45. There is next to nothing in all this to indicate the route. As for the Allobriges whom Polybios (iii. 51. 9) mentions in the fight at the first gorge, they certainly were not the population of the district, as he says (iii. 49. 13–50. 3) they had been following Hannibal’s army for a hundred miles or more, not daring to attack it till it was entangled in hill-country where its cavalry could not act. Narrow gorges can be found on any Alpine route, and also rocks such as Polybios describes. He says (iii. 53. 5) that Hannibal halted on the eighth night at a defensible white rock, _ti leukopetron ochyron_. But “white rock” means no more than “bare rock,” for he says elsewhere (x. 30. 5) that the white rocks themselves could be climbed up by active men; and, clearly, the colour of the rock would make no difference in the climb. There is, however, a rock that is not only bare but white, the Roche Blanche, on the Little St Bernard, another (near St Michel) on the Mont Cenis, and others on other passes, all identified as Hannibal’s; but Polybios (iii. 53. 4, 5) places the rock at the far end of a gorge into which Hannibal was led by the treachery of his guides. Thus, unless the rock was at the point where he regained the proper route, it will not be found on the main road of any pass at all; nor will the gorge be found on the main road of any pass, as it was on a deviation. Yet people have been identifying gorges on the main roads of the different passes as the very gorge that Hannibal passed through by deviating from the proper route. 46. Polybios (iii. 53. 5, 6) remarks, as something quite unusual, that Hannibal was separated from a large part of his force on the eighth night of the march. If the whole force was brought together on the other nights, the rate of marching would be very slow. Polybios (iii. 56. 4) says that, in spite of heavy losses in the Alps, Hannibal arrived in Italy with 20,000 infantry and 6,000 cavalry; and such a force, with elephants and baggage-train, would form a column of enormous length when marching along a narrow track. The head could not advance beyond a point which the rear could reach on the same day; and the distance would be much less than the average march--see paragraph 3--which Polybios reckons as 10 Roman miles a day.