the signal for retreat was sounded, which afforded hopes to the besieged, not only of present rest after such a laborious contest, but also for the future, as it appeared their city could not be taken by scalade and siege.  To raise works they considered would be attended with difficulty, and would give time to their generals to bring them assistance.  Scarcely had the first tumult subsided, when Scipio ordered other fresh and unfatigued troops to take the ladders from those who were tired and wounded and assault the city with increased vigour.  Having received intelligence that the tide was ebbing, and having before been informed by some fishermen of Tarraco who used to pass through the lake, sometimes in light boats, and, when these ran aground, by wading, that it afforded an easy passage to the wall for footmen, he led some armed men thither in person.  It was about mid-day, and besides that the water was being drawn off naturally, in consequence of the tide receding, a brisk north wind rising impelled the water in the lake, which was already in motion, in the same direction as the tide, and rendered it so shallow, that in some parts the water reached only to the navel, while in others it scarcely rose above the knees.  Scipio, referring this discovery, which he had made by his own diligence and penetration, to the gods and to miracle, which had turned the course of the sea, withdrawn it from the lake, and opened ways never before trodden by human feet to afford a passage to the Romans, ordered them to follow Neptune as their guide, and passing through the middle of the lake, make good their way to the walls.

46.  Those who renewed the assault by land experienced great difficulty; for they were baffled not only by the height of the walls, but also because they exposed the Romans, as they approached them, to the missiles of the enemy from different quarters, so that their sides were endangered more than the fronts of their bodies.  But in the other quarter five hundred passed without difficulty through the lake, and then mounted the wall, for neither was it defended by any fortifications, because there they thought the city was sufficiently protected by the nature of the place and the lake, nor were there any outposts or guards stationed there, because all were engaged in bringing succour to that quarter in which the danger appeared.  Having entered the city without opposition, they proceeded direct, with all possible speed, to that gate near which the contest was concentrated; and so intently occupied with this were not only the minds, but the eyes and ears of all, both of those who were engaged in fighting, and of those who were looking on and encouraging the combatants, that no one perceived that the city had been captured in their rear till the weapons fell upon their backs, and they had an enemy on both sides of them.  Then, the defenders having been thrown into confusion through fear, both the walls were captured, and the gate began to be broken