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
They had at their disposal more
than half a million of serviceable soldiers; the Roman cavalry alone
was less good, and relatively less numerous, than the Carthaginian,
the former constituting about a tenth, the latter an eighth, of the
whole number of troops taking the field. None of the states affected
by the war had any fleet corresponding to the Roman fleet of 220
quinqueremes, which had just returned from the Adriatic to the western
sea.
The natural and proper application of this crushing superiority
of force was self-evident. It had been long settled that the war
ought to be opened with a landing in Africa. The subsequent turn
taken by events had compelled the Romans to embrace in their scheme
of the war a simultaneous landing in Spain, chiefly to prevent the
Spanish army from appearing before the walls of Carthage.
