Polybius prepared himself for the task of narrating the Italian campaign of Hannibal by personal inspection. Livy did nothing of the kind. The former travelled through the Alpine passes; and his authority was considered so good that Strabo implicitly followed him. It is to be lamented that, as he was writing to his countrymen, he seldom mentions the name of places; probably he thought they would not be the wiser for the enumeration of unknown barbarian names. But his accuracy in dates and distances enables us to trace Hannibal’s route with correctness. These prove that the passage of Hannibal was by the Alpis Graia, the Little St. Bernard; a statement which had been made by that veracious[983] historian, Cælius Antipater, and also by Cornelius Nepos.[984] It has been since confirmed by the researches of modern travellers, such as General Melville, M. de Luc, Cramer, and Wickham. Strange to say, Livy, although following the route marked out by Polybius almost step by step, at length ends it with the Alpis Cottia (M. Genevre.) The absence of names left the fireside traveller at fault. Cæsar[985] had crossed the Alps by that pass; and, perhaps, Livy named it at a venture, as the most familiar to him. In the succeeding portions of his work, so complete is the confidence which he reposes upon the guidance of Polybius, that the fourth and fifth Decades are little more than the history of Polybius paraphrased. Niebuhr,[986] from internal evidence, gives an interesting account of the manner in which it is probable that Livy wrote his history. He supposes that, like most of the ancients, he employed a secretary, who read to him from existing authorities the events of a single year. These the historian mentally arranged, and then dictated his own narrative. The work, therefore, was composed in portions; the connexion of the events of one year with those of the preceding one was lost sight of, and thus they seem isolated; and the conclusion of a series of events sometimes unaccountably synchronizes with the conclusion of a year.