Please note that Mommsen uses the AUC chronology (Ab Urbe Condita), i.e. from the founding of the City of Rome. You can use this reference table to have the B.C. dates
The Italian allies, however, were largely drawn upon both for the
naval officers, who must have been for the most part taken from the
Italian mercantile marine, and for the sailors, whose name (-socii
navales-) shows that for a time they were exclusively furnished by
the allies; along with these, slaves provided by the state and
the wealthier families were afterwards employed, and ere long also
the poorer class of burgesses.
Under such circumstances, and when we
take into account, as is but fair, on the one hand the comparatively
low state of shipbuilding at that time, and on the other hand the
energy of the Romans, there is nothing incredible in the statement
that the Romans solved within a year the problem--which baffled
Napoleon--of converting a continental into a maritime power, and
actually launched their fleet of 120 sail in the spring of 494.
It is true, that it was by no means a match for the Carthaginian fleet
in numbers and efficiency at sea; and these were points of the greater
importance, as the naval tactics of the period consisted mainly in
manoeuvring.