Next day, encircling the city from the sea by ships furnished with all kinds of missiles under the command of Laelius, and sending forward on the land side two thousand of his strongest men together with the ladder-bearers, he began the assault at about the third hour.
Mago, who was in command of the place, divided his regiment of a thousand men into two, leaving half of them on the citadel and stationing the others on the eastern hill.
After the rest, he armed two thousand of the strongest with such arms as were to be found in the town, and posted them near the gate leading to the isthmus and the enemy's camp: the others he ordered to do their best to defend the whole of the wall.
As soon as Scipio had given the signal for the assault by bugle, Mago sent the armed citizens out through the gate, feeling sure of striking terror into the enemy and entirely defeating their design.
They delivered a vigorous assault on the Romans who had issued from the camp and were now drawn up on the isthmus, and a sharp engagement ensued, accompanied by vehement shouts of encouragement from both sides, those in the camp and those in the town respectively cheering on their own men.
But as the assistance sent to either side was not equal, the Carthaginians arriving through a single gate and from a distance of nearly two stades and the Romans from close by and from several points, the battle for this reason was an unequal one.
For Scipio had purposely posted his men close to the camp itself in order to entice the enemy as far out as possible, well knowing that if he destroyed those who were so to speak the steel edge of the population of the town he would cause universal dejection, and none of those inside would venture out of the gate.
However, for some time the battle was hotly contested, as both sides had picked out their best men. But finally, as reinforcements continued to come up from the camp, the Carthaginians were forced back, by sheer weight, and took to flight,
many of them falling in the actual battle or in the retreat but the greater number being trodden down by each other in entering the gate.
When this took place the city people were thrown into such panic that even the defenders of the walls fled.
The Romans very nearly succeeded in entering together with the fugitives, and at any rate set up their scaling ladders in full security.
Walbank Commentary