younger and hismother resided here, near the sea, their house being separated from the water only by asmall court.
The Piscina mirabile , a vaulted edifice, divided by four rows of arcades, and situatednear the port, is supposed to have formed part of the great reservoirs constructed to retainfresh water for the vessels that entered the harbour of Misenus, which lies immediately underthe hill on which it is constructed, and, according to Suetonius , it was one of the workscommenced by Nero . He alludes to it in the following quotation : “ Inehoabat piscinama Miseno ad Avernum lacum, contectam ; porticibus conclusam, quo quidquid totis I3aiiscalidarum esset converteretur.”
The port of Misenus is protected by high lands on all sides, and its small haven isalways in a tranquil state: Augustus made it capable of retaining all his fleet. It isseparated from the Mare Morto by a narrow neck of land, through which was cut a canal,crossed by a bridge, without interrupting the navigation into the inner port thus formed.The mountains of Procida and Selvaggi afford a shelter from the north : along the shoresextend the famous Elysian fields.
The mole at Misenus is a fine example of another system practised by the Romans; a
double range of arches is so set out, that the piers of one line are placed directlyopposite the opening of the others. The force of the waves and currents were by thisarrangement broken; at the same time there was no chance of any deposit being madebetween the piers, or within the mole ; and no method can be more economical or judicious.
ELEVATION.
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Fig. 153.
OPEN MOLE.