Although Ravenna and Misenum were the principal stations of their navy, the Romans had fleets at various other places. Forty ships and three thousand soldiers then guarded the waters of the Euxine; a very considerable force was stationed at Frejus (Forum-Julii); numbers of Roman vessels cruised in the English Channel to preserve the communication between Gaul and Britain; while, throughout the whole period of her supremacy, a strong force was maintained on the Danube and Rhine to protect the empire from the inroads of the Northern barbarians. But these fleets were the slow growth of centuries; and the navies of Rome were for a long time of comparatively little note, and obtained celebrity only when the first Punic war roused her citizens to extraordinary exertions to deprive Carthage of its maritime supremacy.[288] Roman fleets were then constructed and spread over the Mediterranean with such rapidity that the Carthaginians would not credit the reports of their number and equipment. In their construction they displayed the energy they had ever shown when they had once determined on their plan. Skilled artisans, from friendly or subjected states, were ready to execute their orders, and the banks of the Tiber resounded with the noise of the axe, the adze, the hammer, and the mallet. Nor is there any reason to suppose that the first fleet Rome sent forth to oppose the powerful squadrons of the Carthaginians was so much inferior to the galleys of Augustus as has been supposed by some writers.[289] But the real character of the Roman vessels cannot now be ascertained; as no Roman historian has thought it worth his while, probably from ignorance on such matters, to give details from which they could, even in imagination, be constructed. It is, however, reasonable to suppose that they were much the same as the ships of the Greeks and Carthaginians, or of the merchant vessel, already described, in which St. Paul made his celebrated voyage, and that their form and dimensions were regulated by the services they were expected to perform. In a note we subjoin a list of the number of fleets the Romans are known to have had in the brief space of twenty years, as they will give a better idea than anything else of the vigour of their administration, and of the energy wherewith, in the best days of the republic, they surmounted disasters which would have crushed to the ground a less self-reliant people.[290]