city, prepared for 177 guns, and seventeen infantry breastworks; all of the batteries, however, could not be manned at the same time, in consequence of the deficiency in artillery. It was impossible to gain an admittance into the capital, with an army, except by passing along the elevated causeways, flanked, as has been described, by deep ditches and low marshy grounds — and through the fortified gates. South and west of the city, — the quarter to which the operations of General Scott were confined, — there were five causeways. The San Antonio causeway led directly from San Antonio, through Churubusco, to the plaza mayor. About one thousand yards further west, was the causeway of Niño Perdido, and rather more than that distance beyond it, was the Piedad causeway, both runing parallel to the causeway of San Antonio. The Piedad causeway intersected the Tacubaya, or Chapultepec causeway and aqueduct, at the south-western angle of the city; and the San Cosmé causeway and aqueduct, with the aqueduct and causeway leading from the height of Chapultepec, approached from the west, at right angles with the southern causeways, and, at its entrance into the capital, was nearly one mile distant from the Chapultepec causeway. At the intersection of the Piedad with the Chapultepec cause — way, was the garita of Belén; and there was a garita also, on each of the other causeways mentioned. Besides these main causeways, there was a smaller one, called the Paséo de las Vigas, with a garita, about eight hundred yards cast of the San Antonio causeway.
The enemy anticipated that an attempt would be made upon the city, from the causeway of San Antonio, and their efforts were principally directed to the strengthening of the fortifications in that quarter,
