The soldiers were no longer allowed to stray out of the camp when they chose in search of plunder; while bands of traders and a crowd of idle folk who had followed the army, also in hope of plunder, were banished. Luxuries which had abounded in the camp were forbidden by the young commander. Plain fare and regular drill soon made the army more anxious to meet the enemy than to plunder and waste its days in idleness. Now Carthage stood on a peninsula, a narrow isthmus joining it to the mainland. Beyond this isthmus lay Megara, a suburb from which Carthage procured most of her provisions. When his army was ready for work, Scipio determined to cut Carthage off from Megara, so that she might no longer be able to get food for the city. Across the narrow isthmus the Consul therefore ordered trenches to be dug, three miles in length. Along the trenches, fortifications and towns were speedily built, and when these were finished it was impossible to get a morsel of food into the city by land. Megara was then taken, and Hasdrubal was forced to retire with his army into Carthage itself, of which he was at once made governor. The Carthaginians could now only bring food into the city by sea, and this was no easy task. But with a strong wind blowing, there were many brave sailors daring enough to risk being able to run past the Roman cruisers, and thus to carry food into the harbour. So, although Megara was taken, the city was able still to hold out against the enemy without being starved. Scipio saw that he must now block the sea passage as he had already blocked the land, if he meant to starve the city into submission, and he ordered a strong barricade to be built across the mouth of the harbour. The Carthaginians mocked at the Roman soldiers as they watched them bringing great stones to the harbour, for they thought that the enemy had undertaken a task it would never be able to complete. But as they saw that the Romans worked night and day, and as the huge embankment rose before their eyes, they mocked no more. Perhaps after all the Romans would succeed in blocking the harbour, and if that were done they must starve. So they, too, set to work, but in secret, to make a new opening from the harbour to the sea. Men and women, and even children, joined in the work, and at the same time workmen in the city built a new fleet. It is true the ships had to be built of old timber, or any wood that could be found, but this was not enough to daunt the indomitable courage of the besieged. Noiselessly the work was done, so that Scipio knew nothing about what was going on, until one day when his barricade was almost finished. Then, to his astonishment, he saw a fleet of fifty ships, which was plainly but just built, sail out of a newly-cut passage from the harbour. The Roman was ill-pleased to be thus outwitted by his foe, yet perhaps he also felt that here was a people worthy of his skill.