Under the stimulus of Pius IX.'s apparent sympathy for the cause of national unity in Italy, as well as that of the teachings of Mazzini, the Italian patriots took heart again. One group, consisting mostly of the politicians and military men of Piedmont, centred their hopes in the traditional antagonism of the princes of Savoy against Austria. Charles Albert of Carrignano, whom Metternich had attempted to exclude from the succession, showed marked independence in his dealings with Austria. In 1847, the Italian question came uppermost again when the Austrian Government, on a new interpretation in one of the clauses in the treaty of Vienna, occupied the town of Ferrara in the ecclesiastical states. Pius IX. promptly protested against this trespass of his territories. The King of Sardinia openly announced his intention to take the field against Austria, should war break out. English and French warships appeared at Naples. In Sicily and southern Italy the attitude of the patriots grew threatening. Apprehensions of a general revolution throughout Italy at length induced Metternich to agree with the neutral powers on a compromise concerning the occupation of Ferrara. Lucca was united with Tuscany. Still patriotic passion seethed in Italy. [Sidenote: Mexican campaigns resumed] [Sidenote: Santa Anna outflanked] In America, after several months of comparative inaction, the war in Mexico was renewed with vigor. On August 6, General Scott received reinforcements. Leaving a governor at Puebla, he marched on with 14,000 men. He met with no resistance at the passes of the Cordilleras. On August 10, from the top of the Rio Frio Mountains, the City of Mexico, lying in a fertile, lake-dotted basin, was in sight. The land around the city was under water, and the capital was approached by causeways across the low and marshy ground. The numerous rocky hills were all fortified. Scott passed around Lake Chalco to the southwest, and thence moved west skirting the south shore. Santa Anna, intercepting the Americans, took up his headquarters at San Antonio, five miles from the city. His position was flanked on the west by broken lava, and on the east by marshy ground. The ground was as bad as could well be encountered. Santa Anna sent orders to General Valencia, who held a fortified hill in front of the Americans, to spike his guns, destroy his stores and retreat, but Valencia refused. Riley, occupying a hill in his rear, took his intrenchments in reverse. He was cut off both north and south; 2,000 of his force were killed and wounded; a thousand with four generals were captured, and guns, stores and ammunition fell into the hands of the Americans. [Sidenote: Battle of Contreras]