Books 31-45 are not quite so firm. The chief difficulty here is that there was no contemporaneous historian at Rome for this period except Cato, who wrote a very brief account of a part of it. Polybius was the first to compose the whole story, but excellent as he was, he came some years after the events, had observed, so far as he did, only from his home in Greece, depended largely upon biased Rhodian writers, and knew so little about Rome’s activities outside of Greece that he omitted much, in fact all of Rome’s internal and western history. Campaigns in Gaul and Spain, for instance, did not get recorded at all until they were well permeated with legend, and there was no account available from the opponent’s side. Hence it is that here Livy is of necessity exceedingly uneven, treading on a fairly firm corduroy for most of the important events in Greece, but on a marshy ground of semi-legend when he has to deal with western campaigns. Fortunately the somewhat scanty documents of the state archives had been well culled before him by reliable men like Piso, and these usually kept the legends from dangerous extremes. It is a complete misunderstanding of Livy to suppose that he did not know the weaknesses of Valerius Antias when he used him. Livy knew them all along, but in some portions of this period he had no good source, had nothing available but Valerius and his kind, who had set things down as they heard them, fables and all. Livy’s frequent citation of Valerius Antias does not betoken a gullible love of this writer, but is intended as a danger signal. Here there are several boggy spots. But fortunately the period deals largely with eastern affairs and for that portion the sources were fairly good. It is fair to say that Livy did as well as was to be done in his late day with the material and time available, and that nine-tenths of this portion is acceptable history. The difficulties that an author of Livy’s day had in dealing with the source-materials may be illustrated by a few examples. Hannibal’s famous route over the Alps is still being discussed, though Hannibal had with him on the journey three Greek reporters who described it. Since they had no maps and no compasses, and names of rivers, tribes, and mountains had little interest for them, their accounts were so confused that Polybius and Caelius, who used them, fell into hopeless confusion. Their routes are quite impossible despite the fact that Polybius claims to have searched for the pass. Livy’s route (from the mouth of the Iserè, to the headwaters of the Durance, thence across the passes and down to Turin) betrays lack of autopsy, but it is apparently based upon an identification of place-names mentioned in the sources by the use of some map of the Allobrogic country made, presumably, during Caesar’s campaigns. Thus by using geographical knowledge recently attained he was able to hit upon a very probable solution that was hidden to earlier writers.