remarkable that Polybius, though he censures the exaggerations and absurdities with which earlier writers had encumbered their narrative, does not intimate that any doubt was entertained as to the line of march; and Pompey, in a letter to the Senate, written in 73 B.C., alludes to the route of Hannibal across the Alps as something well known. Hence it appears clear that the passage by which he crossed them must have been one of those frequented in subsequent times by the Romans. This argument seems decisive against the claims of _Mont Cenis_, which have been advocated by some modern writers, that pass having apparently never been used till the Middle Ages--See _Dict. of Greek and Roman Biography_, vol. ii., p. 334, 335. [Illustration: Plain of Cannae.] CHAPTER XIII. SECOND PUNIC WAR: SECOND PERIOD, FROM THE REVOLT OF CAPUA TO THE BATTLE OF THE METAURUS. B.C. 215-207. Capua was celebrated for its wealth and luxury, and the enervating effect which these produced upon the army of Hannibal became a favorite theme of rhetorical exaggeration in later ages. The futility of such declamations is sufficiently shown by the simple fact that the superiority of that army in the field remained as decided as ever. Still it may be truly said that the winter spent at Capua (B.C. 216-215) was in great measure the turning-point of Hannibal's fortune, and from this time the war assumed an altered character. The experiment of what he could effect with his single army had now been fully tried, and, notwithstanding all his victories, it had decidedly failed; for Rome was still unsubdued, and still provided with the means of maintaining a protracted contest. But Hannibal had not relied on his own forces alone, and he now found himself, apparently at least, in a condition to commence the execution of his long-cherished plan--that of arming Italy itself against the Romans, and crushing the ruling power by means of her own subjects. It was to this object that his attention was henceforth mainly directed. From this time, also, the Romans changed their plan of operations, and, instead of opposing to Hannibal one great army in the field, they hemmed in his movements on all sides, guarded all the most important towns with strong garrisons, and kept up an army in every province of Italy to thwart the operations of his lieutenants and check the rising disposition to revolt. It is impossible here to follow in detail the complicated operations of the subsequent campaigns, during which Hannibal himself frequently traversed Italy in all directions, appearing suddenly wherever his presence was called for, and astonishing and often baffling the enemy by the rapidity of his marches. All that we can do is to notice very briefly the leading events which distinguished each successive campaign.