Page:History of merchant shipping and ancient commerce (Volume 1).djvu/241

 Roman magnificence. The accidents to which the precarious subsistence of the city was continually exposed in a winter navigation (a matter more worthy of serious consideration than the costs of transit) and in an open roadstead, had suggested to the genius of the first Cæsar this useful design, which was executed under the reign of Claudius, and finally completed under Nero. Within the artificial moles which formed its narrow entrance, and advanced far into the sea, "the largest vessels then engaged in the trade of Rome securely rode at anchor;" and in its deep and capacious basins, which were situated on the north bank of the Tiber, every facility was afforded for the discharge of their cargoes. This great work was represented on numerous coins and medals of the period, of which the following, struck by the Emperor Nero, furnishes a fair example.

But Ostia must have borne more resemblance to a wet dock of the present day than to a harbour or "port." At the entrance was a tall tower, which served as a beacon by day, and a lighthouse by night for the guidance of vessels coming into the harbour.