and towns. In front of the observer, about forty miles to the west, is the capital of the Republic, while the main road thither descends rapidly from the last mountain slopes, at the Venta de Cordova, until it is lost in the plain on the margin of Lake Chalco near the Hacienda of Buena Vista. From thence to the town of Ayotla it sweeps along the plain between a moderate elevation on the north and the lake of Chalco on the south.
On the 11th of August, General Scott, after crossing the mountains, concentrated his forces in the valley. General Twiggs encamped with his division in advance, on the direct road, at Ayotla, near the northern shore of Lake Chalco; General Quitman was stationed with his troops a short distance in the rear; General Worth occupied the town of Chalco on the western shore of its lake, while General Pillow brought up the rear by an encampment near Worth.
This position of the army commanded four routes to the capital whose capture was the coveted prize. The first of these, as well as the shortest and most direct, was the main post road which reaches the city by the gate or garita of San Lazaro on the east. After passing Ayotla this road winds round the foot of an extinct volcanic hill for five miles when it approaches the sedgy shores and marshes of Lake Tezcoco on the north, thence it passes over a causeway built across an arm of Tezcoco for two miles, and, by another causeway of seven miles finally strikes the city. The road is good, level, perfectly open and comfortable for ordinary travelling, but the narrow land between the lakes of Chalco and Tezcoco, compressed still more by broken hills and rocks, admits the most perfect military defence. At the end of the first causeway over the arm of Tezcoco which we have just described, is the abrupt oblong volcanic hill styled El Peñon, four hundred and fifty feet above the level of the lake, its top accessible in the direction of Ayotla at only one point, and surrounded by water except on