At the same time, as I have before stated, Publius having left his legions under the command of his brother Gnaeus, with orders to prosecute the Iberian campaign and offer an energetic resistance to Hasdrubal, landed at Pisae with a small body of men. Thence he marched through Etruria, and taking over the army of the Praetors which was guarding the country against the Boii, he arrived in the valley of the Padus; and, pitching his camp there, waited for the enemy with an eager desire to give him battle. [Sidenote: Digression on the limits of history.] +57.+ Having thus brought the generals of the two nations and the war itself into Italy, before beginning the campaign, I wish to say a few words about what I conceive to be germane or not to my history. I can conceive some readers complaining that, while devoting a great deal of space to Libya and Iberia, I have said little or nothing about the strait of the Pillars of Hercules, the Mare Externum, or the British Isles, and the manufacture of tin in them, or even of the silver and gold mines in Iberia itself, of which historians give long and contradictory accounts. It was not, let me say, because I thought these subjects out of place in history that I passed them over; but because, in the first place, I did not wish to be diffuse, or distract the attention of students from the main current of my narrative; and, in the next place, because I was determined not to treat of them in scattered notices or casual allusions, but to assign them a distinct time and place, and at these, to the best of my ability, to give a trustworthy account of them. On the same principle I must deprecate any feeling of surprise if, in the succeeding portions of my history, I pass over other similar topics, which might seem naturally in place, for the same reasons. Those who ask for dissertations in history on every possible subject, are somewhat like greedy guests at a banquet, who, by tasting every dish on the table, fail to really enjoy any one of them at the time, or to digest and feel any benefit from them afterwards. Such omnivorous readers get no real pleasure in the present, and no adequate instruction for the future.