the topography of the valley with some minuteness, although it is not designed to recount, in detail, all the events and personal heroism of the battles that ensued. This would require infinitely more room than we can afford, and we are, accordingly, spared the discussion of many circumstances which concern the merits, the opinions, and the acts of various commanders.
Looking downward towards the west from the shoulders of the lofty elevations which border the feet of the volcano of Popocatepetl, the spectator beholds a remarkable and perfect basin, enclosed on every side by mountains whose height varies from two hundred to ten thousand feet from its bottom. The form of this basin may be considered nearly circular, the diameter being about fifty miles. As the eye descends to the levels below, it beholds every variety of scenery. Ten extinct volcanoes rear their ancient cones and craters in the southern part of the valley, multitudes of lesser hills and elevations break the evenness of the plain, while, interspersed among its eight hundred and thirty square miles of arable land and along the shores of its six lakes of Chalco, Xoehimilco, Tezcoco, San Cristoval, Xaltocan and Zumpango, stretching across the valley from north to south, are seen the white walls of ten populous cities 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
