[Sidenote: Hamilcar Barcas takes the command.] +75.+ The Carthaginians, therefore, when they saw his mismanagement of the campaign, once more placed Hamilcar Barcas at the head of affairs; and despatched him to the war as commander-in-chief, with seventy elephants, the newly-collected mercenaries, and the deserters from the enemy; and along with them the cavalry and infantry enrolled from the citizens themselves, amounting in all to ten thousand men. His appearance from the first produced an immediate impression. The expedition was unexpected; and he was thus able, by the dismay which it produced, to lower the courage of the enemy. He succeeded in raising the siege of Utica, and showed himself worthy of his former achievements, and of the confidence felt in him by the people. What he accomplished on this service was this. [Sidenote: He gets his men across the Macaras.] A chain of hills runs along the isthmus connecting Carthage with the mainland, which are difficult of access, and are crossed by artificial passes into the mainland; of these hills Mathōs had occupied all the available points and posted guards there. Besides these there is a river called Macaras (Bagradas), which at certain points interrupts the passage of travellers from the city to the mainland, and though for the most part impassable, owing to the strength of its stream, is only crossed by one bridge. This means of egress also Mathōs was guarding securely, and had built a town on it. The result was that, to say nothing of the Carthaginians entering the mainland with an army, it was rendered exceedingly difficult even for private individuals, who might wish to make their way through, to elude the vigilance of the enemy. This did not escape the observation and care of Hamilcar; and while revolving every means and every chance of putting an end to this difficulty about a passage, he at length hit upon the following. He observed that where the river discharges itself into the sea its mouth got silted up in certain positions of the wind, and that then the passage over the river at its mouth became like that over a marsh. He accordingly got everything ready in the camp for the expedition, without telling any one what he was going to do; and then watched for this state of things to occur. When the right moment arrived, he started under cover of night; and by daybreak had, without being observed by any one, got his army across this place, to the surprise of the citizens of Utica as well as of the enemy. Marching across the plain, he led his men straight against the enemy who were guarding the bridge. [Sidenote: And defeats Spendius.]